Measuring Chain Slack

[SXXP]

The owners manual has you measuring chain slack with the bike on the side stand.  Would these same measurements/limits apply if the bike were on a center stand (if so equipped) with the rear wheel off the ground?

[TenereTragic700]

I had a look at this last week when I replaced the chain and sprockets.

With my bike on the side stand, the rear shock is fully extended, that is no sag.  So the swingarm is at maximum extension.  It is obviously the same when on the center stand - maximum extension.

I am running a heavier spring, so that may eliminate sag when on the side stand - I suspect it makes little difference.

For what it is worth, I have always run the chain slack on the loose end of the range - on all bikes.

Vince

[SXXP]

15 minutes ago, TenereTragic700 said:

I had a look at this last week when I replaced the chain and sprockets.

With my bike on the side stand, the rear shock is fully extended, that is no sag.  So the swingarm is at maximum extension.  It is obviously the same when on the center stand - maximum extension.

I am running a heavier spring, so that may eliminate sag when on the side stand - I suspect it makes little difference.

For what it is worth, I have always run the chain slack on the loose end of the range - on all bikes.

Vince

 

Thanks.  Something to look at when I get home.  I've never paid attention to the extent of the swingarm extension when on the side stand, but the more I think about it, you are most likely correct.

[SXXP]

31 minutes ago, TenereTragic700 said:

I had a look at this last week when I replaced the chain and sprockets.

 

BTW, did you torque those rear sprocket nuts to the prescribed 59 lb-ft in the service manual?  I was holding my breath doing so while building up my spare wheel set two weeks ago.  Seemed excessive for a M10 nut and was fully expecting a  stud to snap.

Edited June 5 by SXXP

[TenereTragic700]

I went to 75 NM (spec is 80nm / 59 lb-ft) on the rear sprocket with some pucker factor - similar to you.  I used some medium strength thread locker.

[Ede-DE]

59 lb-ft for M10 is too much. Considering a material quality (by european industrial standards) of 8.8 the advised torque is 49 Nm / ~36 lb-ft, of 10.9 the torque should be 70 Nm / ~51 lb-ft. Most nuts and screws are 8.8 on cars and bikes. If you're unsure use less torque plus a little spot of loctite 243 (the medium, blue stuff) on the chain wheel nuts.

[SXXP]

9 minutes ago, Ede-DE said:

59 lb-ft for M10 is too much. Considering a material quality (by european industrial standards) of 8.8 the advised torque is 49 Nm / ~36 lb-ft, of 10.9 the torque should be 70 Nm / ~51 lb-ft. Most nuts and screws are 8.8 on cars and bikes. If you're unsure use less torque plus a little spot of loctite 243 (the medium, blue stuff) on the chain wheel nuts.

 

Thanks.  I'm going to loosen and retighten those nuts to a lower torque value - I'm thinking down the road here,  I don't want to have any issues undoing  an over tightened and potentially corroded nut when the time comes.  Hopefully no damage has been done.... I need to learn to trust my instincts more.

[Hollybrook]

If you have torqued a bolt to value that is too high, you should definitely check that it has not elongated. For a critical bolt, you should replace it. 

 

When I was racing sports cars,  we had a torque wrench go out of spec. We started to have the lug nuts bind when hand tightening and investigated. The lugs were visibly thinner in the middle and you could see the longer thread pitch. At least we discovered it before we lost a wheel and someone got hurt! 

[SXXP]

55 minutes ago, Hollybrook said:

If you have torqued a bolt to value that is too high, you should definitely check that it has not elongated. For a critical bolt, you should replace it. 

 

When I was racing sports cars,  we had a torque wrench go out of spec. We started to have the lug nuts bind when hand tightening and investigated. The lugs were visibly thinner in the middle and you could see the longer thread pitch. At least we discovered it before we lost a wheel and someone got hurt! 

 

Torqued to the Yamaha spec of 59 lb-ft which apparently is too much for a M10 nut.  I know I just felt uneasy while doing it as it seemed excessive.  The nut threads onto a stud, but I will check for elongation as best as I can with my naked eye.