Three Speed Hubs?- Mtbr.com
Results 1 to 24 of 24
  1. #1
    SS Addict
    Reputation: czryan's Avatar
    Join Date
    Aug 2004
    Posts
    55

    Three Speed Hubs?

    I caught the SS bug about 2.5 years ago, and progressed from a Supergo hardtail with tensioner to an IRO Highlander. I then rebuilt the Supergo with eight speed and have ridden it exactly once in the last year. I am in the mood to tinker with it and was fooling around with the idea of a three speed. Are there any durable three speed hubs out there that will handle off-road use? I am completely ignint. (BTW I tried searching the forum, but didn't have much luck.)

  2. #2
    The man who fell to earth
    Reputation: Ziggy-Stardust's Avatar
    Join Date
    Jan 2004
    Posts
    335
    I was interested in doing this awhile back too. After researching it I learned there are two big problems. One is that there basically aren't any three speeds hubs that will really hold up to sustained heavy duty offroad usage. The two currently manufactered brands are Shimano (Nexxus) and SRAM, the SRAM is a copy of an old Sachs design. I've heard the SRAM/SACHS design is the stronger of the two. The old Sturmey Archers are pretty tough too, but again they won't hold up for long offroad either. Second, is that the efficiency of these hubs is poor in 1st and 3rd gear, you pay a pretty big penalty in efficiency loss, plus you lose a few percent in gear 2 (usually direct drive). The internal gear meshing eats up power, that's just how it is. The Rohloff hub is the only true offroadable internally geared hub that'll work reliably. But again you pay a weight and efficiency penalty, plus they're beaucoup bucks.

  3. #3
    SS Addict
    Reputation: czryan's Avatar
    Join Date
    Aug 2004
    Posts
    55
    Bummer. Thanks for the highly informative and detailed reply, Ziggy.

  4. #4
    mtbr member
    Reputation: drunkle's Avatar
    Join Date
    Nov 2005
    Posts
    1,898
    wouldn't it also be a turn off having to build a wheel around the hub? assuming this is for a ss frame with no derailler hanger?

    how about a hook type derailler, the low end 5-6 speed type? get a 5-6 speed cassette, pull a couple gears off, space it out, use a friction thumbshifter...

  5. #5
    SS Addict
    Reputation: czryan's Avatar
    Join Date
    Aug 2004
    Posts
    55
    Quote Originally Posted by drunkle
    wouldn't it also be a turn off having to build a wheel around the hub? assuming this is for a ss frame with no derailler hanger?

    how about a hook type derailler, the low end 5-6 speed type? get a 5-6 speed cassette, pull a couple gears off, space it out, use a friction thumbshifter...
    Actually I was thinking of something like this as Plan B, and should have most of the parts laying around. One derailleur is better than two, right? It will at least get the bike off the rack and back into occasional use.

  6. #6
    highly visible
    Reputation: GlowBoy's Avatar
    Join Date
    Jan 2004
    Posts
    3,179
    I've been running a 3-speed hub (SRAM DualDrive Disc) in the back of my Karate Monkey commuter/dirtroad bike for 1 1/2 years now. I spend quite a bit of time standing up on climbs (mostly in L or M gera) on my regular commute route, and at least twice a month I detour through Portland's Forest Park. To get to Forest Park I have to ride several pavement stretches that are 15% grades for 2-3 blocks, and in Low gear I'm standing up and yanking the handlebar with all my might. Not only is this as much torque as I'd ever put on it offroad, I do the same thing offroad once I get into Forest Park.

    With over a year of regular use (I ran the KM with derailer for a few months last summer) I have had ZERO problems with this hub. I would not hesitate to recommend it for offroad use with the following caveats
    (1) I'm 160 lb and reasonably strong, with a SS riding style. I can't say whether the hub would hold up under a heavier rider or an unusually strong rider.
    (2) NEVER shift under load. I've been warned about this by numerous people. To be honest I've accidentally done it a few times I haven't blown it up yet, but it's still not recommended.
    (3) Forget it if you do a lot of jumps. I know a guy who rides lots of 3-4' drops and snapped the axle on his DualDrive. After taking it apart he determined the design was unsuitable for his style of riding. Still, I do simple curb drops on a daily basis with occasional larger air (rarely over 1') and have had no problems.

