Set me straight on Helix angles

I really do appreciate all the advice here. The first thing i am doing is go and pick up a digital gram scale so i verify the true weight of what i am going to be using.

For now until i can find a set of 8BU-10s is try the 8BU-00 since i am getting them and other stuff for free.

So what i am going to try first is leave my secondary basically the same with the 53/47 and green spring but move it to 70deg.....use the 8BU-00s with 2.7g heel and 3.6g tip plus the 48.7 of the weight itself giving me 55g on paper and the WWW primary spring. I will weigh the parts first before i install any rivets.

What do think of that set up as a first attempt?
 
will not work .....................................im sure u will underrave big time...and don't know why the gram on the paper are not accurate ....
 
Well, my sled is currently over reving at 9000rpms with the 8DN-20s loaded with 4.5g/5.0g plus weight= 51.59 grams right now. I do understand the 8BU-00 are more agressive so i was thinking of starting with both holes empty and see what is does but i wasn't sure because the weight itself is only 48.7g.

I assumed when Tony said to get a grams scale he has been down this road before with the accuracy of weights and rivets.
 
Last edited:
yep u need a grams scale thats a must ....the profile of the weigh change things keeping the same helix ....you can get those grams scales for nothing on ebays ..been there done that
 
ReaperSRX said:
Well, my sled is currently over reving at 9000rpms with the 8DN-20s loaded with 4.5g/5.0g plus weight= 51.59 grams right now. I do understand the 8BU-00 are more agressive so i was thinking of starting with both holes empty and see what is does but i wasn't sure because the weight itself is only 48.7g.

I assumed when Tony said to get a grams scale he has been down this road before with the accuracy of weights and rivets.
Click to expand...


u do have a strong motor to run over 51 gram ;)!
 
REAPER YOUR NOT OVER REVING A LITTLE, THIS SLED IS OVER 500 RPM. WAY TOO HIGH HERE. I THINK THE STARTING POINT YOU POSTED HERE FOR 8BU-00 IS GOOD, ALTHOUGH I WOULD LIKE TO SEE YA CUT THAT 53 BACK ON YOUR INITIAL SHIFT ESPECIALLY WITH THESE WEIGHTS, THEY ARE VERY AGGRESSIVE. AND YES NO PAPER HERE, GET A GRAM SCALE. LIKE I POSTED, THIS IS NOT THAT BIG A DEAL, PRIMARY NEEDS WEIGHT, THAT SIMPLE. THIS IS ONE I ALWAYS GO BY WITH A OVER REV.
150 OVER TARGET- SECONDARY LOCATION
250 OVER TARGET- HELIX, SECONDARY LOCATION, GEARING
300 OVER TARGET- BETTER GET INTO PRIMARY, WEIGHTS, SPRING, ROLLER, etc. 3:16(YAMMIE TONY)
 
I am sorry, but that really PISSES me off when they won't even sell/ship to Canada. Just throw them in the mail, airmail and i don't mind the 10 day wait!!!!

Anybody on here in the US willing to work something out i can pay you directly andn you buy them then mail them to me?
 
ReaperSRX said:
I am sorry, but that really PISSES me off when they won't even sell/ship to Canada. Just throw them in the mail, airmail and i don't mind the 10 day wait!!!!

Anybody on here in the US willing to work something out i can pay you directly andn you buy them then mail them to me?
Click to expand...


im in same situation loll :o|
 
8bu-10

if you want those reaper, pm me and I will buy them and send them to you, not a big deal, the cost on them new is $32.48 each-$97.44/3 so youd get all 3 that way for $62.00 plus whatever shipping is to you(shouldnt be very much on that)
 
I just learned a few days ago that the steeper the finish angle on the helix, the less RPM's you will pull. Shallow finish angle will increase RPM's.
 
?? so will a steeper start angle lower your shift RPM's and cause clutches to upshift faster?


I am also guess that the reason that a shallow finish angle in needed with HC's is because there is a lot of mass in those weights both heel and toe which cause it to pull harder and up shift quicker?
 
Well don't think i will get much testing done this weekend, we are still getting snow and should get about 10" when it's done so there won't be too much hardpack to test on, i am just going to adjust my secondary a bit and just ride on Saturday and fish on Sunday with the kids, Saturday going to be cold though -28 for the morning without the windchill :brr

I will get the parts and digital scale tomorrow morning and see what's all in the box and go from there. Until i can find some 8BU-10s i will play with 8BU-00 for now.

Cheers and everybody stay safe on the trails!
 
Last edited:
clutching

ive set up some srxs and viper i had one viper that no matter how much weight i put in the weight it still turned 8900 rpm i put a pin kit in to use cat weights more consistant shift curve then matched the rear with a green spring and a 51-43 rear helix geared down it worked great.i have always had trouble getting a yamaha weight to do want i wanted.just not enough experience with them or no time to fiddle around.i always found the lighter spring and lighter weight worked better for me less rotating mass.
 
You must log in or register to reply here.


Back
Top