So when the original rear sprocket wears do you just replace the entire hub?
Scott
No, just the brake drum. The brake drum is removable from the hub.
The sprocket teeth are actually machined on the outer rim of the brake drum itself.
I know it's unusual compared to other bikes, but that's what the situation is.
That's why everybody always changes the front sprocket on Bullets to make gearing taller. It's a pain in the butt, too.
The UCE restricted front sprocket clearance is a limiting factor, then. But it appears to be easier to change the UCE front sprocket, than it is on the Iron Barrel models.
However, due to the low power of these bikes, they need to be relatively high up in the "powerband"(if you could call it that), to produce enough hp to overcome the wind resistance at higher speeds. If you lower the rpms, then you have to widen the throttle opening position to make more torque at the lower rpms, so that you have enough hp. So, the supposed "benefits" of "improved fuel economy" and "lower engine wear" become dubious.
In most cases with Bullets, 18T front sprocket will give best results because otherwise it starts getting over-geared too much for a stock bike. By "over-geared", I mean it can't reach redline in top gear because of not enough power with that gearing.
When people make the move to a Bullet from larger displacement bikes, sometimes it is a surprise to feel the bike riding at higher rpms on highway cruising. You need to be making nearly 3/4 of your total available hp to just do 70mph. It's not so much the gearing limitation, as it is the power limitation. It tops-out around 80mph, and not because of under-gearing. The little hamsters are running in that exercise wheel almost as fast as they can go.
The UCE only makes about 21.4hp max at the rear wheel. The advertised 27hp is hp at the crank. Rear-wheel dyno tests show about 21.4 at the wheel.
And on top of that, if you use taller gearing, it reduces the torque-multiplier of the gear ratio, and that further cuts actual power to the road at the rear wheel. We don't have much power to "burn" with losing torque-multiplier in gearing changes.