[Race Mod] STM Slipper clutch for CBR600RR Part I

Another addition to my CBR600RR mod, the slipper clutch! I have been looking for this parts for quite some times and I just got the opportunity to test and install it on my CBR. The main purpose of installing slipper clutch is to mitigate the effect of engine brake. 4 stroke engine like one in my CBR have strong engine brake and in a racing situation engine brake can make things “complicated”. See, you have your brake and throttle for bike speed control and with an engine brake you put additional parameter that can effect the bike speed. More over, engine brake only effect the rear tire which during hard brake – the bike load transfer to the front – can caused the rear tire to lock and hop. Thus instability while preparing corner entry.

With slipper clutch install the bike engine brake is reduce significantly thus the only way to control the bike speed is only from the brake and throttle. I like!

This is how I take, for example, the double apex hairpin turn 3 and 4 at Sentul. With full throttle on 5th and pass the 150m mark I grab the brake and down shift to fourth and third, this off course done in sequent while blipping the throttle each time I change gear. Without blipping the engine the rear wheel will for sure lock up. Pass turn 3 apex I downshift again to second gear for turn 4, again with blipping the throttle. Pass turn 4 then open the throttle for the short straight before turn 5.

With slipper clutch installed, I can bang the gear straight from 5th to 2nd and the bike will be stable. No need for me to down shift pass turn 3, and most importantly no more blipping! Make things a lot easier. Just like MotoGP! If you see the on board video at MotoGP which shows the rev and the gear indicator you can see that MotoGP bike can bang the gear from 6th to 2nd easy. Try that with your 4 stroke bike with out slipper clutch and the rear wheel will not be happy!


4 thoughts on “[Race Mod] STM Slipper clutch for CBR600RR Part I

  1. oh wow! finally!
    i thought the slipper clutch comes as standard on 09/10 600rr’s?

    anyways, i was always under the impression that even if you have slipper clutch installed you’d still have to blip during downshifts. crutchlow’s bike even had auto-blipper installed.
    but yea,.. it surely is a very nice addition. brings back 2 stroker feel during pre-corner.

    let us know how it affects your lap time..

    1. Nope, the CBR600 do not come with slipper clutch.

      With the STM slipper clutch you can dial in how much “slip” that suite your riding style, perhaps Cal setup his bike as such that not much slip is generated by the clutch so he still need to blip the throttle pre-corner.

      I’m still having bit problem with the clutch. It gives too much slip, the problem is the installation of the clutch. Unfortunately our local mechanics is still learning how to install the slipper clutch properly 😦

      For sure will report the progress.. 🙂

  2. Hi
    I am part of the engine team of NITK Racing, an FSAE team from India.
    We were considering installing a slipper clutch on our engine. I wanted to know the following things :
    1. How difficult is it to install one of these? And what precautions must one take?
    2. What is the part number and make of the slipper clutch u used? Is it a replacement for the original clutch or is some physical modification required on the engine?
    3. Does it have the same dimensions as the original?
    4. What is the cost of the slipper clutch u used.
    Thanks a lot in advance!!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s