Crank arms

paul20v
paul20v Posts: 267
edited May 2012 in MTB workshop & tech
Hi all
Just a quick question
Is there a crank arm available thats less than 170mm
Im asking as in bends while pedaling sometimes im catching a pedal
Im running a 175mm at the moment so can gain a little with a 170mm but not really much
Cheers :D

Comments

  • estampida
    estampida Posts: 1,008
    http://www.middleburn.co.uk/tech_cranklengths.php

    I have seen half sizes (162.5) but google knows all
  • nicklouse
    nicklouse Posts: 50,675
    paul20v wrote:
    Hi all
    Just a quick question
    Is there a crank arm available thats less than 170mm
    Im asking as in bends while pedaling sometimes im catching a pedal
    Im running a 175mm at the moment so can gain a little with a 170mm but not really much
    Cheers :D
    Why are you pedalling in bends?

    What bike?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • cooldad
    cooldad Posts: 32,599
    nicklouse wrote:
    Why are you pedalling in bends?
    This,
    I don't do smileys.

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    Parktools
  • sloppycowpat
    sloppycowpat Posts: 349
    are you riding a fixie?

    thats the only time that this should happen
    worst moment ever...
    buzzing down twisting single track then.... psssst BANG!!!
  • ilovedirt
    ilovedirt Posts: 5,798
    Agreed with the rest, why are you pedalling in corners?
    Production Privee Shan

    B'Twin Triban 5
  • Twelly
    Twelly Posts: 1,437
    Outside foot down = pedal will never catch

    ..and if it does, you have fallen off.
  • chazkayak
    chazkayak Posts: 193
    I hate to admit, ive been having the same problem.

    Where I ride its a slight uphill with off camber zigzags, If I stop peddling, I stop and loose all speed to get up the hill!!

    I also was thinking of shorter cranks.
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    Learn to tilt your bike to give you the clearance when needed
  • stubs
    stubs Posts: 5,001
    Shimano do some of there cranks in 165mm sizes but 10mm is going to make next to no difference to ground clearance. About the same as fitting fatter taller tyres.
    Fig rolls: proof that god loves cyclists and that she wants us to do another lap
  • paul20v
    paul20v Posts: 267
    edited May 2012
    nicklouse wrote:
    paul20v wrote:
    Hi all
    Just a quick question
    Is there a crank arm available thats less than 170mm
    Im asking as in bends while pedaling sometimes im catching a pedal
    Im running a 175mm at the moment so can gain a little with a 170mm but not really much
    Cheers :D
    Why are you pedalling in bends?

    What bike?
    Hi sorry all been away and only just got back
    Its a cube analogue in an 18"
    The bike is great apart from the issue im having
    In 25yrs of cycling ive never had this problem the bike has a very low BB which i had not noticed when buying
    Im using the bike for road comutting at the moment and pedalling on roads in bends happens :D
    Ive caught the pedal twice in the last week on the outer edge so was willing to try if available a shorter crank as its the only way i can stop this from happening or slow down in corners
    Obviously if i was ridding offroad the style would be different i would also be using my other bike which has a load of BB clearance .
  • paul20v
    paul20v Posts: 267
    chazkayak wrote:
    I hate to admit, ive been having the same problem.

    Where I ride its a slight uphill with off camber zigzags, If I stop peddling, I stop and loose all speed to get up the hill!!

    I also was thinking of shorter cranks.
    Glad im not the only one :D
  • nicklouse
    nicklouse Posts: 50,675
    Time your pedalling differently.

    Shorter cranks will not help. Thinner pedals will Mae more of a difference in that example.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • YeehaaMcgee
    YeehaaMcgee Posts: 5,740
    paul20v wrote:
    In 25yrs of cycling ive never had this problem
    There isn't any bike that this wouldn't happen on. I don't see how you've not had it happen before if you've been pedalling round bends for 25 years.
  • chez_m356
    chez_m356 Posts: 1,893
    paul20v wrote:
    In 25yrs of cycling ive never had this problem
    There isn't any bike that this wouldn't happen on. I don't see how you've not had it happen before if you've been pedalling round bends for 25 years.
    even worse, its on the road, which are usually fairly smooth, so you don't even have the excuse of rocks and roots etc
    Specialized Hardrock Sport Disc 10- CANYON Nerve AM 6 2011
  • paul20v
    paul20v Posts: 267
    chez_m356 wrote:
    paul20v wrote:
    In 25yrs of cycling ive never had this problem
    There isn't any bike that this wouldn't happen on. I don't see how you've not had it happen before if you've been pedalling round bends for 25 years.
    even worse, its on the road, which are usually fairly smooth, so you don't even have the excuse of rocks and roots etc

