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  1. #1
    TBF
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    Spot belt drive system

    looks kinda cool...check out the slot in the drop out for installing the belt.

    http://spotbikes.com/
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  2. #2
    ali'i hua
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    ah, another belt drive. if they've gotten out the kinks in the system of the belt not engaging (read: slipping) under high torque, it might be worthy. havent we seen this from Orange already this year?

    Jericho fooled around with this years ago- couldnt quite get it to work.

  3. #3
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    Looks like this system has fixed some of those bugs. Like a cog with holes in every notch to let muck through, and they developed the belt with a top company that knows what they are doing to prevent stretch and wear. Also they have a cool drop out that allows the belt to easily be replaced.

  4. #4
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    Bicycle belt drive: a solution looking for a problem, IMO.

    An imperfect & questionable "solution" at that.

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  5. #5
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    looks cool but will it work...rubber other then tires on a bike I don't know

  6. #6
    blame me for missed rides
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    Quote Originally Posted by Sparticus
    Bicycle belt drive: a solution looking for a problem, IMO.

    An imperfect & questionable "solution" at that.

    --Sparty
    a belt probably will never need to be replaced. they don't stretch, and when properly tensioned never comes loose.

    the catch i think is that a bike frame is too noodly a structure compared to a car engine.

  7. #7
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    Too much room for like rocks to get in. Mud would likely get smooshed out, but a goodly sized rock tossed in there could spell trouble.

  8. #8
    Retro Grouch
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    Quote Originally Posted by weather
    a belt probably will never need to be replaced. they don't stretch, and when properly tensioned never comes loose.

    the catch i think is that a bike frame is too noodly a structure compared to a car engine.
    I guess I keep my cars longer than you..

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  9. #9
    blame me for missed rides
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    Quote Originally Posted by aka brad
    I guess I keep my cars longer than you..

    Brad
    my car runs a lot more miles than all your bikes combined on each belt.

  10. #10
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    I would have loved the fact that this belt needs no lube as mine chain did 5 separate times during a 100 miler a few weekends ago.

    If they've got all the kinks worked out (as posted) and I can retrofit some kind of opening on one of my stays (S&S coupler maybe?), I'll be rocking this system on my SIR9. Hope it's soon.

  11. #11
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    one of the things i want to touch at interbike.
    personally i dont care if its the bestest final solution that cures cancer, i think its cool when when people throw odd stuffs out there...
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  12. #12
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    Quote Originally Posted by Matty H
    Too much room for like rocks to get in. Mud would likely get smooshed out, but a goodly sized rock tossed in there could spell trouble.
    That's what I thought as well, but some of the reviews claim it will just spit them out. I wonder which gives first though, the belt or the chainstay?

  13. #13
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    Quote Originally Posted by TBF
    looks kinda cool...check out the slot in the drop out for installing the belt.

    http://spotbikes.com/

    Lemme get this straight:
    That gray thing in the drop out is a cover for a slot right thru the drop out.
    So the most highly stressed part of the frame isn't even solid?!?
    What am I missing here?
    If that's the case, I want no part of it.
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  14. #14
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    Pass.

    In the last 100+ years chains have proven themselves strong, light, and robust. I can't see giving that up for the decreased maintenance of a belt.
    Last edited by SSchlemmer; 09-12-2007 at 10:14 AM.
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  15. #15
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    Quote Originally Posted by SSchlemmer
    Pass.

    In the last 100+ years chains have proven themselves strong, light, and robust. I can't see giving that up for the decreased maintenance of a belt.

    I despise chain maintenance. Bring on the belts!
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  16. #16
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    Quote Originally Posted by weather
    my car runs a lot more miles than all your bikes combined on each belt.
    Belts as thick as the ones in your car engine would be a b!tch to pedal, especially the ones designed to be under load.

  17. #17
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    Many timing belts are kevlar reinforced, and in the case of my Subarus are not to be replaced until 100,000 miles. Since my engines idle at around 800RPM, and regularly spin up to 5K (or in the case of my WRX, 7K) under quite a bit of stress. I would only be worried about the belt skipping, but that's about it. No more cleaning or lube from what I can tell, so it can't be that bad.

    Remember, engines came with timing chains at one point, but not as much anymore. But hey, this could be just a fad, like gears, derailleurs, funky handlebars, 29ers...
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  18. #18
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    Quote Originally Posted by Student Driver
    Many timing belts are kevlar reinforced, and in the case of my Subarus are not to be replaced until 100,000 miles. Since my engines idle at around 800RPM, and regularly spin up to 5K (or in the case of my WRX, 7K) under quite a bit of stress. I would only be worried about the belt skipping, but that's about it. No more cleaning or lube from what I can tell, so it can't be that bad.

    Remember, engines came with timing chains at one point, but not as much anymore. But hey, this could be just a fad, like gears, derailleurs, funky handlebars, 29ers...

    i'd still take a car with a timing CHAIN over a belt anyday.
    Oh noes. I'm going to drink the Kool-Aid.

  19. #19
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    Quote Originally Posted by Student Driver
    ... I would only be worried about the belt skipping, but that's about it. ...
    I'd worry about the belt skipping, too.

    Check the tension on the belts under your car's hood. That much tension works fine when a car's engine puts out a couple hundred horses. Try it with a quarter to half a horsepower.

    Without adequate tension the belt will slip. Now add rain &/or mud...

    Don't get me wrong; personally I'd love a belt drive SS provided it didn't suffer excessive drag and would not slip. So far these objectives seem mutually exclusive. I hope they're not.

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  20. #20
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    They are saying close to 98% efficiency on that belt...almost as good as a chain. Our puny HP output should be fine.

  21. #21
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    Quote Originally Posted by jcaino
    i'd still take a car with a timing CHAIN over a belt anyday.
    Great! I am sure you can find a '78 Oldsmobile Delta 88 like the one I had to replace a chain and gears on. You can probably get it for cheaper than the wheels of your SS!

    Me? Nah, I like the belts and they work great. Plus, you don't have to replace the gears. Can't say the same about a timing chain as the gears go with it.
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  22. #22
    blame me for missed rides
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    Quote Originally Posted by kapusta
    Belts as thick as the ones in your car engine would be a b!tch to pedal, especially the ones designed to be under load.
    actually, no. i drive a RWD and the belt is not thick. i'd totally pedal it.

