Sprinting on Biopace chainrings?

Discussion in 'Road Cycling' started by velomanct, Feb 24, 2010.

  1. velomanct

    velomanct New Member

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    What's it like? Worse, odd, better?

    I'm talking lower rpm sprints like up hills at 80-110rpm max.

    I'm just curious and see a bunch of these for sale in my area, might try it out.
     
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  2. alienator

    alienator Well-Known Member

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    I think you'll want to skip Biopace rings. It's been said that the problem with Biopace rings was that the major axis of the ellipse (yeah, they're elliptical), was at the wrong place in the pedal cycle. Supposedly rings made by Osymmetric and Rotor don't have the issue. Rotor chainrings allow you to adjust the major axis' position relative to the pedal stroke.

    Some people say they like Biopace chainrings, but then some people also drink pee. Taste is an odd thing.
     
  3. quenya

    quenya New Member

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    My bottechia has biopace and I love it, I think it rewards harder efforts like out of the saddle climbs, hard TTing, and attacks/counter attacks. IME it is less natural at slower paces, riding with partners who are much slower than me felt even more awkward than normal. If it's not too expensive try it out maybe you'll like it maybe not, but don't assume that because something isn't a commercial success that using it equates to drinking urine.

    The rings aren't really eliptical they're more egg-shaped. I could recite some of Shimano's marketing claims from back in the day as to why this works, but the physics behind it are beyond my education so it would really be regurgitation. What I do know is that I feel comfortable and fast on that bike and have had zero problems with it.
     
  4. alienator

    alienator Well-Known Member

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    It's got nothing to do with commercial success at all.
     
  5. 64Paramount

    64Paramount Active Member

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    My C-Dale has bio pace chain rings on it ( they were original equipment ) and I really don't know if they are better, worse, or make any difference at all.

    Maybe I've ridden them so long that I just don't notice the difference, but my Paramount has round chain rings ( at least I think they are round ) and I don't feel anything different when I change between the two bikes.
     
  6. quenya

    quenya New Member

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    Sorry. I didn't mean to put words in your mouth. I was just having a hard time tryIng to understand why you dismissed a good product so matter of factly. I have read about biopace rings being installed with the crankarms in the wrong position being problematic, but that's a flaw in the assembly not the design. My personal experience gas been very positive.
     
  7. alienator

    alienator Well-Known Member

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    No worries. I didn't take it that way. I was just saying that the downfall of Biopace was likely the cause of complaints to Shimano and/or bad press. I had 'em for a while, but I didn't particularly care for them.
     
  8. quenya

    quenya New Member

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    In 2000-2001 I remember seeing soft yuppies in Folsom killing themselves climbing relatively tame hills on Trek OCLV bikes with Dura Ace. I remember thinking and saying that these guys would have been better served by losing weight and maybe riding a bike with a triple while they got fit. Well if Lance had been riding Bio-pace I think people would have bought it and believed it was the best choice for them.
     
  9. alienator

    alienator Well-Known Member

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    That could be the case, but there was no "icon" in American cycling, in the late 80's, that brought the publicity or the interest in cycling that Armstrong has.....for better or worse.

    It is a tough sell, now, to get cyclists, in general, to buy triples. Tourers don't have that problem. Some of the issue is image: pro's aren't typically seen using triples (although they have), and some cyclists may make some purchasing decisions on what pros use (That is the intended result of sponsoring cycling teams.). Compact, cranks, however are rapidly becoming the go-to crankset. The truth is that almost all of the issues that people have with triples aren't issues at all.

    That said I've no issue with what people buy and have no bias against new riders that have expensive kit.
     
  10. alfeng

    alfeng Well-Known Member

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    +1
     
  11. swampy1970

    swampy1970 Well-Known Member

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    The Rotor chainrings are well made and may powermeter tells me that they're good for going uphills. It's what I use on standard cranks when I'm out on the big rides in the mountains and not training on Power Cranks (with round rings).

    Never really tried them for sprinting but I think there's a few papers written about the effects of the rings during sprints and increased power. YMMV. It's one of those things were you need to get the stuff on your bike and do quite a few tests and then go back and look at the data. I'm not a sprinter but I can say that you have to be stupidly overgeared to get that "bogged down" feeling when jumping hard.

    What I can say is that when I'm fcuked out my head at the end of a very hard ride, doing over 100rpm tends to feel slightly jerky. That's why the 11 sprocket was invented... :p

    They're really well made too and shift almost Dura Ace fast. Find the correct position requires reading (and understanding) the instructions and hints/tips given on the website.
     
  12. Tapeworm

    Tapeworm New Member

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    Short answer is:- don't. Studies I've seen and participated in have demonstrated zero increase in power over normal chainrings. Combine this with possible issues with the front derailleur there seems to be no real reason to use them.
     
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