Gear Change Enhancer Improver

[jjinfrance]

Just flicking through old posts and saw one about this subject. Just wanted to know if they are still available.
Cheers
JJ

[Fat Rat]

http://www.cymarcbikeparts.co.uk/Suzuki-v-strom-and-dl-1000-gear-change-enhancer-great-bit-of-kit-amazing-results-fits-latest-2014-models-too-21-p.asp

[Ianmc]

I am really interested how this actually works in technical terms, and how much it moves the sprocket,I can’t believe Suzuki have got this wrong as it is basic engineering to manufacture drives lined up correctly.Any explanation will be welcome.
           Ian Mc.

[greywolf]

I've become flak here before for this but I'm going to state my opinion again. The first time the question of sprocket alignment came up was at http://www.vstrom.info/Smf/index.php/topic,1499.0.html

Master Mike retired and stopped making modified spacers but others stepped in. There is some argument about whether a real difference is made because it is so easy for a person to feel a difference because one is expected rather than a difference really happening.

I really think there may be an actual change because Master Mike's 2mm change puts the rear sprocket deeper into the hub, taking up so much clearance that a small number of sprocket hubs need light machining to clear the deeper sprocket carrier. What that does is prevent sprocket wobble, especially when the cush rubbers get worn. The sprocket is 2mm tighter against the cushions plus just about any degree of deflection would arse metal on metal. That will keep the sprocket from cocking which would take it out of parallel with the chain.

The Vee and first three years of the Wee have the same rear wheel but the Wee has no reported alignment problems and its cush rubber wear is infinitesimal compared to the Vee. That's got to be because the Vee makes much more power and is quicker to wear the rubber cushions and cause the sprocket to cock in the horizontal plane with the forward part closer than the rearward part due to the power of the engine pulling the top of the chain. Other complex directional forces can cock to sprocket in the vertical plane too.

Anyhow, I think the main advantage of the 2mm movement closer to the hub is it keeps the sprocket from cocking as the cush rubbers wear and keeps the sprocket parallel to the chain run and more in line with the hub. I too am not so sure Suzuki got the front and rear sprocket alignment all that wrong but various people reporting have reported misalignment in both directions, some too far in and some too far out. That may be because some rear wheels had their bearings replaced improperly. See http://www.vstrom.info/Smf/index.php/topic,4250.0.html
If the sprocket side bearing is installed first in error, the sprocket will be too far away from the center line of the bike.

Now the Cymarc spacer moves the sprocket 2mm farther out and makes no change in the relationship between the sprocket carrier, cush rubbers and hub to prevent cocking. That would help bikes with the alignment having the rear sprocket too far in but check your bike with new cush rubbers to see how your sprockets really line up.

Probably the best solution would be a dual row ball bearing instead of the single row. That would do a much better job of keeping the rear sprocket from cocking and I think cocking is a bigger problem than alignment. Sharealike wrote about sprocket cocking too in post 383 at http://www.vstrom.info/Smf/index.php?topic=1499.360 and a dual row ball bearing mod is shown at post 389.

[wurzel]

Great explanation Greywolf,and thank you!

[Ianmc]

Thanks for that GW,the way I look at the spacer mod,is that it would make sprocket alignment worse under load.The only perfect way would be to have the sprocket support bearing directly under the chain line,but original design parameters won’t allow that.If there was room the ideal way may be to put a pair of slimmer ball bearings into the carrier,as the ball bearings will take lateral loads better than a roller type,or change the bearing every tyre change just for peace of mind sake,they are quite cheap anyway,it’s a shame no-one makes a fixed pair of taper rollers in one housing,that I reckon would sort it.Ian Mc.