Track Cog Problems?

Discussion in 'Observed Trials Discussion' started by bwagner, Sep 1, 2004.

  1. bwagner

    bwagner New Member

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    Basically I'm tryingto figure out a small problem here....I've been in shops for a long time, longer than some of you have even been alive!:( But I cannot figure this out. It's been a long time, but hardly anu track bike experience for me in those years.
    I'm trying to help out a friend right now who just picked up a set of Try-all FFW cranks. We've tried two or three different track cogs, and they all seem to have a different thread than on the cranks, a normal freewheel fits fine, but he's trying to use them on a stock bike, with a King rear hub. Are the threads on the cogs different from the standard freewheel threads? Or do you think the Surly cogs are just inferior, and have bad machining tolerances, hence the threads are not deep enough? He's leaving for the worlds in a day, so any help would be greatly appreciated!
     
  2. smudge

    smudge Central Scrrrrrrrutinizer

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    Is the problem that there aren't enough threads for your friend to feel secure or is it that the ID of the cog is smaller than the OD of the crank?

    If it's ID/OD issues, I've experienced that before on some track hubs and Surley cogs. The 8 or 10 that I've worked with have needed some "effort" to get on. Back with QBP was selling them as sub 11, they seemed to be better. The cogs sold over the last five years or so have required a chain whip to thread them down all the way.

    Another word of advice if you don't already know, you might want to put a spacer on the crank before you install the Surly cog...to keep a decent chain line.

    I hope your friend is successful at worlds.
     

  3. Tanner

    Tanner New Member

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    get a try-all track cog...trust me.
     
  4. antidis

    antidis Guest

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    i have the try all ffw cranks w/ a surly track cog and a spacer. The thread spacing matched perfectly, but the depth of the thread depth didnt seem to... after much frustration of trying to figure out what to do, i just put on the cog as far as it would go, put the cranks on and use the pedal torque to tighten it the rest of the way. Been working perfectly for a good 6 mos now but i doubt if ill ever be able to get it off. so there ya go.
     
  5. durkie

    durkie Member

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    the threads are the same. i guess surly cogs are just kind of hit or miss, but i've never had a problem with either of mine. if you're looking at other cogs and chainline is an issue, check out sheldon brown's article on chainline at http://www.sheldonbrown.com/chainline/index.html, as different cogs run different chainlines.
     
  6. digby

    digby New Member

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    I had trouble getting mine on too, when I first started running the track cog/tryall setup. I went to a shop and the roadie guy there, just put a ton of grease on it and carefully put it on with a chain whip. I tried the same thing at home, but I was worried about cross threading it and stripping it out.

    I think graham has mentioned before that he sanded down the threads on his cranks a bit before he put on freewheels/track cogs and that seems to make it easier. I'm not sure you may want to pm him to check.
     
  7. SHiRLEY_CHiZEM

    SHiRLEY_CHiZEM New Member

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    the problem with most ffw cranks is the threads arent cut deep enough.. just lube her up and be sure you're starting the threads right.. it will be fine.
     
  8. bwagner

    bwagner New Member

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    Ok, well thanks for all of your suggestions, but after installation(by my friend) the cranks lasted about four minutes total! He didn't even get in one single pedal kick! I'm so glad I went with Middleburns instead of those FFW things. Now before you all blame him for improper installation or some shit like that, he's a decent mechanic with a few years of experience in a busy shop, it wasn't cross threaded or anything, just a poor grade of aluminum or some shit like that, also another note is that before even installing the cog, I noticed that the shoulder for the cog to tighten against wasn't even flat when compared with the threaded section, it was off by a few degrees, so when the freewheel, or cog as the case is here was tightened down, there was a small space on one side of the gear where it didn't set down flush against the cranks shoulder. It sure sucks that he spent all of that moeny to get some new cranks for the Worlds, and his shit fell apart in less ime than it took to install the damn cog!! Oh well, enough of my ranting. have a good night