    Hi
    I really dont understand why this scenario is so unbelievable for people
    When your going round bends fast you have to lean a bike over it just what happens naturally And if theres any sort of speed wanted you have to pedal so it doesnt matter how smooth it is if you want to crack on the bike will lean
    It just happens the bike has a low BB height And i was wondering about shorter cranks
    I also dont get how i can time my pedalling when there could be a number of revolutions of the pedals in some corners
    Im not looking for an argument im just lost as too some of the answers
    I understand when on a down hill on or off road flat crank position or pedal up on the inside of a bend when pedalling is not needed thats obvious
    but not every corner is down hill or banked
    I have changed the pedals to slighty shorter ones with more cut off side but it still caught a bit the other day hence my original post
    Guess i will just have to ride round a bit slower on this bike :cry:
    Thanks anyway :)
  • nicklouse
    nicklouse Posts: 50,675
    paul20v wrote:
    chez_m356 wrote:
    paul20v wrote:
    In 25yrs of cycling ive never had this problem
    There isn't any bike that this wouldn't happen on. I don't see how you've not had it happen before if you've been pedalling round bends for 25 years.
    even worse, its on the road, which are usually fairly smooth, so you don't even have the excuse of rocks and roots etc

    Hi
    I really dont understand why this scenario is so unbelievable for people
    When your going round bends fast you have to lean a bike over it just what happens naturally And if theres any sort of speed wanted you have to pedal so it doesnt matter how smooth it is if you want to crack on the bike will lean
    It just happens the bike has a low BB height And i was wondering about shorter cranks
    I also dont get how i can time my pedalling when there could be a number of revolutions of the pedals in some corners
    Im not looking for an argument im just lost as too some of the answers
    I understand when on a down hill on or off road flat crank position or pedal up on the inside of a bend when pedalling is not needed thats obvious
    but not every corner is down hill or banked
    I have changed the pedals to slighty shorter ones with more cut off side but it still caught a bit the other day hence my original post
    Guess i will just have to ride round a bit slower on this bike :cry:
    Thanks anyway :)
    Road bike have a lower BB than most MTBs and they don't run shorter cranks to reduce catching pedals.

    On a fixed some use 165 mm cranks but that also reduces the power you can apply.
    And 10mm is very little when taken into consideration. IE change of angle of bike and pedal clearance.

    The biggest change will com from how you ride.

    Saying that I run 175mm cranks n th fixed. Only caught the pedals once and not badly.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • YeehaaMcgee
    YeehaaMcgee Posts: 5,740
    paul20v wrote:
    I really dont understand why this scenario is so unbelievable for people
    I know the pedal will strike the ground when you try to pedal round a bend whilst leaning. I'm not disputing that, at all.
    What I am confused by is how you've apparently managed to ride a bike for 25 years without realising this before.
  • stubs
    stubs Posts: 5,001
    Maybe try watching some cross country races to see how the pros get round corners fast. Loads on youtube and there might be a race on near you where you could go and chat to some of the racers.

    I did have a bike with a low BB a Commencal and I did spend the first couple of months bashing the pedals but without really deliberately doing anything I altered my technique and the problem virtually went away.

    I think the main thing I did was to try and carry more speed into a corner briefly lean bike over hard then get it upright quickly and get back on the pedals. Without seeing myself doing it I cant be sure.
    Fig rolls: proof that god loves cyclists and that she wants us to do another lap
  • YeehaaMcgee
    YeehaaMcgee Posts: 5,740
    stubs wrote:
    Maybe try watching some cross country races to see how the pros get round corners fast.
    Or even road racing. There has to be plenty of footage of the tour de france, for example. And their BBs are way, way lower than any mountain bike.
  • bails87
    bails87 Posts: 12,998
    stubs wrote:
    Maybe try watching some cross country races to see how the pros get round corners fast.
    Or even road racing. There has to be plenty of footage of the tour de france, for example. And their BBs are way, way lower than any mountain bike.

    Yep, I've ridden both road and CX bikes on the road, as said above you have the advantage of knowing exactly where the ground is (No roots, rocks, bumps etc). You just have to learn how far you can lean while pedalling, and then not quite lean that much. Or lean further but stop pedalling.
    MTB/CX

    "As I said last time, it won't happen again."
  • paul20v
    paul20v Posts: 267
    paul20v wrote:
    I really dont understand why this scenario is so unbelievable for people
    I know the pedal will strike the ground when you try to pedal round a bend whilst leaning. I'm not disputing that, at all.
    What I am confused by is how you've apparently managed to ride a bike for 25 years without realising this before.
    I mainly ride offroad , my FS bike has 60mm more bb clearence than my hard tail ive ridden the FS on the road loads and never caught the pedals in fast pedalling bends on the road
    Of course i realise this happens and of course i have belted a pedal or too in the past but on this latest bike i have hit it twice in a weeks worth of ridding
    Im obviously trying not to ride so fast in these corners but they are 2 fast bends on a slight up hill that i commute on that i do as fast as i can and ive caught them twice
    Obviously i ride off road different as it a different thing all together and going into bends fast is usually down hill or into berms Where you can level the pedals or switch them high to low depending where or what your riding this isnt a problem
    Its just tarmac riding on these particular bends damn the black stuff :D
    Any how i wont go on about it
    Thanks for the suggestions all i will have a look at some vids of road guys see if i can see anything different i can do on the black stuff
    Paul