    I think the efficiency issue is overblown, and to some degree it's even a canard. I'll refer you to the only definitive study I've seen on gear hub vs. derailer efficiency. They tested 8 internally geared hubs (including the Rohloff) and 15 selected gears from a conventional Shimano 27-speed MTB setup, at inputs of 80, 150 and 200 watts. Allow me to summarize (averaging all 3 levels of power inputs):
    • Derailer drivetrain: 92.9% efficiency for the 15 tested gears. 94.3% for the top tercile (i.e., 5 tested) of most efficient gears.
    • Rohloff: 90.3% overall. Fairly consistent too, ranging from a high of 92.1% in Gear 9 down to 88.5% in Gear 14.
    • Sachs (now SRAM, similar to my DualDrive) 3-speed: 94.4% overall. Surprisingly, each of the 3 gears was over 94%.
    • Sturmey 3-speed: 93.4% overall. 92.9% in Low, 95.4% in Medium, 91.8% in High.
    • Shimano 3-speed: 91.3% overall. 92.2% in Low, 94.1% in Medium, 87.7% in High.
    • Shimano 4-speed autoshift: 90.4% overall, ranging from a high of 94.8% in Gear 1 down to 86.9% in Gear 4.
    • Sachs 7-speed: 90.7% average of only two speeds tested.
    • Shimano 7-speed: 90.2% overall, from 92.7% in Gear 2 down to 85.2% in Gear 5.
    • Sturmey 7-speed: 89.2% overall, from 93.7% in Gear 4 down to (cough, cough) 84.6% in Gear 7.


    Observations: (1) all the 3-speed hubs were more efficient than all the hubs with more than 3, (2) there is a tendency for the hubs to be more efficient in the low and middle gears where it's more important, (3) there is a lot of variation from one hub to another. I suspect this is due to variations in the quality of the gears as well as the weight of oil used. I think that article mentioned that the SRAM hub used a lighter weight oil than the others. The tradeoff for the improvement in efficiency is that you can't go decades without changing the oil. But even with the lightweight oil a geared hub is far less maintenance than a derailer system.

    And remember that these tests were done with a clean, dry chain. When the chain gets dirty, a derailer drivetrain quickly suffers and can lose an additional 10% in efficiency or more, whereas a non-pulley drivetrain (singlespeed or internal hub) is not affected anywhere near as much. At this point the hub gear system is substantially more efficient than a derailer system. My KM is my wet-weather geared bike, and at this point I wouldn't even think of going back to a derailer for that use. I just lube the chain occasionally and my drivetrain just works smoothly and flawlessly, rainy day after rainy day.

    drunkle, you raise a good point about building up a wheel around this hub. If the point is just a low-cost way to get some gears on a frame without a derailer hanger, you're better off getting the Shimano Tourney derailer with the built-in hanger. The SRAM hub is quite expensive (about $200), and once you build up a wheel and buy the other necessary hardware (shifter and clickbox) you've invested well over $300. Worth it for my use, since I'm riding this over 2k miles a year, but not for someone who just wants to tinker around.
    Last edited by GlowBoy; 06-07-2006 at 02:19 PM.
    "People like GloyBoy are deaf. They are partisan, intellectually lazy & usually very angry." -Jaybo

  7. #7
    Occasionally engagedů
    Reputation: Ptor's Avatar
    Join Date
    Jan 2004
    Posts
    1,634
    Quote Originally Posted by GlowBoy
    Allow me to summarize... Worth it for my use, since I'm riding this over 2k miles a year, but not for someone who just wants to tinker around.
    Wow! Great post -- I always read your comments GlowBoy, and this type of post is why.

    Anyway, I just spent the last nine months on a singlespeed (50 gear inches), but last week put my Rohloff back on. It's nice to have the gears and it works great, but I do miss the mindless simplicity and light weight of the singlespeed. The reason I've put the Rohloff on is that the high country has opened up and I've got a lot longer and steeper climbs available now (and at an elevation of 7200 feet and going up from there), and I just blow myself up on the singlespeed. I can handle many climbs, but the long rides and the longer races in the Rockies beg for the occasional 20 inch gear. Suprisingly, I'm not missing the big gear -- it's the small one that I need. Hence my thinking about the Schlumpf Mountain Drive bottom bracket -- I could have a direct drive of 50 gear inches and for those occasions of steep long climbs I could tap my heel and have 20 gear inches. I use to think I would need a high end and a low end: 20--50--80 gear inches on a 3-speed hub was my ideal. But off-road, 50 gear inches works fine for 95% of my riding -- that other 5% needs a low gear.
    "The plural of anecdote is not data." -- Attributed to various people in a variety of forms, but always worth remembering...

