I replaced the belt on my 2017 800 Trail today. It was my chance to see whether a trailside belt swap would be do-able .
I have often wondered because plenty of the rides we do would be considered long and expecting a tow from some fellow rider for 80 miles over mountain and river and valley, is pretty much out of the question. Any fellow machine trying it would itself be damaged.

At spitting distance to 6000 kilometers I though it was prudent to go inside and see if the spare belt I bought some time back, was urgently needed.  (I wish there was a plug on top of the CVT case you could pop out and measure the belt width!)

I did take the aluminum CVT cover off without removing any more plastics than the battery cover. 1/4" drive 8 MM socket and ratchet on 6" extension for most of the cover bolts, 8 MM socket and ratchet alone for 4 of the forward ones and an 8 MM box end was needed for the most forward of the cover bolts.

I was blessed more than NMKawi apparently as the CVT nuts came off pretty much as expected. (No rust apparent in the whole project). Maybe they saw that 1000 Ft Lb. air impact and they just surrendered.

So I looked with an eye to seeing if a trailside belt swap could really be done on an 800.
I made careful measurements with a top quality vernier caliper and found that the belt is on average 16.94 MM thick when measured from the top of a corrugation to the bottom peak of a corrugation. The space between the outer flange of the secondary clutch plate and the gasket surface of the CVT compartment varies a bit as you go round but the closest is 16.14 MM space.

This means that in the tightest spots (top and bottom) the belt is thicker by 9/10 of a millimeter than than the space it must pass. That's IF it were at the optimal alignment to fit in that space, which it is not. It would need to twist a good 45 degrees to achieve that and it is very stiff and not compliant at all. An attempt to twist it the needed degree with a wrench was not successful, something would have been damaged. Here's where it has to go to come out with the rear clutch intact. The sheaves turn freely CCW only.


The belt material is very stiff and does not 'give' much at all to pressure.

My conclusion? A field belt change would not be possible unless the rider carries a 1/2" impact gun (maybe a battery electric one like Milwaukee) and sockets. You'd need:
-A jack for the back axle.
-17 MM socket and 6" extension and impact gun
-10 MM socket and 6" extension and ratchet for the battery cover
-13 MM box wrench for the battery hold down
the 10 MM will do for the battery posts
-8 MM socket and the 1/4 drive stuff for the CVT cover
-8 MM box end wrench for the forward cover bolt
-clutch spanners for front and rear clutches to hold them against torque
-1/2 drive 36 MM socket, short for the secondary clutch
-1/2 drive 32 MM deep socket for the primary nut (in lieu, a 3/4 drive 1 1/4" short socket with
1/2"-3/4" adapter is a perfect fit! You'll make that nut your bitch)
-A 1/2" torque wrench at 85 Ft Lb. for final reassembly
A tube of red loc-tite and the spare belt and you're laughing. You can do a trailside belt swap on a CF Moto 800.
Otherwise without all that stuff forget it. Ain't gon happen.

I found that my belt at 6000 Km. my stock belt still measured 34.7 MM against a recommended replacement spec of 33 MM. It was only 1/3 worn out! No cracking or deterioration seen. Amazing.
Replaced it anyway on the advice of my dealer, a very savvy man with CVT's in many applications.
It was very clean in there, considering.
https://imgur.com/JNk3ynj
Blew a lot of toxic dust out of the primary. I was very happy to see that for all the dusty environs I have traveled, the secondary showed very little sign of wear.
https://imgur.com/kFGtrVb
Still I am measuring and planning furiously, toward the vision of installing a particle separator for both CVT and motor. Chuck that dust right back where it came from.
Doesn't the statue of liberty bear the caption: "Bring us your huddled masses yearning to breathe free"? My 800 wants to breathe free.

[2015 Z Force 800 53/Trail EPS]

Like you after doing all the measurements came to the conclusion I would need ...well..a few less tools but still..several pounds worth and a lot more work then I was willing to do. Then Bill did videos on how he was able to R&R the belt after opening up the secondary and not taking either one off. Not saying the belt was completely unscathed..and not sure I would put a belt through that.. but.. he did it. The vids are here somewhere and I'll post links when I find them.

Interesting because of course opening the secondary just moves the inner sheave further in, and doesn't change the position of the outer sheave flange that's the tight spot. 

I had the thought that if a guy ground down about a consecutive fifteen or so of the inner corrugations, down a good 2 MM that might be a trail mountable get-home belt that could be put on just by taking the wheel off and the battery and the CVT cover. Well, it would be better than abandoning the machine.

