ESE's works engine tuner

[husaberg]

Rob and I have already talked about a sidecar with CVT, it'd be awesome though if you were using a whole scooter engine/transmission some sort of strengthening would be required to handle the loads when cornering though I already have that sorted in my mind. You'd let the front pivot flex a bit and have a seperate swingarm type of part connected to the standard scooter shock mounts via short adjustable rods using rose joints taking all the torsional loads rather than trying to resist them with the engine/transmission.

I can't believe we are talking about sidecars without Kickaha..........

[Kickaha]

Rob and I have already talked about a sidecar with CVT,

Guy in Canada races a Sidecar which is powered by a snowmobile engine which must runs something like a CVT transmission

[Buckets4Me]

Guy in Canada races a Sidecar which is powered by a snowmobile engine which must runs something like a CVT transmission

I thought Guy was from england and raced a gsxr1000 ?

[TZ350]

Garry and Dave, this years GP winners. The bike was prepaired and tuned by Speedpro.

http://www.flickr.com/photos/dty1/82...7632091510369/

[wax]

You have to remember that if the clutch is held against the bell and the bell is doing 10000 rpm then it will still stay out there. It doesn't care what it making it spin. Remember back I mentioned the dr pulley clutch it has a little ramp in it that pushes the shoes out against the bell and makes it stay in place until quite low in the rpm. well it will jump about 6500 to 7000 on mine. As soon as you gas it the motor just pulls up to what you set the cvt to and away you go. instant with no lag.
Its also very important to make sure that your torque driver (rear pulley) and the variator( front pulley) slide well so that they will change gear consistently. I lubricate my ones every race day with graphite powder, much like you guys do with the chain. when you set up a variator you need digital scales so you can be accurate. If you have a data logger it so easy. you just look at the rpm versus speed and make sure your rpm is constant. if it dropping then lighten up the weights as it getting to much load. If it rising then load up the engine.
Its really easy after a while

[wax]

Rob and I have already talked about a sidecar with CVT, it'd be awesome though if you were using a whole scooter engine/transmission some sort of strengthening would be required to handle the loads when cornering though I already have that sorted in my mind. You'd let the front pivot flex a bit and have a seperate swingarm type of part connected to the standard scooter shock mounts via short adjustable rods using rose joints taking all the torsional loads rather than trying to resist them with the engine/transmission.

or use a gp1 derbi engine
http://www.bikepics.com/pictures/2085857/
http://www.stuntbase.com/slikice/derbi_project/3.jpg

you can then use your normal swing arm

[TZ350]

I thought Guy was from england and raced a gsxr1000 ?

Guy Martin

[husaberg]

Weird i thought "Guy from England" was the last ever honest person to enter parliament.

Ended with flames also though

[Frits Overmars]

the musing about the gear box and CVT was to get around the FIM and formula 1 rule regarding number of gears ....

A CVT is considered to offer an infinite number of transmission ratios between its lowest and its highest ratio.
You propose to use infinite plus five. Now that is definitely more than the maximum of six allowed by the FIM....

...They don't freewheel when the throttle is closed. What happens is that without load the CVT moves to the highest ratio meaning that essentially it shifts to top gear. Still not what you'd be used to on a shifter bike but I reckon you'd get round it no problem.

You need to know why it happens. Look at the picture of the secondary pully; you will see that the top heave is fitted to a bush with angled slots in it. The three pins in the picture fit through these slots into the secondary shaft, inside the bush. The heaves of the secondary pully are pushed towards each other by a spring (not shown) that fits around the bush.
Because of the angulation of the slots, comparable to a coarse pitch, the torque being transferred from the heaves via the slots and the pins to the secondary shaft, also tries to screw the heaves towards each other; this helps the spring.
Close the throttle and the torque is reversed; now the angled slots work against the spring; the heaves can be easily spread by the belt, the CVT 'shifts to a higher gear' and crankshaft revs drop; just what granny expects when she closes the throttle of her scooter.
For racing you want to keep the revs at max power rpm all the time; all you need is a stiffer spring and axial instead of angled slots. Simple as that.

...Its also very important to make sure that your torque driver (rear pulley) and the variator( front pulley) slide well so that they will change gear consistently.

And it's important that the spring can rotate freely against the secondary pully. On the left of the picture you see a bush with a collar that fits around the bush with the slots, preventing the pins from flying away.The spring seats in this collar and often it is a tight fit. Removing the paint from the spring's bottom coil and polishing the bottom area will much improve the CVT's responsiveness.

[SS90]

A CVT is considered to offer an infinite number of transmission ratios between its lowest and its highest ratio.
You propose to use infinite plus five. Now that is definitely more than the maximum of six allowed by the FIM....


You need to know why it happens. just what granny expects when she closes the throttle of her scooter.
For racing you want to keep the revs at max power rpm all the time; all you need is a stiffer spring and axial instead of angles slots. Simple as that.
.

Thanks for that, are you saying that many of the aftermarket kits (like the Dr Pully Branded "Hit Clutch" that was mentioned earlier) are not necessary?
I only ask because it was mentioned that "if you don't have one, you aren't winning", and I wonder if these clutches are sold as an easier set up option to spring rates etc.

[Frits Overmars]

Thanks for that, are you saying that many of the aftermarket kits (like the Dr Pully Branded "Hit Clutch" that was mentioned earlier) are not necessary? I only ask because it was mentioned that "if you don't have one, you aren't winning", and I wonder if these clutches are sold as an easier set up option to spring rates etc.

I can't say because I don't know anything about those kits. Maybe the slot angles are different, maybe the pully angles are different, maybe the pully diameters are different, maybe the sheave surfaces are different (sandblasting may help), maybe the springs that come with the kits are different.
And that is only considering the secondary pully. The centrifugal governor on the crankshaft, the belt itself, the rear clutch and the final gearing offer even more variables.
Nevertheless, making your own CVT is a lot simpler than making your own gearbox. I'm not talking about finding suitable shafts, clutch, gears, shift drum and forks; I'm talking about making them.
(It can be done; look at what Jan Thiel and Martin Mijwaart produced 45 years ago after their day jobs, with a third-hand milling machine and a worn-out lathe)

[SS90]

(It can be done; look at what Jan Thiel and Martin Mijwaart produced 45 years ago after their day jobs, with a third-hand milling machine and a worn-out lathe)

Every now and then someone reminds me that (by in large) many of us are spoiled to the point we forget that there is plenty of "guys in sheds" that make some amazingly good stuff with basic resources.

[wax]

The doctor pulley clutch is that just a clutch. It has nothing to do with the cvt torque driver or variator.

So it has nothing to do with the angles of the torque drive that frits is talking about. SS90 I cant help get the feeling by reading your posts your here that you have made your mind that its never going to work and your more intent on discrediting than learning

It may help to follow some of the links I post so it explains it better to you http://www.youtube.com/watch?v=h1BZP-31-Pg

[wax]

http://www.zumaforums.net/index.php/...p?f=57&t=16564
these work very well to free up the spring and its the same thing I use on my scooter, Here is a link showing you how its done

[TZ350]

The full set of results from the 1st round of the Pacific Club North Island Series and the Two Hour including lap times.