Bonneville America Forums Forums Technical Forums General Tech rear sprocket slack

i was coming to work this morning, at a stop light i guy pulled up and said my rear sprocket was lose that it move before the tire moved. so at the next red light i stood up and let the clutch out and noticed the sprocket hub move about 1/4 of inch before the tire started to turn. so my question is should this be or do i need to pull the rear tire and tighten? as i was looking the sprocket it self is not moving but the hub the sprocket is attached to moves.

Sounds like the cush drive has a little play. IIRC there is no spec from Triumph on acceptable play. Quite a few here have replaced it with a cush drive rubber from a thunderbird for a tighter fit. Do a search for "cush" and you'll find plenty of info.

Have to remember you were looking at it with the bike on the ground using your clutch. It is rubber to cushion the force when you engage the clutch so it does compress some. When you go out to the bike before you go out again. Leave the bike on the side stand and in neutral. Try and move the sprocket back and forth with your hand, that will show you how much play is in it.

what kind of guide on how much movement?

There is no real guide I would be comfortable with about 1/8" or less but thats up to what you think. 1/4" probably wouldn't hurt anything but is probably more than it should be. When new the sprocket hub should fit snug so use reasonable judgment.

i am guessing this would prolong the life of the chain and sprocket. but doesn't this take away from throttle responce?
if this was solid wouldn,t our bikes be faster off the line? also what happens when if the cush drive or bushing, (i don't know the real name of this part)is to worn?

I don't think it effects the off the line take off,or throttle response , it is just easier on the tranny and clutch.If you were drag racing on the clock you might see a slight lag then but not for a typical rider.

so what is the name of this part?

Its referred to as a "cush drive rubber" If you replace it use part number T2012211 which is the Triumph PN for the Tbird cush drive rubber which provides a tighter fit than the stock item.

thanks man you always got good info. hey what's up with the photos?

You would have to address your question on the Photo-post being down to one of the mods.

I have no idea when it will be fixed.

From Bikebandit.com - T Speedmaster -UNDER - Rear Wheel / Final Drive
10: RUBBER, CUSH DRIVE 5567931-001 $76.84
Gary

Also,on BikeBandit.com the Tbird listing shows two different wheel-hub assemblies and the pictures of the cush drive rubber appear different(picture or drawing layout?)
On BikeBandit.com the T Bird listing shows two different wheel-hub assemblies with two part numbers and the pictures of the cush drive rubber appear different as well.
7:
RUBBER,CUSH DRIVE 5557395-001
$76.86
For serial #29155 and below
REAR WHEEL / FINAL DRIVE (SERIAL NUMBER 29156 AND HIGHER
Serial REAR WHEEL / FINAL DRIVE (SERIAL NUMBER 29156 AND HIGHER

7:
RUBBER,CUSH DRIVE 5567927-001
$76.86
For serial # 29156 and higher

The stock cush drive rubber on my Speedmaster is molded all in one piece (but 5 sets of rubber blocks attached at edges with only minimal linkage from one block to the next.
Just info