I posted this in the softtail area and didn't get a response. Thought I would try here. I have a Heritage and a Rocker. I was doing the 5000 mile maintenance today on the Rocker and the belt tension specs got me wondering. What's the technical reason the Rocker & FLSTN belt deflection specifications are so much tighter than other Harley's. Deflection calls for 5/16-3/8 in. with rear wheel in air. Other bikes call for 11/16-3/4 in. Seems awfully tight. Thanks. Ozark Azz

 

Merry Christmas Ozark
Here' a link to a fairly detailed explanation.

http://www.epi-eng.com/rotorway_heli...elt_issues.htm

I know it says Helicopter, Rotor drive, but section #4 in the artical goes into detail about these Gates belts on Harleys

 

My 09 Road Glide has the 5/16 to 3/8 spec or something really close to that for all late model touring bikes. Street Glide has a 1/4 to ? spec because it is lowered. I think that when Harley went to the narrower belts than before, the belt tension specs increased (tighter).

 

What other bikes?

My old 'o6 Road Glide and my new '11 Limited are about 1/4-3/8".

11/16-3/4" is way to loose.

 

lowriderrob, thanks, and Merry Christmas to you. The article was very informative and shows the danger of an under tensioned belt and why preload would change for different suspensions and even horsepower used at a given time. Thanks Again. Azz

 

jcanrun, thanks for your response. I went to garage and checked the suspensions on both bikes. The rocker does have a narrower belt (over 1/8") and the suspension doesn't move unless you hit something really hard. My kidneys can attest to that. With a firmer suspension you can expect less travel and it appears that the tighter you can run a belt, the better (within reason). The Heritage suspension really is bouncy in comparision, but rides much better. Thanks, Azz

 

1flhtk4me, thanks for taking time to respond. I have a service manual with the 2008 bike, but only an owners manual for the 2006. I referenced my manuals again and 2006 owners manual wants it on the jiffy stand with a rider sitting in seat. The service manual for 2008 models calls for bike on jiffy stand with no rider. I didn't catch that difference until now. Or the bike can be upright with rear wheel in the air for a greater deflection. Thanks to you guys for helping me understand. Azz

 

Excellant info on this post. Thanks, kinda like to know the "why" rather than just accept, waay cool!! Great question and great answers.