#8 Nose bearing clearance

[Neven911]

Hi, Can anyone tell me what an acceptable nose bearing clearance is?
Thanks Neven

[cgarr]

I do not have the spec in front of me but one thing you want is clearance on the tighter side, this is one end where oil enters the crank, excessive clearance will reduce the oil flow

[Trackrash]

Bore 31.041-31.084
Shaft 30.980-30.993
Clearance 0.048-0.104
Shaft wear limit 30.970

[Neven911]

Originally Posted by Trackrash

Bore 31.041-31.084
Shaft 30.980-30.993
Clearance 0.048-0.104
Shaft wear limit 30.970

Thanks, My shaft is 30.976 so on the low side and I'm measuring the bore of a bearing I have here at 31.076 so clearance of 0.10, I'm thing a new standard bearing might be worth it

[Trackrash]

If you get a new one, let us know how it measures. As I am in the same boat.

[Neven911]

Originally Posted by Trackrash

If you get a new one, let us know how it measures. As I am in the same boat.

Will do, I have asked the local group in NZ if they have any I can measure, Cheers Neven

[Mark Henry]

Last time I bought a #8 the tolerances were terrible, it was an aftermarket german bearing. I ended up DFL coating an used std. bearing I had.

[cod7]

what an acceptable nose bearing clearance is

[dannobee]

Spec is 0.048-0.104mm (0.0019-0.0041")

Crank spec is 30.980-30.993mm (1.2197-1.2202")

IMHE, they never seem to be on the tight end of the scale.

[Neven911]

Originally Posted by dannobee

Spec is 0.048-0.104mm (0.0019-0.0041")

Crank spec is 30.980-30.993mm (1.2197-1.2202")

IMHE, they never seem to be on the tight end of the scale.

I'm getting that impression, I think they are not really a 'bearing' per se but rather a collar for oil delivery to the crank, though I'd prefer a clearance smaller than the upper end of range