rear wheel slipping

[smnw10]

I wanted to see if anyone knows of what this problem might be...

I have a Moser frame and recently when I put in a hard effort, either sprint or hill climb etc, the rear wheel moves to the left to where it either touches the brake pad or sometimes far enough that it touches the inside of the chainstay. To cut down on how often this happen I have to clamp down that quick release so tight that it is incredibly hard to undo. I've tried a different set of wheel and still have the same problem so i'm pretty sure it is the frame...

does anyone know a solution to this or what the problem may be?

thanks
John

 

[lokstah]

Wow. Well, assuming it's not a matter of skewer setup, and assuming you've cycled some reasonably well-made wheels in and out, I suppose you've got to consider the obvious: this could just be nasty frame flex.

Are you a particularly heavy rider? Do you consider yourself a muscular uber-masher?

 

[artmichalek]

Most likely the hub isn't gripping the dropouts well enough. You can fix the problem by putting one of those star shaped lock washers on each side in between the quick release and the dropout.

 

[lokstah]

Most likely the hub isn't gripping the dropouts well enough. You can fix the problem by putting one of those star shaped lock washers on each side in between the quick release and the dropout.

If I'm not mistaken, he's talking about his rear wheel rim touching the brake pad or even the frame under pedal load (though "slipping" isn't the term I'd use for this). I don't think adding a star washer to intensify the skewer bite is going to correct this--either his rear triangle or his wheelsets are flexing considerably, it sounds like.

 

[53-11]

I wanted to see if anyone knows of what this problem might be...

I have a Moser frame and recently when I put in a hard effort, either sprint or hill climb etc, the rear wheel moves to the left to where it either touches the brake pad or sometimes far enough that it touches the inside of the chainstay. To cut down on how often this happen I have to clamp down that quick release so tight that it is incredibly hard to undo. I've tried a different set of wheel and still have the same problem so i'm pretty sure it is the frame...

does anyone know a solution to this or what the problem may be?

thanks
John

You have vertical drop-outs right?

 

[smnw10]

thanks for the quick replies

I weigh about 165, 6'4" so it's not weight that's the problem
I do race Cat4 and am competitive in that category so that should give an idea of what I do with the bike and what kind of stress it may go through
the frame is also made out of 7003 aluminum

I got it second hand on ebay almost 2 years ago with the intent of getting into racing and never had a problem with it until late in the racing season last year and then all of this year

lokstah - you're right, that's a better way of describing it, the rim touching the brake pad or if it's bad enough the tire touches the chainstay under pedal load

 

[smnw10]

You have vertical drop-outs right?

well.....about a 45 degree angle
not straight up and down but not horizontal either

 

[artmichalek]

I wasn't sure from your original post if it the wheel was just moving under load or if it was shifting and staying there. With that much flex, it could be that your frame is cracked.

 

[smnw10]

I wasn't sure from your original post if it the wheel was just moving under load or if it was shifting and staying there. With that much flex, it could be that your frame is cracked.

yea once it moves it stays there...so i have to either release the brake or if it's touching the frame i have to get off and unclip the wheel and reset it

this actually happened to me in a race yesterday...only touching the brake though so my teammate saw it and released my brake so I was able to stay with the pack

 

[53-11]

I'll bet it comes with those chi-chi external cam skewers. Good some good internal cam shimano skewers and see what happens.

Whoever said a crack in the frame? That could be happening too.

 

[smartie]

Sounds like the wheel hub moving in the dropouts. If it was a cracked frame, as soon as he stopped it would flex back straight again, or with that much movement the rider behind would see it moving.

It sounds like it is taking up a permanent set which is being re-alighed each time by pulling the wheel off.

 

[alienator]

I'll bet it comes with those chi-chi external cam skewers. Good some good internal cam shimano skewers and see what happens.

Whoever said a crack in the frame? That could be happening too.