  8. #8
    SS Addict
    Reputation: czryan's Avatar
    Join Date
    Aug 2004
    Posts
    55
    Absolutely killer post, Glowboy. Thanks!

    That pretty much kills the 3 speed hub option for me on several counts. I need to be able to shift under load, and I don't want to be putting $300 into an experiment. I love my SS, but there are trails where I do a lot of walking. There are also some trails I want to explore, and I would like a little bit more versatility. My current plan is to use a rear derailleur and thumbshifter from the parts box and set up the center cog and chainline at my normal SS gearing (34x18). Then I will go probably three teeth larger on the inner cog and probably two on the outer cog (I'm not worried about going much faster). Of course, I could always set up the 34x18 as the outer cog if I wanted to have two lower gears.... This is going to be a good project.

    One last question - has anyone ever set up a cassette using non-ramped (i.e. SS) cogs? I have several Novatechs lying about. Does it make shifting difficult or impossible?

    Thanks again for everyone's input.

  9. #9
    mtbr member
    Reputation:
    Join Date
    May 2004
    Posts
    189

    why add a derailleur?

    I run a 2sp 36:20 and 42:13 which have a similar chain lengths. I'm sure I could find a granny gear that had a similar chain length and make a 3sp. This setup is great for riding the roads to the trail, then undo the quick release for a quick gear change for the dirt.


  10. #10
    bhc
    bhc is offline
    mtbr member
    Reputation:
    Join Date
    Sep 2005
    Posts
    443
    how long did it take you to figure out what gears would work together at a certain length of chain? Or did I not pay attention back in school in some class to the obvious answer to this one

  11. #11
    The man who fell to earth
    Reputation: Ziggy-Stardust's Avatar
    Join Date
    Jan 2004
    Posts
    335
    Glowboy, when I said the efficiency of the internally geared hubs was relatively poor, I was mostly comparing it to the efficiency of the singlespeed drivetrain, not to competing gear drive systems. A clean, well oiled singlespeed drivetrain in good condition, properly maintained/aligned/adjusted and broken in approaches 100% efficiency. Efficiencies on the order of 97-99% are commonly achieved with an SS drivetrain under these circumstances. For a human powered vehicle, power is at an absolute premium, so having a roughly 5-10% increase in efficiency is really a huge separation from the various geared systems (especially internally geared hubs). Of course the downside is that you're stuck in one gear, but it really is amazing just how good a transmission the human body can be given a little training/acclimitizing in producing a wider bandwidth of torque and spinning speed (within reason of course).

    And thanks for the referenced study, looks pretty interesting. You state that this is the only definitive study you've seen on this topic. I had a copy of a similar test that was conducted in '83 if memory serves, but I can't seem to find it on my pute. It showed that a deraileur shifter arrangement had superior efficiency to the three speed hubs (and all others with higher gear ranges). I dont remember what flaws that test might have had, I'll post it if I can find it. In this later (2001) study I notice they don't include the efficiency of an SS drivetrain as a point of comparison, not sure why that is. And again, this study does repeatedly refer to the significance of even seemingly minor differences in efficiency (i.e. ~2%) on rider performance, especially under competetive conditions - which would obviously bode well for the SS drivetrain had it been included. Plus they state that the SA and SACHS 3 speed hubs were broken in and that the grease which normally comes with them had been removed and replaced with a thinner oil. The other drivetrains were brand new and unbroken in. Of course replacing the grease with light oil and using a well broken in hub is not really a fair comparison with the remaining drivetrains, and undoubtably increases the performance of the hub beyond what it would be under normal circumstances (and probably explains its surprisingly high performance in this particular test). Plus there's no mention of what happens to the durability of the hub if used for heavy duty offroad use using a light weight oil as opposed to what it was (apparently) engineered to be lubricated with (i.e. grease). Also no mention is made of the sealing system of these hubs and how tolerant they will be to repeated mud/water exposure common to offroad riding (and the long term negative effects that dirt/moisture contamination would have on efficiency and durability). Also there's no mention of how long these drive systems were tested for. Prolonged tests, especially at higher wattage inputs would have warmed the oil inside the threespeed hubs beyond what might be expected under normal riding conditions (especially with plenty of cooling air present during normal riding). This may (or may not) have further decreased oil shear losses inside the hub and again falsely promoted their efficiencies.

