CVT CVT Transmission?

[capturedbyrobots]

Hey guys,
I'm CVT crazy.

I've been modding them (X2 CVTs) to put on my chain drive gopeds, and they are awesome.
The trick is in the details.

You really need to shim the contra spring on these to get good takeoff and eliminate belt slip
and remove 3 of the rollers in the variator to get the engine in it's powerband, it helps to replace the bearings with better ones (SKF)
and vent the cases and belt cover to keep heat to a minimum.

I did a whole bunch of articles about modding them on gopednation.com
in the DIY section, if you want to try any of these mods.
Here's a link to that section with "CVT" as a search,
Happy reading....
http://www.gopednation.com/forum/search.php?searchid=1513418



I just got a disc rear hub today for my MB (sprocket mounted to disc mount)
so I'll be adapting a CVT to that next.
I just hate the scrubber drive for my MB, I have to adjust it constantly.

 

[Large Filipino]

There are some cheap ~$50 CVT transmissions available for pocket bikes:
http://www.scooterparts4less.com/web_gas/x1_Pocketbike_cvt_transmission.htm
http://www.partsforscooters.com/CVT...e3eTaxaQbxmTe34Pa38Ta38Oahb0?sc=9&category=60
http://www.scooterparts4less.com/web_gas/x2_Pocketbike_gearbox.htm

Holy S%$#. That first link especially. Looks like it can bolt right up to my Titan. My head is seriously spinning here.

 

[capturedbyrobots]

Holy S%$#. That first link especially. Looks like it can bolt right up to my Titan. My head is seriously spinning here.

Hate to tell you, but the first link is NOT a CVT, even though it says it is.
It is a simple chain in a box. X1's do not have CVTs.

 

[Large Filipino]

Well that 3rd link is a definite CVT and that looks bolt on as well as long as the clutch housing's the same size and the bolt holes line up. The sprocket would have to turn counter clockwise to the engine's clockwise rotation and the sprocket alignment would be off so a jackshaft alignment would be necessary.

 

[Zomby Builder]

Cvt

Wished that I had listened before. Zacks CVT & related mounting plate was FAR superior to a solid mount gear box. Almost no vibration before & definate difference now. Robot is on track.

 

[spad4me]

I read your posts on goped nation capturedbyrobots

Hey guys,
I'm CVT crazy.

I've been modding them (X2 CVTs) to put on my chain drive gopeds, and they are awesome.
The trick is in the details.

You really need to shim the contra spring on these to get good takeoff and eliminate belt slip
and remove 3 of the rollers in the variator to get the engine in it's powerband, it helps to replace the bearings with better ones (SKF)
and vent the cases and belt cover to keep heat to a minimum.

I did a whole bunch of articles about modding them on gopednation.com
in the DIY section, if you want to try any of these mods.
Here's a link to that section with "CVT" as a search,
Happy reading....
http://www.gopednation.com/forum/search.php?searchid=1513418



I just got a disc rear hub today for my MB (sprocket mounted to disc mount)
so I'll be adapting a CVT to that next.
I just hate the scrubber drive for my MB, I have to adjust it constantly.

I would like to try a rack mounted flipped 460 with a cvt.
and possibly a small chain drive to a 50 tooth sprocket to finish up.
any ideas ?

I currently use and enjoy a happytine framemount.
I may also look into replacing the output drive gear with an adaptor to a cvt as well.
The gearing would not be right I fear.


Those go peds look incredibly fast.

 

[jimst]

CVT transmission

Anyone use one of these?
http://www.partsforscooters.com/CVT...e3eTaxaQbxmTe34Pa38Ta38Oahb0?sc=9&category=60

 

[loquin]

Several folks have had success with CVTs.

With Pocket Bike CVT's, there is just one calculation you need to look at. This is the total reduction at top speed The second calculation, the reduction at startup, is just nice to know.

Many suppliers will tell you the reduction is about 7:1. But, they check by simply rotating the clutch bell until the output shaft rotates once, counting the number of rotations of the bell. THIS is the startup reduction. The pocket bike CVTs have belt reduction of about 2.2:1 AND an approximate 3.2:1 gearbox after the belt reduction. (But, some older 'Long' Pocket Bike CVTs had a 4:1 gearbox after the CVT belt reduction.) You'll need to take the cover off, then rotate the output sheave on the belt drive, counting rotations, until the gearbox output shaft rotates once. THIS is the reduction you need to use in your design.

Your FIRST calculation is to determine the top end speed, and to size your total gearing appropriately. A 2-3 HP motor can push you along at 30 MPH, but if you gear your system to try to go much faster than that, the CVT may well NEVER get completely 'shifted' into the high range, and you are going to walk away thinking that CVT's suck - that the belts just don't last, that the thing is always breaking, and the motor is always bogged down. The bike will take off fine, but it 'dies' at the top end. For 26 inch bikes, 18:1 TOTAL top end reduction is what you should realistically shoot for. Ignore the 7:1 number; instead, if you divide that 18:1 number by the CVT gearbox reduction (3.2 or 4) only, you see that you need another 5.6:1 (4.5:1 for older CVTs) reduction after the CVT. This means that you probably have to use a jackshaft. (You could use a whizzer belt drive, and weld a drive pulley to the standard sprocket on the output of the CVT. Which would make for a nice, smooooooth ride.)

Once you've got the top end gearing set, everything else falls into place. Since you have that 18:1 total top end speed, multiple that by 2.2 to get nearly 40:1 at low speeds. This means that going up a long hill, you'll only have a top end of about 13-14 MPH. But, you can 'jog' up that hill at that speed all day long. Also, your acceleration will be great. But, the 'feel' is a lot different. It'll feel more like a motorboat - the motor will get up to max output RPM (in the 5500 RPM range quickly. The speed increases rapidly at first, even though the motor barely speeds up. Once your speed 'catches up' to the engine RPM at 15-20 mph, then the engine RPM is 'locked' to the speed (not really, but it seems that way.)

Remember though, a CVT isn't magic - it will actually reduce the top end speed that the motor could push you, by roughly 5-10 percent. (At best, it's about 95% efficient, and with a badly worn belt, about 85%) But, to offset this built-in efficiency loss, it will get you up to speed substantially faster, and will really shine on those long hills by 'shifting down' automatically, as you need it, when you need it.

 

[jimst]

Thanks for the help. I will let ya know if I get the trike going. It is heavier

https://motoredbikes.com/media/trike.53546/