Rocker B: MY ROCKER C MOD THREAD
#71
Looks like I'll be going with a 70t pulley after all...I was hanging out at my local indy today, I like to go by every couple weeks and shoot the **** or bend his ear about mod plans..He had three bikes there now (one of them his) that have open belt drives primarys... after talking to him about it, I thought that would be a cool mod for the Rocker. I figure if I'm doing that, I might as well go to a 30t front pulley!! Get the full 13% increase and not have any clearance issues with the 72t.. Thinking I would do the work, I asked him about the install, how hard it would be, he said that if he did it, he would charge me 2 hours labor for the belt drive, and since he's in there, he would only charge me 30 minutes more labor to install the 30t!! He only charges $75 an hour, I like to wrench...but for under $200 bucks labor, I'll let him do the job!! Time to pick out a open belt drive kit!!
I'd love to see that open primary that is going to look sick- BUT! be aware that the open primaries usually come with different ratio motor / clutch pulleys- so you may not want to buy 30/70 belt pulleys yet until you buy the open primary kit and determine your new primary drive ratio. from there we can figure out what the best secondary ratios (belt pulleys) will be, and chart your rpm/mph graphs.
also I'm not sure but I think you'll need to modify the calculated gear ratios in the ECM. Would be well worth talking to Rivera about doing this if nothing more than to just see what all is involved.
Last edited by LA_Dog; 03-17-2016 at 11:57 AM.
#72
I'd love to see that open primary that is going to look sick- BUT! be aware that the open primaries usually come with different ratio motor / clutch pulleys- so you may not want to buy 30/70 belt pulleys yet until you buy the open primary kit and determine your new primary drive ratio. from there we can figure out what the best secondary ratios (belt pulleys) will be, and chart your rpm/mph graphs.
also I'm not sure but I think you'll need to modify the calculated gear ratios in the ECM. Would be well worth talking to Rivera about doing this if nothing more than to just see what all is involved.
also I'm not sure but I think you'll need to modify the calculated gear ratios in the ECM. Would be well worth talking to Rivera about doing this if nothing more than to just see what all is involved.
Last edited by Rocker B; 03-17-2016 at 02:37 PM.
#73
Oh ok, I didnt realize that...Right now I'm leaning towards a Belt Drive Limited kit..I just talked to Scott there, and they have a really nice kit that fits the Rocker and BO..It has a 52t front and a 69t rear with a 142t belt..I can change the ECM ratios with my FP3...but how would I figure out the new ratio?? How do I know if I need to? What is the stock tooth size set up?
Your Rocker has the six speed trans correct? if so then the below stock data should apply:
Drivetrain
Primary Drive Chain, 34t motor /46t clutch sprockets
Final Drive Belt, 32f/66r pulleys
Clutch Multi-plate, wet
Transmission 6-Speed Cruise Drive®
Gear Ratios (overall): U.S.
- 1st 9.311
- 2nd 6.454
- 3rd 4.793
- 4th 3.882
- 5th 3.307
- 6th 2.79
Primary Drive Ratio 1.3529411764705883 (engine to trans sprockets)
Final Drive Ratio 2.0625 (trans to rear wheel pulleys)
Overall Drive Ratio 2.79 : 1
#74
#75
Alright here is the bottom line in very simple terms- and please confirm this with BDL. This is assuming your bike's stock data is the same as for the Breakout. But it should be the same with all current 6 speeds that run a 32/66 belt pulley combo.
So overall you will be *good to go* and get a nice performance increase as long as you also do the 30/70 wheel and primary pulleys. Otherwise you'll be sucking eggs but with a really nice looking open primary
- by going to the BDL primary with new 52/69 pulleys, you will LOSE 2% of rear wheel TQ
- By going to 30/70 final drive belt pulleys, you will GAIN 13% in rear wheel TQ.
