Singlespeed & Fixed Gear - 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'd like to know how steel and aluminum can be (JB)welded

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 (http://www.bikemannetwork.com/biking/p/HU1047) (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

sorry: i forgot to mention that i am going to have a front brake on the bike.Then it's no longer a suicide hub. Ride as it is.

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

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.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

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

+1:D

try explosion welding. modern marvels, anyone?

yes, risk $9000+ in hospital bills or even your life just because you dont want to spend ~$100 bucks on a real hub. please do it. totally worth the risk.

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

that's exactly what i did. that cog is going NOWHERE. the brake will help, when i find one. i am not riding it until i get a brake, and the weather is total crap right now anyways.

edit: i am going to save for a proper track hub in the meantime. i have been lacing my own wheels for years, so that's not a problem. my fear is having to buy a new set of spokes because the flange size on the new hub might be different.

yes, risk $9000+ in hospital bills or even your life just because you dont want to spend ~$100 bucks on a real hub. please do it. totally worth the risk.

Word. You can get a Formula track hub from Harris Cyclery (Formula hub labeled as a house brand) for $45. You can find $45.

get a beach cruiser.

Word. You can get a Formula track hub from Harris Cyclery (Formula hub labeled as a house brand) for $45. You can find $45.


+1 unless your as broke as i am right now. And if you don't have money to have the Wheel laced, Now is as good as time is any to learn, Then get the LBS to Tension the spokes should be good to go cost 60$. but if you Really don't have 60$ do the aforementioned rotafix+loctite

If you really think you cant afford a 45 dollar hub then cancel your internet or phone for a month and use that. or steal some **** from walmart and sell it on ebay

Word. You can get a Formula track hub from Harris Cyclery (Formula hub labeled as a house brand) for $45. You can find $45.

plus the $36/$32 for spokes, unless his current hub happens to have exactly the same flange size as the new one.

I second the suicide hub suggestion. I rotofixed my cog, then cranked on a bb lockring. I didn't use Loctite. It never slipped in the four months I rode that. Then my lovely wife bought me one of those Harris Cyclery hubs (and spokes and rim.. and tire and tube and what else?) for Christmas. As a bonus gift to myself, I built the wheel myself.

But the suicide hub worked great and I'd still be riding it if Christmas hadn't come around.

If you really think you cant afford a 45 dollar hub then cancel your internet or phone for a month and use that. or steal some **** from walmart and sell it on ebay

i love when i hear of people stealing **** from walmart. after seeing that documentary a couple years ago, i've never set foot in one again.

*sigh*

5000 plus hard km on my ghetto road bike... pushing 2000 km on my ghetto winter fixie... there have been no problems whatsoever.

When I did swap the cogs on my road bike (I used industrial strength red loctite) it took three people to remove the cog... one person to hold the front of the bike, another to hold the chain whip, and me turning the wheel for better leverage.

I also had to torch the cog after our initial attempt to remove the cog failed.

If you do ride a "ghetto" conversion you need to do it up right and run a brake / brakes...something every bike needs anyways.

Also remember that Loctite 271 requires approximately 24 hours to cure and achieve 100 % strength.

Also remember that Loctite 271 requires approximately 24 hours to cure and achieve 100 % strength.

i think this is the #1 cause of loctite failures: insufficient curing time. as long as you let that cog sit for a day and make sure that both threads are completely free of grease or dirt before putting on the loctite that cog will hold.

Sheldon Brown's site says its OK to not use a lockring (i.e., put a fixed cog on the freewheel side of a flip-flop hub) as long as you have a brake (and don't want to skid, I suppose). No mention of loctite at all.

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.


I used JB weld on my conversion for a while. It was fine.

Sheldon Brown's site says its OK to not use a lockring (i.e., put a fixed cog on the freewheel side of a flip-flop hub) as long as you have a brake (and don't want to skid, I suppose). No mention of loctite at all.

No, it's only OK if you have TWO brakes.

I DO recommend LocTite for this application.

See: http://sheldonbrown.com/fixed-conversion.html#freewheelhub

Sheldon "Redundancy" Brown

+---------------------------------------------+
| I have suffered from being misunderstood |
| but I would have suffered a hell of a lot |
| more if I had been understood. |
| --Clarence Darrow |
+---------------------------------------------+

thread over.

Agreed. Everyone go home.

i've rota-fix before and that ***** stayed put...then again.. i wasnt trying to skid.
There is a place in the boston area that sells rear wheels for like $30 for a fixed/flip.

i think this is the #1 cause of loctite failures: insufficient curing time. as long as you let that cog sit for a day and make sure that both threads are completely free of grease or dirt before putting on the loctite that cog will hold.

+ 1

I should also add that I don't do skids to amuse the peeps (and wear out my tyres) and only do this when it's absolutely needed.

For $7 put a bmx freewheel on it, and be done, forget fixed.

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.

While I have never used JB Weld for this application, I have had much success with other applications.

Sheared the head off a bolt holding down the water neck on an old Ford Aerostar while trying to replace the thermostat. I cut the guts out of the thermostat, creating a restrictor plate, then used JB Weld to hold everything together. Everything held together for another 80,000 miles until the obsolete transmission blew out.

I used JB weld to repair damaged rear dropouts on aluminum beach cruiser frames. The damage had occurred when the brake arm's bolt had broken off, and when the brake was applied, the retaining nut dug into the frame. Removing the rear wheel was a PITA. Then I had to file the dropout back into some kind of shape after the axle deformed it. Then I used the JB Weld to fill in the gouge and reshape the dropout. After letting it set for 24 hours, I would file down the JB Weld into what would be a correct looking shape. Then I cleaned and painted the repair, and you could not tell the difference afterward. You could tourqe down the axle bolt and you'd never know if it was repaired or not.

IMEO, JB Weld would work well enough, if not better then, red loctite.

For $7 put a bmx freewheel on it, and be done, forget fixed.

That's fine if you like riding an ss.

Cost of medical bills > new hub

>>>Canadian<<<

No worries.