  23. #23
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    Chain = 120 moving parts
    Belt = 1 moving part

    Love the simplicity, the cleanliness, and the lack of rust!

    All the technical problems are fixable.

    The real problem is that good quality belts & sprockets are expensive, whereas a decent chain and cogs are cheap.
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  24. #24
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    i think mud and rocks can be easily kept out with a guard of somesort. A CF one wouldnt weigh much at all. That to me is a stupid argument against using a belt.

  25. #25
    ali'i hua
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    Quote Originally Posted by xc-ss'er
    i think mud and rocks can be easily kept out with a guard of somesort. A CF one wouldnt weigh much at all. That to me is a stupid argument against using a belt.

    actually, getting much in between the cog and belt is a valid argument- unless you could create some sort of a belt guard to cover the entire system (a silly idea, i'd think) I dont think that the belt drive would be the best choice for those of us in a drier climate, especially with the rocks, pebbels, dirt and dust that get thrown around on a regular basis.

    heck, I've had pebbled get lodged in between my sorry ass and my seat on loose descents.

    ever been hit in the face with flying rocks? if they can make it to your face, getting to your drivetrain would be far less an issue, especially with the rock-throwing tires being relatively close to said belt drive system.

    for a commuter/beer bike? bring it. I'd embrace the tech at that point

  26. #26
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    With all the above mention "problems" & "issues" being solved ?
    Its a cool idea even if not new....

  27. #27
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    Ta'hell with the belt...and chain for that matter. Give me a drive shaft!

    But really I don't see the huge concern about getting debris caught up in it, I've never had a big rock get caught between my chain and cog and I doubt much of the tiny stuff actually slips through between the side plates of a chain link...

    One huge downside is that if you change your gearing you may have to replace the belt rather than just adding or replacing a couple of chain links

    I'd give it a go, so long as I was sure i wouldn't need to chaing my gearing too much.

  28. #28
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    Belt drives are no where near the efficiency of a chain.

  29. #29
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    How is a toothed belt going to 'slip' under load? I'm honestly asking, as to me it seems to be no less likely than having a chain jump under load.

  30. #30
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    Don't remember where I saw it, it's the Internet so it could be wrong, but last I heard, chains reported 97% efficiency. There is a claim in this thread that this belt is 98% efficient. Does anyone have any data to back up either of these claims? Just throwing out a random "It's no where near as efficient as a chain," with no evidence does little to support either side of this issue.

    Also, why do people keep complaining about debris getting caught under the belt? It's rubber and there are holes in the cog / 'chainring'. If anything is going to get caught and jam up this system, that item is definitely going to have done more damage to an inflexible small precision component such as a chain. I've ridden all over this place and maybe once had a rock or something jam up my drivetrain. And mud would be more of an issue with a chain as well. How about we see how the belt works in this application for a bit before we start e-speculating about how it sucks.

  31. #31
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    I don't think...

    that small debris such as small rocks and mud would present a huge problem with the "open" system that this uses, but here in the Southeast, moss and vines are a real problem. Not so much with the SS due to the fact that you don't have a derailleur hanging down, but I have had to stop many times to clear a mess of moss or vines out of the chain and rear cassette. This has happened mostly on my geared bikes, but even the single speed has come to a halt due to this. I would think that the wider surface of the belt along with the square edged teeth may be even more prone to snagging "trail debris" such as vines and moss. Once into the cog, even a chain slips, so the belt would definitely be done until you cleared the mass out of it.

  32. #32
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    how about if someone rides one of these bikes and report back?

    It is interesting that people assume we have low power output. If you consider a crank is about 10" long and a strong person should be able to press 300lbs with one leg, that is 250 lb/ft of torque at the bb spindle. Horsepower incorporates speed into the equation where our 80-100 rpm is very slow and will register low horsepower but torque is what breaks things.
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  33. #33
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    I tend to look at it as Sparticus, a solution looking for a problem. Probably great for commuter type rigs but will it really be better than a chain off road? What do you gain with it? The chain drive is a pretty wonderful thing.

    That said, I wait to see and hear more before pronouncing judgement. I talked to a guy testing the Orange setup at SSWC and he had nothing bad to say about it, only praise.

    One thing I haven't heard discussed is changing of gear ratios. Personally I run one ratio on my MTB bikes and that is it, day in and day out no matter where I travel. But there are a lot of people on here who switch gearing depending on terrain or a race course, etc. For that, it looks like you are going to need multiple belts along with the associated gears. Seems to me that would be a deal killer for a lot of people. Food for thought.
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  34. #34
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    Quote Originally Posted by riderx
    One thing I haven't heard discussed is changing of gear ratios. Personally I run one ratio on my MTB bikes and that is it, day in and day out no matter where I travel. But there are a lot of people on here who switch gearing depending on terrain or a race course, etc. For that, it looks like you are going to need multiple belts along with the associated gears. Seems to me that would be a deal killer for a lot of people. Food for thought.
    i change gears enough that i bought a chain for each cog. i highly doubt a belt will cost more than a chain or a pulley more than a cog. but i agree that a chain works really, really well...
    what would rainbow unicorn do?

  35. #35
    ballbuster
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    Quote Originally Posted by SlowSSer
    ah, another belt drive. if they've gotten out the kinks in the system of the belt not engaging (read: slipping) under high torque, it might be worthy. havent we seen this from Orange already this year?

    Jericho fooled around with this years ago- couldnt quite get it to work.
    I think the problem Jericho had (and I could be wrong) is that the belt needed so much tension that it wore the bearings out really quickly.

    I'm not sure what problem they are actually tring to solve with this. I never break chians on my SS. Then again, I'm a big fat 90 pound weakling (who weighs 200 pounds) compared to most of the SSers I know. I only break chains on my gearie bike, and that is usually because they get crudded up and chainsuck. Most SSers I know don't break chains either. I think the biggest enemy to chains is the derailleur.

    I guess it will save some weight, but that is the only advantage I can see. Most SSers I know don't really care about weight much anyway.