I'll second this. What kind of wheels/skewers do you have? I had this very same problem w/ Mavic Cosmos wheels and the Mavic skewers. The rear wheel would ****, give a high enough load, no matter how tight the skewers were. The mavic skewers had some cheesy plastic seat against which the skewer cam acted. When I switched rims to Bontrager Race X Lites, the problem went away....even though the Bontrager QR's also had a plastic seat for the skewer cam. Lookin' back, methinks the Mavic cam must have had a lousy profile. Internal cam skewers(Campy, shimano, others) are the sure fire solution.

 

[topcat]

I wanted to see if anyone knows of what this problem might be...

I have a Moser frame and recently when I put in a hard effort, either sprint or hill climb etc, the rear wheel moves to the left to where it either touches the brake pad or sometimes far enough that it touches the inside of the chainstay. To cut down on how often this happen I have to clamp down that quick release so tight that it is incredibly hard to undo. I've tried a different set of wheel and still have the same problem so i'm pretty sure it is the frame...

does anyone know a solution to this or what the problem may be?

thanks
John

I had the same problems a few months back, whenever i sprinted the back wheel would hop out slightly, once it nearly came off compleltey, got it fixed and i think it was something to do wiv the spring in the skewer or something like that, might wanna give that a check etc...

 

[smnw10]

I got different skewers yesteday and tried them out. These are not quick release, rather you have to lock them down with an allen wrench but it's the same idea as a few of you have posted to try.

results....same friggin thing! still moves

the guy at the bike shop suggested that if it still didn't work that I should try to rough up the drop outs so that the skewer could grip it better...so that is my next thing to try today if the thunder storms stay away

 

[lokstah]

the guy at the bike shop suggested that if it still didn't work that I should try to rough up the drop outs so that the skewer could grip it better...so that is my next thing to try today if the thunder storms stay away

Hmmm... I'd try the star-washer solution before attempting to modify your dropouts. If the skewer or hub is simply shifting in its place, a star washer or two should do the job. At the very least, you could rule something out.

After this shifting occurs, do your examinations ever yield any clues? Is there a way, for instance, to accurately identify skewer movement? Might be worth devising some scheme.

For the record, have you had the whole rear assembly of the frame carefully examined for defects or damage?

 

[smnw10]

After this shifting occurs, do your examinations ever yield any clues? Is there a way, for instance, to accurately identify skewer movement? Might be worth devising some scheme.

For the record, have you had the whole rear assembly of the frame carefully examined for defects or damage?

yea it always shifts/cocks to where the wheel/tire rub on the left side of the frame and the right side "lock" on the skewer will have moved, the left side of the skewer does not but I just assume that this is because of the pull from the chain on the cassette.

I have looked the frame over for cracks etc and the only thing is a while back my chain popped off the chainring to the inside and got jammed between the little chainring and the frame...denting the frame pretty bad on the right chainstay. The bike store looked at that and said it shouldn't be the problem.

 

[lokstah]

Well, I suppose the next logical step is to do what others had suggested yesterday: impose some sort of better bite into the skewer/dropout relationship. Again, I'd definitely try a star washer before attempting to maul the droupout. Keep us posted? I think we're all a little captivated.

 

[artmichalek]

I have looked the frame over for cracks etc and the only thing is a while back my chain popped off the chainring to the inside and got jammed between the little chainring and the frame...denting the frame pretty bad on the right chainstay. The bike store looked at that and said it shouldn't be the problem.

Not to get off topic, but that dent was probably there before. A lot of frames have a dent on the outside of the right chainstay to provide extra clearance for the chainrings.

 

[smnw10]

Not to get off topic, but that dent was probably there before. A lot of frames have a dent on the outside of the right chainstay to provide extra clearance for the chainrings.

no i'm positive this wasn't there before...the chain actually busted when i pulled through on my stroke, ripped all the paint off that part of the chainstay as well as scraped it pretty bad, and the dent isn't a nice oval or anything

I'll give the washers a try though and keep everyone posted as to what happens...