- If you subtract these from each other, you end up with a GAIN of 10.84% rear wheel TQ
So overall you will be *good to go* and get a nice performance increase as long as you also do the 30/70 wheel and primary pulleys. Otherwise you'll be sucking eggs but with a really nice looking open primary
#76
here are some charts showing rpm and speeds for the primary and secondary changes. the first chart is "stock", just your bike's (assumed) stock configuration.
the second chart shows the primary modified with the new BDL 52/69 pulley primary ratio, and stock 32/66 pulleys as the "stock" configuration. there is also a "compare" with the new 30/70 pulleys, those values are in red and green in the charts. so while this chart says you would get a 13% increase (shorter) in ratio over stock, you still have to subtract 2% for the switch to the 52/69 open primary pulleys vs stock (the rocker-stock.jpg graph). so it balances out as 10.84% total increase (shorter) overall drive ratio.
I'm not sure if you need to mess with ECM gearing calculations due to the 2% difference in motor and clutch sprockets. you'll need to ask BDL or someone else knowledgeable about that.
the third chart would be your NEW speeds per gear at redline of 6000k with the BDL primary and the 30/70 pulleys.
the second chart shows the primary modified with the new BDL 52/69 pulley primary ratio, and stock 32/66 pulleys as the "stock" configuration. there is also a "compare" with the new 30/70 pulleys, those values are in red and green in the charts. so while this chart says you would get a 13% increase (shorter) in ratio over stock, you still have to subtract 2% for the switch to the 52/69 open primary pulleys vs stock (the rocker-stock.jpg graph). so it balances out as 10.84% total increase (shorter) overall drive ratio.
I'm not sure if you need to mess with ECM gearing calculations due to the 2% difference in motor and clutch sprockets. you'll need to ask BDL or someone else knowledgeable about that.
the third chart would be your NEW speeds per gear at redline of 6000k with the BDL primary and the 30/70 pulleys.
Last edited by LA_Dog; 03-17-2016 at 03:40 PM.
#77
Alright here is the bottom line in very simple terms- and please confirm this with BDL. This is assuming your bike's stock data is the same as for the Breakout. But it should be the same with all current 6 speeds that run a 32/66 belt pulley combo.
So overall you will be *good to go* and get a nice performance increase as long as you also do the 30/70 wheel and primary pulleys. Otherwise you'll be sucking eggs but with a really nice looking open primary
- by going to the BDL primary with new 52/69 pulleys, you will LOSE 2% of rear wheel TQ
- By going to 30/70 final drive belt pulleys, you will GAIN 13% in rear wheel TQ.
- If you subtract these from each other, you end up with a GAIN of 10.84% rear wheel TQ
So overall you will be *good to go* and get a nice performance increase as long as you also do the 30/70 wheel and primary pulleys. Otherwise you'll be sucking eggs but with a really nice looking open primary
Last edited by Rocker B; 03-17-2016 at 03:55 PM.
#78
#79
Hey thanks Dog...I talked to Scott again at BDL...he said that there is no issues with the ECM and ratios. ..This kit has been used on several Rockers and BO's with no reported problems except for one guy that had a problem with no 6th gear light after install..but it turned out having nothing to do with the kit... he said the only thing I might notice is a little more power dew to the weight drop with the kit installed... so it sounds like the 30/70 combo is the way to go!!! Thanks again for the numbers...
I wonder if you are able to do a "before and after", 0-60 time so see what the net effect is.
#80
Also....got more good news from Randy at SMW today...I really wanted to run a wider tire when I get the 21" front wheel, but I was finding almost no options for a 3.5" wheel that fits the Rockers narrow front end, the hubs are to wide. Skid pimp has the Rocker replica wheel in the 3.5" and it looks nice, but I really wanted something different...Well Randy came thru for me!! Like the 72t pulley, (when I thought I would try one), he told me he will build a wheel for me with the Rocker stock hub size in a 3.5"!!! ...So now I will be able to run a 120/70/21, with the wheels I wanted!!! which I'm sure will be a big handling improvement over the stock, skinny, 2.15" wheel and 90/90/19 tire, and I just think it looks better having a wider tire on a 21" wheel!!
Last edited by Rocker B; 03-18-2016 at 12:47 AM.