Question re placement of the rear wheel in the dropouts

[Llewellyn]

Imagine that you’re looking from behind the bike. Does the axle on the rear wheel have to be pushed all the way to the back of the dropouts or can it be placed and secured so that the wheel is an equal distance from each chainstay (eg the right side of the axle is pushed right to the back of the dropout but the other side sits a few mm forward in the dropout).

The reason for asking is that I have a rear wheel that sits too close to the left chainstay if it’s pushed right to the back of the dropouts and the QR tightened. To my mind it should sit slap bang in the centre of the rear triangle but the only way I can seem to do this is if I secure it as I've described above. Is there another way that I should fix this?

[alancw3]

based on what you have described i would say that the wheel is not dished properly to fit the rear spacing of the frame.

http://www.sheldonbrown.com/gloss_sp-ss.html#spacing

http://www.sheldonbrown.com/gloss_da-o.html#dish

because you seem to have horizonal dropouts, based on your description, my guess is that you may have an older frame with either 120 or 126 spacing. someone may have also tried to cold set the spacing so that modern 130 wheels could be used. perhaps the frame is not aleigned properly or the frame rear triangle has been damaged. but to answer your original question the wheel should sit evenly in the rear dropouts. one of the reasons campy 1010 a and b rear dropouts had adjusting screws. these dropouts were considered the gold standard of rear dropouts back then.

[rustychisel]

old steel frame? Frame out of alignment, quite likely. You can measure it. Many frames had grub screws for centring wheels in the dropout for just this reason. They can also be used to butt the axle when a slightly more 'wheel forward' position was wanted. If the wheel is secure you should be okay, but there exists the possibility of the wheel slipping and the tyre rubbing the inside of the triangle.

You probably should have the frame checked out, especially if you're not the original owner. It may have been shunted, bent, or built that way. Bikes which 'crab' the road (wheels not in planar alignment when seen from behind) are not uncommon.

[Llewellyn]

Thanks for the replies. It's an old 6 speed frame so would be 126mm I think. I've reverted back to 6 speed on this one, but I did briefly run it with an 8 speed set up but I didn't specifically cold set the frame, just applied enough pressure to part the rear triangle so I could fit the wider hub in there. Sounds like that could be the problem.

[Llewellyn]

old steel frame? Frame out of alignment, quite likely. You can measure it. Many frames had grub screws for centring wheels in the dropout for just this reason. They can also be used to butt the axle when a slightly more 'wheel forward' position was wanted. If the wheel is secure you should be okay, but there exists the possibility of the wheel slipping and the tyre rubbing the inside of the triangle.

You probably should have the frame checked out, especially if you're not the original owner. It may have been shunted, bent, or built that way. Bikes which 'crab' the road (wheels not in planar alignment when seen from behind) are not uncommon.

Is that Alex in Adelaide, formerly of ACF and YACF??

I guess Sheldon has info on how to measure whether a frame is aligned properly. Off to Google I go

[rustychisel]

Is that Alex in Adelaide, formerly of ACF and YACF??

I guess Sheldon has info on how to measure whether a frame is aligned properly. Off to Google I go

Busted on the internet? Priceless.

Yeah, it's me. Who goes there?

Yes, Sheldon and others have the string method explained for measuring. Best.

[oldpotatoe]

Imagine that you’re looking from behind the bike. Does the axle on the rear wheel have to be pushed all the way to the back of the dropouts or can it be placed and secured so that the wheel is an equal distance from each chainstay (eg the right side of the axle is pushed right to the back of the dropout but the other side sits a few mm forward in the dropout).

The reason for asking is that I have a rear wheel that sits too close to the left chainstay if it’s pushed right to the back of the dropouts and the QR tightened. To my mind it should sit slap bang in the centre of the rear triangle but the only way I can seem to do this is if I secure it as I've described above. Is there another way that I should fix this?

Either the wheel isn't dished or the frame rear triangle, dropouts, aren't straight, aligned, even somehow. The rear wheel should be equidistant from each chainstay, seat stay.

[Llewellyn]

Busted on the internet? Priceless.

Yeah, it's me. Who goes there?

Yes, Sheldon and others have the string method explained for measuring. Best.

I used to be alchemy in a former life. From Perth. How've you been?

[ultraman6970]

If i got this right because my english sucks, just wonder if the rear end of that bike is not seated where it should be.

You need to be sure the rear is aligned first. You can use the string method, just be sure the pin u use has marks at both sides and equaled distanced.

Second thing, droppouts, be sure are parallel. I did my own tool buying some long screws, washers and bolts at the hardware store, or take the bike to the shop.

Dunno what bike are you talking about but if the wheels are dished right, and if the rear end is straight too there is a big chance the dropouts are not in the right position, thing i have seen before.

This is the detail you have to look onto, if the dropouts are long, it wont make too much of a difference because you can sit the wheel in the front or middle of the dropouts (it should be this way any ways) instead of all the way to the back as some people does, between you and me you always have 1 mm or 2 of difference between the dropouts, so is kind;a normal, nothing is perfect 100% sometimes.

Second detail, if the bike has short dropouts then you have a problem, some of them do not have dropouts adjusters, some do. If you dont have them, what you can do is to find a wheel that you are sure is super well dished and file the drop out a tiny until the wheel seats in the right place. Obviously you have be sure the rear end and dropouts are parallel 1st.

God luck.

[professerr]

An alternative, less bad explanation: the chain stays on the bike were crimped or otherwise smooshed unevenly by the builder to make room for the tire.

I have an old Mercxk which I bought from a framebuilder. He said it measured straight, and after I bought it I had Cupertino Bikes put it on their table, and they said it was dead straight. But when I put a big fat tire in the rear it was clear that when the wheel was placed evenly in the drop outs like the OP describes, the left chain stay was closer to the tire. I checked the bike out using the string method and it was straight. Finally I noticed the right chain stay was significantly skinnier than the left one because it has been squished to a more oval shape where the tube exits the bottom bracket lug.

Anyway, this makes it more difficult to align using the adjusting screws on the horizontal drop out because you can't use the seat stays as an easy reference. So I use a framing straight-edge laid against two points on the rim and two points on the front triangle to determine where to position set screws so the centerline of the rim and the centerline of triangle are on the same plane. Not surprisingly, the result was pretty close to where I'd came out just doing it by eye, using the seat tube as a reference instead of the chain stays.