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  1. #1
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    Drivetrain limits @ 280lbs

    I went riding today. 9 miles of nice flowing singletrack.

    I have an airborne zeppelin elite.

    Just switched to clip less today and was really able to push the hills and get much more spinning in.

    My issue is I went otb twice hard. The crank would lose grip and fly forward when I crank throwing me over the bars. I can hear the crank grinding and flexing.

    Is there anything I can do to fix this?

    Otb hurts!

    Thanks

  2. #2
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    The sudden loss of drive is worrying. There are several possibilities I can think of, and its drivetrain related IMO, not the crank itself.

    Sudden dropping of chain off the front ring.....old chain or chainring is usually a culprit
    Gears slipping at the rear....could be adjustment or wear
    Freehub pawls are either sticky or damaged, causing the slippage under torque.

    As you're a big guy, you'll tear up gear much quicker than smaller riders. Can you post some pics of your chainrings and cassette??
    Checking how much the chain has elongated will be a pretty important maintenance task for you too.
    Rimmer - "There's an old human saying - if you talk garbage, expect pain"

  3. #3
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    I too am a big guy at near 300lbs on a XXL HT, I have the Holow tech Deore 3X10 24/32/42 and XT shadow rear and Deore top pull front. Using the stock 10 speed deore 11-36T. With XT shifters. This is the baseline for my size, I have not been thrown yet but have had the chain come off once but I was shifting through some rough downhilling in the middle chainring. I am also cleated in, I will not go back to toe clips. But it does put more Tq on the drivetrain and you will need stronger Cmpts.

    Mark
    2012 XXL Carve Expert

  4. #4
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    I am a clyde and I am thinking that it could be the freehub, this is the problem that i had. However I have had very similar problems with a loose wheel skewer.

  5. #5
    Airborne Product Dude
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    Quote Originally Posted by jkidd_39 View Post
    The crank would lose grip and fly forward when I crank throwing me over the bars. I can hear the crank grinding and flexing.
    Can you go into a little more detail? Is the chain coming off?

    Your Zepp may be in need of some adjustments and tuning.

    You've also been riding a lot, which could result in some chain wear. Have you measured the chain to see how much wear is on it? It may be time to replace it. If it is do it now before it wears your cogs and chainrings as well.

    Jeremy
    Airborne Dude.

  6. #6
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    The chain is not coming off. It's staying right where it should be. But the pedals will just loose grip and move just a bit but that loss of grip combined with me going up a hill causes a bad situation.

    It makes me think the freehub is losing grip and than catching it again.

    How do I measure my chain?

  7. #7
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    Quote Originally Posted by jkidd_39 View Post
    ..snip...
    How do I measure my chain?

    With a 12" Ruler

    Chain Maintenance Thanks Google
    Duct tape iz like teh Force. It has a Lite side and a Dark side and it holdz the Universe together.

  8. #8
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    Ok. Went riding tonight. Had a knowledgable friend take a closer look. Rear rim is bent bad. Front is bent slightly too.

    Time for a wheel set. Any opinions on a good set??

  9. #9
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    I'm not sure on your budget, but Hope, Chris King or Dt Swiss are all strong hubs and are built to last.

    I'd look at wheelbuilder or similar to find something suitable with either of these 3 hubs.
    Rimmer - "There's an old human saying - if you talk garbage, expect pain"

  10. #10
    Trail Tire TV on blogger
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    Quote Originally Posted by jkidd_39 View Post
    The chain is not coming off. It's staying right where it should be. But the pedals will just loose grip and move just a bit but that loss of grip combined with me going up a hill causes a bad situation.

    It makes me think the freehub is losing grip and than catching it again.

