I was just wondering if it's possible to modify a freewheel cassette so that it is fixed? Anyone ever try it? I figured a quick bit of welding might do it?

I have one that I'm going to dump a bunch of JBweld in. This will be for a beater (bike polo). I doubt I would ride one on the streets for a long period of time.

A guy came on a few months ago proudly showing pictures of just such a setup with blobby cold welds holding an old 5 speed freewheel.

We all pointed and laughed, then sobered up and said we hoped he didn't take out any innocent bystanders when he died on that thing.

Haven't heard from him in a while. I sure hope he didn't take out any innocent bystanders.

P.S. don't try to weld bike parts if you don't know how to weld. Cold welds are weaker than glue, and you can't weld dissimilar metals i.e. steel to aluminum. Stick with the epoxy, and learn to weld on something that won't hurt you if it falls apart.

Agreed, I just want to get the feel for it before I put $$$$ into the bike. I've actually quite enjoyed removing all the unneeded components and chopping the drop bars.

you can braze it shut. i've seen trials and track riders to this, but i wouldn't suggest it for street fixed riding. just commit and buy a real hub. as mattface pointed out, you can't weld aluminum and steel... especially considering you use opposite currents to weld each specific metal.

i was just wondering about him the other day...i pm'ed him...i'll see if i can't get ahold of him.

https://aebike.com/site/page.cfm?PageID=30&SKU=HU9020

but for that price, i'd just build a new wheel.

Way back in the summer of 1972, I took a 5 speed Suntour freewheel, a Sturmey Archer 3 speed hub, and went to the local autobody shop. The guy tossed everything into the solvent tank for awhile, and then he used brass (brazing) to fill up the space between the geared and spinning parts of the freewheel so it no longer turned. Then, he welded the now solid no-longer-a-freewheel to the cog carrier of the SA hub, giving me a 15 speed rear hub.
Now that I look back, I can claim credit for the world's first 125mm spaced road bike, but who knew back then? Certainly not the fifteen year-old mad scientist/ bike nut that I was then.

So, it was built up with a triple crank and since I used a 14-28 freewheel, was able to use a scavenged Simplex derailleur from a Peugeot. 45 speeds!!! True, a lot of the combinations were useless: I couldn't spin the lowest gear fast enough to stay upright on flat ground, for instance, but I was for sure the only kid on my block with one of these jammies!

Remember this was a road bike, I'm not sure I'd pull the same stunt on a fixie. Then again I'm not 15 and immortal, either.

yeah thats me, and i do in fact actually know how to weld, i just didn't bother cleaning up the welds because i doubted it would work anyways, it did for a while though.

Eventually though, i hit one rather large bump and the casette stripped the threads on my hub and i broke my axle in the process.

It is not a good idea to weld your casette, for mulitple reasons:

1. looks ugly for the most part, if you want a suicide hub then just do lots of locktite on a cog
2. with all the stress you are putting on the cassette because it is fixed, the chain tends to want to jump up a gear, and thats no good.
3. when it fails, it fails big time, and i was lucky enough to be out late at night when it broke and didn't hit anything or anyone.

for those of you who care as to what i'm riding now though, that old bike now is still a suicide hub, but i upgraded to a d-ace 15t cog and loads of red locktite on a used wheel from my lbs, it was cheap, and thats my delivery, large grocery getter now.

i ride a fuji track now, WITH A LOCKRING! and no welds.

Wasn't it metallopesante? I think he still posts from time to time... If I recall correctly, that welded freewheel unscrewed (imagine that) and he went with a standard suicide wheel.

shhh, i'm trying to stay cool here... i know it didn't work, but i knew nothing about fixed gears at the time, the bike was worth nothing anyways, so i just had the idea that if i welded it, it would be fixed, and it was, for about a week.

What about using one of the SHimano notfreewheels that they used with their goofy freewheeling chainring setup? They were 5-speed clusters that didn't freewheel... and I think they screwed onto a standard freewheel hub.

as soon as you try and skid or even put a little bit of force on the cassette then it's just going to de-thread itself since there is nothing holding the casette onto the hub like a lockring or anything.

I'm glad to see you survived that little experiment in tact, and didn't clobber anyone, and I apologize for insulting your welding skills. I only brought that up to make the point that welding bike parts is not a good idea if you can't make a good hot weld.

Now let's hear it for the voice of experience! It was all well and good for us to point and laugh, but then none of us pointing/laughing types had tried it. Despite all the voices shouting "that things a deathtrap", you had to try it and prove us right. In a way that's a good thing, because in spite of a firm belief that it wouldn't work, a part of me wondered if I wasn't just parroting the common belief.

In a desire to keep costs down I too have contemplated various "suicide hub" ideas for my first fixie, and though I decided not to risk it, a part of me wondered if all this hysteria over suicide hubs wasn't a little alarmist. I certainly think it's fine to say better safe than sorry, but an example of what can go wrong from someone who's experienced it is more valuable than all the safety parrots in the world shouting "Suicide hub!"

I think suicide hubs are fine for a starter and if you have brakes.

i used to have an ACS free-coaster on one of my old freestyle bikes. it had a little thumbscrew which i imagine must have just done something to the pawls, but i'm not sure. i was 13 and didn't really give the technology much thought at the time.

i remember reading something on sheldon brown about him welding a freehub to make a fixie. i dont believe it mentioned how good it was because i think it was a more recent experiment. but welding a free wheel is a bad idea. i would just buy a cog and some lock tite that should last you long enough to get the feel for it and see if you like it.
-sam-

Sure, and chainline will be a *****,a nd there's a zillion other reasons not to do it... but it might be interesting, anyhow!

yep, you pretty much said everything going through my mind.

You're right, no update on how the welded freehub worked out though. Doesn't Sheldon suggest using a track cog on a freewheel hub with locktite (is that considered suicide?). If I understand correctly, he also suggests using a British BB retainer nut to "double nut" the cog.

those are very useful for shimano equiped disk wheels.

Cog+locktite= suicide hub. Using a BB lockring helps a little, but is no substitute for a real track hub with lockring.

I've heard Mr. Brown advocate the suicide hub if it has a front brake.

The first attempt lasted a few hundred miles before the brazing (not welding) let go, but that was a very slapdash job, just three blobs of braze around the back of the freehub body.

I re-did it later running braze all the way 'round, and that's working just fine.

See: https://sheldonbrown.org/bass


Nope, I only advocate this if the bike has two brakes.

I must admit that I don't always follow my own advice, but I only do that with high gear ratios, such as the 53/12 on my Moulton and the 46/12 I had on my Raleigh Twenty until recently. With such high ratios, (necessitated by the small wheels on these bikes) there's much less torque on the sprocket, so I feel relatively safe.

Sheldon "Tinkerer" Brown