Help! Bent rear dropout screws, what to do?
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PJT posted 14 weeks ago.
Your best bet is to get to an LBS, ask them for some matching screws (taken off a new bike if necessary) and buy those. You do want to make sure that the threads aren't shot in the dropouts.
As far as riding without:
I don't know about Felt, but Cervelo set screws only are there to allow you to align the wheel straight in the dropouts. The screws actually tend to move a bit if the skewer moves once the wheel is on. Do an internet search, and you'll see lots of P2 riders complaining about the flex of the frame causing rear wheel rub. It isn't actually frame flex per se, rather it's a too loose skewer, combined with somewhat mobile set screws and just enough frame flex to cause tire rub in the cutout.
If you can't find replacement screws, I think you could try riding without. Just make sure to use a super heavy duty skewer--internal cam, no titanium--and make sure the wheel is clamped on tight and as perfectly aligned as possible. Then get out and ride the bike hard and up steep hills while standing. Those are the conditions in which the wheel is most likely to slip and start rubbing in the cutout. If the test ride goes OK, you can try racing with it.
Edit: I'm still wondering how set screws can get bent outward. Sounds like the screws were not rigid enough to begin with, maybe?
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xc800runner posted 14 weeks ago.
fastdog5 wrote:
(EDIT: I was able to get both screws out. Can I safely ride w/out them?)
Yes. I have been for 2 years now. Just lock the skewer down tightly and you'll be fine.
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fastdog5 posted 14 weeks ago.
xc800runner wrote:
fastdog5 wrote:(EDIT: I was able to get both screws out. Can I safely ride w/out them?)Yes. I have been for 2 years now. Just lock the skewer down tightly and you'll be fine.
Cool; is there a trick to getting the wheel aligned properly without the screws?
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NotAsFast posted 14 weeks ago.
The screws determine the distance that the tire sits out from the frame as well as the general alignment of the wheel on a left to right axis.
If it is bent, obviously you cant screw it in anymore, and is prone to bend more or even break, which is not a go thing as you will have a screw in the frame with no way of getting it out easily. Replace it as soon as possible.
I have the Felt DA which has the same horizontal dropouts. Go to your local hardware store (Lowes/Home Depot/Ace) and they have a section of special bolts. You may find somthing there, if not try your local Auto parts store, or if that is no good go to your LBS. (No necessarily in that order). Make sure you match the thread of the screws you get, by placing them together and the threads should interlock. VERY IMPORTANT. You dont want to strip the threads on the bike frame, otherwise the frame becomes useless.
When you get the new screw(s) (Always buy more than you need), install them using Loctite Blue. It will make the thread secure and prevent it moving, especially when you remove and install the wheel.
Finally, make sure you have the screws set so the tire is as close to the frame without scraping. On the S22 it isnt as big a deal as with the Felt DA or B2's lines as the frame is Aluminum, but on Carbon, scraping is a very bad thing.
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NotAsFast posted 14 weeks ago.
I wouldnt ride without the screws, because if you dont get the alignment right or if the wheel moves on you while powering up a hill or sprinting the wheel will scrape something on the frame.
Training, not a big deal, but in a race, it will cost you a lot of time.
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wannakona posted 14 weeks ago.
My rear tire was rubbing the frame in front of it, it was that close. The screws in the back were not far out enough. I took it to the LBS and after explaining to them for 30min what is happening and what i want them to do they pulled out the screws farther out but because they were loose they glued them permanently with some special glue that is used for motorcycles, don't know what it is but that is how it was explained to me.
Konstantin
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NotAsFast posted 14 weeks ago.
The glue they used would of been loctite blue which secures the screw tightly, but is permanent, so it can be removed again in the future.
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jwillia852 posted 14 weeks ago.
Are the dropouts of a carbon bike still aluminum?
If they do strip out, can they be tapped and sized up?
Jeff
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xc800runner posted 14 weeks ago.
fastdog5 wrote:
Cool; is there a trick to getting the wheel aligned properly without the screws?
Trial and error?
I basically grab the tire with one hand around the frame, line it up with the cutout by sight, and clamp down the skewer. And I'm using a titanium Bontrager skewer, too. Works fine.
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PJT posted 14 weeks ago.
NotAsFast wrote:
but on Carbon, scraping is a very bad thing.
Define "very bad." Is there a fix?
PJT
(who might have some scraping in his wheel cutout)
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NotAsFast posted 14 weeks ago.
Yep, dont scrape the frame. Put the screws in as designed, and adjust so the tires dont scrape. Not rocket science. And yes, "Not Permanent". I would have to beleive they put some extra carbon layers in the wheel area in anticipation of this problem, but I have no idea. Never cut one up to see.
The drop outs on the DA are made of some alloy and fuse into the carbon. So if they strip, they probably could be tapped out and a larger screw put in, but I would be very careful to use the slightest increase of diameter as possible to make sure the strength and structural integrity of the dropouts are maintained.
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NotAsFast posted 14 weeks ago.
PJT, if you have scraping and it hasnt gone though the carbon, you may be ok depending on where.
Post a pic if you can.
I have seen some people who have had this issue with the wheel scraping a gouge in the wheel well of a carbon bike, use kevlar and some resin to patch it up. Not the pretiest, but it seemed to work. Involved so sanding afterwards to get the resin smooth, and some paint, but it looked resonable, and you couldnt see it once the wheel was on.
If the clear coat on the carbon is breached but there really isnt much carbon removed, you may just be able to seal it with resin. You just dont want water to get into the exposed carbon. May cause delamination.
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jwillia852 posted 14 weeks ago.
If you are worried about the rub, we used to use this stuff called HeliTape by 3M. Strongest stuff ever at almost 20mm thick. If you can get a hold of that and apply to the sensitive parts of your carbon, you can be assured it will be protected from the most vicious tire rub. Plus it's clear.
Jeff
When changing a tire today I noticed the adjustment screws in the rear dropouts (horizontal) are bent outward. I think this is new, as I am pretty sure they were fine the last time I looked at them, which admittedly is not often. I could get an allen wrench into one of them, but it doesn't turn properly; the other is a bit mangled & I could not even get the wrench into it. So what do I do now? Has anyone had this problem, how hard is it to fix, & is it a big deal? Do these actually serve to hold the wheel in place or center it, or are they merely guide screws for placement of the rear wheel? The bike is a Felt S22 if that matters. And of course, I have a race in 3 days. Thanks.
(EDIT: I was able to get both screws out. Can I safely ride w/out them?)