Hammer worth it?
Grand HDF Member
Joined: May 2006
Posts: 3,636
Likes: 1,208
From: Ohio
This is the info on gearing. Note, this is directly from Hammer Performance website. I recommend anyone interested in upgrading their engine, spend some time there reading and you will learn a lot.
- Should I change my 883's gearing when I do a conversion? What are my options?
- The vast majority of conversions are done without a change to the gearing. It's completely optional.
- The advantage of the shorter 883 gearing is quicker acceleration.
- The advantage of the taller 1200 gearing is reduced engine rpm at highway speeds.
- If you have a 1991-2003 model:
- 91-03 XL883 and XL1200 models share the same primary gearing: 35T front sprocket and 56T clutch basket.
- However, the final drive differs. Belt drive 883 models came with a 27T front sprocket and 1200's came with a 29T front sprocket. Both models came with a 61T rear sprocket.
- Changing your 883 to the 29T front final drive sprocket will result in a 7% reduction in rpm at any given speed. So for example, if you're turning 3000rpm now, at that same speed you'll be turning about 2800rpm after changing to the 29T sprocket
- If you have a 2004+ model:
- 2004+ XL883 models have a 34T front primary sprocket and 2004+ XL1200 models have a 38T front primary sprocket. Both models have a 57T clutch basket.
- XL883 models from 2004-2010 came from HD with a 28T front final drive sprocket, and 2011+ came with a 29T front final drive sprocket.
- 2004+ XL1200 models came from HD with a 29T front final drive sprocket.
- HD also offered a 30T front final drive sprocket on certain international models.
- All 2004+ models, 883 and 1200, came from HD with a 68T rear final drive sprocket.
- Here are all the possible gearing combinations with factory sprockets, in order of shortest to tallest:
- (57/34) x (68/28) = 4.07 overall in top gear (stock 2004-2010 XL883)
- (57/34) x (68/29) = 3.93 overall in top gear (stock 2011+ XL883)
- (57/34) x (68/30) = 3.80 overall in top gear (XL883 primary with HDI final)
- (57/38) x (68/28) = 3.64 overall in top gear (XL1200 primary with 2004-2010 XL883 final)
- (57/38) x (68/29) = 3.51 overall in top gear (stock 2004+ XL1200)
- (57/38) x (68/30) = 3.40 overall in top gear (Stock 2004+ 1200 primary with HDI final)
- From the shortest combination above, to the tallest, you would reduce your rpm at any given speed by about 16%, which is a LOT. For example, if you're turning 3000rpm now with the shortest combination, you'd be turning only 2500rpm at that same speed with the tallest combination
Road Captain
Joined: Feb 2014
Posts: 607
Likes: 243
From: Arizona
Based off the seat of my pants riding my 22 I'm going to 100% agree with these dyno numbers and curve shapes. Also note how easily it pulled away from just off idle in 5th
https://www.cycleworld.com/2016/02/0...ormance-chart/
https://www.cycleworld.com/2016/02/0...ormance-chart/
Grand HDF Member
Joined: Mar 2023
Posts: 4,362
Likes: 1,348
From: Westland, Michigan
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