Hey everyone. I have a 1987 sportster 1100 and it has a belt final drive conversion on it. My question is whether the belt drive has a different final gear ratio than the stock chain ratio did? It seems to be revving fairly high while riding on the freeway but then again the speedometer isn't currently working so i have no idea lol. The bike came with the belt drive conversion when i bought it. Thanks.

 

Bump. The front pulley at the transmission has a part number 10e90 with an H-D below it so I think whatever kit was used was a Harley brand kit but I cant seem to find any belt conversion kits for my bike anywhere. Anybody have any ideas for a reference number to the kit or that number on the pulley so I can see how many teeth are on the pulley? I am trying to avoid pulling off my belt just to count the teeth on the pulley. Thanks.

 

It's not difficult to count the teeth. Mark one of them with a piece of chalk or similar and count from/to there. As for actual gearing, it will be similar with chain or belt. The belt pulleys may be larger in OD, because a belt cannot bend around a small radius in the same way as a chain.

Your stock chain drive was 21F/48R = 2.29:1. I'm going to guess your belt is either 29F/61R = 2.1, or 27F/61R = 2.26, both of which are pretty close to the stock chain!

As for riding on a highway, wear ear plugs - best tuning aid known to man!