    I'm all for innovation, but this seems like a lot of work to fix a not so big problem.

  36. #36
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    why?

    Quote Originally Posted by Student Driver
    Great! I am sure you can find a '78 Oldsmobile Delta 88 like the one I had to replace a chain and gears on. You can probably get it for cheaper than the wheels of your SS!

    Me? Nah, I like the belts and they work great. Plus, you don't have to replace the gears. Can't say the same about a timing chain as the gears go with it.
    Timing chains still have to be replaced in engines, and I can tell you from working on them, they are WAY harder to replace, not to mention the tensioners. If you don't replace the tensioners to an engine with a timing chain (and I'm talking an OHC engine here, not the push rod V engines where the chain is super short) the chain starts lashing back and forth and breaks anyway.

    I dunno if timing chians in car engines are a good ananlogy for this.

  37. #37
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    There's a lot of naysayers on this topic with lots of theories as to why belt drive won't work.

    So here's a question - has anyone actually ridden a belt drive bike?

    (BTW I own one - a rough prototype)
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  38. #38
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    I rode two at EuroBike

    Quote Originally Posted by Velobike
    There's a lot of naysayers on this topic with lots of theories as to why belt drive won't work.

    So here's a question - has anyone actually ridden a belt drive bike?

    (BTW I own one - a rough prototype)
    I asked the engineer at Nicolai if there are any real issues in performance with the belt drive and he told me that there would be a reduction in efficiency due to the increased contact surface area between the belt and the cog/chainwheel versus the chain drive,so I thought I should try it out myself and see how that felt.I head over to the Orange bikes booth and they had two of their bikes set up with the belt drives and shimano alfine gear hubs,one suspended and one non-suspended.I tried the suspended one first and I was amazed at how smooth the ride was,I could not detect any reduction in efficiency myself even though I was looking for it (maybe someone else can,but not me).It did however skip once which I first thought was a problem with the alfine,the guys at Orange explained to me the belt somehow pinches on itself at some point between the the chainwheel and the cog (on the lower belt line)so when this pinch reaches the cog it skips a tooth.They said that they are working on a roller that attaches to the rear dropout to iron out the belt of any pinches before they reach the cog,they seemed optimistic that it would work.
    When I rode the rigid bike I could not get it to skip,it just rode smooth.
    The guys at Orange told me that the main challenge with the system at this time is that the belt drive places a great load on the bearings that a normal chain drive would not,this makes the bearings wear out quick.I have hear of several proposed solutions by different camps that seem that they would work,but no one has implemented them yet to my knowledge.From looking at the slots in the chainwheel and cog I do not see there being any problem with debris getting caught in there,but I can not say from experience as I only rode them around a bike show and not on the trail.
    The fact is that the system works and this is great news whether you choose to use it or not,it will simply give you more options and hopefully serve you in creating a ride that best suits your specific requirements.I imagine that soon we will be seeing threads that are similar to the platform VS clipless threads only with belts VS chains,BTW I plan on using both.
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  39. #39
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    Quote Originally Posted by riderx
    ....One thing I haven't heard discussed is changing of gear ratios. Personally I run one ratio on my MTB bikes and that is it, day in and day out no matter where I travel. But there are a lot of people on here who switch gearing depending on terrain or a race course, etc. For that, it looks like you are going to need multiple belts along with the associated gears. Seems to me that would be a deal killer for a lot of people. Food for thought.
    Quote Originally Posted by long hazy daze
    ........
    One huge downside is that if you change your gearing you may have to replace the belt rather than just adding or replacing a couple of chain links
    ....

  40. #40
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    Changing gears would be an issue, but only for certain gears. I recently switched from an 18t to a 19t for a race and didn't have to change the length of the chain.

    Anyone have a guess at how much these belts might actually cost?

    I really want to try this system, but I'll be the first to say, if it does slip/suck I will be right back at a chain.

    Oh, and whoever mentioned the shaft drive,... get working on that. All the prototypes I've ridden have been geared towards townie bikes or have just plain sucked. Without access to a lathe, my designs are simply sketches in a book.

  41. #41
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    check out this link for a little more info.

    http://www.cyclingnews.com/tech.php?...007/news/08-28

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  43. #43
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    Quote Originally Posted by jcaino
    i'd still take a car with a timing CHAIN over a belt anyday.
    Amen to that.

    All belts provide is a quieter engine and the ability for your dealer to make $500 when you come in to have to replaced at 60k miles. Or $5000 when it breaks and your interference engine spits out valve and piston cud.

  44. #44
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    The topic of a belt drivetrain sounds like a noteworthy idea, if nothing but for the sake of being an alternative to the chain. I personally dislike chains, but there's really no other viable options on the market today.

    Chains are obviously under fairly light tension, usually only provided by a derailer or very lightly stretched to span the length of the chainstay. They don't slip however because of the deep teeth that engage the chain and gear. Using the same tension, with the same sized teeth on a belt should yield similar results, except that the rubber teeth on belts bend, where as the steel chain simply does not. Applying tension to the belt helps decrease slipping, but at the added cost of higher friction and rolling resistance between belt and pulley.

    As someone mentioned, chains are better than belts in high torque applications due to the decreased efficiency of a belt as tension is increased.

    The idea of a shaft driven bicycle also sounds good until you take into fact that current shaft-based drivetrains have nasty effects on efficiency. I've often heard reports of a 10% power loss simply by using a shaft drive system over a chain. (regarding ATV's)

    It would seem to me chains are here to stay for a bit longer. None of the alternatives are extremely practical or trouble-free. Until a new drivetrain surpasses the chain in every regard, no one is really switching.

  45. #45
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    Good job!

    Now if they offer a FIXED version...........

  46. #46
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    I've just posted a rather lengthy reply on singletrackworld, I'll copy paste the contents here as it addresses some of the questions raised - as I'm not a regular visitor to MTBR I'll just explain that I don't want to use the forums to talk "work", this post is just an attempt to help peeps understand the subject and see where we are, its in my own time and I'll struggle to find time to get involved in a debate .

