fast & Slow

[Bunners]

Ok
Call me dumb if you like what is the difference between a fast twist grip and a slow twist grip? other that some smarty pants saying one is fast the other is slow, they both connect to the carb in the same manner, cable goes to said twist grip using the same route, one rolls said twist grip and cable activates slide so???????????????

[dave higgins]

Quick action & slow action , means with the quick action, you only have to twist the grip a small amount to get a lot of throttle slide movement at the carb, as used on mx bikes.
Slow action is the opposite whereby you have to twist the throttle a lot to get a little bit of movement at the throttle slide, ie used by trials bikes, they are basically geared throttle units, some higher, some lower.

[Bunners]

fast & slow

Ok so where is the gearing? it can only be in the cable guide wheel, larger or smaller or the twist grip itself. I have just fitted a slow action to the Scottish it does take a while to pick up. don't like it one little bit. Bugger this keyboard every now and then it goes AWOL and moves the cursor back two rows and what I type is double Dutch.

[Phil Hyde]

Surely, it's all to do with the diameter of the twist grip drum. Put another way, a bit like riding a scrambler with a trials action throttle, and vice versa.

Simples.

[dave higgins]

Yes phil, the bigger the the cable wheel on the throttle grip, the quicker the cable is going to react, this is not rocket science & i only used the term g/box to help bunners understand the general idea of how it works, prehaps i should have used different terminoligy.

[Phil Hyde]

No probs Dave. In olden days, we would have called it mechanical advantage.

[Guest]

Ok so where is the gearing? it can only be in the cable guide wheel, larger or smaller or the twist grip itself. I have just fitted a slow action to the Scottish it does take a while to pick up. don't like it one little bit. Bugger this keyboard every now and then it goes AWOL and moves the cursor back two rows and what I type is double Dutch.

I have that trouble!! Drives me mental, it is Microsoft Internet Explorer based. I changed my browser to Mozilla Firefox and it more or less fixed the problem.
Hope this helps.

PS a fast twistgrip has a longer radius on the cable flange therefore it moves further for a given amount of twist. Never helped me ... I still fell off.

Keith

[Brian Catt]

Of course the ideal for ISDT etc was a progressive throttle, where the initial opening was slow for delicate path picking and then when the tap needed to be open wide, you needed a quicker throttle response. I can remember seeing one of the "comics" showing one of our aces cutting the groove in his throttle drum with 2 hacksaw blades to make a progressive unit. I'll try to see if I have this cutting, or maybe someone else has it in their library.

[aa will]

fast and slow

i have always altered the twistgrip drum on my trials outfits to suit my style of riding , by modding the drum you can get just the amount of movement that suits you , you can get an slow action progressing to a flat out in one throttle movement with the overall movement that suits your own personal taste,

[anglian man]

trials throttle

I always reduce the diameter of the cable groove for the first part of throttle movement, progressive start then leave the later part as is.

[Brian Thompson]

Slow, slow, quick quick slow....!

Gentlemen.....let us not forget that 'modern' technology has also embraced (finally caught up with?! ) this idea, in the form of 'interchangeable/variable' throttle cams no less..... (see attached pics.)

They are available for both 2 and 4 stroke applications, and the 'flat' part on some cams is apparently meant to 'increase control in the trees', according to one 'instruction video' I saw....I suppose in my case it may make them easier for me to hit then.....

I first heard of this a good few years back via KTM as a retro-fit 'solution' to the jerky throttle response on their RC8 roadbike, and it seems to be making a comeback these days as more and more 'modern' bikes seem to be afflicted, what with 'fly-by-wire' throttles and (on some bikes) 3D digital fuel injection maps that should have left the factory 'right' in the first place......When you think of the R&D budgets for these things, and then having to use a 'mechanical' device to sort it out....well, the mind boggles....

Indeed, KTM even supply a handy 'throttle response chart' for their system......(see last pic attached)....there's hours and hours of fun and games (not to mention happy reading) to be had there....!!

Where will it all end etc......

Brian.

[Bunners]

fast & slow

So not such a dumb question after all judging by the response.