Hand Clutching

[Mehul Botadra]

Hi,

We're using the hand clutch this time. I tried looking through the forum but didnt come up with something fruitful. My question is that if you use the handclutch, is it entirely necessary to implement the hydraulic system with it? I know the hyrdraulic system will reduce the effort for the driver but I tried the clutch on my engine and it required hardly any effort. Its a Honda CBR 600 F4i. So will a cable operated hand clutch without any hydraulic systems work good enough?

[Mehul Botadra]

Hi,

We're using the hand clutch this time. I tried looking through the forum but didnt come up with something fruitful. My question is that if you use the handclutch, is it entirely necessary to implement the hydraulic system with it? I know the hyrdraulic system will reduce the effort for the driver but I tried the clutch on my engine and it required hardly any effort. Its a Honda CBR 600 F4i. So will a cable operated hand clutch without any hydraulic systems work good enough?

[RollingCamel]

I think that it should be extremely light because you don't want the driver fingers and arm muscles fatigue in autocross and endurance, and to be quick. If I were you, I would let the driver test it for the time and number of shifts he may do in endurance and see what he feels.

[Tom W]

We have used a cable operated hand clutch for as long as I have been in the team. The weight is absolutely no issue.

On a related note we switched to the sxv550 this year from r6's, without changing the cable actuation system we did lose all of the feeling in the clutch. I'm curious to know if other aprilia teams have found the clutch lacking in feel?

[RollingCamel]

How much mechanical advantage are you running btw? Our Gixxer 600 engine required around 25KG statically.

[Mehul Botadra]

@ Tom

It works good?

[MegaDeath]

It depends, are you planning on clutching during shifts? I assume not because it is very unnatural/difficult to use your hand to clutch for every shift.

If that's the case, then yes. Using a hand clutch that is only cable operated is 100% possible and they work very well.

[Mehul Botadra]

Clutch during down shifts. Our drivers have a little issue with throttle blipping.

[AxelRipper]

well we've been running a cable clutch for several years (exception: 2007 Mahle) at least on the cars as they are now.

our 2006 car seems as if it was retrofitted after competition with the hand shifter setup (evidence points to an electronic shifter at comp). The cable can be a little hard for people with weaker left hands to squeeze fully, but no one has really ever had a problem. Our 2009/10 car also has run a cable clutch, and that one is really easy to operate.

I should also point out that none of our drivers clutch anything other than launch and stop. This is with both an F4i (06) and CRF450 (09). I dont (consciously) blip on the downshift, and have never had any problems with it.

[Mehul Botadra]

Thanks!

[TMichaels]

Make sure that your steering wheel and quick-disconnect are able to handle the extra forces.

Regards,

Tobias

[Demon Of Speed]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TMichaels:
Make sure that your steering wheel and quick-disconnect are able to handle the extra forces.

Regards,

Tobias </div></BLOCKQUOTE>

If you are running a mechanical shift linkage you can run the handle directly off from the shift lever and don't have to worry about that at all.

Also, mechanical shifts weigh less than pneumatic/electric shifters (if done correctly)

[Wesley]

Mechanical setups are fine. Just use that mechanical advantage! It's easy to calculate what your necessary leverage should be.

@Tom: The clutch throw on the Aprilia vs the F4i we used to use was considerably shorter, it was pretty on-or-off comparatively, with the same advantage. That makes some sense, since the clutch is stiffer in general with the Aprilia. We also never grenaded an Aprilia clutch while I was on the team. We killed 4 or 5 f4i clutches. They're pretty squishy compared to the Ape's.

[Tom W]

Thanks for that Wesley, good to know we aren't the only ones finding it fairly touchy.

One other random note with the ape clutch is that the first guy we had working on it had done a summer internship at GM's Australian arm Holden in their transmission division, one day when we had to pull the clutch apart for something he commented that the clutch plates were identical to ones he had been testing in an auto transmission for a sports car, he pulled them out of a transmission that had I think gone through 200 000km of testing a significant part of which involved repeated full abs stops from about 160km/h. When he pulled the clutch plates out he could read the serial numbers off the faces. So the clutch plates in the aprilia are certainly hardy!

[Adambomb]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Demon Of Speed:
If you are running a mechanical shift linkage you can run the handle directly off from the shift lever and don't have to worry about that at all.
Also, mechanical shifts weigh less than pneumatic/electric shifters (if done correctly) </div></BLOCKQUOTE>

+1

Having a steering-mounted clutch would be incredibly clumsy unless you also hard steering-mounted shifting. When you throw it on the shift lever it's just a regular grip-clutch deal...just like on a motorcycle. Personally I've found it's very easy to get used to just blipping the lever back with your fingertips for up-shifts, then giving it a full open grasp to clutch-downshift. Plus I've never been fond of engine-braking, so it's no problem for me, just grab it, run it down a notch or two, then rev-match and ease back into the power with the clutch. Don't have to downshift fast. Depends on your driving style I guess.