Rekluse auto clutch causing power loss

swatdoc
Posts
1083
Joined
6/29/2014
Location
Temecula, CA US
Hey everyone - I was told the other day by a very reputable person in the industry that the Rekluse auto clutches create a pretty marked loss of horsepower - I was told about a 4 HP loss. This person regularly dynos MX bikes, and says he doesn't like the clutches because of that.

I actually have 3 of the clutches in various bikes, but I installed them when new, so I didn't have a back to back comparison.

Also - I've never read a single review of the auto clutches that mention a horsepower loss.

I personally love them - I have always had a bad tendency of locking up the rear wheel when braking and stalling the motor - the Rekluse pretty much eliminates that problem for me. I also just like the way the bike rides with them too.

Has anyone else ever heard of this or experienced this before? (the loss of power)
|
Bruce372
Posts
6341
Joined
4/1/2008
Location
US
4/19/2017 9:58pm
A friend that has ridden for years bought a used bike and swapped it out for a manual Hinson for that reason, albeit track feel.

For $200 You can buy a new manual style pressure plate from rekluse and test it for yourself
Bruce372
Posts
6341
Joined
4/1/2008
Location
US
4/19/2017 10:01pm
Maybe it looses torque at low rpms when the exp plate is kicking in and the plates are still slipping
swatdoc
Posts
1083
Joined
6/29/2014
Location
Temecula, CA US
4/19/2017 10:36pm
It sounded like the person I was referring to meant that the power loss was from peak HP, so that would mean at the upper limit of rpm's, so not when the clutch is starting to engage, but when it should be fully engaged and transferring all the power. He termed it "parasitic loss"

I still like the overall feel of the auto clutch, and like a mentioned before, preventing stalls is a huge thing for me, so right now I'm having my 350 tweaked with porting, cams, ignition, and pipe - should bump it up to around 64 or so hp at peak, so even losing a few hp with the clutch shouldn't be too big of a deal - hopefully.
RussB
Posts
851
Joined
7/12/2014
Location
GB
Fantasy
1164th
4/20/2017 12:50am
My stock 15 RMZ450, with fresh top end and Yoshimura full system dyno'd at 53.1hp and 34.4 ft/lb torque with a Rekluse EXP disc in it.

RMZ450's are said to be around 54hp stock I believe?

So this claim might actually ring true? Although I don't see why the clutch would cause a power loss at peak?

Funnily enough I have actually switched back to the standard manual clutch now but haven't noticed any improvement in power, on the track that is. Would be interesting to re dyno it and see if it does make a difference.

The Shop

swatdoc
Posts
1083
Joined
6/29/2014
Location
Temecula, CA US
4/20/2017 10:06pm
Russ on a 450, that .9 hp difference probably wouldn't even be felt - and besides different dynos and different test conditions could make more difference than that.

4 hp on a 350 is pretty big. Again, with all the test reports from magazines and individuals, I've never heard anyone mention loss of power.

I'm encouraged that you switched back and didn't notice any change.

Post a reply to: Rekluse auto clutch causing power loss

The Latest