Hinson
BTL Series Slipper Clutch
Four-strokes have compression braking-that's the bike's deceleration when it's going faster than the engine's rpm when you're off the throttle. Some four-strokes have a lot, some have a little, and all have more at higher rpm. Many riders use this to their advantage, like an anti-lock rear brake, and in theory, that's the best technique. But a lot of riders, myself included, prefer the freewheeling feel of a two-stroke when the throttle is chopped. I love four-strokes' smooth power, and I can jump them much more consistently than a pinger, but I can't dive into corners like I used to.
So I went to Hinson Racing to try to make a four-stroke engine perfect for me. Its slipper clutch is designed to minimize the bike's braking effect when entering turns. On the track, the unit does exactly what it's supposed to. The bike has a lightweight, freewheeling feel when you chop the throttle and get on the brakes, more so higher in the rpm range. It's still not a twostroke, but it helps keep a four-stroke feeling nimble and moving forward. This helps because I can balance through the braking chop based on brake lever input, not try to react to the engine's own idea of how quickly we're going to slow down.
At $1050, it's a big investment. You can turn up the idle speed to minimize compression braking and that helps. But a higher idle can throw you off in slow corners and make the bike more diffi cult to relight when it's hot (after a crash). Installation diffi culty is equivalent to replacing a clutch basket (you can run your stock basket with this slipper provided it's in good condition). If you're comfortable getting that deep into your sidecover, the install or slipper spring swap (you can adjust the level of slip) won't trouble you.
If your smooth four-stroke power gives you confi dence on the track but you're not diving into corners like you used to, consider a slipper clutch before you drop money on another big-ticket item like an exhaust. Because if you're looking to lower lap times, going into the corners faster will have you coming out of them faster. -Pete Peterson
| Hard Parts | 85.0 |
| Installation | 15/20 |
| Function | 47/50 |
| Durability | 9/10 |
| Design | 9/10 |
| Price | 5/10 |