View Full Version : Drive Belt

Old School One
06-08-2009, 08:05 PM
Would someone be willing to explain just how does the belt tension wheel perform its job. Does it move all by its self or is it adjustable via hand tools.
Should that tension 'wheel' move freely with or without a rider on board?
Recycle: Go ride your bike....AGAIN...

06-08-2009, 08:49 PM
No it doesnt move or adjust automaticaly. When your swing arm travels up and down, the length between the trans and the wheel change. When your suspension is unloaded, the bile would need a shorter belt. When the suspenion is colapsed, it would need a longer belt. Therefore the belt is long enough for when the suspension is colapsed and the tensioner takes up the slack when it is not loaded.

The reason this happens is because the pivot of the swing arm is not directly in line with the wheel and the trans. If it was, there would be a little bit of change in the length needed, but not enough. THe other advantage is the fact that we dont have to keep checking the adjustment on the back axle.

Hope this clarifies a little for you.

If I missed something or if there is something I am wording wrong feel free for someone else to step in an help out.

06-09-2009, 03:23 AM
Sounds cut-dry to me Tuneport, nice explanation. [up]

06-09-2009, 10:32 AM
From an engineering point of view, I think the design is flawed. Buell do not fit tensioner wheels, they fit fixed Jockey wheels. They are designed to keep the belt under constant tension and whilst I am sure that the geometry of the drive train has been specificallly laid out so that the belt tension doesn't change with suspension travel, they certainly make no allowance for stones being caught between pulley and belt and the like.

The other downside of the design is that it necessitates a significant and constant force on the gearbox output shaft bearings, wheel bearings and tensioner bearings. There has been a lot of discussion on other forums regarding failures of these bearings due to belt tension.

Because of these concerns, I fitted a Freespirits tensioner:


Obvious benefits are the bike is a lot easier to push, the clunk I used to get engaging first has gone and gearchanges are sweeter. Long term, I reckon on reduced belt failure and avoidance of the massive repair costs associated with output shaft bearing failure.

That's the plan, anyway........:)

06-09-2009, 01:06 PM
Yes I agree the aftermarket tension is deffinately better on the equipment. It will help in the long run to reduce equipment failure. I plan on either adding one like you mention to mine or fabricating my own. Thanks for the additional information.:)

06-09-2009, 10:34 PM
After market spring loaded pully. YES.

But I dissagre with tuneport67ss,
The belt has more tension with the suspension unloaded, excessive tension. The belt has less tension with the suspension completly loaded.

Old School One
06-10-2009, 05:26 PM
Much thanks to all who have taken the time to inform all interested owners. I will be installing a Freespirits unit on my ride ASAP... I feel a wave like shudder up through the seat & foot pegs around
60-70 mph in 5th gear. This started just after my 1st
new set of tires were installed. The HD shop mech.
road tested my ride but did not feel the sensation...
Wheels will be re-checked for ballance at a local
V-Twinn shop. I will check back with results...
Thanks for the product info Lordfenwick.

06-10-2009, 05:34 PM
Now available in black [smirk]

06-10-2009, 05:36 PM
You're welcome!:)

Old School One
06-11-2009, 01:10 AM
Is there any Stateside shop that sell Freespirit equipment? Their web page has some great gear!!!
Thanks again!

06-11-2009, 02:59 PM
Not sure....I'm in the UK :p

I had a quick look on their web-site and they don't mention a US distributor, but they do mail order themselves. I know Matt at Trojan Horse (Adrenalin Moto) ships a lot of stuff to the states. He also has some top gear: Trojan Horse (http://www.adrenalinmoto.co.uk/)

Hope this helps