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Two Technical Questions

(11 posts)
  • Started 11 years ago by Wilmington's Cow
  • Latest reply from chdot
  • This topic is not resolved

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  1. Wilmington's Cow
    Member

    .one
    I got a single chainring chainset today to give it a try on the Kaff, giving me a weird 10spd, single up-front thing. But obviously the chainring isn't made for 10 speed - will the chain fit? (okay, easy for me to find out tonight, but then we can see whose thoughts are correct). It's a neat chainset because the ring is stepped out from the spider, so about in the position that a middle chainring on a triple (which is what it's replacing) would be.

    .two
    If one crank is 170mm, and the other is 175mm, will you actually notice when riding? (bearing in mind the other thread on knees and SPDs, I'm more than aware of the limitations of my knees, so any indication while riding that it's a problem and I'[ll be seeking replacement - the slightly longer left hand crank was all the Bike Station had matching).

    Posted 11 years ago #

  2. Cyclingmollie
    Member

    I've no ten speed kit but I have an eight speed cassette/single chainring bike which only worked properly once I had replaced the o.e. cheap pressed steel chainring with an aluminium one with superfluous ramps and pins costing a sixth the price of the entire bike. And that was with a chain guard and dog-fang trying to keep the unruly chain-line under control into the bargain.

    I would like to hear how the mismatched cranks feel. I suspect you may not notice, though you will know.

    Posted 11 years ago #

  3. wingpig
    Member

    Chain might possibly get held a little too tightly by the fatter teeth of the chainring, especially in the presence of pathsludge.
    You'll notice. You can notice the difference when one foot is slightly differently-placed on the pedal, all crank lengths being equal.

    Posted 11 years ago #

  4. kaputnik
    Moderator

    .one

    I've seen it done, so it must work. you could always either replace the ring with the correct one (using the new spider) or file down the teeth if it's proving to be too wide! It might "work" but might wear through chains faster as it will undoubtedly put more internal lateral force on the chain than the correct tooth width.

    If one crank is 170mm, and the other is 175mm, will you actually notice when riding?

    Eventually. It means one leg is effectively pedalling in a slightly different gear than the other one. But then again your legs may be slightly different and you never do notice!

    Posted 11 years ago #

  5. DaveC
    Member

    one.

    ?? I defer to those more knowledgable than I.

    two.
    [joke] you'll eventually end up pedaling in circles[/joke] This sounds like they only had one side of the crank and sold it cheap? Presume you no longer need a triple/double up front for simple commuting?

    I'll get my coat.

    Posted 11 years ago #

  6. allebong
    Member

    @DaveC you better check both arms on your coat are the same length before putting it on.

    5mm over a 170mm crank doesn't seem all that significant, especially when you throw in all the other tolerances, maybe wearing a thicker sock on that side will counteract it? (edit: :P) Then again I've never ridden with mismatched crank lengths.

    Posted 11 years ago #

  7. Bhachgen
    Member

    I think the chainring might well be OK. Bearing in mind you won't be asking it to change gear so the fact the chain will be a bit "tight" shouldn't be an issue.

    The different length cranks I don't much fancy. Instinct says it can't be good for the knees. If it was your only bike I would guess that you wouldn't notice but if you ride others regularly I think you will notice this one being a bit "squinty"

    All conjecture so look forward to being proved wrong...

    Posted 11 years ago #

  8. Wilmington's Cow
    Member

    All academic... The teeth on the chainring are too wide, the chain won't sit right down into them (and riding it they'd be trying to force the plates apart!).

    Will stick with the triple for the time being and ponder more.

    Posted 11 years ago #

  9. Instography
    Member

    Couldn't the chainring be replaced by a 10-speed compatible one? Or just make it a single speed at the back and run a wider chain. I'll give you the back end gubbins - spacers and cog - since I have it attached to a wheel and will never use it.

    Posted 11 years ago #

  10. Wilmington's Cow
    Member

    I did consider a while back singlespeeding it, but I want it for weekend pootles with Mel as well, and the gears are nice for taking it easy up hills.

    Don't know where my mind is - heading out tonight I thought I'd see if the middle ring on the current setup has the same BCD to do a swap over. That's what I'll look at tomorrow night.

    Posted 11 years ago #

  11. chdot
    Admin

    For newer people -

    http://sheldonbrown.com/cribsheet-bcd.html

    Posted 11 years ago #

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