    Oh, I have ridden a poly chain bike and its probably the reason why I'm so convinced about the possibilities it holds

    Copy lifted from Singletrack, original post at http://www.singletrackworld.com/foru...6422&t=3256422

    Oops, sorry been busy and didnt spot this one.

    Ill try and answer what I can, sorry I cant get into more of a discussion on it but Ill try and give as full a reply as possible, apologies for the long read.

    In no particular order

    Efficiency no-one has accurate data for chain vs belt efficiency, even chain efficiency varies according to chainline and which size sprockets are selected. There are various documents and studies but a lot of the data does go back to the 1937 Renolds paper which seems to suggest 98% for a clean, well lubricated chain. Few studies have used low power/low RPM scenarios (The HPV one does), most have related to motorbike or other applications with higher revs and more power transmitted. Most of the stuff Ive seen suggests that belt will be as efficient or better but it does rely upon the tensions used.

    TBH for MTB use I question whether its a real issue, MTB chains are usually covered in crap so it would need a totally different study but more importantly we ride around on 2.35 inch super tacky tyres, the small amount of energy loss on a drive chain has got to be fractional compared to that!!

    Belt type yes, there are other belts out there, most are aramid/rubber construction and stretch or are affected by water, Shimano have made special hubs and cranks for Bridgestone and Corratec to allow this type of belt to be used, they needed tensioners in the crank to work. The system weve been playing with is actually a poly chain developed by Gates Power Transmission Division, the construction is different to the old technology and its a patented process, Ive been to the plant and the procedure is kept very secret, all recording devices removed, phones etc as Gates have invested considerable time and money into the development of poly chain. Unfortunately most people see the bikes and call it belt, poly chain as a name is a lot closer to what it actually does.

    If you have access to the Audi Channel keep an eye out for a programme called Science in Sport on cycling, there is a short section with an explanation from one of the Gates engineers on what the poly chain is and what it does.

    Belt lengths/sprocket diameter currently the available belt lengths are limited by the molds and tooling available, weve used 3 lengths varying from 1200 to almost 1300mm. The sprockets are calculated on a final ratio say 1.8:1, 1.9:1 or whatever suits the hub/use - we vary the sizes to suit chainstay length, ratios and available adjustment, most run 56/30 but it would be easy enough to alter that to say 54/32 if we wanted a lower gearing, itll be more difficult just to swap front or back by itself. As demand for polychain grows Gates will invest in more diameters, each mold has a crazy cost (in excess of 60K I believe) so whilst its only us and Spot I dont think well ever have enough volumes to justify that

    Sprocket design we prefer the cut away sprockets as seen on the bike Singletrack have, these allow mud and grit to be pushed through by the tooth form. The Alfine bikes are a bit more difficult to design sprockets for, the belt width is critical to performance and leaves little clearance so we need to offset the sprocket, the cut away design is done with an undercut but we cant machine that into an offset sprocket. Rohloff is different offset again as is SRAM i9 and yes, weve got versions of all 3 under development, the Rohloff bike hasnt been seen yet but is based on a Sub Xero. Weve never had a stone jam in the belt, Im pretty sure that the reason motorbikes dont use it off road is that they run with belt tensioners to take up suspension movement, this means a stone can be in the belt and get squashed in, weve never seen this happen when we run without a tensioner hence the ful sus concept bike with a BB pivot ( no chain tension change, no tensioner needed), the belt can skip but it actually unships from the point of low tension and jumps at about 7 o clock on the rear sprocket not where the belt is under tension.

    Frame design does need altering, not just for the split chain/seat stay but also to take into account the different diameters of front chain wheel and chainline, its also involves different cable stop positions etc etc. Ideally this needs doing with the hub makers which is one of the reasons we are pushing Shimano and SRAM to help.


    Snapping yes, it is possible to snap the belt, this usually happens if the belt has been pinched during fitting ( they dont like tight radii) Gates know the problems on this, have faced it in motor industry and any assembly company will be briefed on the importance of correct installation.

    Belt with link not possible, it uses thin strips of carbon running around the ful diameter, the clever bit is how Gates join this into one loop and then seal it with the outer material, the material is self lubricating and hard wearing, check the Gates website if you want more info on it. A lot of people who ride the bikes say the poly chain feels different, more smooth and even power transmission, we think it could be the way the load is spread around the carbon cord rather than the energy being passed from link plate/roller to link plate/roller in a chain. I cant feel it as much as some people do, maybe Im used to new clean chains


    Why??? - I guess Im like a lot of riders, I hate looking after my bike and if I ride a lot hate having to replace expensive chain/cassette and chainwheels within months of buying a bike IMHO only enthusiasts will put up with that.
    Id quite happily put up with a slightly heavier bike to get rid of that ( although Id prefer it to be the same weight).

    Itll come down to what individual riders want, Id think racers, performance junkies will always go for chain/derailleur unless Shimano and SRAM really invest time and energy on good internal hub or gearbox. If anyone has heard or seen any of the interviews Ive done theyll know how big an advocate of these systems I am, putting my bike industry hat on I know that as an industry we need to improve our products to appeal to new customers, maybe tempted in to bikes because of congestion charging or fuel prices but the only way well keep them is is we have product that matches their expectations, cars have service intervals at 2 years now, we get less than 3 months on some chain/sprocket/BB combinations, honestly, that isnt good enough and we need to look at how we make it happen.

    The only way the big players (Shmano/SRAM) will respond with better product (XTR/X0 level internal hubs etc etc) is if small companies like Orange and Spot show them there is demand and threads like this are very important to that hence why Ill spend time writing this rather long reply Even if the big 2 just go down the internal gear route at first the technology they develop for that is quite easy to swap to a gearbox

    When we can make singlespeed bikes fairly quickly, certainly by mid 08, geared versions for city/commuter use should be doable in 08, full suspension with gears might take a lot longer


    Hope it helps with your discussions folks

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    I'd much rather see...

    ...all this energy directed toward resolving creaky EBBs and ridding us of flexy, heavy wheels.

    The SS chain driven transmission is efficient, simple, reliable, inexpensive, easy to maintain, and extremely effective. Is there really that much to improve upon?



    (Not trying to bash Spot; they make a very nice bike.)

