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  1. #1
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    New question here. Why bother with a Front Derailleur???

    As I'm building up a new bike and desiring to shed some weight... I'm wondering, Why bother with a front derailleur?!?

    Here's my thought process...

    1) I ride a SS currently and I've got almost no problems clearing the climbs in my area (ok, maybe 5% cause me to dismount and run... )

    2) If I've got a good spread on the back cassette with a 2:1 ratio in the middle gear, wouldn't that cover like 90% of what most people with gears actually use?!?

    I'm not a card carrying weight weenie and don't really want to be (205+ lbs and I'm hard on equipment due to riding style), but why bother with all the extra parts and weight?

    and last question, if you were to run a single ring system up front and gears in the back, will I need a chainguide system like the Black Diamond or DH guys/gals are using? What about a XC or trail version of a guide?

    Any one care to add to my thoughts or join a debate?!?

  2. #2
    Elitest thrill junkie
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    Quote Originally Posted by sengert
    As I'm building up a new bike and desiring to shed some weight... I'm wondering, Why bother with a front derailleur?!?

    Here's my thought process...

    1) I ride a SS currently and I've got almost no problems clearing the climbs in my area (ok, maybe 5% cause me to dismount and run... )

    2) If I've got a good spread on the back cassette with a 2:1 ratio in the middle gear, wouldn't that cover like 90% of what most people with gears actually use?!?

    I'm not a card carrying weight weenie and don't really want to be (205+ lbs and I'm hard on equipment due to riding style), but why bother with all the extra parts and weight?

    and last question, if you were to run a single ring system up front and gears in the back, will I need a chainguide system like the Black Diamond or DH guys/gals are using? What about a XC or trail version of a guide?

    Any one care to add to my thoughts or join a debate?!?
    I think this is a fine line of reasoning. I've been riding climbs in my middle gear that i used to do in granny, just because my singlespeed buddy does them with no problem on a singlespeed. It's mostly mental, and if he can do them SS, then I can do them in the middle ring, and I've been amazed over the last few months at what I've been able to do (when others have themselves absolutely convinced a climb is not doable in anything other than granny).

    I've also always wanted to build a hardtail with a simple 1x9 setup, about a 30t front ring, and 11-32 cassette. I could make it even easier, but that would be a little easier than what I ride everyday, and be a good deal lighter.

    I almost never use the big ring, so I'm sure I'd never miss that one.
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  3. #3
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    Why not

    The reason for a FD is to rapidly change gears due to rapid elevation changes or to start from stop. Depending on where you ride you might be able to do away with the RD and shift just the front three rings. Each shift in the front is equivalent to a 2 to 3 ring shift in the back. That way you could start in the small gear up front and rapidly shift to larger gears as your speed increases. It would save more weight to remove the RD (250gm) and Cassette (300gm) when compared to the FD (120 gm) and triple crank (+100 gm over single ring). Sheldon Brown has an excellent Gear Calculator for determining what would be the best combination of gears for you.

    Removal of FD has been employed succesfully on road bikes for Time Trials and just to shave weight. Google "Pista Grouppo" for road groups without a FD.

  4. #4
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    Quote Originally Posted by userid
    The reason for a FD is to rapidly change gears due to rapid elevation changes or to start from stop. Depending on where you ride you might be able to do away with the RD and shift just the front three rings. Each shift in the front is equivalent to a 2 to 3 ring shift in the back. That way you could start in the small gear up front and rapidly shift to larger gears as your speed increases. It would save more weight to remove the RD (250gm) and Cassette (300gm) when compared to the FD (120 gm) and triple crank (+100 gm over single ring). Sheldon Brown has an excellent Gear Calculator for determining what would be the best combination of gears for you.

    Removal of FD has been employed succesfully on road bikes for Time Trials and just to shave weight. Google "Pista Grouppo" for road groups without a FD.
    hhhmmm... I'm having trouble buying into your logic purely based on my experiences... relying no a mechanism to push on the chain until it just happens to drop down onto the grannie gear right when the trail jump 10% in grade has almost never been successful for me, besides with todays quality in shifters you can slam through 3+ gears at a time on the rear in just one full stroke of a trigger shifter (heck, on my grip shifters it'll shift as fast as I can twist)...

    On the other point, if you are at a stop you can simply shift to the lowest gear no matter which system, right?

