Lifan X-Pect Rear Sprocket Size?
 

My wife's Lifan X-Pect is supposed to come in this coming weekend and I'm wanting to change out the sprockets on it to give it some more top end speed so we can maintain 55-60 MPH without the RPMs being 8,000+ for hours on end. I found and ordered the 17 tooth front, but I'm wanting to drop the rear 3 or 4 teeth as well to help out top end speed. Any X-Pect owners out there who can chime in on what model line of JT Sprocket to look at for the rear sprocket (with the stock chain)?. I know the factory size is 46 tooth, I'm thinking 42 tooth is probably about perfect to drop the RPMs and gain more top end without losing all the bikes torque.

How many bolts? Measure the hub diameter and bolt pattern diameter. I'll see what I can find. If you can't find anything stock you can always have one made like I did for my X22R. https://shop.pbisprockets.com/product.sc?productId=503

I don't have the bike yet, I was checking to see if anyone knew what the compatibility was off the top of their head so I could go ahead and get a 42 tooth sprocket ordered and delivered so I can install it day one as I assemble the bike.

My guess is the 17/46 will be just what the doctor ordered. Not that 42 would be a bad thing, but if you had to compromise, I doubt the 46 would do you wrong.

Thank you! Just the info I needed, much appreciated!!

I ordered the 42 tooth. I'll make a video for everyone that shows a 15/46 top speed and RPM @ 60 MPH, a 17/46 top speed and RPM @ 60 MPH, and a 17/42 top speed and RPM @ 60 MPH.

Cannot wait! Small Engine Velocity has a video of him on the freeway, stock. The bike was not broken in, and he is short on videos, so we are left hanging since he did not want to push it.

Anyone have a particular # for the 42 rear sprocket?

Also check out my YouTube channel South Florida Adventure Sports for everything Lifan x-pect

See if the JTR810 looks compatible as mentioned above.
Edit: http://www.jtsprockets.com/catalogue/part/JTR810/

The JTR810 is a perfect fit. I swapped mine out this weekend. I did some gearing calculations based on the engine’s advertised power band which landed me on a 17t/38t sprocket combination. While the numbers looked good on paper, they turned out to be overly optimistic when reality of wind resistance kicked in at highway speed. Changing to a 15t/38t worked out a lot better. I would love to see what other riders get with different gearing combinations.
Note: Currently the 38t is only available from England, so if someone wanted to try this ratio for themselves, 17t/43t may have better availability for roughly the same final drive ratio.

With a 17 drive sprocket and the standard rear I do 50 MPH at about 6000 Revs and 60 at around 7000 rpm and I have opened up to 65 mph for short stints as I am only at around 800 miles on the clock and I am very pleased with the lifan x-pect.

YouTube Channel?
 

Did you post the video on YouTube? If so, can we get a link to the video?

With a 15 front and a 46 back sprocket you have a ratio of 3.06 revs of the drive to 1 rev of the wheel.
With a 17 front and 46 back the ratio drops to 2.7 : 1
With 15 front and 42 back it goes to 2.8 : 1
So you can see where the most gain is, and also the least cost and work.

Absolutely right if the 2.7 ratio does what you need it to. I tried that initially and it was definitely a quicker job. I ended up opting for the rear sprocket swap a short while later because it was still revving the engine too hard at the higher speeds. The 2.53 ratio I ended up with has been a good balance for me so I can still get decent low end and cruise at 60 more comfortably. These smaller increments seem to be a bigger deal when we’re working with only 14 horsepower

Moto, where did you pick up the 43 rear sprocket and do you have a part number. I am only 170 lbs and would really like to keep the revs lower.

I actually installed a 38 tooth rear (not in the US catalog, but available from UK) and went back to 15 tooth front. The 15/38 ratio is very close to 17/43 ratio.

The JT Sprockets part number would be JTR810.43

See the catalog listing here:
http://www.jtsprockets.com/catalogue/part/JTR810/

Looks like many of the sprockets are out of England on eBay, but I got mine there and total cost was about $25 and only took a week to arrive.

Here’s an example of a 43 tooth:
https://www.ebay.com/itm/33310350429...4AAOSwBlRcfmdm

I am about the same weight and I am pretty happy with the gearing. I think if the ratio was just a hair taller (17/42) it might peak the top speed a little since peak HP is at 7000 and seems to start dropping off as you near 8000. Hard to say without actually trying it, which I may do later on. Hope this helps.