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Welding an aluminium bike frame
rodgling - 2/7/12 at 07:02 PM

Quick question: a friend needs some work done to his bike frame as he's just discovered that it's been properly screwed up in the past. What's a reasonable price to get this sort of damage fixed? To me this looks like cutting out the damaged section and replacing it, maybe an hours work max for a good welder? He was quoted £280 for it which sounds crazy expensive?



[Edited on 2/7/12 by rodgling]


nick205 - 2/7/12 at 07:19 PM

If it's a half decent frame it would have been heat treated after the original fabrication. Any welding repair will obviously lose that effect. Likewise if it's a decent frame the tube may well be butted (varying wall thickness) and/or formed into a curve etc.

Looking at the picture I wouldn't attempt to simply cut the tube and replace since it's lapped into the rear drop out increasing strength and stiffness. Replacing the tube any other way will greatly weaken the structure (bike frames take a lot of force for the size they are).

£280 for a reputable frame builder to repair and ensure it's straight afterwards, including heat treatment (looks like a removable rear swing-arm) materials and paint doesn't sound that unreasonable to me. £280 for a general fabricator to repair sounds like a bad idea.

Probably worth investigating a replacement swing arm if the frame is that good. Alternatively there are some very good frames available these days for not a lot more.


rodgling - 2/7/12 at 07:25 PM

He's very serious about cycling so I suspect the frame is a very good one, hence worth repairing properly. Thanks for the info though.


franky - 2/7/12 at 07:35 PM

Langdale lightweights in notts have done a friends before for about £170ish.


se7ensport - 2/7/12 at 08:41 PM

It can't be worth it.

Looking at the angle of the two tubes its either a cheap rear suspension frame as its rim braked or a trials frame, the gear cable makes the later very unlikely.

What is the bike used for? if commuting I would simply fill the holes or leave it as is, anything that's likely to put a high level of stress through the bike I would bin it and start again.