To start with I'll pre-empt some of the negative comments this thread is likely to get, to wit: Yes, it's a "non-issue", "I'm scraping the bottom of the barrel", yes, "I have too much time on my hands", "need to get a life", "thread's too long", ...etc...
. This saves the usual suspects the bother of doing it.
Of course there's no power in it either. In my opinion there's a lot of pleasure and satisfaction in riding a machine where all the controls work efficiently and with smoothness and precision. This is often forgotten in the pursuit of power and performance.
Anyway, here it goes:
Following the successful elimination of the numb throttle hand effect, commonly complained about with phrases such as "throttle hand going to sleep", by applying member Aarik's mod involving the elimination of lateral or side to side movement of the throttle sleeve, aptly called "throttle wank", the following mod was devised to refine and improve the throttle action and eliminate the movement at the same time. A ridiculously simple, low-cost friction cruise control device has also been incorporated.
This is the thread where the previous, temporary mod was described:
I'm so impressed by how effective that mod was, at least for me, that I spent a long time searching the Net for opinions as to why it should work and trying to find others that have applied it, to no avail. No-one has heard of it.
What I did find is lots of references to the elimination of numb throttle hands once some sort of cruise control was fitted. This seems to confirm that it is likely the lateral movement of the handgrip that's causing the problem. The fitting of a cruise control indirectly stops that movement, as well as its primary function of easing the effort of fighting the throttle return spring. I still find it difficult to believe, mainly because I can't fathom the reason why it does, but it works.
My previous mod involved taking up the side to side play by introducing some sort of shim or spacer to take up most of the lateral play but that introduces some largely unwanted friction in the system. This new mod does away with that and as a bonus produces a silky-smooth, accurate throttle action, free of stiction and unwanted friction.
I can't claim it's my invention, the idea came from a well-known accessory (at least among Harley and Buell owners) by Arlen Ness, reference 07-099 Roller Bearing Throttle Kit, this costs around 22 to 35 USD depending on source and it's described as "Features an innovative roller bearing design that eliminates throttle stiction and play. Intended for use with your Original Equipment throttle pipe". No claim is made about the curing of the numb hand syndrome, but from evidence from comments on forums, it does that as well. My version is lots cheaper though, total cost if you re-use the OEM bar-end weight doesn't exceed $5.
You can see it here at the maker's site, but a search reveals lots of suppliers for it:
The only difference is that I've used a common and easily obtainable sealed ball bearing rather than the roller bearing that they use. It works just as well.
To enable the mod to be fitted the standard threaded insert or plug inside the OEM bars has to be drilled and re-tapped to take an M6 screw rather than the easily damaged M5 screw with a tiny 3mm allen head that has given so much trouble among members here. This was no hardship for me as I had already done just that to enable me to try out different bar-end weights in the past in an attempt to ease the numb hands effect. You'll also find that bearings with a 5mm inner race and the required diameter are not available whereas ones with a 7mm ID are available off the shelf at any bearing supplier.
Another minor change is that the throttle assembly has to be moved outwards from the end of the handlebar by some 9-10mm or so. In the case of the SE, the other items like the RH switch cluster and brake master cylinder/lever assembly also has to be moved to keep all these items close together.
The bearing used has an international reference which is 627 2RS. Any supplier will identify it from that number and they only cost a couple of Dollars. It has the following dimensions: OD 22mm, ID 7mm, witdh 7mm. Note that the 22mm OD is exactly the same as the handlebar tubing OD and we need it to be a little bigger to keep the sleeve from contacting with the handlebar tubing to minimise friction. This was done by supplementing it with a plastic sleeve made from a heat-shrinkable piece of tubing. The throttle sleeve has an ID of 22.8mm. The plastic sleeving has a wall thickness of just over 0.4mm and this enables the bearing to fit snuggly inside the throttle sleeve.
This only works for 7/8" (22mm) handlebars, of course. For 1" (25mm) bars you'll need to use a bearing with an OD of something like 26mm, but these come with an ID of 9mm or so. This means that the bars threaded insert would have to be opened to take an M8 bolt. The M6 screw could be used by sleeving the shank of the screw where it passes through the bearing from 6mm up to just under 9 to match the bearing's ID. It's possible that the Arlen-Ness kit could be adapted to the 1" bars as I believe Harleys use that size handlebars.
The distance from the bar threaded insert or plug to the bearing inner race has to be bridged by a suitable distance piece. It musn't be allowed to touch the plastic seals or outer race though, otherwise it won't work. I used a 10mm wide spacer with a 6mm inner hole and a total length of 15mm. To enable the distance piece to stay put inside the bar space a rubber grommet was slipped over it. This holds it central.
I considered re-fitting the OEM bar-end weight, but this would have to be cut down to fit, so I hit on the next idea: I modified one of PJ Glassfibre's passenger footpeg eliminators by drilling and counterboring. This is of a larger diameter that the OEM weight and overlaps the rubber handgrip by a few mm. This enables the fitting of a 20x3mm "O" ring over the handgrip. It can be slid over the end of the grip up to the new bar-end where it lightly wedges against it creating enough friction to act as a cruise control...Bliss!.
The total weight of the bearing, spacer, bolt, etc plus the new bar-end comes to 75 grams. Coincidentally this is the same weight as the original Triumph bar-end weight, so no difference there.
Note that no matter what sort of bar-end weight you use, the standard one cut down or a home made one like mine, you'll need to space it from the bearing with some sort of washer to stop it applying pressure to the outer race or the plastic seals. The clamping forces should only be applied to the centre race part of the bearing.