    And a final thought would be that keeping the rear at least gives you about a 300% range with 9 index points (34T chainring with 11-34 Cass) versus 200% with 3 index points (44-32-22T Standard XT Crankset).

    You are certainly correct though if weight were the only concern then removine the rear would be better... As to other examples, what about Down Hillers and Free Ride guys???

  5. #5
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    Psst....the "Gear Calculator" is a link where you can check the math.

  6. #6
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    The numbers driving some of my thoughts...

    Here's my calculations that are driving my thoughts...

    Summary: Using standard XT gears and crank, you get a total range of 582-618%. I think realistically if you take out the absolute top gear and bottom gear you end up with 467-462%... I'm saying realistically because how often does any average Mtn. Biker use the absolute top gear, and secondly does anyone really actually need a 0.65 to 1 bottom ratio (considering most SS'ers out there are jamming away very close to 2 to 1).

    Comparing these "XT" standard ratios versus an XT cassette with a 34T chain ring you get a 291-309% gear range. That's about 150% less range... but look closer at the numbers, with the No-Front set up you cover ratio's that are effectively 3rd from the absolute top gear and 3rd/4th from the absolute bottom.

    So, I again I wonder about how much gain riders are actually getting for those last couple of gears on the top and bottom of the ranges?!? Wouldn't a rider be better suited by getting truelly evenly spaced gear ranges across a No-Front system?
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  7. #7
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    Hmmm...a 3x1...that is an interesting idea. It'd be kind of like an intermediate, quasi-single speed. You'd have a gear for going up, a gear for going level, and a gear for going down, but you wouldn't do any shifting in a given regime. It'd be pretty light, too, and you wouldn't have that vulnerable derailer dangling down there. I'm not sure how much of a pain the chain tensioner would be, though. It could be a good set up for a weight weenie or an SSer with knee problems.

    As for me, I use my lowest and my tallest gear on almost every ride. I like to keep an even 90 rpm cadence. I'm sure I'd do fine without them, and my previous bikes didn't have such a wide range (22-32-42 front, 11-34 rear), but I'm glad they're there when I need them.

  8. #8
    Gravity Rides Everything
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    Quote Originally Posted by sengert

    On the other point, if you are at a stop you can simply shift to the lowest gear no matter which system, right?

    you have to be pedaling to shift.


  9. #9
    mechmann_mtb
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    sengert...

    i have been riding my enduro as a 1x9 for quite a while now. there are very few places that i have run into where i can't make it up a hill. i still havn't bought the 30t front ring from extralite, but i plan to soon. it should make the super steeps and super long climbs a bit more tolerable.

    lightest setup to keep the chain on the middle ring with no mechs is to get a spot brand ring guard and a N-gear jumpstop.

    if you search for posts by me and my wife (aword4you) you can find quite a few pictures of my setup.

  10. #10
    I <3 29ers
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    I toyed with the idea of a no-RD set-up only to be stumped with one problem - how do you take up the chain slack? Think about it - spanning a difference of ~20 teeth (ie 22-32-42T) is going to leave you with some chain slack. What chain tensioner out there will take up THAT much slack?

    I've been toying with the 1x8 myself (i'm not a 9-speed guy). Interesting, for sure.

    As for the chain guide - if you set up your chain line properly you won't need a guide. Think about it - do you need one now? There's no difference between running on the middle ring with or without the big'n'little gears on either side as it is now. Put on a bashgaurd IF you feel you need one (and watch the weight savings disappear).
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  11. #11
    mechmann_mtb
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    AndrewTO...

    i had the same thoughts as you on the chainguide. i figured that if there is tension on the chain then it will stay on the gear. this is somewhat correct. my chain stayed on while riding around in the parking lot, on a road ride to the LBS, etc. but would not stay on at all as soon as i was riding trails. trail riding without something to keep your chain in place is not a possibility. the front mech keeps the chain on when going over bumps and stuff. the N-gear jump stop is way lighter than a front mech and is sufficient to do the job. a full on bash ring is thick and heavy, the spot brand ring guard is much thinner and gets the job done without weighing much more than a big ring. the big ring can do the same job, but you lose some clearance and in the event of a crash a ring guard won't leave those nice evenly spaced punctures on your body.

    weight savings comes from losing the mech, cable, shifter, hardware, small ring, short/med. cage RD, shorter chain

    another HUGE bonus is that the bike is so much quieter over bumps. it really cuts the chain slap down having this setup.

