Helix Question Bearcat secondary

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Doggydoggen

New member
Hello calling from sweden.
my first post..=)
and my tec english realy sux..but i will give it a go..=)

anyway i have put a Bearcat secondary on my -92 vmax and have some issues..
anyone tryed to fit a bearcat secondary and have some info on cluching?..
i no have a straight 49 helix and it works pretty good but th backshift should be better..
i now thinking of changing the helix to 49/43 an ofcourse reclutch the primary.

anyone have some ideas?

/Doger
 

No replys.

Some info on how it peform..
hitting the throttle from zero
it explodes to about 8400 rpm and stands there all the way to top speed,pulls realy hard
going 50km and then pulls the throttle..well it take some time to hit 8400 rpm,it doesent backshift properly
i want it to be like 0,2 sekund to hit 8400..now it is like 0,5(you feel that the engine have a hard time recovering the rpm)

next issue is that when i easy out from throttle and almost stop..then the primary clutch doesent shift down and the secondary seams to force
the primary to shift down making the engine brake the speed..dont know how to explain in english..=)

my own thinking is that i should loosen the secondary spring tension to prevent the secondary to force the primary..
then ofcourse the upshifting will increase and i drop rpm and the backshift will be worse..But..
then im thinking this..if i then increase the primary spring tension to increas the shifting speed and then adjust weight to the primary?
do you think im going the right way,or?..some hint what direction i should move?

if i had 10 diffrent springs 10 diffrent helix,well that would be the way..but..:/

Dogge
 
Many racers in sweden uses the bearcat secondary because It has a larger diameter which would be like starting in a lower gear..You can run a much taller gear, for top end and mileage, and still be strong out of the hole because of the lower gear ratio acheivable with the bigger sheaves of the bearcat..it is 28,9cm od(11 3/8 OD)
 
Doggydoggen said:
No replys.

Some info on how it peform..
hitting the throttle from zero
it explodes to about 8400 rpm and stands there all the way to top speed,pulls realy hard
going 50km and then pulls the throttle..well it take some time to hit 8400 rpm,it doesent backshift properly
i want it to be like 0,2 sekund to hit 8400..now it is like 0,5(you feel that the engine have a hard time recovering the rpm)

next issue is that when i easy out from throttle and almost stop..then the primary clutch doesent shift down and the secondary seams to force
the primary to shift down making the engine brake the speed..dont know how to explain in english..=)

my own thinking is that i should loosen the secondary spring tension to prevent the secondary to force the primary..
then ofcourse the upshifting will increase and i drop rpm and the backshift will be worse..But..
then im thinking this..if i then increase the primary spring tension to increas the shifting speed and then adjust weight to the primary?
do you think im going the right way,or?..some hint what direction i should move?

if i had 10 diffrent springs 10 diffrent helix,well that would be the way..but..:/

Dogge
Click to expand...

The most important thing that I found with these clutches is your belt deflection. A little means allot. We tuned for weeks with helixs and springs and later in the game we found the center to center could have been a little further out. Once we figured that out the helix and secondary spring became ultra fine tuning.
 
Doggydoggen said:
No replys.

Some info on how it peform..
hitting the throttle from zero
it explodes to about 8400 rpm and stands there all the way to top speed,pulls realy hard
going 50km and then pulls the throttle..well it take some time to hit 8400 rpm,it doesent backshift properly
i want it to be like 0,2 sekund to hit 8400..now it is like 0,5(you feel that the engine have a hard time recovering the rpm)

next issue is that when i easy out from throttle and almost stop..then the primary clutch doesent shift down and the secondary seams to force
the primary to shift down making the engine brake the speed..dont know how to explain in english..=)

my own thinking is that i should loosen the secondary spring tension to prevent the secondary to force the primary..
then ofcourse the upshifting will increase and i drop rpm and the backshift will be worse..But..
then im thinking this..if i then increase the primary spring tension to increas the shifting speed and then adjust weight to the primary?
do you think im going the right way,or?..some hint what direction i should move?

if i had 10 diffrent springs 10 diffrent helix,well that would be the way..but..:/

Dogge
Click to expand...

getting a spring w/a higher "rate", will slow the rate of shift down......
getting a spring w/a lower "rate" will increase the rate of shift.....
 
Well it sounds like you going in the right direction, however, what are you running this on? Where are you located at what altitude? I'm assuming a 750. If that is the case it sounds like you have too much weight in the front and it is overshifting and you can't get it to backshift until you almost stop? Right.

We used to commonly run a 55 0r a 53 in the secondary, yellow spring 4th hole, 8BU-00's in the front with like 3 grams added, 15.5mm rollers, and I can't remember the spring.

We used Arctic secondaries but there were issues with the Bearcat, while you do get a lower gear out of it, you will most likely run the belt into the bottom of the clutch. All the overdrive kits that were made here used the standard AC secondary, and we machined them in the middle to get them to close farther for belt deflection.
 
Last edited:
I have changed the belt deflection further out,it did make it better..thanx..=)
i have now order a black max secondary spring and i found a helix on ebay(60/54)..the helix i now use is a 49/47
see what happens..=)
i have experiment with diffrent length/wide of belts,distans between the clutches and so on..i put inc on the shaves made a speed run, and then a mesure ,over and over again..
i think that issue is solved know.?
Sorry for my bad english..

Kaw550..

Yes it ia a 750..ported and altered original pipes.
I dident understand what you mean with"and we machined them in the middle to get them to close farther for belt deflection"
did you machine the primary or?
 
No we would machine the secondary at the bottom of the sheave and wher ethe shims sit to make the clutch close further so you could have less belt deflection, you don't have to take much off, if you look at a later 800 secondary Yamaha had to do the same thing
 
i have now shorted everything out..
i have tryed a lot of helix and the one that works best is a
i60-54 helix and a artic cat Black max (black) secondary spring and i must say it works incredible good..i dident belive how good the upshift and downshift worked..
you cant compare it with the stock,light years better..
i also fitted the Atacc controll..=))
i have changed the rivets on the primary so many times that i dont remeber what i have anymore..
Anyway..
Today i raced a piped Mach Z -98 and i was leaving him like he was driving a formula 500..=))
before we raced he smiled and told me that would not have a chance in hell..
well now he doesent smile anymore..=)

Dogge
 
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