Originally Posted by GDCobra
I guess if that were seen as a problem one could cut 10mm off the end of the h'bar and use a 5mm spacer instead of 15 so keeping twist-grip in the same position.
You could also use the same mod for 1" h'bars using the same bearing by machining up a bush with ID equal to the bearing OD and OD equal to the throttle sleeve ID.
I'd be tempted to look at making up a PTFE sleeve for the inner end of the twist girp.
I'd also leave the thread at 5mm also rather than modify it.
Do you feel a benefit to your riding or is it more a case of feeling more sophisticated?
Thanks for your comments. Once long term testing is completed I might do what you suggest: cut a bit off the bars and shorten the spacer.
I had already drilled and tapped the threaded bar insert to experiment with different bar-end weights. If I hadn't, then I would need a bearing with a smaller inner race diameter and I couldn't see any in the bearing listings. The closest was 7mm ID and I made up the difference between the M6 bolt and those 7mm with a plastic sleeve made, once more, out of a short piece of heat shrinkable sleeving.
The previous experiment involved a much heavier weight and the "Throttle wank" mod, and that worked well. I'm now running with more or less the standard weight and the wank mod.
I may increase the bar-end weight a little, as this morning I got a twitch of sleepy hand after about 80 km. The throttle action is a bit smoother and feels more precise and controllable when negociating slippery surfaces like fallen leaves and twigs at this time of year. It could be a placebo effect I suppose, but it does feel nice. I've always kept things like the throttle cables, mechanism, cam and sleeve well greased anyway, so the improvement is marginal.