Increase the hydraulic ratio on the clutch?

[FloydV]

Being 61, I find that I have what is called "essential tremor." That is a condition where the more I use my left side (in particular), like my left hand, and the harder I use it, the more it shakes.

So, holding the clutch in at long lights and a lot of shifting makes my left hand tremor more and more. It is kind of a reverse Parkinson's disease. When at rest my left hand is very steady. The more I use it, the more intensely it tremors. It is not the arm or hand that is bad, it is the part of the brain that initiates the activity that becomes increasingly dysfunctional the more often and hard that it gets stimulated.

So, to my question. Is there a way to decrease the pressure required to hold the clutch in. A larger hydraulic cylinder--that kind of thing?

 

[SHADiGUY1]

i dont beleive so but others may chime in.

 

[roadthing]

Regardless of what you do, you will feel the effort on the clutch through the lever to some extent. I understand what your condition causes, as I have worked with customers with the same syndrome. I am curious as to whether your particular situation is more sensitive to resistance, or range of motion?

A larger bore master cylinder will move a larger volume of fluid, but may require more lever travel to get the clutch to disengage. A smaller bore MC will cause the fluid to move at a greater rate, producing higher PSI more rapidly than a larger bore MC. Either way, there is no "ideal" fix in changing MC bore size alone.

You really can not reduce the clutch spring tension on your 'Busa, without sacrificing safety, and performance. Have you considered an electric line lock? You could perhaps use one of those to hold the clutch for you when stopped at a light, etc. You can also add a hydraulic force multiplier, but that's a lot of plumbing, and a bit of work, as well. A negative aspect to a force multiplier is that once set, you will probably not be able to feel the friction point.

Worst case, and kind of weird idea might be to link your front and rear brake with a proportioning valve, and use the brake pedal and associated hydraulics as your MC and actuator for the clutch. It's not all that much of a Rube Goldberg set up, and it would work, just might be too impractical on a performance machine. Don't laugh, or flame this idea yet. I have done stuff like this for amputees. Where there's a will, there is a way. And necessity is the mother of invention, and all that.

Just trying to help out.

 

[heykenny]

roadthings suggestion of master cylinder change is the right track..  but i'm afraid he has the ratios backwards.... a smaller master cylinder piston will result in less pressure required at the lever, but more total lever travel...   if you can find specs on the radial master cylinders for a late GSXR or ,dare I say it, ZX Kaw may also be a choice....   also consider looking for any aftermarket clutch company that uses a diaprhagm spring to replace the original coils springs....it's a trick used by some companies to provide a relief of lever pressure.... (company called STM used to have something, I believe)... good luck!

....

edit... late Bandit 12 clutches use diaprhagm springs... same size

anyone know??

 

[roadthing]

roadthings suggestion of master cylinder change is the right track..  but i'm afraid he has the ratios backwards.... a smaller master cylinder piston will result in less pressure required at the lever, but more total lever travel...   if you can find specs on the radial master cylinders for a late GSXR or ,dare I say it, ZX Kaw may also be a choice....   also consider looking for any aftermarket clutch company that uses a diaprhagm spring to replace the original coils springs....it's a trick used by some companies to provide a relief of lever pressure.... (company called STM used to have something, I believe)... good luck!

....

edit...  late Bandit 12 clutches use diaprhagm springs... same size

 anyone know??

Read the second paragraph again. You are 1/2 correct, and thanks for catching it.

Great advice on the alternatives, and mods (even the Kaw part!). I'm not sure that the diaphragm spring, like in FUJI style clutches is going to be the best fix though, IMHO. It would definitely an option, though.

I think the first thing to do would be to assess just how much pressure is uncomfortable, and take it from there. The fix may be as simple as a modified lever. I threw all that previous stuff out there, 'cuz I over think things way too often!

 

[heykenny]

yea, I'm the same way once I start chewing on a problem... we're on the same page.. a little persistence and some parts-bin shopping might be all that's necessary

 

[SANDFLEA85]

I've seen a cable clutch mod,kinda like a bicycle brake,dont know if it is easier to engage though,but you may want to investigate it,

 

[FloydV]

Regardless of what you do, you will feel the effort on the clutch through the lever to some extent. I understand what your condition causes, as I have worked with customers with the same syndrome. I am curious as to whether your particular situation is more sensitive to resistance, or range of motion?

A larger bore master cylinder will move a larger volume of fluid, but may require more lever travel to get the clutch to disengage. A smaller bore MC will cause the fluid to move at a greater rate, producing higher PSI more rapidly than a larger bore MC. Either way, there is no "ideal" fix in changing MC bore size alone.

You really can not reduce the clutch spring tension on your 'Busa, without sacrificing safety, and performance. Have you considered an electric line lock? You could perhaps use one of those to hold the clutch for you when stopped at a light, etc. You can also add a hydraulic force multiplier, but that's a lot of plumbing, and a bit of work, as well. A negative aspect to a force multiplier is that once set, you will probably not be able to feel the friction point.

Worst case, and kind of weird idea might be to link your front and rear brake with a proportioning valve, and use the brake pedal and associated hydraulics as your MC and actuator for the clutch. It's not all that much of a Rube Goldberg set up, and it would work, just might be too impractical on a performance machine. Don't laugh, or flame this idea yet. I have done stuff like this for amputees. Where there's a will, there is a way. And necessity is the mother of invention, and all that.

Just trying to help out.

Thanks for the info. The electric lock would probably be the easiest.

To answer your question, the longer I have to hold at significant pressure, the worse the tremor becomes. It's not really the muscle, it is the part of the brain that controls it becoming more excited as it tries to flex the muscles in the hand, because it can't decide where to hold position.

To put it another way, if I stand long enough with my most of my weight on one leg, my leg will begin to tremor, because the brain can't decide which way to hold the muscle. The leg will want to twitch left, then right. If I hold the clutch in long enough, and then hold the hand out, it will shake. If I hold my right hand out at the same time, it is steady. Kinda sucks.

It's not a huge problem if I can just shift and then relax the hand. I hate a lot of stops for that reason.

 

[Mr Bogus]

a "line lock" sounds like the most practical... safe enough for brake systems, it should handle the light pressures of the clutch easily... many drag racers use them

 

[Mr Bogus]

here ya go... install, put an switch or momentary switch somewhere and away you go... (could make for a rapid clutch engagement however if you accidentally throw it without holding the lever..

http://store.summitracing.com/partdetail.asp?part=sum-760002

 

[hondpwr]

They sell kits to change it to cable. I guess you could do that with a set of softer clutch springs.