Topic: Front axle torque - how tight do I get the axle nut? - SOLVED

[Yamahawk]

I am installing my front axle in the ComStar rim getting ready to put it back into the fork lowers with the retainer caps. However, I remember that the axle nut was pretty tight when I removed it, and now, if I tighten it up past snug, it seems to bind in the front hub. If I snug it, and take all the play out of the axle, spacer, speedometer drive, etc. it spins in the hub fine. Is this correct, or is there something wrong? I had noticed before that the bike was a hard roller, especially backwards. Is it possible that the PO had the axle too tight in the hub, binding the bearings? I can't find any instructions but 'tighten the axle' in the hub prior to assembly in the forks. I understand the fork lower caps capture both ends of the axle, so is 'snug' good, or is there a problem with my bearings?I guess the wheel should spin on the axle, but should I install it and see if there is any binding, as the inner race, spacer, and axle should be tight together. Maybe I am just under thinking on this one lol. So. when I am tight, should the axle spin without force in the wheel hub?
Charlie

[Erny]

Hi Charlie,

K7 specifies 5.5-6.5 kg-m (40-47 ft-lbs)
Both for K version and also F version (comstar) see attached pic from shop manual

[Yamahawk]

Thanks, Erny, if i am this tight should the axle still spin in the hub? it is really hard to turn, or won't spin at all when i tighten the axle, yet both bearings spin with my finger when the axle is removed.
Charlie

[Erny]

Well, actually my only experience is with my axle - it does not spin, if I try to rotate by hand. But I have stock, 42 years old bearings (9000 miles on them) that I plan to change, so I let it be for the moment. I did not disassemble it, so I suppose it is like that from new, never done

[Yamahawk]

OK cool, I have re-installed the axle, torqued it tight, and put the caps back on the forks, and it seems to spin with a little drag, but not much. I will take it for a spin later, and see how it does, Thanks Erny!
Charlie

[slikwilli420]

Bearings should spin easily once torqued. If they don't something is binding.

[Yamahawk]

Bearings should spin easily once torqued. If they don't something is binding.

Is this after installation in the front forks? or just the axle twisted by hand in the hub? I installed the axle back in the forks, and the wheel spins pretty well, not as free as other bikes, but it doesn't feel too bad. That is without the brake caliper on also.
Charlie

[my name is nobody]

Is your axle nut hex head on one end(?), make sure it is installed with the hex end closest to the wheel.(?)
the early 750 and 550 are like that and act like that if the nut is installed wrong way around.

[Yamahawk]

Is your axle nut hex head on one end(?), make sure it is installed with the hex end closest to the wheel.(?)
the early 750 and 550 are like that and act like that if the nut is installed wrong way around.

Yeah, the axle nut is with the flats on the hub side, so it is inside the fork leg. I didn't tighten up the lower fork cap nuts until I pumped the forks a couple times to center and relieve any fork binding also, then tightened the 2 cap nuts on each fork lower.
Charlie

[PeWe]

Speedo gear must be set in correct position, if not the wheel will lock up when tighten.

[Yamahawk]

Speedo gear must be set in correct position, if not the wheel will lock up when tighten.

It did key in, and rotated the flat blade... if it wasn't keyed in, wouldn't it have not fit into the seal flush? I mean, wouldn't there have been a gap?
Charlie

[jgger]

The standard for unknown bolt torque is tighten it until it starts to get loose again........then back off a quater to a half turn. You have been riding long enough to know that Charlie! Jeez

[przjohn]

The wheel should spin freely with no feeling of drag. When the axle is mounted to the wheel will it spin freely holding the wheel in your hands? If there is any feeling of drag something is wrong. Is the spacer installed? The spacer may also be wrong, I have found pieces of pipe in wheels for spacers.

[Yamahawk]

Speedo gear must be set in correct position, if not the wheel will lock up when tighten.

PeWe, you were correct, thought it keyed in but it was off a smidge, and it was binding, I took it out and straightened it, and now is working well.

The standard for unknown bolt torque is tighten it until it starts to get loose again........then back off a quater to a half turn. You have been riding long enough to know that Charlie! Jeez

Hehe I tried that, but was using too little of a wrench to get it to loosen up again, and my cheater was nowhere in sight...

The wheel should spin freely with no feeling of drag. When the axle is mounted to the wheel will it spin freely holding the wheel in your hands? If there is any feeling of drag something is wrong. Is the spacer installed? The spacer may also be wrong, I have found pieces of pipe in wheels for spacers.

Yep, the spacers were all proper, it was me, as the loose nut...
I now have a working wheel lol. Thanks everyone for the advice.
Charlie