I'm about to build two minibikes for my 9yo sons for Christmas. I'm going to use azusa frame kits and stock non-hemi predators that I have sitting in the boxes still. I'll probably grab them a header, carb, and filter to start off. I have built one predator with billet parts, ported head, black mamba cam and some extras and will eventually do some more serious mods to theirs. They want the minibikes to run at the dragstrip (local 1/8 mile) and I was wanting to know if I should grab them a cheap torque converter or a clutch for these bikes since later they'll be making decent power and turning a good bit of rpm's. My boys weigh 80lbs and I'm wanting them to launch decent and still run good on top end. E.T. means more the mph to me. I know the torque converter will launch good but how will topend be later if the motors are turning 6000-8000rpm's? Any help will be much appreciated. I have a drag car and would like to have them something to run while they are at the track, just want to start them off close to stock but have a some room to grow as they get used to racing them.
Another tav vs clutch question.
- Thread starter durandbagwell86
- Start date
- Tags clutch question tav
A clutch just engages and disengages and sticks only with the sprocket ratio and tire size the CVT setup hits every ratio from 2.73:1 to .90:1 plus whatever sprocket ratio you want and with a TAV you can not only change engagement but how the unit shifts by preloading the driven unit so with the TAV it would be faster all around the tricky thing is getting them setup right
8000 RPM is too much for the belts. Comet recommends something under 4K RPM max. Other members here have used these on 9000 RPM motors and experienced sticking. (Wulfs)
Over the years that have been several threads about this. Generally, if you want to run those high revs, you need to be into the snowmobile CVTs, 340's and the like. There are also some torque problems with the TAV's once you get them turning that fast that can not be mitigated with spring replacement.
Over the years that have been several threads about this. Generally, if you want to run those high revs, you need to be into the snowmobile CVTs, 340's and the like. There are also some torque problems with the TAV's once you get them turning that fast that can not be mitigated with spring replacement.
If I put a tav on it that has 12t sprocket and a 72t rear (what the kit comes with), 11.5" diameter rear tire, and it is governorned to 3900 rpm's how slow would it be? I'm thinking mid 20's. Maybe I'll go with a clutch like a Hillard inferno so I can change sprockets out for top speed. Is there a better clutch I could buy to take off decent and be able to gear it for 30+mph?
Ratio sans TAV would be 6.0:1 giving you 22 MPH at your other parameters. TAV 30 high range is .90:1 so I assume you'd get an extra 10% of top speed. Where you make the money is launch, since the TAV 30 is 2.68:1 on top of what you're geared at.
I generally make an error someplace in my computations so be warned.
With your kids weighing in at 80 pounds, or even 100 pounds, and a 6-plus horse engine, a straight clutch setup would be more than adequate I think. Grown men on here are having problems doing wheelies with a straight clutch setup.
It's your money, but to start off like this? I'd go with a slightly modified motor and a max torque, then see how it all goes. Heck, they might REALLY dig it, and get you thinking about a Jr dragster.
I generally make an error someplace in my computations so be warned.
With your kids weighing in at 80 pounds, or even 100 pounds, and a 6-plus horse engine, a straight clutch setup would be more than adequate I think. Grown men on here are having problems doing wheelies with a straight clutch setup.It's your money, but to start off like this? I'd go with a slightly modified motor and a max torque, then see how it all goes. Heck, they might REALLY dig it, and get you thinking about a Jr dragster.
I know they'll love it. I just hate to spend big bucks on a Jr. Dragster. I might get them a max torque clutch then and a few boltons until they want more power. I still have my built predator that I could swap on one for them to run later. Thanks for the help. Eventually I'd like for them to run 40+ and I know it'll be a lot easier when you have a motor that'll turn twice the rpm's as stock.
tav's are a whole new set of problems. i got a cart with a tav and a 20hp honda vtwin , and the weights inside the driven stick and it wont stop unless you pop it into N , or hit the brakes till it forces the engine to stop. when it pops outta gear you can hear the weights pop back in place and you may put it back into F or R. if they dont go back youll know when you put it back in gear 150%. id go with a nice racing clutch and a great gear ratio.