low rolling resistance tyre

[triplerotor]

I did actually. I wanted to post but rules only allowed me to post link after i made 5post.
This is the winning team from indiana(link on next post)
Can you guys help me to identify what type of wheel is this?
Lightest wheel available here is aluminium spoke wheels, which i x sure whether i can fit a tubeless tyre or not. If x im need to opt for a lightest forged wheels.
I just found out the organiser did supply a specially made michelin tyres but for 200usd per pcs which is too much for me. So i have to find another option.

So ill post the picture after this

[triplerotor]

Heres the wheel picture

[CapriRacer]

Thanks for the detail. Your first post had very little to go on.

First, I am not aware of anyone that has done RR testing on scooter/motorcycle tires (tyres). I would suggest you do some research on tires that will fit on the existing wheels. You ought to be able to figure out how to make a rig to test the force needed to keep a tire and wheel assembly rotating at a constant speed.

Alternatively, you could power up an assembly on a loaded wheel and count how long it takes to coast to a stop.

[jkv357]

Originally Posted by triplerotor

Heres the wheel picture

That doesn't look like any motorcycle wheel I'm familiar with. From the design (not symmetrical side to side and hollow spokes on the backside), I'm guessing it's not an actual motorcycle wheel.

[Grant-53]

A chain or gear drive is more efficient than a belt CVT. The number of ratios needed will depend on the torque curve of the engine and the amount of incline on the course.

The wheels in the picture are specially made for lightweight and four wheel suspensions.

[triplerotor]

i understand the efficiency for cvt is lower than chain drive gear, but from my understanding as the cvt have unlimited ratio and im mostly driving 18mph and other teams also doing the same so driving 18mph at what rpm is more important.the lower rpm the better. for chain n drive lowering the gear ratio to achieve lower rpm at the speed will have a drawbacks on the acceleration. would cvt have the same drawbacks?

i cant imagine anything 4 wheels using suspension that are having that thickness except for drag wheels.
this is 15x3.5 wheels. but i still need car hub to fix it which will increase the weight.

[Grant-53]

At 18 mph and a vehicle weight under 50 kg with 4 wheels you can likely use industrial plastic wheels and tubeless mountain bike tires. The issue with the CVT is in belt slippage. With a centrifugal clutch system the engine will reach a specific rpm before the wheels engage. Depending on the engine cam and timing, operating rpm would be 3000 to 4000 rpm. Compare engine torque at that speed to the rating of the internal gear hubs for bikes. A 50cc all terrain vehicle might be a source of parts also.

[stiletto2]

Originally Posted by triplerotor

i understand the efficiency for cvt is lower than chain drive gear, but from my understanding as the cvt have unlimited ratio and im mostly driving 18mph and other teams also doing the same so driving 18mph at what rpm is more important.the lower rpm the better. for chain n drive lowering the gear ratio to achieve lower rpm at the speed will have a drawbacks on the acceleration. would cvt have the same drawbacks?

i cant imagine anything 4 wheels using suspension that are having that thickness except for drag wheels.
this is 15x3.5 wheels. but i still need car hub to fix it which will increase the weight.

CVT's do NOT have unlimited ratios. They are continuously variable within the available, but limited ratio it has. The ratio is limited by the size of the diameters of the pulley faces where the drive belt can move to on both the variator end and clutch end of the drive system. Since the CVT gives variable ratios to the drive whereas the chain drive is more fixed, the CVT will ease the transition from start to its top or cruising speed, but is less efficient. Loss because of friction from resistance of belt being forced up the variator pulley faces and down the driven pulley faces while under tension. (and it is always under tension)

At some point, rpm that is too low will not be enough to force the variator to its top ratio. Heavier weights would help as they would force the variator to work the pulley faces together at lower rpm, but it would take a bit of experimentation to get closer to what might work and acceleration may still be slow but maybe not lug the engine as much like a fixed ratio would. Like most things, there are trade offs. Some of this for some of that... good luck with your project.

[stiletto2]

Originally Posted by jkv357

That doesn't look like any motorcycle wheel I'm familiar with. From the design (not symmetrical side to side and hollow spokes on the backside), I'm guessing it's not an actual motorcycle wheel.

They might be custom made or possibly wheels from a moped. It does a have disc brake on one side, but there isn't much bulk to the hub where it attaches. Maybe some bulk was removed from the wheel hub. An extreme close-up of the inside part of the wheel toward the back of the image seems to look that way.

[triplerotor]

Thank you stiletto and thanks for clearing it up ! now it make sense as i saw there are some high gear ratio kit for gy6.

after asking around with some friends, the wheels might be from a bike with a single swing arm, ill try to googling it around.


ive found out how to some sort of method to measure rolling resistance from this pics. hopefully we can start some sort of database of rr for bikes as there are none outhere?