Dropout Repairs - Old Fashioned Engineering...

[boblo]

I have a plastic bike with aluminium dropouts. Over the years, the front of the driveside and the rear of the non drive side have worn a bit so the wheel can sit a bit squiffy within the chain stays. Even with the QR's well tightened, the wheel can 'pull' over under the immense load of my Amazonian thighs...

I wondering about a bit of remedial work by a proper bicycle engineering company (rather than a shifter of Taiwan derived boxes...). I'm thinking of some sort of machined adapter or weld plus machining. I'd want to minimise damage to the carbon and paint so I may be asking too much.

Any experiences in fixing this and/or recommendations for pukka cycle engineering companies please? The grubbier and oilier the better as these tend to be a better bet.

If you want old fashioned engineering, then shim it with precision shims. These are readily available in a variety of sizes,in the form of car feelers gauges

Cut them up, find the one that's the correct thickness then glue it in place so it doesnt fall out when you take the wheel off.

I've fixed multiple worn suspension fork drop outs this way2

That was exactly my plan. The only reservation I have is the gluing area is quite small and I'm concerned the shims will make a bid for freedom. I did an experiment with the tube/sleeve idea with aluminium tube for ease if working. The resulting tube shims are ~0.5mm thick and a bit fragile.

I thought both solutions a bit of a bodge hence going back to first principles and fixing the dropouts - properly.

Thanks for the suggestions.

[jo' bo]

I have a plastic bike with aluminium dropouts. Over the years, the front of the driveside and the rear of the non drive side have worn a bit so the wheel can sit a bit squiffy within the chain stays. Even with the QR's well tightened, the wheel can 'pull' over under the immense load of my Amazonian thighs...

I wondering about a bit of remedial work by a proper bicycle engineering company (rather than a shifter of Taiwan derived boxes...). I'm thinking of some sort of machined adapter or weld plus machining. I'd want to minimise damage to the carbon and paint so I may be asking too much.

Any experiences in fixing this and/or recommendations for pukka cycle engineering companies please? The grubbier and oilier the better as these tend to be a better bet.

If you want old fashioned engineering, then shim it with precision shims. These are readily available in a variety of sizes,in the form of car feelers gauges

Cut them up, find the one that's the correct thickness then glue it in place so it doesnt fall out when you take the wheel off.

I've fixed multiple worn suspension fork drop outs this way2

That was exactly my plan. The only reservation I have is the gluing area is quite small and I'm concerned the shims will make a bid for freedom. I did an experiment with the tube/sleeve idea with aluminium tube for ease if working. The resulting tube shims are ~0.5mm thick and a bit fragile.

I thought both solutions a bit of a bodge hence going back to first principles and fixing the dropouts - properly.

Thanks for the suggestions.

All the glue needs to do is sustain the weight of the shim, when he wheel is removed, its held in place by the axial at all other times.

As its material missing, I'm betting any " proper repair" with consist of sticking some adhesive or other on to it and then cutting it size, you could do much the same with epoxy resine, I consider the,shim idea to be better engineering particularly to prevent it wearing again.

You do however really need,shim steel rather aluminium tube, hence the feelers gauge suggestion

[rjb]

Riders sometimes used thin copper washers between the qr and the drop out, use to be common with chrome ends to stop the wheel slipping. Use a piece of copper tube to fabricate a washer if you cant obtain one of the size you need. If you didnt know you can anneal copper easily by heating to red hot then quenching in water, this softens it and it will work harden in use.

[boblo]

I've ordered some 0.5mm stainless strip and will trial a cover/shim arrangement. It's the front of the inside of the driveside dropout and the rear of the non driveside that have eroded a bit (I think). So I'll make little cap/shims for these initially held in position with the Q/R's but probly glued once proven. If 0.5mm is too much/little, I've the option of filing or adding/removing material from a sacrificial set of feeler guages.

I'll let you all know how I get on.

[Ant...]

I had the same problem on my Argos 753 frame, I tried all sorts of QR skewers but still had a problem, in the end I bought a Surly Tugnut not the prettest solution but hey it works great, the only down side is it takes longer to remove the wheel, a small priceto pay when compared to having to stop on hills because I pulled the wheel over, yes I know try going uphill in a lower gear you say, but hey thats the way I climb.