Clutch Lightener

[Brian Catt]

OK, poor drawing as I'm full of head cold and can't see much (not far from normal!)

Arm is pivoted at the bottom and has the Primary cable from the handlebar lever to the top slot.

A distance down the arm, a second slot is cut so it has approx 70% of the measurement of the primary. To this is attached the secondary (usually the original) cable.

Your effort is decreased to 70% of the original, but so is travel of the secondary, so adjustment and condition of clutch is paramount.

[Colin Sparrow]

Never heard of them before - and like most good ideas, dead simple.

I can think of bikes I've owned which would have benefited from one of those!

[Brian Catt]

The idea has also been used in throttle control, to slow down the opening of Triumph twin trials bikes' throttles back when they ran the pre-unit bikes.

[dave higgins]

This is what they really look like inside, as you can see from the design it has three position pin selection, it does not matter where over the length of the cable you position it & it does not need crucial cable adjustment or custom cables, i`ve been using them for years & i only wish it was me that invented it because they have been selling in bucket loads.
As i said earlier if you have weak front brake performance, then they work extremely well in that department as well. dave

[Colin Sparrow]

That operating lever looks as if it's made from the same zinc alloy (AKA "crappite") that the cover is.

Not too sure I'd want to trust it for brakes - but I supose you could copy it in steel...

[dave higgins]

Absolutely right colin, looks like cheap monkey metal, but seems to be quite strong when in place, i`m no engineer, but the weakest point to me would be between the two cable nipples, because they are pulling against each other, taking the load off the brass pivot pin.
Like i said, my griffon clutch was a two handed job, fitted one of these & difference was unbelievable, so despite the hong kong looks, i think they are very tough little units. dave

[Peter Rotherham]

Clutch Lightener.

AHA !

Thanks lads. I see now. Its the same operation as you get in the VANG or KICKER mechanism on Sail Boat Booms. There, a system of forces acting at different points on a lever between two external points is used to control the height of the boom which pivots on the mast.

By a multiplier system, a small amount of movement/power in a rope can be transformed into a larger amount of movement /power at the actuating point.
These are made in Stainless steel, alloy, high impact plastic, etc., and last very well considering the pressures employed. On a 'bike, it really needs packing with grease to minimise wear, as this would cause binding.

(The only thing I see wrong is the loss in actual movement length of the cable, hence plate lift/brake application.)

[whitehillbillies]

clutch lightener

I added on of these miller lighteners, for my wife when she was learning to ride my 24TCS, which was registered, and on the road, as with her small hands, had trouble pulling the lever in, I also had the long bong car lever added, but with the compition springs fitted to the clutch, it was just to hard. The device was a good addition to lighten the clutch. It was the oldest bike they had seen at the test centre when she took and passed her test!!! slow riding around the cones with low trials gear and weighed flywheel helped a lot.

whitehillbillies