Singlespeed & Fixed Gear - how much torque before you have to worry about stripping threads?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




explody pup
09-16-05, 04:33 PM
Just got a new cog. Removed my old cog via rotafix method. Greased up my new cog. Tightened it finger tight. Tightened it some more via rotafix method (yes, I am using a lock ring, but I have no chainwhip). I'm just curious how much force I should apply. I can put it back on to tighten it some more and it'll budge a little. But since this is only the 2nd cog I've ever put on, I have no idea what kind of limits I can put on my hub threads. Or am I just over analyzing this?

FYI: formula hub, EAI cog.

tanks.


genericbikedude
09-16-05, 08:47 PM
not tooo positive here, but it seems to me that stress in pedaling would be far greater than any stress you could give it by hand. if you are worried, stop tightening it, and go ride. if it loosens when you try to fight the pedals, just tighten it on the street, and carry your lockring tool with you.

LóFarkas
09-17-05, 04:03 AM
You can tighten it much more by the rotafixa method than by riding (otherwise how could you get cogs off the rotafixa way???). I am not sure you can possibly strip the threads by overtightening, though...
Maybe tighten it with the amount of force it took to remove the old cog. Your muscles should remember how hard you turned the wheel then. Then put on the lockring, tighten it down hard, and forget about it.


dustinlikewhat
09-17-05, 09:50 AM
www.parktools.com

they've got torqure ratings for damn near everything.

BostonFixed
09-17-05, 11:03 AM
I was testing the rotafix method out on an old freewheel hubbed wheel. I wanted to see how tight I could get it, and if it were actually possible to strip the threads on the hub.
Using all the force that my brawny 140 pound body could muster, I could not strip the threads on the hub by the rotafix method.

I don't how this relates to you, but I couldn't strip the threads.

I also thought that most stripped hubs were the result of stripped lockring threads, not stripped cog threads?

explody pup
09-17-05, 04:35 PM
Thanks, BostonFixed. That's definitely good to know.

How do the lockrings get stripped? Is that usually a case of undertightening, giving the cog room to come unthreaded?


The EAI cog is great, by the way. I was surprised how much more quiet it was than my Soma cog.

LóFarkas
09-19-05, 02:10 AM
How do the lockrings get stripped? Is that usually a case of undertightening, giving the cog room to come unthreaded?

Sadly, I can answer that from personal experience. It takes:
-A crappy hub made of soft aluminium with a poor design that leaves only 2-3 threads for the lockring if you use a normal, realitevly wide cog setup

-A very silly rider who doesn't torqe his cog down enough

-A very silly rider who doesn't torqu his lockring down enough (lack of proper tool at the time)

-A few weeks of brakeless riding, the cog moving three or four times, coming up against the lockring

When I finally bought a good lockring wrenc, I found I can't tighten the ****er down any more...

Edit: I can consider myself lucky: quite a few guys have used the same recipe to strip the cog threads, too. And on expensive hubs as well. My hub will cost all of $13 to replace. And that's not an exaggeration. $13 is the retail price of these flipflop "trackhubs". Of course, you get non-sealed loose ball bearings and funny lockring threads, etc.