  48. #48
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    Quote Originally Posted by Miker J
    ...The SS chain driven transmission is efficient, simple, reliable, inexpensive, easy to maintain, and extremely effective. Is there really that much to improve upon?...
    It is also filthy and high maintenance. Yes there is lots to improve upon.

    As far as I'm concerned it's a choice between full chaincases or belt drive. I've ridden a belt drive bike and it's even simpler and quieter. (A chain is anything but simple - there's well over 100 moving parts in a piece of precision engineering that we drag through abrasive dirt).
    As little bike as possible, as silent as possible.
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  49. #49
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    Filthy chains....

    Quote Originally Posted by Velobike
    It is also filthy and high maintenance. Yes there is lots to improve upon.

    As far as I'm concerned it's a choice between full chaincases or belt drive. I've ridden a belt drive bike and it's even simpler and quieter. (A chain is anything but simple - there's well over 100 moving parts in a piece of precision engineering that we drag through abrasive dirt).
    ... are the result of over or inappropriate lubing.


    I have another "chain" I use for hauling logs out of sites. It has hundreds of "moving parts" and I would still call it a very simple device.

    SS chains are a relatively simple affair from an engineering standpoint. That's why you can get a good one for about $12.
    Last edited by Miker J; 09-29-2007 at 06:40 AM. Reason: ad on

  50. #50
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    if the belt does break, it looks like you'll have to replace the whole belt. right now I carry a chain tool and a few links... it would suck to carry a HUGE belt in my pack.

  51. #51
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    Quote Originally Posted by Miker J
    ... are the result of over or inappropriate lubing.
    so no dirt of any sort will ever land and stay on a properly lubricated chain? does your lube have a magical force field?

  52. #52
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    When I used to ride my belt drive motor bikes in the bush (in Australia) no dirt ever got wedged between the belt and cogs despite a considerable mileage.

    A rock getting wedged in a belt system would be as likely as a small rock getting jammed between the links of a chain. Not impossible but infinitessimally small odds.

    Chains are very efficient and highly evolved, but they are also dirty and require maintenance. Belt drive is in its infancy for bicycles although there have been a number of previous attempts, eg Thun with Pirelli belts, Beltrans in Taiwan, EP-X synchronous drive in Australia, and Bridgetone in Japan. Also there is the Strida which is aimed at commuters and which is currently available.

    Too many expert naysayers on this post, methinks. (Or as an former Prime Minister of Australia was alleged to have said "That may work in practice, but it doesn't fit my theory")

    I think I'll now go out and fettle my belt drive bike for winter
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  53. #53
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    Quote Originally Posted by sean salach
    so no dirt of any sort will ever land and stay on a properly lubricated chain? does your lube have a magical force field?
    Same force field as a belt.

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  54. #54
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  55. #55
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    The only reason cars use timing belts and not chains is because belts are easier to use for the application of overhead cam. The routing necessary is much easier done with idler pulleys then idler gears to route chains. Now, the LT5 engine is one that successfully used chains, but that engine was built with unlimited budget so don't pull out examples of random exotic engines. Cars with cam-in-block setups typically use chains because chains are stronger and last longer.

  56. #56
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    Wink

    Quote Originally Posted by Schmucker
    The only reason cars use timing belts and not chains is because belts are easier to use for the application of overhead cam. The routing necessary is much easier done with idler pulleys then idler gears to route chains. Now, the LT5 engine is one that successfully used chains, but that engine was built with unlimited budget so don't pull out examples of random exotic engines. Cars with cam-in-block setups typically use chains because chains are stronger and last longer.
    All applications are different: Auto engines that use chains run in oil bath, as do many motorcycles that use chains to drive the cams. I don't know of an auto with an exposed chain let alone that requires maintenance. Older Chevy and Ford used Chains for timing purposes again bathed by oil. When we hotroded them we used gear drives in place of the timing chain and cogs.
    I do see one thing not applied to chains to remember when transporting your belt drive bike be sure not to 'FOLD" or kink the belt or else it will crack.
    I think the applied power of belt vs chain will be smoother, but what do I know...I guess it's like a girl: I will have to buy one and live wth it for while...LOL!

    Nice talk'in with ya!

  57. #57
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    The most interesting aspect of this whole thread is that only 10% of the "2%ers" are truly "2%ers". Quit fighting change and free your minds people. Belts and IG hubs are the future. Take the Blue belt....
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  58. #58
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    i want one...

    next bike. when i have a custom Ti built up. they'll definitely be using the belt dropouts.

    mmmm blue.
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  59. #59
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    Little bit of a cross post from this thread: https://forums.mtbr.com/internal-gear-hubs/new-rohloff-product-363454.html

    New availability dates and info have been posted on Carbon Drive's website (www.CarbonDriveSystems.com).

    If I'm reading the data correctly, the belt pitch is 11mm per tooth, making it possible to calculate required belt length based on chainstay length and gear selection. The belt sizes are:
    - 1243mm (113 teeth total)
    - 1298mm (118 teeth total)
    - 1342mm (122 teeth total)
    - 1375mm (125 teeth total)

    The chart below is my take on Spot / Carbon Drive's belt lengths & cog combos and how they **ought to** relate to a bike's chainstay length. Because the belts don't stretch, I would be surprised to see any dramatic variations.

    This still hasn't been vetted with the Carbon Drive guys, but I've emailed them for more info and have asked them to chime in on the post I linked to, to correct any errors on my part.

    My chart works kinda' backwards: Your choice of ring, cog & belt length will determine the chainstay length required for a workable setup. More realistically, you'll figure out your chainstay length and then figure out what combinations of the three components suit your bike. Either way...

    ...since the belt requires either an eccentric bottom bracket, sliding dropouts or horizontal dropouts for proper tensioning, it's just required that the chainstay lengths I listed fall somewhere inside your range of adjustment.

    <img src="https://www.booboodog.net/images/cd-belt-lengths.jpg">

    All six rear cog sizes are shown as available soon for standard 9-spline freehubs. CDS lists 24T and 22T as the only Speedhub, SRAM and Shimano Alfine options. The only cog listed for Nexus is 24T.

    Of the three drive rings, 50T and 46T are 4-bolt compact, and 55T is 5-bolt 130 BCD. By my calcs, a 50T drive cog should be approximately the same diameter as a 43T conventional chainring.

