I want to convert a bike to a fixed gear and was going to buy a pre-built wheel with a flip-flop hub however someone suggested that instead I should just get a wheel and tack weld the cog onto the hub. Is this even possible? I've never heard anything like this however to get a wheel with a flip flop it would cost around $150 and to tack weld an existing wheel it would only cost about $10. Thanks in advance for your help.

How would you weld a steel cog to an aluminum hub?

You could weld it if you really needed to I suppose. You would never be able to change the cog and you would always have a little concern about the welds cracking. You could jb weld it too.

You could get a wheel for less than $150. You can get a wheelset with cog and lockring for $110 shipped from bike island so there must be some good deals on rear wheels out there. Check craigslist.

edit: didnt really think about the actual welding. I'm not so sure you would want to do that.

If they're both of the same metal, then yes, it's possible.

Just buy a new wheelset for the sake of your fate.

just Rotafix it! if you use a break it will never slip!

Brake.

Next. They need to be the same metal.

Next. I got a crappy wheelset (New Alex 450's) WITH a 14 tooth no name cog, and no name hubs off ebay for ~$90 shipped.

besides bikeisland is there a site that sells inexpensive rear wheels?

similar-ish question... i saw a fixed mtbr the other day at a light and it looked like his cog was bolted on, what's the deal with that?

ah, i'm dumb, probably disc hubs eh?

edit: https://www.63xc.com/jasom/milldisc.htm

I have that exact same wheelset, ($100 @ www.fixedgearfreak.com) except I took it to our high end LBS, and let the wheelsmith work on them for an afternoon. ($50 for both wheels)
now when I ride the wheels make a sort of "ringing" sound when I get up to speed, and they seem MUCH stiffer, and it feels like it takes less effort to hold speed.

could be all in my head, but I like those wheels, especially after the wheelsmith tuned them up.

I've welded up a few old road freewheels (kept the lock-ring, screw on gear and ditched the rest) and loc-tite'd them back onto old hubs. They tend to fail at the worst possible time. Also welded up an old bmx freewheel, never rode it hard, just something to play around with while stuck in Alaska for a couple months.

Basically, you are better off getting a $20 track cog, $2 bb lockring, some loctite and doing some roto-fixin'.

A friend welded the freewheel of his cassette, and then welded the cassette to the hub, and he's ridden it pretty hard for quite some time now, and it's been fine......super super cheap too! But not visually pleasing.

Agreed

ROTAFIX! Jeez. This shouldn't even be a question anymore.

Welding AL to Steel? Not sure if it's possible or not, but it's certainly not allowed in structural applications. W/O a brake, I wouldn't recommend it.

Are you shure that person was talking about cog to hub(wich is just stupid) or welding up a freehub(disabling the mechanism inside the hub by means of JB or brazing)

Certainly possible. Though his description was rather vague

Mean't the OP

Yeah... I mean, I have no complaints. Its my townie so not like Im track racing with them. They get the job done.

Braze it. Solder.

So did I. Miscommunication ftw.