    Lastly, I think some of their methodology of testing the derailleur system is, practically speaking, a bit off. It's been a long time since I've run a geared bike, but there are a few factors in this test that are making the derailleur system look more inefficient than it actually is under "real world" conditions. For one thing they include some gear numbers that require quite a bit of chainline deflection to achieve. Specifically, gears 10 and 18 employ maximum deflection possible in the chainline. Gear ten has the largest cog on the back (which is all the way inboard) matched with the big ring up front (which is all the way outboard). Likewise gear 18 does the same thing with the inboard granny ring and the 12t cog on the outside. When I rode geared bikes I would never select these ratios, especially offroad, and I dont think any reasonably knowledgeable rider would either. I remember the chain skipping and popping and attempting to derail if I tried to use these ratios because of the huge chainline deflection between the front and rear sprockets. This study including these grossly mismatched (and unrealistic under practical real world riding conditions) ring/cog combinations serves to falsely lower measured performance in my view. Also he includes three gears in his test that all use the small, efficiency killing, 12t cog on the back. Again, I don't know about other riders but I would almost never use the smallest cog on the back offroad. If I needed more gear I would just go to the big ring which rarely needed anything less than a 16t on the rear to get rolling. Even onroad the 12t cog was uncommonly used, unless going downhill (where efficiency is no longer really an issue). So by including these "unrealistic" gear selection scenarios and incorporating their associated (low) measured efficiencies into the aggregate very significantly lowers the final tallied averaged efficiency, making the derailleur system's performance look quite a bit worse than it really is in practice.

  12. #12
    mtbr member
    Reputation:
    Join Date
    May 2004
    Posts
    189

    my starting point...

    is the number of total teeth for ring+cog, 36+20=56. then fine tune from there using different rings and cogs. I first tried 42:14 which also has 56 total teeth, but that combination needed more chain. 42:13 is not exactly the same as 36:20, but close enough that it's useable.

    it's a myth that the same number of total teeth gives the same chain length. I think it's due to the increasing slope of the chain as the ring/cog ratio becomes larger. kinda like the hypotenuse of a right triangle... it gets longer as the leg of the triangle gets longer.

    I'm sure some of the math whizzes on the boards can generate a formula on a spreadsheet for you so that you won't have to use trial and error method like I did.

    Quote Originally Posted by bhc
    how long did it take you to figure out what gears would work together at a certain length of chain? Or did I not pay attention back in school in some class to the obvious answer to this one

  13. #13
    mtbr member
    Reputation:
    Join Date
    Jan 2004
    Posts
    59

    3 speed...

    I have been running my bike as a three speed with the shifting up front. A 19 tooth freewheel with a 22, 33, 38 up front and a paul melvin tensioner to take up the chain slack. I would perfer a 26 instead of the 22 but have not sorced one yet. I use non-ramped non-pinned chainrings so they shift slower but hold the chain well and a paul thumb shifter does the shifting duty. As for chainline, it is set to the middle ring where the bike lives probably 85-90% of the time.

    I don't shift much but the higher end makes getting to/from the trail head easier and the granny helps on the long climbs late in the ride. It has worked great for me...

  14. #14
    highly visible
    Reputation: GlowBoy's Avatar
    Join Date
    Jan 2004
    Posts
    3,179
    Quote Originally Posted by Ziggy-Stardust
    Glowboy, when I said the efficiency of the internally geared hubs was relatively poor, I was mostly comparing it to the efficiency of the singlespeed drivetrain, not to competing gear drive systems. A clean, well oiled singlespeed drivetrain in good condition, properly maintained/aligned/adjusted and broken in approaches 100% efficiency.
    Absolutely agreed on that point. The losses in either type of shiftable drivetrain are probably an order of magnitude higher than in a singlespeed. I've noticed the difference on-road (where I was able to step up to cog 1 tooth smaller after ditching the tensioner) and off-road (where it does seem just a touch harder to climb a steep slope with my 3-speed in the middle (1.0, direct drive) gear than it does with a singlespeed hub run at the same ratio.

