rear chain adjustment


Way too tight for that little spindle. 120nm is about the max I would go...

I've always been of the same opinion, so, for at least the past couple of years I've been doing the same. Recently, I took my bike in for its first MoT, and got a couple of advisories:
  1. Chain tension a bit tight (I measured about 22mm, more than Yamaha's recommendation, as I pointed out to the examiner). I generally run 20-25mm. More than 25mm and gear changes tend to get a bit snatchy.
  2. Slight play in rear wheel bearings.
With the bike on a paddock stand, I could move the wheel slightly. A mate of mine, however, suggested the movement might be due to insufficient torque on the spindle nut. We loosened the nut, then torqued it up:
100Nm - clearly some play, and a definite clunk.
120Nm - slightly less play, noise reduced.
130Nm - much less play, still a slight click.
150Nm - no sideways play at allnew bearings are going into stock.

So, for all you people out there who are running less than Yamaha's specified 150Nm, check your rear wheel for play. It does seem excessive, but there appears to be a reason for it.

As an aside, the MoT inspector initially failed my bike - for having no pillion pegs! This was a new one on me, but apparently I'd have been ok if I'd fitted a plastic seat hump / pillion seat cover, so that nobody could sit there. If you have a pillion seat, you MUST have pillion pegs OR a seat strap! If I still had the stock seat, with the strap across it, I would have got away with having no pillion pegs. Crazy, especially when you consider that leaking fork seals, which is truly hazardous, nowadays only attracts an advisory, rather than a fail. As it was, I had to book a (free) retest and take the bike back with the pillion pegs fitted. I thought the tester would step outside, see that I'd fitted the pegs, then print me a ticket. But no, they took the bike into their workshop, and I had to wait for 40 minutes while they, presumably, counted the number of foot pegs (1...... 2...... 3....... 4!) on the bike. Suffice to say, I will no't be taking it back there again.

Take note all who have fitted pillion peg blanking plates!