Makes me wonder if there's been a bona-fide case of a CF Moto belt going to heaven while on a trail ride. Don't think I've heard of one.

[2015 Z Force 800 53/Trail EPS]

I think opening the secondary gave him enough play on top to work enough angle on the belt to fit the non-movable sheave edge between the coggs just enough. Check it out:

https://www.facebook.com/bill.welker26/videos/2380450955308106/


https://www.facebook.com/bill.welker26/videos/2380451575308044/

I thought about milling a few thousands off that sheave edge and then taking the inside edge off the case across the top..might just be enough.

I wouldn't wish on anyone trying to swap that drive belt out on the trail....bad enough in the shop  During the engineering process I'm sure the design could easily have been improved, then you would have to think about what happens in the field.......after sale.

Just did a clutch service including a new belt 2013 Commander, getting to the clutch cover & then taking it off would be annoying on trail....doable.....just like the ZFORCE. The reward with the Commander is you spin in a 8mm bolt into the driven clutch, lift the drive belt off & install the new. Then their is the CFMOTO........

Thanks for the links NMK. it all comes back to me now, especially as I responded on that thread!
Bill did it. Kudos for success.
Too bad the video starts out with the belt already in between the top sheave edge and the casing, a feat I have a hard time imagining doing on mine. I wonder if there are slight manufacturing tolerance variables in any of the parts, especially the belt?
I'd be leery of trimming the sheave at all, due to the point that the belt was riding as high in the secondary as I ever like to see in a modified King Quad CVT. The plies of the belt were right at the edge of the flange as found.
Trimming the inner case at the gasket surface ought to work but I think I'd rather trim the inside of my old belt as an emergency spare. These inner corrugations only keep the belt from flopping over edgewise and they can do that with some of them being a couple of millimeters shorter.
Either way it would likely mean carrying a means to turn the rear CVT clutch like Bill did, the 36 MM nut.

All so unnecessary. Damn you, CF Moto engineers. Sometimes I just want to shake you and ask, 'Why?'

ps: I greased the outer cover primary clutch bearing too, though it was a bit of a bugger. I left the bearing and seal in place and used a mini grease gun and U joint point tip to put a level of grease at the bottom of the well so that when the case was replaced the shaft end it should push grease toward the inside of that bearing. Not having taken it out, I don't know if it is a sealed bearing or not but I gave it the benefit.

[2015 Z Force 800 53/Trail EPS]

Yeah I pulled the retainer and the seal, then flushed it with spray brake-kleen, air dried it, then pushed grease with my finger through the back side so there must not be a seal on that side. Reinstalled the seal and retainer and all was good. It was about to F'k itself cause it was bone dry and those types of bearings running at crankshaft speeds like they do really should have a lube source. Not a smart design.

Mine didn't feel exactly like a happy bearing so I think it must have been hurting for grease too. A guy could drill that bump on the outside of the cover to #3 and tap it 28 tpi for a mini grease zerk as long as he's judicious with how much to put in, and how often. Like one pump hardly ever. 

I always have a water bottle with me. If a belt must be changed I cut up the bottle and place a piece of it on the inner ridge. Then the belt dus not hook up on the ridge and you can hammer the belt in. That works for me.

Maybe the 500s are different but I've changed the belt 3 times on my 2016 uforce 500 and never taken the clutch off. I use a long 8mm bolt threaded into the secondary and it opens it up enough to take the old belt off and install the new one.

[2015 Z Force 800 53/Trail EPS]

Maybe the 500s are different but I've changed the belt 3 times on my 2016 uforce 500 and never taken the clutch off. I use a long 8mm bolt threaded into the secondary and it opens it up enough to take the old belt off and install the new one.

Yeah...the 500s's case is different.

You should be able to use this method https://www.youtube.com/watch?v=3_q1rEhlbFQ

I have heard a few people say they change the c force 800 belt (should be the same engine and cvt on the z force 800) with the method i showed in the video link above

[2015 Z Force 800 53/Trail EPS]

You should be able to use this method https://www.youtube.com/watch?v=3_q1rEhlbFQ

I have heard a few people say they change the c force 800 belt (should be the same engine and cvt on the z force 800) with the method i showed in the video link above

Nope...well some is the same but all 800s have an issue with the back cover patruiding over the secondary about the 11-12:00 position that doesn't allow the belt to easly pass between it and the outer sheave, even open...because it's the inner sheave that moves, not the outer. None of the rest have this issue. If you bevel that lower edge and take about 2mm off the outer sheave, the belt will pass between it without using excessive force.