    Quote Originally Posted by Ziggy-Stardust
    Also no mention is made of the sealing system of these hubs and how tolerant they will be to repeated mud/water exposure common to offroad riding (and the long term negative effects that dirt/moisture contamination would have on efficiency and durability).
    Good point. I'll continue my long-term test of the SRAM hub. I live in a very wet climate (western Oregon), and this is my wet-weather bike. It is ridden in the rain a substantial amount of the time, is exposed to a steady diet of road grit, and also sees quite a bit of sloppy mud on its weekly dirt detours. It will take several years of testing to determine whether how well it will truly hold up under these conditions, but so far so good. A solid year of trouble-free use in this climate is better than can be expected of some cassette freehubs I've used!

    Quote Originally Posted by Ziggy-Stardust
    Also there's no mention of how long these drive systems were tested for. Prolonged tests, especially at higher wattage inputs would have warmed the oil inside the threespeed hubs beyond what might be expected under normal riding conditions (especially with plenty of cooling air present during normal riding). This may (or may not) have further decreased oil shear losses inside the hub and again falsely promoted their efficiencies.
    That's speculation at best. I've ridden this hub at a wide variety of temperatures and power inputs and haven't noticed much variation in efficiency. I've done the 1000' climb to my riding area in 95 degree heat and never noticed any efficiency reduction in the transmission. The efficiency of the engine was dramatically reduced, but that's another story.

    Quote Originally Posted by Ziggy-Stardust
    Lastly, I think some of their methodology of testing the derailleur system is, practically speaking, a bit off. It's been a long time since I've run a geared bike, but there are a few factors in this test that are making the derailleur system look more inefficient than it actually is under "real world" conditions.
    Agreed, their choice of which gears to test was quite poor. Most sensible riders are only going to use about 15 of their 27 gears, and they should have picked the 15 that actually made the most sense. That's why I mentioned that the top tercile of 5 most efficient gears tested averaged 94.3% -almost precisely the same efficiency as the Sachs 3-speed. Even the most efficient gear (44x20) was only 95.1%, just very marginally better than the 3-speed.

    This is consistent with my real-world experience. I switched back and forth between the DualDrive and a 1x4 derailer system a couple of times last year, and I could not detect any substantial difference in pedaling efficiency. If there is a difference between the two systems, it is small. I certainly could detect a substantial difference between either of these systems and a singlespeed, however.

    Both systems have their strengths: gear hubs shine in bad weather, require very little adjustment or maintenance, are comparably efficient, and -- if 3 gears is all you need -- don't weigh any more than a 1xN derailer system. For wet weather, being able to ride a shiftable drivetrain that works flawlessly day in and day out in all conditions (including mud) is absolutely priceless to me. The advantages of derailer systems are that they weigh less if you need more than 3-5 gears, are more widely available and a bit cheaper to build, allow you to customize gearing, and start to gain an efficiency edge for riders who regularly put out in excess of 200 watts (probably not me!). I use a derailer for dry-weather commuting and road riding because I can tailor the gears.
    Last edited by GlowBoy; 06-09-2006 at 05:49 PM.
    "People like GloyBoy are deaf. They are partisan, intellectually lazy & usually very angry." -Jaybo

  15. #15
    highly visible
    Reputation: GlowBoy's Avatar
    Join Date
    Jan 2004
    Posts
    3,179
    Quote Originally Posted by czryan
    Absolutely killer post, Glowboy. Thanks!

    That pretty much kills the 3 speed hub option for me on several counts. I need to be able to shift under load, and I don't want to be putting $300 into an experiment. I love my SS, but there are trails where I do a lot of walking. There are also some trails I want to explore, and I would like a little bit more versatility. My current plan is to use a rear derailleur and thumbshifter from the parts box and set up the center cog and chainline at my normal SS gearing (34x18). Then I will go probably three teeth larger on the inner cog and probably two on the outer cog (I'm not worried about going much faster). Of course, I could always set up the 34x18 as the outer cog if I wanted to have two lower gears.... This is going to be a good project.

    One last question - has anyone ever set up a cassette using non-ramped (i.e. SS) cogs? I have several Novatechs lying about. Does it make shifting difficult or impossible?

