I've done CVT tuning for a long time now, but I've never had and engine that made me so unconcerned about dialing it in before. I had a blast for a whole year out of tune! LOL
@@MarkSmith-rc8bx It depends on the setup. The high strung stuff with OR kits seem to require more fine adjustments. With something closer to stock, 1/2 gram may get it close. If you can log RPM, you'll be able to see if you need smaller changes by looking at how much the RPM changes with a 1/2 gram up or down.
Hi Brent. Great video.When you do the follow up CVT video, I would love to see/hear a breakdown of CVT tuning to the best of your knowledge (I consider you to be one of the best on RU-vid) My understanding of CVT tuning has expanded quite a bit since I started monkeying around with scooters 2 years ago but it still feels like trying to hit a moving target.... The relationship between rollers weighs and RPM, The relationship torque springs and roller weight and clutch springs vs. RPM are the areas that are still kind of a mystery to me and I'm sure thousands of your subscribers...
I just finished the voice over stuff for the next vid minutes ago and I have I think 3 more videos past that to take care of so I have weeks of work already before I do anything else. The CVT is yet another of those very simple things that can be incredibly complex at times. In general, I think a lot of people would be well served to compartmentalize the CVT to some degree. The clutch is off the line. It can slip initially for a bit and affect RPM, but mostly think of it as off the line and then influencing the first seconds of takeoff. Then just remember that the contra spring and rollers work with and against each other. You need a contra spring stiff enough that the belt doesn't slip. Doesn't slip a lot is possibly more accurate, because a CVT wouldn't work without slip. Too stiff and you lose power and reduce belt life. I think too many people focus on really stiff springs when they probably don't need them. Rollers/sliders just need to be the right weight to work with/against the spring to achieve the desired RPM. Don't think of heavy weights for going faster or lighter weights for acceleration as some do. Just think about heavier as lowering RPM and lighter as increasing it. The entire goal for performance is to keep RPM within the range that the engine is the strongest as much as we can. Beyond that, you can dive into a deep hole of things like belt length, belt width, shimming, drive face angles, ramp designs, torque driver angles, pulley diameters, and on and on and on. Most of the time we can do quite well focusing on the basics listed above and dealing with the more in depth stuff more or less as needed. Hope that helps a little for now at least.
@@49ccscoot Thank you Brent. That was a great explanation. I have been trying to tune in 1/2 gram (per roller/Slider) increments. I didn't realize the CVT was that sensitive. Again, thank you for your help and great videos... I continue to learn a lot from you.
Hi, have you thought about making your own dyno? It doesn't cost that much and it brings a much simpler tuning. BTW I watch every video, great job. Keep going!
Thanks. Definitely thought about it. Allegedly it doesn't cost that much, but I don't really know of local sources willing to hand over a giant electric motor or big chunk of steel cheap. Closest I came was a lawn roller, but it was old and not smooth and I questioned it's integrity. Still would have cost quite a bit to get it machined to work and it was a risk IMO.
I have considered it. I was going to cut the mounts off and weld them back about 3-4". I decided that I'd like to try lowering first and see what happens. The center of gravity is quite high on this scooter, so maybe I could make a difference that way and it could potentially be beneficial by having a smaller frontal area.
I have a 10.29:1 final drive ratio (14/39 primaries). I could switch to 9.35:1 (15/38 primaries) and it may be less aggressive off the line and/or possibly pull a little better up top... but power wheelies from a roll are pretty darn fun.
Thanks for the aluminum foil tip. I was at a loss for 8.75g roller in my majesty swapped elite50. I managed to fudge 3g into the stock 14.3g rollers and make my desired 70g total. She’s gonna rip 7.99 or better now!
