UKC

Hi.

I've got a super six carbon road frame, second hand. The left rear dropout is very slightly worn such that the wheel sits slightly off centre and almost rubbing the frame now.

Can these dropouts be fixed, replaced, bodged????

Try a washer on the worn side.

I’d probably be wondering how the rear dropout, which should of course be a non-moving part, has come to be worn in the first place. Or whether it is, for example, impact damage being passed off as wear... or some other damage to the frame causing the misalignment of the wheel. Presumably the wear is fairly significant, to be causing problematic wheel misalignment, and is also going to need some very precise bodging to return it to actually being properly straight (not to mention staying that way!).  Obviously it’s your call, and you may have additional knowledge about the frame’s previous life that gives you reason to trust the frame/ seller. However, I don’t think I would want to have any doubts about my bike’s integrity, or specifically the bike-wheel interface, when descending at 50 mph. 

Yeah. Good point.....50mph and downhill with dodgy drop out.

It's the drop out that is no longer a perfect circle.....gone abit oval ish....if that makes sense. 

I'll maybe contact canondale and ask them.

The frame came like it......probably why it was sold I guess. It's been bought off ebay a year ago. Always been abit off. 

I think it is a fairly common problem. Ideally I'd pay for new hangers placed if was possible unless cheaper to get new frame. 

Thanks anyhow.

I'd be tempted to pad our the drop out using some resin (chemical metal?) using the wheel in place as the mold if there isn't a better repair.

I don’t normally post, but...

I had a similar issue on my bike last year in lockdown v1 and concluded that the chemical metal stuff suggested by gravy was the trick to fix it; much as described.

In reality, and perhaps it’s just I didn’t do a good enough job with surface prep, it just seemed to prevent the qr grabbing the dropouts correctly and I ended up with 6 weeks in a cast with a broken scaphoid 😂

Shit! It's my sons bike. He's 6months on from brain surgery too😬.

Wasnt sure if should thumbs up or down you😂.

I can see this costing.....but.....fk it it's only money.

I'd first check the wheel is true and dished correctly. Then if it really the dropout that's the issue you could repair it with epoxy. Could you get a photo of the damage?

I had the same issue with one of mountain bike, years of taking the rear wheel every weekend to get it in the boot of the car led to a worn drop out on the non drive side. I changed to using a cup and cone hub and replaced the QR axle in that with a M10 threaded. I'm  now able to clamp it tight enough in the correct position that it doesn't slip. I've also switched to using a roof mount bike carrier to prevent this happening with my other bikes. And yes it is a pain having to carry a 15mm spanner around incase I get a puncture. Whether or not a carbon dropout is strong enough to withstand clamping between 2 pieces of steel, I don't know?

Hiya,

Are you sure the dropout is worn, and it's not the other one which is obstructed somehow? I've seen this where 1 has a ton of paint or a manufacturing flaw which prevents the axle seating fully. 

Rather than packing the worn one, is there enough material to work with such that you could file down the other one to match? 

I wouldn't bother contacting the manufacturer, but a good old school LBS might have some good ideas.

Cheers, Ross 

could also be the derailleur hanger preventing full seating. i had same problem using wide tyres on my gravel bike and using a circular file on the drive side worked a treat- didn't need much filing to see an effect..

https://forum.bikeradar.com/discussion/13090758/possible-dropout-defect

Cannondale's QC is bloody awful, so much so they are referred to as Crackandfail in certain circles

What are you calling the left and side, drive side or non drive side ?

i suspect my GT al gravel frame was also a bit off but my first thought from that thread was the derailleur hanger not flush with frame (should be lower in photo) so filing out the d hanger would fix (assuming rubbing on non-drive side)

Non drive side. Left as I sit on it.

Take the wheel out, take the QR out and have a look at the ends of the 'axle'.  Are they both in good order?  Put the QR in the wrong way round and see if the wheel will fit with cassette on the wrong side.  Does it still sit offset to the same side?  Wile you've got it all out, give the drive side drop ou a good clean - there may be a build up of stuff in that (too high, as opposed to too low on the other side).  Finally, is the tyre fitted evenly and correctly? 

The drop out should be a non wearing part (unless the bearing seized and the outboard side of the axle was forced to rotate in the frame - which was why they sold it....

That should have vertical drop-outs and I've never seen them worn - even taking wheels in and out as much as I have on my bikes over the years.

Are you sure it isn't the rear wheel that's either slightly buckled, or incorrectly dished?

If me, I would take the cassette off and put the wheel in back to front and see if it off-sets the other way - take it to a decent LBS/wheel builder to be checked on a proper jig if not sure.

Also, are you sure the tyre is correctly seated? Might be an issue if the tyre is very tight on the rim - some rim/tyre combos are notorious for fit and this could be a symptom.

Had a worn dropout on my wife's bike. 

I tried all the liquid metal / epoxy stuff but it doesn't stick well and just peeled off. 

Local frame builder wanted £90 to replace the whole thing plus £100+ for a respray. 

Local fabrication shop ran a tiny bead of weld along the dropout for free and I spent 10 minutes with a file getting it back in shape. 

Bike is probably better now than it ever was. 

In fact here are my photos. 

Red bit was worn so wheel was moving in the blue direction under load. Green arrow is the only direction is should move and that's when removing. 

I don't seem to have a finished picture. 

Hmmm....so I put the wheel back in the wrong way and it sits ok that way. 

Maybe the wheel is dished. It's not buckled.

QR and axle ends and drop outs all look clean. 1 drop out is a little worn but I think that was a red herring.

Argh...the chain stay where rubbed has gone into the carbon abit. I guess this may not be safe.

Off tut bike shop.

Ta for tips

Weird, All rear wheels are dished but the rim should still be in the centre relative to the axle, sounds like the wheel is built wrong, or has a spacer where it shouldn’t?

It's a campag Zonda...abit beaten up. Got a new wheel coming today.....23mm tyre....see if that sorts it. 

My brother had a Mavic rear wheel where he noticed the tyre must have occasionally been scuffing on a chain stay, his rim was true but offset from the centre of the axle as when fitted the wrong way round it was closer to the opposite chain stay.

Mark 

Well I wouldn’t expect anything less from Mavic! 

I've used a guy called Mark who runs Carbon Reincarnation (have a look for him on Instagram) for a seat stay repair (among a few other bits) - I know he also replaces drop outs. Honestly, the guy is a wizard with frames.

Worth sending him a message, he was very helpful when I first contacted him and did a really good job on my frame at a third of the price of some of the other main carbon bike repair places I had quotes from. 

Edit: This is him - http://www.carbonreincarnation.com