Tire Locks

[mack]

I took my tires and wheels apart and discovered the E had tubed tires and tire locks in the back wheel. I've never seen them before. Big black wedges that pull up snug to the rim. Why did yamaha do this? Do I need to reinstall them with tubeless tires?

[natemoen]

The front tube rim has a very different rim profile on the bead seating edge than the tubeless rim and I would say that it is an absolute must to use the bead locks. The rear tube wheel though has the same profile as the tubeless rim and you could easily tap and plug the holes where bead locks go through.

[crazy steve]

The fronts don't have the bead locks.... and the rear locks are a PITA to install. Look here... http://www.xs11.com/forum/showthread.php?t=35442

[motoman]

The fronts don't have the bead locks.... and the rear locks are a PITA to install. Look here... http://www.xs11.com/forum/showthread.php?t=35442

Interesting that Yamaha felt the need to keep wheel from slipping on tire under torque load. More for safety on a tube type. A pinched off valve stem from a 'slipped' tire would not be a good day. Majority of my moto-x bikes had two rim-locs on rear wheel, 90degrees apart. Not particualrly a PITA, just loosen nut to top of threads, keep pushed in to top of those threads and nut when dismouting tire. Same for re-mounting tire/tube. Keep pushed in and away from bead till tire is inflated/bead seated, THEN re-tighten nut pulling bead-loc down against inside of tire bead.

[bikerphil]

Do I need to reinstall them with tubeless tires?

The bead locks can't be used anyway with tubeless tires, the air would leak out the mounting holes. Gonna have to plug those holes when going to a tubeless tire.

[mack]

Thanx

Interesting that they would have two different systems like that. My SF didn't have them. Was the 78 the last year for this or was there two schools of thought about which was better?

[bikerphil]

My 79 Standard had those locks.

[crazy steve]

The Specials never had the rim locks, but the early production '79 standards did. Yamaha phased them out pretty quickly, I'm assuming when they ran out of those wheels....

[motoman]

My 79 Standard had those locks.

Hmmm.......maybe the 79Standard still carried the 78's 17" wheel, where'as the first-year Special having the 16" rear wheel was a 'new' casting followed with later yrs. of all models being of tubeless type rims.

[DiverRay]

Tubeless tires were rare in '77 when the XS was "finalized". The '78's ALL had tube type rims, and as motorman said, they phased them out in '79 as the tubeless rims came up to speed. I think Yamaha, used to the enduro/dirt bikes, didn't want the rear tire to spin on the rim. With a 4.50 rear tire and 95HP at the crank, they didn't want to take a chance. After all, this was their FIRST superbike, and it HAD to be right.(JMHO)