    How do I measure my chain?
    actually, it does sound like the the chain is slipping... either a worn chain, or worn rings is possible.. I had it happen to me... was doing a "test" to see how long I could ride on a drivetrain I never replaced... got 3 yrs and a boat load of miles, but then the chain would literally skip over a few teeth now and again. I first thought was hanger issue,.. then cassette and chain... then rings.. I ended up figuring it out as the rings (which were actually 5 yrs old) were toast.

    could be the freehub or a few other things also (like a slightly bent hanger)
    Going to try and bring Trail Tire TV back. go take a look... http://trailtiretv.blogspot.com/

  11. #11
    Airborne Product Dude
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    I'm thinking that it's probably the chain. Measure it for wear and if it is worn past the tolerance point, replace it. And check the cogs and rings to ensure they aren't sharkfinned and due to be replaced as well.

    I doubt its the freehub. Usually when they let go its a catastrophic failure and you know that's what it is.
    Airborne Dude.

  12. #12
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    Quote Originally Posted by BigDaddyFlyer View Post
    I'm thinking that it's probably the chain. Measure it for wear and if it is worn past the tolerance point, replace it. And check the cogs and rings to ensure they aren't sharkfinned and due to be replaced as well.

    I doubt its the freehub. Usually when they let go its a catastrophic failure and you know that's what it is.
    Measured the chain. It's fine. Found a ton of spokes were ubber loose on both rims tho. That kinda sucks.

    I'm pretty busy with work I think I'll drop my bike off and let my local shop clean up my drivetrain and see if they can find my problem.

  13. #13
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    I'm a bigger guy too. Weighed almost 270 when I got serious about riding in '06. Thankfully down to around 200 now.

    Make sure you change out your chain often. Not unreasonable to change it out 1/2 way though the season if you ride a lot, but at least once a year. If you're not doing that, the chain is lengthening & mangling your chainrings - esp if you've got alloy chainrings. If you've been riding with the same chain for longer than 1 year, swap that mother for a new one.

    Bigger guys tend to rip up freehubs too. You might want to open up your freehub & check the pawls & teeth. If you find a bunch of shards of metal in there, you've got some ratchet teeth broken off & need a new rear hub. Put a few drops of light oil (NOT grease) on the pawls. Might be as simple as a pawl that needs lube.

    BTW: doing this maintenance yourself is way preferable to taking it to a bikeshop. Get to know your bike & you'll know exactly what's wrong when something breaks. Tweaking on a bike is actually a fun aspect of this sport - you can drink beer while you do it!!. While you've got to fork out some money at the beginning for tools, the tools will save you a crapload of money and time vs. taking the bike in to a shop every time you need work done.
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  14. #14
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    What rear hub do you have? At 330, i blew 4 shimano freehubs including a 529 before i upgraded to a dt swiss rear hub. Could very well be the chain skipping on your rear cassette too though if your drivetrain has a lot of wear.

    If you upgrade your wheelset, get a Hope hub or DT Swiss 350 hub at least, dont cheap out on a rear hub if you are a big powerful guy.

  15. #15
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    I got a deal on a set of roval rims off a specialized epic for $200. Gotta go pic them up.

    I had to cut my ride short today. My rear rim is so bent it's rubbing on my front derailleur.

    I kicked down to my 22T front cog bc today was a lot of climbing. I noticed only once gear on my cassette is junk. It slipped and jumped but go up or down on the cassette it's smooth.

    Cassette junk? Recommendations on a good once since ill be changing wheels as soon as I go pick them up.

    Thanks guys

  16. #16
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    XT is a good price/performance mix. Also if the wheels have a alloy freehub then the carrier of the cogs reduces the damage to the splines you get with separate cogs meeting the freehub.
    Rimmer - "There's an old human saying - if you talk garbage, expect pain"

  17. #17
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    jkidd, Your description suggests a worn cassette, with the chain probably worn. Need to replace both. It could be the freehub, but that feels different than a worn cassette and, in my experience, usually just stops working (if Shimano). But possible. Doubt it is your chainrings, but possible if they are very old.

    Cassettes and chains can be inexpensive. SLX cassettes are pretty cheap, and I usually can find a SLX/XT quality chain pretty cheap too. But some people use basic Deore type stuff very successfully.

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