    Thanks again for everyone's input.
    Definitely consider running two chainrings and two cogs. As long as the difference in teeth is the same in front as in back, the effective chainstay length is (very nearly) the same and you won't run into any chain tensioning issues. I'm currently running my Vulture with 34x22 for most riding and 30x26 for very steep climbs.I can switch gears without having to adjust the EBB. I can't shift while riding of course, but I do get all of the efficiency benefit of a singlespeed.

    When I run my Karate Monkey singlespeed, I have it set up for 36x22 for offroad and 40x18 for onroad. Same deal.

    You could set yours up with 34x18 as your mountain gear and (for example) 36x16 or 38x14 as your street gear. Depending on chainstay clearance, you might also be able to do 30x22 or 28x24 as a super-granny gear too, if you wanted. Lots of possibilities.
    "People like GloyBoy are deaf. They are partisan, intellectually lazy & usually very angry." -Jaybo

  16. #16
    ravingbikefiend
    Reputation:
    Join Date
    Apr 2006
    Posts
    2,322
    I've been planning on building a wheel around an old SA hub for light trail and commuting use... being that I ride an old Superbe with an SA three speed I know that they are a fairly efficient unit and maintainence really is nominal.

    Putting the same drive in a lighter bike would be a fun project.

    Increasing the rear cog size or running a smaller chainring up front is a must if one is going to do a lot of hill climbing as these internal hubs are geared quite high.
    I ride with 65'er...he's a mountain goat....But then again, we need to throw him in the mud and pack his pockets with lead shot before a scale will read him. - Psycho Mike

    -Environmental stickers don't mean shite when they are stuck to CARS!-

  17. #17
    highly visible
    Reputation: GlowBoy's Avatar
    Join Date
    Jan 2004
    Posts
    3,179
    Quote Originally Posted by Sixty Fiver
    I've been planning on building a wheel around an old SA hub for light trail and commuting use... being that I ride an old Superbe with an SA three speed I know that they are a fairly efficient unit and maintainence really is nominal.

    Putting the same drive in a lighter bike would be a fun project.

    Increasing the rear cog size or running a smaller chainring up front is a must if one is going to do a lot of hill climbing as these internal hubs are geared quite high.
    Are you going to re-space it, and if so what is involved? I've also got an old S-A hub lying around and would love to use it to build up something for my wife, but it's spaced 110 or 118 or something like that.
    "People like GloyBoy are deaf. They are partisan, intellectually lazy & usually very angry." -Jaybo

  18. #18
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    151

    Re

    I've been seriously considering an internal gear hub myself for one of my bikes (more off road). You guys have totally quenched my thirst for answers that have been brewing in my head for a while. Thank You Thank You Thank You

    1 Vote for seriously adding this thread to the FAQ's of this forum!!! (anybody listening )

  19. #19
    Where's Toto?
    Reputation: endure26's Avatar
    Join Date
    Oct 2004
    Posts
    1,188
    I'll offer up two links 'o inspiration. Neither are off road specific, but both are using SA three speeds to log some INCREDIBLE miles...

    Joel's messenger Sycip...

    http://www.blackbirdsf.org/bikes/

    (pic of bike http://www.sandsmachine.com/a_syc_r1.htm)

    The Turtle and his 3-speed Kogswell - 600k on 3 gears in 32 hours...

    http://www.mile43.com/peterson/3Speed/KogswellG3.html

  20. #20
    ravingbikefiend
    Reputation:
    Join Date
    Apr 2006
    Posts
    2,322
    Quote Originally Posted by GlowBoy
    Are you going to re-space it, and if so what is involved? I've also got an old S-A hub lying around and would love to use it to build up something for my wife, but it's spaced 110 or 118 or something like that.
    From the "building a commuter" standpoint, I know the older Raleigh frames were built to take either a 5 speed or 3 speed SA hub so there should not be too many spacing issues there (if any)... the old Raleigh frames are also very well made and reasonably light and should you find one built on Reynolds 531 tubing please send it to me... ha ha ha.

