Welding fixed cog to hub

[eorta7]

I was talking to a guy at school about fixed bikes. He told me has a never used a true fixed hub. He explained that he tightens the cog and lockring and has it welded to the hub. Has anyone ever tried this?

[Bill]

(02-10-2011, 12:36 AM)eorta7 Wrote:  I was talking to a guy at school about fixed bikes. He told me has a never used a true fixed hub. He explained that he tightens the cog and lockring and has it welded to the hub. Has anyone ever tried this?

This would be something you would want to discuss with a welder in your area. Welding something that small should not be all that much.

[KC-Steve]

I jokingly mentioned doing something like that a while back on another thread and it was pooh-poohed right away. But I can't remember why. I was just kidding around as usual.

Steve

[eorta7]

(02-10-2011, 09:30 AM)KC-Steve Wrote:  I jokingly mentioned doing something like that a while back on another thread and it was pooh-poohed right away. But I can't remember why. I was just kidding around as usual.

Steve

Yeah, he told me a bike messenger told him about it and where to go. It cost him $15. He asked me why I wanted to waste money on a wheelset when I only need a small adjustment. I have to admit some of the wheelsets I've been seeing are pretty nice.

[DaveM]

There are some technical issues with trying to weld steel to aluminum. Cogs will almost always be steel. Any decent hub will be aluminum. I'm not sure of all the ins and outs, but I know it isn't the same as welding steel to steel. With a steel hub, seems like it would be a quick, simple way to make a solid fix wheel.

[CurrenSith]

Aluminum and Steel atoms have a harder time diffusing into each other compared to steel and steel.

I have the same problem, the rear hub on my fixie rotates when I try to skid. Is welding really a viable option, can anyone school me on some options.

[DaveM]

(05-03-2012, 06:02 PM)CurrenSith Wrote:  the rear hub on my fixie rotates when I try to skid. Is welding really a viable option, can anyone school me on some options.

Probably means you have a loose lock ring. If it's been loose a while or won't stay tight, it probably means that the threads are stripped. In which case, welding or epoxy may be you're only options.

I always warn people to have hand brakes on any fix that is jerry rigged somehow, but that's advice to use at your discretion.

[CurrenSith]

I believe your right the threading is stripped. Any ideas on what i need to replace it on my own. Can i just replace th hub and cog?

[DaveM]

(05-03-2012, 06:57 PM)CurrenSith Wrote:  I believe your right the threading is stripped. Any ideas on what i need to replace it on my own. Can i just replace th hub and cog?

Yeah. If the threads strip, it is usually the ones on the hub because it is aluminum and the lockring is steel. So probably would just need a new hub. Note however that replacing just a hub means relacing the spokes on the wheel which is not a minor job.

[Bill]

I'm trying to remember where I saw the post but I do agree with everyone above that welding metal to aluminum is really NOT a great idea down the road. You may end up walking instead of riding to your destination. As some one here once said wheels are consumables. I will try and look up some sources if you give the size of the wheel you want.

[Joe_W]

Well, it is less welding the sprocket to the hub but more welding the freehub body to the hub itself so that the freehub mechanism is blocked. I believe that it could be done better by machining a thing that replaces the ratchet mechanism (if it can be accessed) and blocks it. I believe there are some howtos on the net to convert a Sturmey Archer 3 speed to a fixed gear, start from there. There are also conversion packages for Shimano freehubs, though those are almost as expensive as a track hub. Other than that: I would go for the correct solution and get a track hub or an old road hub (for freewheels), though you might not be able to correctly mount a lock ring on that (so: don't rely on locking up the rear wheel as a brake, bad for muscles and joints anyway).

Oh, @Bill: I usually say that rims are consumables... hubs should outlast the rims (if cared for and maintained well).