$1 Quick Turn Throttle Mod

[posplayr]

A cheap alternative to the R1 throttle tube mod no reason to buy new tubes or grips and it can be installed in about 10 minutes.

I just cut a piece of 1" schedule 40 PVC water pipe about 10mm wide and then cut a section out of the ring and it fits right around the throttle tube and is captured inside of the right hand housing. You can glue it as well but not nessesary and no worries about it falling out or glue breaking.

To be clear by adding the PVC pipe you are increasing the radius that the cable pulls on. That means you have to turn the throttle tube through a smaller angle (20% less) to pull in the same length of cable. It also makes it a little harder to turn by 20% harder.


IMG_3519.jpg

Merry Xmas for that less than $0.25 performance upgrade

Throttle tube goes from 29.6mm dia to 37.5 mm WOT throttle twist drops by 20%. Here is a pic of how much total rotation is required for 0 to WOT on my 81 GS750EX

[posplayr]

Pics are worth a k of words

Here is a pic of the PVC ring installed on the throttle tube.

Merry Xmas

Pos

IMG_3520.jpg

[bwringer]

Sheer genius, and easily reversible, too.

If you really want to get crazy, you could attack the ring with a file to create a different profile -- thinner at the beginning of rotation, thicker at the end.

[mriddle]

My son Adam talked about that concept ..

Sheer genius, and easily reversible, too.

If you really want to get crazy, you could attack the ring with a file to create a different profile -- thinner at the beginning of rotation, thicker at the end.

[Mark M]

Here is a pic of the PVC ring installed on the throttle tube.

Merry Xmas

Pos

Good info, Posplayer. Now take that ancient, rock hard grip off and try a set of Pro-Grip gel grips and you will never go back to the old rubber ones!

Thanks for the tip, I am going to look at my GSXR1K throttle and the 1100E and see what I can work out.

Mark

[kokopelli]

i'm knew to the performance thing with this 81 gs650gl cafe-ish project being my introduction so that being said here's my question, how does this help with throttle? is it just the fact that it cause more cable to wrap around the bottom as you twist the throttle? figure it must be just i like to make sure i'm fully grasping the concept behind things. also i noticed the post about tappering it from thin at the beggining to thick at the end... wouldn't that create less an effect than thick all the way?
lastly,i'm assuming this can be done to most any bike right?

[jed.only]

i'm knew to the performance thing with this 81 gs650gl cafe-ish project being my introduction so that being said here's my question, how does this help with throttle? is it just the fact that it cause more cable to wrap around the bottom as you twist the throttle? figure it must be just i like to make sure i'm fully grasping the concept behind things. also i noticed the post about tappering it from thin at the beggining to thick at the end... wouldn't that create less an effect than thick all the way?
lastly,i'm assuming this can be done to most any bike right?

exactly. makes the ratio better for wrist movement to go from closed to WOT. it opens at a faster rate.

[posplayr]

Fitted the mod to my GS750

See attached pic of how it worked out.
The net effect was to give 0 to WOT in a little less than a 1/4 rotation. It was in the very low 60's today so I only went on back road ride (about 20 miles) however the result was good. There is a slight increase (20% to be exact) increase in pressure to roll the throttle but it takes less roll to get to WOT (20% to be exact). Throttle is not twitchy, just easier to get to WOT.

Meaure how much room there is inside of the housing. My SG750 had about 8.5mm. Cut down a ring of PVC so it has room but cant move around too much and let the cable fall off of it. Cut a notch out of the ring (about 1") and pop it onto the throttle tube and reassemble.

You probably dont even need to adjust the throttle cable.

Pos

[kokopelli]

thats pretty f'in cool... why didn't i think of that? well i'mdeff gona have to play with this one
thats why i love this site lol

[NetBSD]

bookmarked this and the link to the original thread, im deff gunna do this on my 450 if it fits, sucks how much it takes to get WOT on my bike

[oshanac]

I was reading the gsxr thread on this. Does it affect the "snap back" of the throttle when you let off? How about the throttle rising if you turn the wheel hard left or right at a stop?

[NetBSD]

I was reading the gsxr thread on this. Does it affect the "snap back" of the throttle when you let off? How about the throttle rising if you turn the wheel hard left or right at a stop?

if you read further youll see that turning fron stop to stop will not effect this, that user had issues with the way he routed his cable. i dunno if it will effect the snap back but i dont think it will if done right

[posplayr]

Snap back

If you size the PVC ring so it does not rub inside the right hand switch housing, then the force provided by the return spring actually has a 20% increase in mechanical advantage in that it is now operating through a larger moment arm (the increased diameter of teh cable wrapping around the tube).

The increase in torque required to twist the throttle is the same torque increase that you get from the return spring.

Return time should only decrease.

No different in function to the R1 throttle tube.

Pos

[Guest]

Jim you genius! I'm doing this one for sure!
Friggen engineers.

[posplayr]

Bill

Awe shucks it wurnt nutin . But it do work and is real simpler

Pos