Rear vertical drop out thicker on the drive side

[garygkn]

Many thanks Brucey.
The drop outs are Campagnolo.
I took the derailure off the bike yesterday it threaded off OK. Maybe I should thread it back on just for now? If I can find the parts I'll have a look at it tomorrow.

I'm a trendy consumer. Just look at my Moto G (4) using hovercraft full of eels.

[Brucey]

another thought occurs to me; if you had a lot of 120mm OLN wheels already and you didn't want to buy a load of new axles you could 'convert to 6s' (or 7s)simply by spreading a frame (or having it built thusly) and brazing in a spacer such as you have; with a 6s (or 7s) freewheel fitted to a 120mm OLN hub, the last sprocket will come about flush with the locknut, and the spacer will give enough clearance to use the smallest sprocket. It would also allow you take race service using 120mm OLN wheels if required.

Interestingly this approach results in lower bending stresses in the axle. It might not sound like much difference, but IME 5s (120mm OLN) axles with threaded freewheels are considerably more reliable than 126mm (or longer) ones; my own spate of axle breakages started when I converted away from 5s/120mm OLN.

cheers

[gxaustin]

If the mech hanger breaks would it be possible to use an external hanger (one that bolts onto the dropout)? That's what my 1978 Falcon uses and I don't have any problem with the derailer.

[tatanab]

^^^ Difficult with vertical dropouts as there is nowhere to bolt the external hanger. I have reset a hanger like this using 12" parallel jawed adjustable spanner.

[garygkn]

I think I'll have to order a new 10mm solid axle with nuts and washers I had a look for a spare but there was nothing suitable. I'm going to give Brucey's method ago sometime next week.

I'm a trendy consumer. Just look at my Moto G (4) using hovercraft full of eels.

[Brucey]

doesn't have to be a solid axle M10x1 in the dropouts, a 3/8" axle will do here. If the gear hanger is Al, a hollow M10x1mm threaded axle will work just as well as a solid one.

FWIW I have a Park tool hanger aligner and the pointer is rubbish (it just gets in the way; really it needs to hinge away somehow when swinging the tool) and the threaded thing that goes into the hanger managed to knacker itself somehow. I recently 'repaired' it by simple dint of throwing the pointer away (and vowing to use Vernier calipers which is better anyway) and using an M10 axle (complete with cones etc) in the business end of the tool. Much better, because there can be a nut on the far side of the hanger and there is no danger of stripping the threads in it. I can 'repair' the tool indefinitely in this way provided I have a supply of M10 x 1mm axles, which of course I do; this is the most common threading for QR axles and a broken one is usually long enough, so.....

cheers

[garygkn]

Used a thick adjustable spanner and bent the hanger back.

Re measured the rear drop out and face to face it's 120mm. I thought about getting a Sun xcd 120mm cassette hub the original wheel is not worth keeping. I do have a Tippo rear wheel it is I think 125mm? I'm going to order some digital vernier calipers. I guess I will need to remove 2.5mm in spacers from both sides? I'm not going to have the skills or knowledge to redish the wheel.

I'm a trendy consumer. Just look at my Moto G (4) using hovercraft full of eels.

[Brucey]

we don't know how the rear alignment is, i.e. the usual faces of the dropouts could be centred or the 'new' faces of the dropouts could be centred.

This will affect whether you fit a conventional 120mm OLN wheel or a 126mm wheel with spacers removed, and whether the spacers are removed from both sides or just one.

cheers

[garygkn]

Brucey this is the point that I was just to report back to you with. I just put in a different old 120mm rear wheel it has a narrow 6 block. I would d say the wheel is not running central it looks to go to one side of the stays. It's too dark to check now. Tomorrow on the 125mm spaced wheel which won't drop in the back I could remove a spacer from the drive side and fit it to see if that works?

I'm beginning to think it would be easier to remove that extra material and have the thing re-spaced and realigned including the drop outs this way it would be easier going forward.

I'm a trendy consumer. Just look at my Moto G (4) using hovercraft full of eels.

[Brucey]

dishing and respacing wheels is 'easy'.... remachining frames is, by and large, not.


Putting wheels in is all very well but I suggest you check the frame alignment using a length of cotton.

FWIW a standard 126mm 6s wheel with a spacer removed on the RHS is certainly worth a go.

cheers

[garygkn]

Thanks Brucey.

I'm a trendy consumer. Just look at my Moto G (4) using hovercraft full of eels.

[Brucey]

FWIW if I had a frame like that, I'd probably engineer my own portacatena system, together with a 6s ultra freewheel, and access the gears using (say) 7s indexed shifters, so that the 7th gear position was the chain holder, or something like that. As it is, the frame is almost unique; so you may as well take advantage of that.

cheers

[fastpedaller]

The OP did well by getting the hanger straight again. I had a similar issue (though not the spacer) with a very cheap (£70) Alu MTB I bought from Halfords (crikey time flies ,it must have been over 10 years ago). Anyway, on some rough ground in a small gear, a twig snagged on the rear mech, chain wrapped round and it was a mess. I shortened the chain, bypassed the mech and rode it 30 miles home. Now to mend..... I had to scrape the remaining paint off the bent vertical dropout (with a combined hanger rather than a bolt-on, so not typical). Remembering my old-school methods a bar of soap was rubbed over the dropout and the dropout was heated until the soap residue went black. After it had cooled, I took an adjustable and gently tried to straighten the dropout. The process was repeated until success. Then came the tricky bit, as the threaded hole for the mech was ovalised and missing its thread, which had ripped out. I used some 'lumiweld' to build up the missing metal, and then (after dripping some molted alloy on my knee! -moral wear long trousers rather than shorts ) drilled the hole out with an 8mm drill and used a M10x1 (yes I had one!) tap to make a new thread. It needed a forceful once-only turning action rather than a back-and-forth method one would use in steel. It lasted me a further 4 or 5 years before I passed the frame and various parts on to a needy local, and may still be going strong.

[rjb]

Thread revival as I just spotted the special gear lever which one uses to drop the chain onto the Portacenata. Depressing the cup allows extra movement to allow the rear mech to move further.

[Brucey]

I thinnk it should be spelt 'portacatena'. IIRC briefly the hot ticket for road racing was to have a 13-up freewheel but use the special portacatena lever with it, set so as to only access the 13T sprocket intentionally eg. whilst sprinting. The rest of the time 14T was deemed 'enough'.