Cycling UK Forum

Tell me please, on a singlespeed or hub geared bike with disc brakes and track ends to slot the rear wheel in, when moving the wheel back to tighten the chain, how then is the grabber thing (sorry, don't know the proper name), adjusted to cope with the moved disc?
And is it time consuming and difficult? Thanks.

You mean how's the brake caliper adjusted? On a frame with track-ends the holes in the frame's disc brake mount normally allow for some fore-and-aft adjustment, like this:-

The adjustment is made by loosening the bolts fastening the caliper to the disc mount, sliding the caliper along and re-tightening the caliper bolts back up again.

IME slotted dropouts and a chainstay mounted caliper normally add appreciably to the faff factor when replacing the rear wheel; the issue is that (as well as the caliper needing to be moved if the wheel moves forwards or backwards) if the wheel is not quite straight in the chainstays, then the brake rubs which is annoying. Some calipers are a lot easier to adjust than others.

By contrast vertical dropouts and a top mounted caliper, whilst not ideal in other respects, are a lot easier if the wheel is going in and out often.

With an IGH or SS you can have vertical dropouts if you use a chain tensioner or EBB system.

cheers

Thanks both,very helpful. It's more or less as I thought. The faff-factor is the thing I'm trying to minimise. At the moment, not finding many frames that take 700c wheels (or 29er in modern trendy parlance)and have trackends and canti-mounts. Thinking of transfering the bits across from my single speed B and T bike onto a new frame. But this disc brake question is one of the things to consider. (Would rather stay with canti's to be honest).

My Surly Ogre has this arrangement but I haven't found it a problem because for minor chain tightening it isn't necessary to move the caliper every time.

I do like that colour!

Just have to be careful not to park it on grass.

BeeKeeper wrote:My Surly Ogre has this arrangement but I haven't found it a problem because for minor chain tightening it isn't necessary to move the caliper every time.

The chain adjusters must help, too...?

cheers

I would look at the problem on three different levels.

Firstly pads are thick enough that if they overhang the outside of the disc eventually they will touch each other and absorb most of the braking pressure and braking ability. I dont think failure would be instant but it possibly wouldnt take much more braking to lose it altogether

Secondly, I like to have my pads going back to exactly the same place on my discs as they have worn down together, to get this correct every time you remove the wheel and especially adjust the axle position would be a major pain.

Thirdly you could just ignore the brake caliper repositioning and as long as you never overhang on the outside of the disc, it will all just wear out any misalignment and you will still stop fine, so you could just forget about it and not notice any great problems. Again so long as you dont let the pads overhang the outside of the disc.

Hmmm.... thanks. I think I'll continue my search for a 700c frame with canti studs and either track ends or semi-horizontal drop outs. Only two so far, the Pompino (but not really enough fat tyre clearance) and the Surly Cross Check.

Brucey wrote:

BeeKeeper wrote:My Surly Ogre has this arrangement but I haven't found it a problem because for minor chain tightening it isn't necessary to move the caliper every time.

The chain adjusters must help, too...?

cheers

They do have the advantage that after removing the rear wheel it is very easy to put it back in the same place. The thumbscrews also make it easy to make fine adjustments to chain tension and wheel alignment but I really haven't found it necessary to make frequent adjustments. They can also open crown corks but I haven't tried that yet! Where I have been caught out is as the axle is moved backwards the torque arm on the Rohloff begins to slip out of the nut it engages with on the other side of the screw you can see at 8 o'clock from the axle.
An eccentric BB would probably be better but the Surly arrangement works once you know its foibles.

Its not complicated. Either the frame or the mounts that convert post to Is mounting with be L shaped or a curved L.this means that when the wheel is moved fore or aft the caliper can be pstioned so that the same bit of the pad can be match to the disc. Dead easy, 2 seconds to back off 2 bolts, move and then tighten.
I like SS and disc. Is all seems so neat and tidy.

pioneer wrote:Tell me please, on a singlespeed or hub geared bike with disc brakes and track ends to slot the rear wheel in, when moving the wheel back to tighten the chain, how then is the grabber thing (sorry, don't know the proper name), adjusted to cope with the moved disc?
And is it time consuming and difficult? Thanks.

pioneer wrote:Hmmm.... thanks. I think I'll continue my search for a 700c frame with canti studs and either track ends or semi-horizontal drop outs. Only two so far, the Pompino (but not really enough fat tyre clearance) and the Surly Cross Check.

I've got the Pompetamine which is also the frame I showed in my previous post. I don't find it time consuming or difficult to adjust the caliper when tightening the chain. By all means rule out the Pompetamine based on fat tyre clearance (if you want to go beyond 32~37mm) but I wouldn't rule out track-ends with disc brakes entirely.

Sum, On One state the widest tyres these frames will take is 35mm. Would you agree this is the max size?

Not a great help but I have found PX under estimate that a bit. My kaffenback is taking 37mm hybrid tyres with a 2/3m gap when it should handle 32mm max. I suppose it depends how much clearance you want.