Basic clutching ?? Need higher shift-up RPM..

[BigMac]

2002 Viper with Bender triples. It's clutched according to Bender's exact recommendations (using their clutch kit recommended for the pipes). Stock OEM gearing. V-force reeds. Camoplast 1.25.

Bender's specs call for engagment at 4500 RPM, with shift-up at 8700. The machine is running fine, but I note that on a 28 degree day with somewhat soft snow, engagment is at 4400 RPM and max RPM at shift-up is 8000. Backshifting seems to be OK. Max speed on the soft snow was about 100

The fine points of clutching have always been a little bewildering to me, I'm looking for a little advice as to how to best get the max RPMs up a little and keep engagement about the same 4400-4500 RPM.

TIA

 

[yamaholic22]

keeping the amount of weight in the heel (bottom end) of the weight will keep your engagement and bottom end performance the same, changing the weight in the mid of the weight will affect midrange, and changing the tip weight will affect top end. All areas overlap a little bit, but that is a very good rule. If you are under revving in the midrange and top end, subtract weight from the middle and tip of the weights. Helix angles and secondary spring pressure will also have an effect on the speed of the upshift and load on the engine (and therefore the rpm) as well, but you don't want to be changing secondary components with the intention of changing rpms. Hope that helps somewhat.

 

[BigMac]

keeping the amount of weight in the heel (bottom end) of the weight will keep your engagement and bottom end performance the same, changing the weight in the mid of the weight will affect midrange, and changing the tip weight will affect top end. All areas overlap a little bit, but that is a very good rule. If you are under revving in the midrange and top end, subtract weight from the middle and tip of the weights. Helix angles and secondary spring pressure will also have an effect on the speed of the upshift and load on the engine (and therefore the rpm) as well, but you don't want to be changing secondary components with the intention of changing rpms. Hope that helps somewhat.

Yes, thanks...it's kind of what I thought. I only have 30 degrees on the secondary spring, which is what Bender calls for, so I was contemplating increasing that a little, but I guess in my heart I knew it was going to be clutch weight at the tip. I hate grinding those damn rivets out.