R1200S throttle pulley modification

[Corvus]

Wouldn't a twist grip with a larger actuating radius be an answer? It wouldn't solve the problem of the non constant radius action at the TB, but it would result in less angular movement at the twist grip translating to more movement at the TB. So for every degree you move the twist grip, you'd get more degrees movement at the pulley. A heavier feeling throttle would result. There's no way out of that bit. A change in mechanical advantage is what's needed to get to where you want to be.

An intermediate compensating lever would also work. As would making a new pulley!

Cheers.

I've actually come to this answer as a side effect of using the rather naff 'grip puppies'. They actually make the (too skinny in my opinion) grips about the same girth as the 1100S grips. This gives more throttle opening for the same amount of twist in the grip. This in conjunction with the plastic insert at the twist grip has actually made a noticeable difference and has helped my dodgy wrist as I am accessing more power earlier than before.

Ay up.

I meant a larger radius from theoretical centre of rotation (that's a brilliant topic in it's own right!) to the centre (theoretical, of course) of the cable nipple.

Increasing the diameter of the grip itself is an interesting one as the angular movement doesn't change. But it does make one wonder how much hand/finger input is truly angular and how much is tangential.

Cheers.

[Corvus]

In fact devising an intermediate pair of levers would not only allow complete control over the amount of "magnification" but, by changing the angle at which the levers sit, would allow a degree of control over how much of the non linear action is kept. Sitting on bearings the throttle would feel smooth and accurate (rotary things generally are low stiction). Cunning design could allow accurate balancing. Return springs could be added or subtracted easily.

Just how madcap is this idea?

[gus]

thread digging

so does anyone have a step by step or images on which parts to remove? i can see that some rollers are removed but not sure how to do it myself

im interested in having a more 'linear' throttle pull as sometimes it feels like the bike has a '2 step' throttle

Hi remove all wiring to injectors and tps. Remove injectors. Undo the metal clips which hold throttle bodies to intake stub and air box connector. Remove throttle body. Slacken off cable on each throttle body. Remove circlip on protruding pin which sits against black pulley. Remove rollers. Remove black plastic cap off throttle stop screw. Adjust throttle stop screw virtually all the way in. Make they are the same on both sides. Adjust cables so that there is a little play. Make sure throttle butterfly's close full when throttle closed and are fully open when throttle is open. Lube all moving parts.
Reinstall throttle bodies and do a throttle synch procedure.
Gus

[dave the german]

Concise as ever Gus. What's you opinion of the mod?

[gus]

Concise as ever Gus. What's you opinion of the mod?

I,ll tell ya when I get the engine in the bike.
I run a QA throttle and the non linear action peed me off.
It's not a ideal mod, but it works.
I have a spare set of throttle bodies I will mess about with to try and get some improvement.
Gus

[dave the german]

More important for you on a race bike. When I first bought my 12s I didn't notice it too much but as Boxered mentioned, having now more than 1 bike, Has made me notice it more

[The Teutonic Tangerine]

Wouldn't a twist grip with a larger actuating radius be an answer? It wouldn't solve the problem of the non constant radius action at the TB, but it would result in less angular movement at the twist grip translating to more movement at the TB. So for every degree you move the twist grip, you'd get more degrees movement at the pulley. A heavier feeling throttle would result. There's no way out of that bit. A change in mechanical advantage is what's needed to get to where you want to be.

An intermediate compensating lever would also work. As would making a new pulley!

Cheers.

I've actually come to this answer as a side effect of using the rather naff 'grip puppies'. They actually make the (too skinny in my opinion) grips about the same girth as the 1100S grips. This gives more throttle opening for the same amount of twist in the grip. This in conjunction with the plastic insert at the twist grip has actually made a noticeable difference and has helped my dodgy wrist as I am accessing more power earlier than before.

Ay up.

I meant a larger radius from theoretical centre of rotation (that's a brilliant topic in it's own right!) to the centre (theoretical, of course) of the cable nipple.

Increasing the diameter of the grip itself is an interesting one as the angular movement doesn't change. But it does make one wonder how much hand/finger input is truly angular and how much is tangential.

Cheers.

A pal of mine had such a device on a Ducati 900SD way back in the early 80's. The throttle was fully closed to fully open in about 2/3rds of a full turn. It was great for blatting around the lanes but on the open road just holding the thing open was hard work. The return springs in the air slide carbs were quite strong and effectiveley you had raised the gearing making it harder to open them.