urbanknight

On a bike I recently bought used, I noticed the rear wheel shifts a little after riding. Taking it apart, I found that the right dropout was larger and keyhole shaped, measuring at 11.2mm compared to 9.8mm on the left. Is this a thing that happens, or did the previous owner mess with something?

FWIW this is on a 2005 Raleigh Pursuit tandem.

Crankycrank

Can't tell if this is the same or not but do a search for other mfrs of the dropout to compare. My guess is yours is damaged/worn. Tandem - 2005 | Rear, Mech, & Gear Derailleur Hangers | DerailleurHanger.com Hangers don't normally wear that way unless maybe the bike was ridden with a loose quick release for awhile or it was filed to correct a misaligned rear triangle or ???

urbanknight

I already found the right hanger and am expecting it next week, and yeah for some reason derailleurhanger.com has the wrong one, but thanks anyway! I hadn't thought about the loose QR possibility, maybe that's it. Either way, it's getting replaced.

Andrew R Stewart 

Most replacement hangers are made of Al. There are different alloys of Al with different hardness ratings but most all hangers will be made from a easily formed alloy and we don't see significant differences between OEM and aftermarket ones. of at least the dozens we replace each year. One factor that can effect hanger face wear is what the QR axle end cap/nut is made of (in addition to the mentioned clamping force). An Al end cap will indent and wear the hanger less then a steel end cap/nut. We have seen bikes with heavily worn/indented drop out faces, generally on Al frames/hangers, but rarely enough to hinder axle/QR purchase to the drop out. Andy

trailangel

I would say...... that wear doesn't matter.....oversize is ok. The axel locates on the dropout, not the hanger.

Andrew R Stewart 

There are replaceable hangers that contact the axle ends, Many Cannondales come to mind.

The Paragon dropouts that I have used on the last two disk braked frames I've made have a steel hanger option, for better or not, in addition to the usual Al. Andy

urbanknight

Edit: I see what you're saying now. The dropout in the frame is also notched like that.

Andrew R Stewart 

The only image so far in this thread is of a replaceable hanger, NOT the drop out. So your above statement is showing confusion or you posted the wrong photo... Andy

urbanknight

Edit: Now I understand what Trailangel was trying to say, but wouldn't the opening on the hanger still be considered part of the dropout? Anyway, the right dropout on the frame is also notched like that.

urbanknight

This conversation did make me realize that this problem isn't just on the derailleur hanger but also on the frame itself. Just pulled the wheel off again to check and yep! Looks like the previous owner did it on purpose, although I can't imagine why. So what is my best plan? Hope the new hanger fixes the problem and holds the axle in the correct place by itself? File away at the other side until the axle fits in straight again? Something else I haven't thought of?

Crankycrank

Could be the frame was bent or just not manufactured with perfect alignment. You won't know until the new hanger arrives if there is a problem and if there is you'll need to determine if the frame can be re-aligned or if the only solution is to file the dropout. Also, if you have a slipping axle tightening the QR certainly helps but you don't want to have to use gorilla strength. What brand/type of QR do you have (photo?). Some are better than others.

urbanknight

They're some generic external cam ones, but the reason the axle slips is because that notch is just slightly below the top of the opening. Just enough to locate the wheel properly when putting it on, but not enough to let the wheel stay there when the drivetrain starts pulling on it. Either way, I wouldn't want to rely on a QR to keep an axle in its place.

I guess I'll just see what happens when the new hanger gets here.

Andrew R Stewart 

I have done this very "correction" on both production frames and some I have made. Vertical drop outs have very little tolerance for being having equally lengthed stays. Horizontals have some fudge in the chain stay plane at least. Likely at some point before you owned this bike someone decided to do this modding of the drop out to, likely, center a rim between the stays better. Or the QR was so un tensioned for so long that the axle's threads (it is a threaded axle?) acted as a file and chewed away the dropout and hanger's face during riding.

If with proper QR tightening the wheel won't stay put and shifts forward on the RH side the solution is to file the LH side dropout face to match and/or recenter the rim between the stays.

BTW if you're using one of those poorly designed open cam QR's ditch it for a steel end capped and enclosed QR for better retention. Andy

urbanknight

Thanks. Unless you see a reason not to, I'll see if a better pair of QR's combined with the new hanger solves the problem, then resort to filing the left side as plan B.

*Off to search for a 145mm axle internal cam skewer.

Andrew R Stewart 

Search for a tandem QR. Andy

urbanknight

Just as Trailangel said, the new hanger and skewer did not solve the problem. Before I take a file to the left dropout, what would make that side of the wheel stay forward in its new place since it's not being torqued forward by the drivetrain like the right side?

Crankycrank

Even in the old days of horizontal dropouts this was not an issue with a quality QR. I would also still use the old dropout that's already filed properly if it's still usable. Good example of a quick release doing all the work of holding the wheel in place.
.

urbanknight

That doesn't seem to be the case with the right side, perhaps because (unlike a horizontal dropout) there's no material on the bottom to grab?

trailangel

You might post some pics of each side of frame dropout, what QR you have, etc.

adipe

magic gear...

some folks will file from the dropout and derailleur hanger to be able to use a chain that is either a bit too long or too short on a singlespeed setup with no chain tensioning device. i haven't done this thing yet.

ShannonM

Replace them with either Shimano-or-better internal cam skewers, or the allen-wrench Phil Wood ones. I had the Phils on my aluminum (Rodriguez) tandem, never an issue.

Tandems are hell on (rear) wheels, and cheap external-cam skewers suck even on singles.

--Shannon