    Installing an SA hub in an off raod bike would involve more serious modifications due to the much wider spacing between the dropouts. Sheldon Brown would probably have info on what's needed re: needed parts and spacers.
    I ride with 65'er...he's a mountain goat....But then again, we need to throw him in the mud and pack his pockets with lead shot before a scale will read him. - Psycho Mike

    -Environmental stickers don't mean shite when they are stuck to CARS!-

  21. #21
    Where's Toto?
    Reputation: endure26's Avatar
    Join Date
    Oct 2004
    Posts
    1,188
    If you could find one of the 2005 or earlier Redline Monocogs, they had 120mm rear spacing (also compatible with BMX hub...Redline's roots) and should be able to take a SA rear hub without re-spacing the frame. The Monocogs were pretty inexpensive, but well made. May even be able to find a NOS someplace.

  22. #22
    mtbr member
    Reputation:
    Join Date
    May 2004
    Posts
    742

    I've been riding a 2x3 for over a year

    Quote Originally Posted by czryan
    I caught the SS bug about 2.5 years ago, and progressed from a Supergo hardtail with tensioner to an IRO Highlander. I then rebuilt the Supergo with eight speed and have ridden it exactly once in the last year. I am in the mood to tinker with it and was fooling around with the idea of a three speed. Are there any durable three speed hubs out there that will handle off-road use? I am completely ignint. (BTW I tried searching the forum, but didn't have much luck.)
    I used two dx cogs with full teeth and a 28t cassette cog with pickup teeth. It's on an xt hub so it's as strong as any xt cassette hub. I have good chain line, easy shifting with a cheap plastic thumb shifter.

    I have two rings up frt between a jump stop and a rock ring. No frt der. It works grear and doesn't require any tweeking to shift good. Gearing is perfect for any terrain. It doesn't cost much to make.
    Attached Images Attached Images

  23. #23
    ravingbikefiend
    Reputation:
    Join Date
    Apr 2006
    Posts
    2,322
    Well... I worked into the wee hours last night and looked into swapping that 3 speed hub into the Raleigh Criterion I picked up on the weekend.

    The SA hub dropped right in to the frame with no need for any spacing adjustments so I just took off from there and removed the deraileurs, fitted and tensioned a new chain, set up the shifter and now the "Critter" is ready for some serious road testing.

    My short test rides last night went really well as the bike feels solid, rides really nicely, and performs really well... without a speedo I can't tell exactly how fast I was going but I'd estimate I was cruising at well over 20 mph with very little effort.

    The SA hub in a lighter road rame experiment seems to be successful and she looks like she will be an excellent all weather, low maintainence commuter. She might even see winter duty as the lack of deraileurs and sealed hub seem ideal for that purpose.

    More road testing is required to see which way I go with the gearing and I figure that a slightly smaller Shimano rear cog will be going in to up the top end a little and address the chain size issues.. the old 3 speed cog won't take 6 speed chain so I had to use the larger 3 speed chain.

    She's a scruffy looking bike (the frame needs a repaint) but the 3 speed hub gives the bike a really clean and cool look.

    Pictures will be forthcoming once I get her polished up.
    I ride with 65'er...he's a mountain goat....But then again, we need to throw him in the mud and pack his pockets with lead shot before a scale will read him. - Psycho Mike

    -Environmental stickers don't mean shite when they are stuck to CARS!-

  24. #24
    ravingbikefiend
    Reputation:
    Join Date
    Apr 2006
    Posts
    2,322
    Some pics of the work so far...

    She's not very pretty (yet) but I am planning on stripping her down and painting her in a nice shade of copper orange.



    This is what the new driveline looks like... the ring up front is a 40, the chainguard was fabricated from the old 52 tooth chainring, and there's a 20 cog in the rear. That gives me gear ratios of 40, 52, and 74 gear inches if my math is correct. My top end is close to a 1:3 ratio while the bottom end is a 1: 1.5 which gives me a perfect range for all manner of urban assaults.



    Another shot of the chainguard which I am quite pleased with (although that chain has to go ).



    I'll be putting in a new cog in the rear to increase the gearing and address the chain issues and am thinking an 18 would increase my top end ratio to 86 gear inches and still leave me a decent bottom end of 43 gear inches.

    I went out on a 15 mile test run tonight and was really impressed at how well the Critter performed at high speed, on hills, and I especially like the ability to shift at any speed or no speed at all..
    I ride with 65'er...he's a mountain goat....But then again, we need to throw him in the mud and pack his pockets with lead shot before a scale will read him. - Psycho Mike

    -Environmental stickers don't mean shite when they are stuck to CARS!-

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.