    On their updated website, Carbon Drive is claiming "a measly 120 grams for the entire system." I don't see how that is possible, but I'm sure we'll be seeing a breakdown of the weights of the individual components soon.

    If you can't tell, I've been looking forward to this system since it showed up at Interbike. Even though I've got to wait another 6 months for the cog I need for the Speedhub to become available, I'm pretty excited about it (got a nice elevated chainstay Mrazek Boh frame which is going to work perfectly). Looking forward to a SS demo at Sea Otter.
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  60. #60
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    Great info Speedub. Thanks!
    Show Charlie Murphy your hubs

  61. #61
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    Has anyone taken delivery of a production bike yet?

  62. #62
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    No production bikes shipped yet

    I've been talking with a couple shops that carry Spot to find out when they will arrive. Sports Garage in Boulder is a Demo Center and is closely related to Spot. They don't even know (last time I talked with them was about a week ago) when they will be arriving. I am anxiously awaiting the bikes to test ride.
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  63. #63
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    http://oskarbluesbrewsbikes.blogspot...demo-tour.html

    Where are all you Spot Brand promoters? There are quite a few in my neighborhood. Take a look at this link, and lots more on this blog. Happy, successful riders.
    puddytoes

  64. #64
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    I guess the one thing I've taken away from reading the various posts on this thread is that people really fear change.

    The reality is, if this system is successful or not, innovation drives future success. If we sit back on our laurels, we will never advance.
    MTBR is serious stuff.
    You never get better until you get out of your comfort zone.

  65. #65
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    @bigwheelboy_490:

    Dude,
    What did you expect? This is the single speed forum, where modern conveniences like gears, suspension and common sense don't apply. Some of these guys probably view brakes as a nuisance...

  66. #66
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    I demo'd a Spot 29er at the Bar H Bash in Saint Jo, Texas. I had it out for about an hour and a half on singletrack, and I liked it a lot. Now I just have to figure out a way to pay for it. They ain't cheap.

  67. #67
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    I was really intrigued with a belt drive, played around some with a prototype at a shop[ in Golden, CO. They seem like a neat alternative to a chain, but the extra cost and the high belt tension put me off a bit. I think they'd sell better if there were a cheap retro adaption to existing framesets without changing the dropouts.

    The tension is high, very high, I'd really worry about bearing wear, but then maybe it's not any more than the pressure a rider puts on the bearings when cranking hard. For me the cost is a big issue as I'm a low budget rider.

    Neat concept, though maybe it is as another poster stated: " a solution looking for a problem". I like my chrome chain just fine

  68. #68
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    I'm not really the person to ask.....but I think there is a tensioner on this system. I know I've heard the racers talk about different tensions for different conditions. Wouldn't that affect the amount of pedal required? If you have questions about this, (I am not an expert, and shouldn't be acting like one!), go to the www.spotbikes.com site. I think it looks like the tension can be adjusted in the pics; email an expert for expert advice. There's some new pics on the oskarbluesbrewsbikes.blogspot.com site as well, including a very dirty Spot Brand bike with close ups of the belt drive system. Leave a comment, and you should get a quick answer to your questions from someone who had been riding one all winter. And yes, they are not cheap. Maybe the price will come down in time :-) but then bikes are as much or as little as you want to pay, don't we know? :-(
    puddytoes

  69. #69
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    This guy has a cross Spot belt drive (link), and no tensioner.

    Another thread (link) with good pictures and no tensioner.

    One more, the Interbike review by FC (link).
    "The physician heals, Nature makes well" - real fortune cookie

    CCCMB trail work for trail access - SLO, CA

  70. #70
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    I work at a bike shop and even for us there is very little information out on these things. To me it seems like the ultimate advancement in bike technology. As an avid but poor rider, I am constantly looking for ways to stop sucking at shifting. An Alfine hub and belt drive looks like the solution. Too bad I have to hack my Ti Carver 96'er apart to introduce it.

    We're unable to get the accouterments from anywhere but Spot itself...which leads me to believe that it will work wonders on my credit card. Oh well. Money's there to be spent!

  71. #71
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    Quote Originally Posted by Bear Spleen
    ...Too bad I have to hack my Ti Carver 96'er apart to introduce it...
    Don't cut it until you are absolutely sure that everything will line up. I've done a few conversions now and it's not as straightforward as it seems.
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  72. #72
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    Quote Originally Posted by runbuddha
    looks cool but will it work...rubber other then tires on a bike I don't know
    why wouldn't it work? Harley has been using belt drive for years and that has a lot more torque than a human and it doesn't slip.

  73. #73
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    I have about 400 miles on mine, and I really like it and VERY impressed with it. Once you get the chainline dialed, its a great setup, but thats with any other bike, chain or belt driven.

    The only thing I don't like about it is the availability of "cogs".


    I'm putting money aside for the beltdriven CX bike.
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  74. #74
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    Spot Longboard

    I have a Spot Longboard SS 29'er XL belt drive I bought to use as my winter bike here in Edmonton. The trails can get tricky, as some are never cleared, and with the only trail made by other bikes, the snow melts and freezes into hard ridges. The SS belt drive is a good thing I think, as I found the cassette and chan etc could get easily clogged, and I usually end up in one useable gear anyway to avoid problems.

    What I really want is a Rohloff hub. Anyone who figures out how to do it let me know. Anyone with questions or wanting pics I'm glad to help. I'm far from a hardcore Mountain biker, but I'm a full-time commuter who might race cyclocross on my other bike (TriCross Comp).

    I appreciate all the great info from posters here. Thanks.

  75. #75
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    According to the Gates website Cogs for Rohloff, NuVinci, SRAM hubs are coming soon.
    http://www.carbondrivesystems.com/fo...rs.php?lang=us

  76. #76
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    Quote Originally Posted by Smallfurry
    According to the Gates website Cogs for Rohloff, NuVinci, SRAM hubs are coming soon.
    http://www.carbondrivesystems.com/fo...rs.php?lang=us
    They've been saying "coming soon" (or variations thereof) for at least two years.
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  77. #77
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    I like to switch between two cogs depending on what I'm doing, since I do a lot of urban riding yet my urban gearing on a trail would annihilate me.

