Threaded Pedal Crank

foxydan
foxydan Posts: 83
edited September 2012 in Workshop
So out on a ride today i felt my pedal move and then it was at some funny angle. Stopped to see that my pedal had come out and completed threaded the crank. Luckily managed to get home.

I wanted to know how difficult is it to change the crank? Can I do this myself or is it a lbs job? I am fairly competent at fixing things but what tools, parts do i need to get?

Any help would be appreciated.

Comments

  • jockywilson
    jockywilson Posts: 89
    Very straightforward job if you've got the right tools i.e. crank extractor. If it's a decent crankset in good nick you might want to look at getting the lbs to put in a helicoil insert which will give you new threads. Got this done a couple of years ago for about 20 quid.
  • foxydan
    foxydan Posts: 83
    jockywilson wrote:
    Very straightforward job if you've got the right tools i.e. crank extractor. If it's a decent crankset in good nick you might want to look at getting the lbs to put in a helicoil insert which will give you new threads. Got this done a couple of years ago for about 20 quid.

    Interesting. How long does this hold up for? Are these easily to do yourself or do you need specialist tools?
  • jockywilson
    jockywilson Posts: 89
    Should last the lifetime of the cranks assuming the helicoil inserts been fitted correctly, certainly not had any issues after approx 8,000 miles. Wasn't able to get a replacement non-driveside crank after I originally stripped the threads so the 20 quid cost for the helicoil was much cheaper than replacing the entire crankset.
  • Monty Dog
    Monty Dog Posts: 20,614
    If your LBS can't do a helicoil, try Highpath Engineering. Helicoil is a steel insert, so will be stronger than the original alloy.
    Make mine an Italian, with Campagnolo on the side..
  • foxydan
    foxydan Posts: 83
    Looking at my crank....it has a hex type nut. Is it as simple as just using a hex key to remove it?

    Will ring the LBS tomorrow to ask if they do the helicoil repair. If not will attempt to replace the crank myself. Do i need anything else in terms of tools to do this? I mean will the hex tool be enough?
  • jockywilson
    jockywilson Posts: 89
    Depends what type of crank it is - some are self extracting others eg square taper will need a crank extractor tool. Park tools website has good guides to identify what's needed.
  • foxydan
    foxydan Posts: 83
    So if i reove the hex bolt and have a look i should be able to tell what type crank i have?
  • foxydan
    foxydan Posts: 83
    ok i have removed it to see i have square bolt so need a crank tool to remove it. My next question is regarding the crankset. I have found this
    http://www.chainreactioncycles.com/Mode ... elID=78798

    it states it is 9sp. Does this reflect the amount of sprockets (cassette) you have at the back? I have 8 so figured mine is an 8sp. Will the 9sp work or do i need a specific 8sp crankset?

    Cheers guys. Need your help before i go buying parts.
  • cycleclinic
    cycleclinic Posts: 6,865
    If your LBS can't do it. Post it to me, I can.

    If you buy new cranks, 9 speed will work with 8.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • trekvet
    trekvet Posts: 223
    With the crank puller/remover tool (you need a big adjustable') be sure to clean the fine threads that are exposed once you remove the big allen screw. You must screw the tool fully in to the bottom of these fine threads before you use the spanner on it. Use the tools button the correct way round, and the crank will pull off. Keep tool safe, don't loan it to anyone.
    The Wife complained for months about the empty pot of bike oil on the hall stand; so I replaced it with a full one.
  • foxydan
    foxydan Posts: 83
    Thanks guys,

    I have two in mind now although am just stuck on the length of cranks now. Link above is for 165mm but the one below is 170mm. Is there that much difference. The threaded crank is 170mm and would like to replace like for like but as you can see it is double the cost of the 165mm. It is also an 8sp and not 9. I have a 8sp cassette and again feel as if i should go like for like. My bike is a giant defy btw with a fsa tempo crank.

    http://www.chainreactioncycles.com/Mode ... elID=40623

    What do people think?

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