Dr. Pulley 21 gram sliders -- a review.
With about 5500 miles on my 2006 Burgman 400 I installed Dr. Pulley 18 gram sliders. The original rollers were still in good shape, but I wanted to lower the engine speed at highway speeds. Belt dimensions were pretty much as new and the clutch thickness was as new also, so no changes except cleaning up the parts.
The first ride was a pleasant surprise -- engine speed was reduced from about 6700 RPM to about 6000 RPM at an indicated 75 MPH (about 70 true). Acceleration from a stop seemed a bit quicker as the engine quickly revved to about 5000 RPM and held there as speed rose. No noticeable change in gas mileage over several tanks.
There was a definite "hole" though when re-accelerating from reduced speeds in traffic, which was bearable, but annoying. Still, I could live with it.
After seeing Dennis49's offer of 21 gram sliders on this site I went for them, mostly as an experiment. Got them a few days ago and installed them today.
Another improvement! Initial acceleration is now occurring at about 4200 RPM and highway engine speeds are down another 200 RPM or so. At 75 indicated the tach now shows about 5800 RPM, which is what I was after with the original Dr.Pulley sliders. The re-acceleration "hole" is gone completely from a traffic slowdown and speed up again. This seems like a good compromise as the first generation 400s have their torque peak at about 5500 RPM, and performance is not noticeably reduced by the RPM drop. I'm going by a seat of the pants reaction, no real measurement.
For me, the 21 gram sliders are an improvement over the 18 gram units -- if they made even heavier sliders I'd consider them as well, maybe 22 or 23 grams. I'm happy with the 21 gram sliders though and will enjoy the more relaxed sounding engine on the highway now.
Just my opinion.
Ray Nielsen, in Minneapolis and back from a supper ride!