    What do I do with belts? I can't... take a link out...

  78. #78
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    Quote Originally Posted by GoFaster2
    Belt drives are no where near the efficiency of a chain.
    I know belts stay at 90% efficiency their whole life!!
    a chain turns to $hit quickly and efficiency will be cut almost in half in supper muddy conditions
    Quote Originally Posted by thefuzzbl
    aluminium has a tendency to fail when you need it most. i.e. you end up with a bad day.

  79. #79
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    Quote Originally Posted by Speedub.Nate
    They've been saying "coming soon" (or variations thereof) for at least two years.
    Somebody is putting Gates drives on Rohloffs:

    http://nicolai-colors.blogspot.com/

  80. #80
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    Thanks for the responses. Good catch. This is the first good pic I've seen. Gives me hope.

    My LBS have a call into Rohloff (I'm told). Maybe something up for Sept Interbike? Just guessing. I'd love the new light Rohloff on my Spot.

    I've been riding the Spot for a week now. I'm still getting used to it, and it'll take awhile. Very strange feel to me, but part of that is the singlespeed, and part is the mountain bike, 29'er, etc. I'm used to my beautiful TriCross Comp, which is still a dream to ride. I'm glad my second bike is different though. It's for winter, so that'll be the real test. My office moved, and it's gonna be a tough commute this winter. Everything runs weird when the temp gets under about -25C.

    The Rohloff would do the trick for me, I'm sure. Please, before winter.

  81. #81
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    Quote Originally Posted by perttime
    Somebody is putting Gates drives on Rohloffs:

    http://nicolai-colors.blogspot.com/
    There are some one-offs and prototypes out there, including some for the originally introduced belt design. Neil from Cyclemonkey had one two Sea Otter's ago that was a custom job (rode pretty smooth, too).

    I heard there were production setbacks with the change in tooth pitch of the belt, of the way the cog pressed on the Speedhub's seal, and with the anti-wear coating they were using. But this all seems so long ago. I have no idea why these aren't out and available now.
    speedub.nate
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  82. #82
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    Quote Originally Posted by Roasted
    I like to switch between two cogs depending on what I'm doing, since I do a lot of urban riding yet my urban gearing on a trail would annihilate me.

    What do I do with belts? I can't... take a link out...

    you ride with a spare belt of different size around your neck/body and the extra gear in your pocket. don't forget the wrench to move the slider when you change gear.
    Out riding, leave a message

  83. #83
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    Quote Originally Posted by Student Driver
    Remember, engines came with timing chains at one point, but not as much anymore.
    You need to venture away from the ricer crowd a bit and study up on your engines. Timing chains are very much still alive and are present in a lot your high-end big motors.

    Quote Originally Posted by Student Driver
    Great! I am sure you can find a '78 Oldsmobile Delta 88 like the one I had to replace a chain and gears on. You can probably get it for cheaper than the wheels of your SS!
    Again, you're stuck on old cars and rice rockets. Take your blinders off and realize that there is more to the automotive world than Oldsmobiles and Scoobies.

    Quote Originally Posted by Student Driver
    Me? Nah, I like the belts and they work great. Plus, you don't have to replace the gears. Can't say the same about a timing chain as the gears go with it.
    As far as having to replace the gear along with the chain, your right. But there's very little additional work in replacing the gears. Most of the work is actually getting to the belt/chain.
    -Brian

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    Quote Originally Posted by weather
    a belt probably will never need to be replaced. they don't stretch, and when properly tensioned never comes loose.
    Wrong! Belts DO stretch and they DO require frequent replacement.
    -Brian

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    Quote Originally Posted by Schmucker
    The only reason cars use timing belts and not chains is because belts are easier to use for the application of overhead cam. The routing necessary is much easier done with idler pulleys then idler gears to route chains.
    There's no need for "idler gears" in an overhead cam chain. The tensioner is basically a smooth piece of plastic that the chain runs along. Belts, on the other hand, need an idler since they have too much friction to just slide along side a stationary tensioner.... +1 for the chain.

    Quote Originally Posted by Schmucker
    Now, the LT5 engine is one that successfully used chains, but that engine was built with unlimited budget so don't pull out examples of random exotic engines. Cars with cam-in-block setups typically use chains because chains are stronger and last longer.
    Are you serious. You think the only overhead chain driven cams are in exotics???

    You don't know much about modern day V8 engines. Sure, most rice burnes use belts, but a majority of V8s use a chain. Hell, the Ford 4.6L V8 is an OHC motor and has been using dual timing chains successfully since 1996.
    -Brian

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    FWIW, my '92 325iS has a DOHC I6 and the chains have never been changed... it's clocking somewhere around 290,000 miles now.
    -Brian

  87. #87
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    I'm sorry to clutter the thread with a lot of car facts, but when people were trying to back up the belt technology with false automotive facts, I had to set it straight so as to not give the belts and unfair upper hand in the arguement.
    -Brian

  88. #88
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    Quote Originally Posted by jsu1995
    Wrong! Belts DO stretch and they DO require frequent replacement.
    Could you quote some actual (as opposed to anecdotal or opinion) figures on this for the Gates Carbon Belt in cycle use?

    I haven't been able to find any wear figures. I've rough idea what to expect out of a chain. I've done a number of belt drive conversions and I really like to know what life to expect from a belt system.
    As little bike as possible, as silent as possible.
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  89. #89
    skillz to pay billz
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    they say it should 2x what a normal chain will do. FWIW.

    best to have a spare on hand anyway.

  90. #90
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    from my research Gates is claiming around 8,000 miles with little to no stretch.
    Quote Originally Posted by thefuzzbl
    aluminium has a tendency to fail when you need it most. i.e. you end up with a bad day.

  91. #91
    Jambo100
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    Quote Originally Posted by jsu1995
    Wrong! Belts DO stretch and they DO require frequent replacement.
    Don't know what kind of belt you're using. I don't think carbon stretches.