  12. #12
    I <3 29ers
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    Quote Originally Posted by mechmann_mtb
    AndrewTO...

    i had the same thoughts as you on the chainguide. i figured that if there is tension on the chain then it will stay on the gear. this is somewhat correct. my chain stayed on while riding around in the parking lot, on a road ride to the LBS, etc. but would not stay on at all as soon as i was riding trails. trail riding without something to keep your chain in place is not a possibility. the front mech keeps the chain on when going over bumps and stuff. the N-gear jump stop is way lighter than a front mech and is sufficient to do the job. a full on bash ring is thick and heavy, the spot brand ring guard is much thinner and gets the job done without weighing much more than a big ring. the big ring can do the same job, but you lose some clearance and in the event of a crash a ring guard won't leave those nice evenly spaced punctures on your body.

    weight savings comes from losing the mech, cable, shifter, hardware, small ring, short/med. cage RD, shorter chain

    another HUGE bonus is that the bike is so much quieter over bumps. it really cuts the chain slap down having this setup.
    Hmmmm, never thought about the FD keeping the chain in place. Interesting. Sounds like some experiments to conduct next year (JUST finished my last outdoors ride for the year). Thank you muchly!
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  13. #13
    ballbuster
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    Sure, wny not?

    ...although, in my case, I wish for a taller big ring gear at times.

    I use my granny gear often enough so I could not loose it and still clean everything I can now. That said, on a Sea Otter pre-ride, I cleaned Hurl Hill in the middle ring when I sheared off my granny gear CR bolts early in the ride. I was amazed I cleaned it, and it hurt... a lot. My legs were toast for the rest of the ride (with 15 steep miles to go).

    I also spin out my top gear (44*11) often enough so I can't get rid of that.

    If you go 1*9 (or 1*8 as the case may be) you should prolly install a jump stop or have some kind of chain control device. An SS chainring would prolly help too with the extra tall teeth and no ramps or pins.

  14. #14
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    Quote Originally Posted by pimpbot

    I also spin out my top gear (44*11) often enough so I can't get rid of that.

    On the trail you spin out your 44x11 That's over 37 mph. That's pretty quick.

  15. #15
    mechmann_mtb
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    hmmm...

    if i spin my 1x9 with 32:11 i get about 26 mph on flat ground and 30 going down. that is good enough for me. i don't think i get above 28 on trails, and i am NOT spinning at that speed on a trail.

  16. #16
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    I ran a 1x9 with an 11-32 cassette and a 40t in the front.
    Loved it for the most part.
    Tore up a lot of cassettes (LX and XT). But I seem to do that on my NRS, too.
    Maybe the chainline was too far out, so crossing to the larger cogs puled at too great of an angle...or the K2 Disco Monkey was too flexy in the rear and led to a side load under torque.

    I has the narrowest BB spindle that would let the crankarm spin, and the chainring was on the inside of the spider.

  17. #17
    What Would Happen?
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    Quote Originally Posted by userid
    Removal of FD has been employed succesfully on road bikes for Time Trials and just to shave weight. Google "Pista Grouppo" for road groups without a FD.
    Are you for real?

  18. #18
    mechmann_mtb
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    40T in front with an 11-32 cassette would be hell. there are plenty of places that we encounter on a weekly basis that gearing that high would be nearly impossible to turn, even standing.

    i bought a 30T CR on ebay and will see how that works. if i am lucky i will have it on my bike for this weekend. we are planning to make it up to the OC and i want to compare the climb up Mathis. i was absolutely dying on Mathis this last weekend with 32T CR.

  19. #19
    Got A Lust for Life...
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    About keeping the chain in place...

    I just dropped my FD. I found that when I dropped the biggie for a bashguard, I started to pay attention to how much I used the granny. Then I started to pay attention to how much I the damn thing actually shifted into the granny when I actually wanted to use i...which was never. I ended up riding everything in the middle ring. I didn't want to drop 130 bucks on a chain guide that would add more weight. Sooooooo I bought one of these...
    http://www.universalcycles.com/shopp...06&category=56

    I put the chain on the largest cog in the back and got the chain stop as close to the chain as possible in the front. I ride a Heckler very aggressively cross country or on whatever and have yet to drop the chain. Think about it...it weighs one ounce and costs ten bucks. Works like a charm. I do not miss my FD, little ring, or the hassles. I don't even think about it. A friend had the ngear on his ride and loves it as well. I will never go back.

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