welded-cog suicide hub
 

more noob questions:

i bought a bike with a loc-tite-ed suicide hub but i dont trust it. a machinist friend has offered to TIG weld the cog to the hub. i have NO money to buy a track hub right now, so don't bother suggesting that. it will make the cog permanent, but its an old hub, so i would not lose anything that way.

would welding the cog to my hubshell be a safe alternative? in the meantime, i could put a freewheel on the hub and ride it as a single-speed freewheel bike until i can save some $$ for a proper track hub.

Ride it with a brake and you'll probably be okay.

can you properly tig weld a steel cog to aluminum hub?

*assuming the hub is aluminium.

i think the hub itself is steel, but if it is aluminum, my friend said he can still weld it. i don't know anything about welding, but he said you justs use a different material for the rod you use to weld aluminim and steel together. i can't say i know that's true, but i trust his judgement.

Both options seem really sketchy to me. If you the
integrity of your skull and teeth then think about coming
up with a third, mechanically sound option. I appreciate
the creative solutions of loctite and welding the cog to the
hub but neither are mechanically sound. If you have a bike
kitchen or other cheapo bike shop around just use a regular
rear wheel until you can get yourself a proper set up.

I'd like to know how steel and aluminum can be (JB)welded

a bunch of my friends told me that the regular suicide hub with loc-tite is "safe" and "will not fail" but i dont trust it. i popped the cog, which was held on with loc-tite, off the hub with a few light taps of a hammer. not very sturdy if you ask me.

san antonio is not a bike-friendly city to begin with, so all of the bike shops are expensive. i am bikeless until i find a solution or pull some money out of my ass and buy a hub. all of my chromoly bmx bike parts are TIG-welded together (right?) with a heavy bead, so i would think that kind of bond would hold a cog/hub together, but its a different kind of force that is put on a fixed cog, so i could be wrong.

i thought about JB weld, but it sounded too kooky. anyone know enough about JB weld to know if it would work? probably not, but it's worth considering.

okay, loctite is not the ideal solution by any means, but there's definitely a lot of fud about them. your loctite job should be perfectly safe IF

1. you have hand brakes. i mean, "duh".
2. both sets of threads were cleaned really well with degreaser before the cog was threaded on with the loctite
3. the bike was not ridden for 24 hours after the cog was put on
4. the cog was tightened on properly the first time. ie. with a chainwhip and big arms.

a suicide hub is not, despite the name, necessarily a dangerous thing. if done properly, your loctite job should hold perfectly well... and even if it does fail, all that's going to happen is that your going to lose your drivetrain. now, if you don't have hand brakes, that's a formula for death. but you have hand brakes, right? so, having your hub unthread will be an annoyance, but certainly not a death sentence.

Yeah, me too. Sounds like your friend has solved and issue that has plagued metallurgists for a very long time.

sorry: i forgot to mention that i am going to have a front brake on the bike.

if the hub is aluminum and the cog is steel, which is by far the most likely, your friend can certainly hit it with a welding torch and some filler. it would probably affix the cog to the hub in some capacity, but it wouldn't be "welded" since afaik steel and aluminum will not coalesce using standard equipment and procedures.

if you're set on this, consider seeking out an aluminum cog. that'll probably work better. no matter what you do keep a brake.

edit: i'll go ahead and be that guy that reminds you that you can get a track hub + peace of mind for less than forty bucks (and less than that if you do some homework and are patient)

Then don't bother doing anything. Just go ride your bike.

I ride mine with no loctite or anything, just a BB lockring, and a front brake, but the cog is Really tight and i can stop with just the backpedal really easily.

A suicide hub without any welding or locktight will work just fine if done properly.

http://204.73.203.34/fisso/eng/schpignone.htm

Then it's no longer a suicide hub. Ride as it is.

If the term "suicide hub" refers to a hub with a thread-on cog but without a lockring, then the presence of a front brake is irrelevant to the use of the term. At any rate, suicide hub is a stupid term. Riding without a lockring is not suicidal and not necessarily even more dangerous.

rotafix, it works. It's safe, I weigh 210 and rode one for almost a year of hard riding with no failure.

Thumbs Up

Seriously guys, I've ridden my "Suicide Hub" conversion harder than I ride my track bike pulling heavy skids and skips without any failure, I'm sure with the large amount of torque I put on the damn thing the thread will strip before it comes loose. I use Red Locktite with a Bottom Bracket Lockring. Obviously if it's just the cog on the hub...DUH, it's gonna twist off.

get a job

agreed

I can say that I've personally had a Loctited suicide hub fail on me and come unthreaded right in front of an intersection. Luckily it was a fresh red so I was able to get through before there was any crossing traffic - looking back I can't believe I was crazy enough to run that setup without a brake, but I was a noob and didn't really understand what was going on. Just do it with a brake and it it'll be more of an inconvenience than a safety hazard if it wants to come unthreaded on you.

rotafix cog w/ loctite + loctite a bb lockring + front brake= best ghetto solution.

Crank that Sucker down with rota-fix, Red loctite on the Cog and a BB lockring, As long as your running a brake its not really that unsafe its certainly as safe/safer than running brake less with a proper hub