    I saw Canadian drag racer Terry Capp last weekend. He has a belt on his 6000 horsepower dragster. They don't stretch, according to him. He's been racing since I was a kid, more than 30 years. It's more durable than a chain. His is a lot wider than the bike ones though.

    I have one on my bike. There's no way that thing stretches. Not on a bike. Not even if you have the strongest thighs in the world. The only way they break is through mishandling the belt during or prior to installation. If you kink it, or twist it, you can damage the carbon threads.

  92. #92
    Jambo100
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    The problem I'm having is getting the proper alignment. Trying different combinations of spacers, etc. The LBS thought they finally had it dialed in, but it's not even close now. It's pretty finicky, and I think because nobody has any real experience with it, it's trial and error now. I'm going to fiddle with it some more.

    I've heard I may be able to get a Rohloff after EuroBike in October, but I'm not holding my breath.

  93. #93
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    I've been riding a Spot all season with a Gates Carbon belt drive. The setup on the Spot frame is finicky, for sure with the horizontal drop-outs. Proper alignment requires tuggers and a bike stand to achieve, in my experience. I haven't had to fix a flat on the trail, and I'm really thankful for that.
    On the up side. I've been running the same belt all season and have competed in multiple races, including DS&G (which was unbelievably muddy), CCP100, 24 Hrs of Adrenalin Solo Worlds, and 24 Hrs of Grand Targhee. I rode the Spot the entire time and had ZERO issues with the belt. Never even thought about it. It cleans itself incredibly well and is super strong.
    The only hitch with the system, in my experience, is the set-up and the fact that the cogs and the belts are $$$.. That's my $.02.
    The combination of super patriotism with piety, used in the service of fear to elicit votes while suppressing equality works, but it is lethal for America......

  94. #94
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    Quote Originally Posted by ketchd
    I've been riding a Spot all season with a Gates Carbon belt drive. The setup on the Spot frame is finicky, for sure with the horizontal drop-outs. Proper alignment requires tuggers and a bike stand to achieve, in my experience. I haven't had to fix a flat on the trail, and I'm really thankful for that.
    On the up side. I've been running the same belt all season and have competed in multiple races, including DS&G (which was unbelievably muddy), CCP100, 24 Hrs of Adrenalin Solo Worlds, and 24 Hrs of Grand Targhee. I rode the Spot the entire time and had ZERO issues with the belt. Never even thought about it. It cleans itself incredibly well and is super strong.
    The only hitch with the system, in my experience, is the set-up and the fact that the cogs and the belts are $$$.. That's my $.02.

    I am getting my belt drive bike this weekend!!, what do you estimate for total miles on your belt?
    Quote Originally Posted by thefuzzbl
    aluminium has a tendency to fail when you need it most. i.e. you end up with a bad day.

  95. #95
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    I don't know really cuz I don't use a computer, but I'd guess at least 1k miles & 150K ft of climbing.... It's quiet! The other thing to consider, which maybe you already know this, but I was advised to go with the full width free hub instead of the SS hub. The larger width of the belt cog needs more adjustability than the SS hub can provide. That's what I was told, so that's what I did. I'm running it on AC 29" wheels and it's been great.
    Also, FWIW, I'm running the 46T ring up front and switch between a 28T and a 32T in the rear. I can do both of those combos with the 122T belt that I have.
    The combination of super patriotism with piety, used in the service of fear to elicit votes while suppressing equality works, but it is lethal for America......

  96. #96
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    That is what my friend noticed when he bought his belt drive bike. He went out and bought a chris king bottom bracket and it failed after 10 rides (guessing) he thinks it has to do with the high tension from the belt. He had it rebuilt and the BB seems like it's about ready to fail again after a few rides
    I am not saying anything bad about belt drive or chris king BB but it is very interesting...
    He loves the bike by the way

    Quote Originally Posted by Nurse Ben
    I was really intrigued with a belt drive, played around some with a prototype at a shop[ in Golden, CO. They seem like a neat alternative to a chain, but the extra cost and the high belt tension put me off a bit. I think they'd sell better if there were a cheap retro adaption to existing framesets without changing the dropouts.

    The tension is high, very high, I'd really worry about bearing wear, but then maybe it's not any more than the pressure a rider puts on the bearings when cranking hard. For me the cost is a big issue as I'm a low budget rider.

    Neat concept, though maybe it is as another poster stated: " a solution looking for a problem". I like my chrome chain just fine

  97. #97
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    Interesting. I built mine up this spring. Spent a week riding it around my parents place in VA and then went down to TN for a 12 Hr Race (DS&G) that was VERY muddy. After the race, I packed up the bike and then it sat at my parents house in VA for about a month before they shipped it back to me. When I put it back together, the BB was seized on the non-drive side. The BB was an XT and I assumed that it was just from the contamination of the race and then sitting for a month before being cleaned etc. I replaced it with a King BB and have had zero issues since. I still think that the racing conditions and the neglect for a month afterward were the major factors in play, but still it was a very uncharacteristically early failure for an XT BB.
    The belt tension is certainly tighter than a chain, but is nothing compared to the force you put in while pedaling. Maybe there's something I'm missing, but it doesn't seem to me like the belt tension would be a factor. You're supposed to have it tight enough that the belt "deflects" somewhere around 1/2-3/4" with 5 lbs of pressure or something like that. In other words, it shouldn't be as tight as a banjo string, just tight enough not to skip...
    The combination of super patriotism with piety, used in the service of fear to elicit votes while suppressing equality works, but it is lethal for America......

  98. #98
    blet drive
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    sick i need one... they look and sound so smooth .. or the one i rode did...
    Save a tree & wipe your butt with an owl.
    Thank your local Sierra Club.

  99. #99
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    I gave up on the beltdrive. I now run a set of ENO's and a chain. The belt engagement was nice, but I couldn't go a week without throwing the belt off, and beltline was always dead on.
    Livin' the dream.

  100. #100
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    Spot

    I have ridden the SPOT longbaord SS with belt all summer and love it. My issue is not with the bike but with the company. I don't think there is a bigger bunch of slackers out there. They do not return calls from bike shops and now I am waiting on a part that they said they sent out 2 weeks ago. Going to miss SSW09 if it does not show today. I just can't imagine how they operate. They must just have a bros club that supports them.

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