Rear Axle Nut Question

[hc243102]

I cant seem to find and specs in the shop manual as far as how much to torque my rear axle nut. The manual says "Tighten the axle nut and lock with cotter pin". Thats it. Sorry if this is a stupid question, but i feel this is worth asking as I dont want my wheel to fall off. 78 CB750K

 

[hillsy]

If you tighten it with a 12" wrench / spanner / socket with your hands you will not be able to overtighten it (unless you are a cyborg). The cotter pin then holds the nut in place so your wheel doesn't fall off.

For arguments sake and if you want a torque figure try 70 ft/lb.

 

[hc243102]

Much appreciated.

 

[AlphaDogChoppers]

Axle nuts are often overtightened. For some reason, people seem to think they need to stomp on the wrench tightening the axle.

 

[cyclefreak]

Re: Re: Rear Axle Nut Question

Axle nuts are often overtightened. For some reason, people seem to think they need to stomp on the wrench tightening the axle.

Absolutely right. Most specs on bikes I have worked on usually call for 50-70 ft/lbs of torque.

 

[Kanticoy]

And if you wanna get really crazy my BMW is torqued to 23ft. lbs. But a sealed roller is different than a tapered roller

 

[Scruffy]

On my Honda, the directions say "Tighten rear axle nut until the wheel drags, back off one flat and install cotter pin". Sounds like setting the preload on one of my antique trucks... couldn't be right. Could it?

 

[cyclefreak]

Could be Scruffy. They can actually be over tightened so easily to a point where there is hardly any free spin left at all.

 

[Kanticoy]

There's nothing to preload on a sealed roller bearing. Most wheels have an inner locating tube that rides on the inner rolling surface. You're just locating everything tightly. Don't read too much into it. Get it tight and lock it with the cotter. No worries. I'm having a hard time imagining how a sealed bearing would get so tight that it would cause drag on the wheel without breaking something in the process. There would have to be something binding against the non spinning portion of the bearing and if that is the case, something is wrong...

 

[hc243102]

Duly noted, thanks all.

 

[Scruffy]

There's nothing to preload on a sealed roller bearing. Most wheels have an inner locating tube that rides on the inner rolling surface. You're just locating everything tightly. Don't read too much into it. Get it tight and lock it with the cotter. No worries. I'm having a hard time imagining how a sealed bearing would get so tight that it would cause drag on the wheel without breaking something in the process. There would have to be something binding against the non spinning portion of the bearing and if that is the case, something is wrong...

That was my thought too, but, the bike is 50 years old, so... stranger things have happened. I just decided it was "Engrish"...

 

[cyclefreak]

Re: Re: Rear Axle Nut Question

That was my thought too, but, the bike is 50 years old, so... stranger things have happened. I just decided it was "Engrish"...

Past experience. When I was a teenager (loonnng time ago) and didn't have a torque wrench available, I did a chain adjustment on a buddies bike and tightened the piss out of the axle nut. Never pulled anything completely off just loosened adjusted re- tightened. Afterwards the wheel would hardly spin at all by hand. Loosened it up a bit and spun fine. And later after torquing to specs no issues.
It doesn't sound right to me either. I can see possibly premature wear of the bearings. But causing that kind of drag surprised me. Now days I am pretty much a stickler for finding the torque specs on most anything I put a wrench on.