CVT CVT Project On Restored Cruiser

Well there seems to be alot of interest suddenly on CVTs and I've been asked to show my project. So I'm gonna go ahead and post what I've been working on.
I won't bore you with a bunch of stuff about the restore; just a couple of pics. I scored a Western Flyer cruiser for $10 last summer. The next day the guy's neighbor asked me if I wanted another? FREE. Magic words indeed. This one was a Murray West Port. Both bikes date around the '70s. So between the two, and my new best friends at Bikeworldusa.com, I made one really heavy bike. I guess for the purpose of this post we can refer to them/it? as a Western Flurray?
I started with the wheels and laced 11ga. spokes from Husky onto the two rear wheels. I'm using a rear coaster brake in the front and back. I may also add calipers to it, but so far these things are working great! Each wheel weighs in at 11lbs.
Not shown in the pics are the neat lights I'll be adding with a 12V SLA and generator/charging system. There will be a torpedo fender light up front using a small halogen reflector bulb. The regular headlight will merely be upgraded with 12V auto bulbs. There will also be a pair of driving lights next to it (Harley type setup) one a 10W halogen flood the other a 20W halogen spot. That combo was working great on my other bike and I commute in the dark and these let me see everything. Finally on the rear fender will be a Harbor Freight small LED marker light and up above on the rack a Flash Gordon looking 12V tail light, just because. The springer fork and seat give this thing quite the cushy ride.

Rear Rack Fabrication

I'm using the Robin engine from my friction drive coupled to a goped/pocket bike CVT. Since the CVT output sprocket spins opposite the input clutch pulley, it was necessary to mount the engine in similar fashion to the friction drive setup. That is, on the left side of the bike. The original plan was to do a frame mount, but due to the height of the Subaru engine and the offset of the CVT, there just wasn't any room in the frame without using a jackshaft. The pedals also presented the usual problem with the frame mount so, rack mount it was.
While the engine still sits off to the left side of the rear wheel, the weight is distributed more evenly than just the friction drive setup as the CVT weighs almost as much as the engine!
You may notice that the CVT is mounted upside down. That was to facilitate the chain alignment. If the CVT was mounted as it should be, the chain would be too far to the rear. There is an oil breather vent hole in the TOP side of the CVT. That had to be sealed to keep oil from running out as top is now bottom.
Also, in order to be able to change the inevitable flat tire on the rear, I slotted the rear rack support (like the friction drive had) so that it acts as a chain tensioner too. The Staton kit that I had, was used for the front bike to rack mount. The Staton rear supports were too short so I had to make those. Now to change a tire is the same as any other bike and aided by the double center mount kick stand.

GO , GO Nuttsy

that IS a well planed out rack and mount. still just alittle concerned about the chain clearance going down thru the rack, maybe it's the angle ?

are you going to match paint it ?

steve

Mounting the Engine

Actually, mounting the engine was pretty straight forward. Four mounting holes on the bottom of the engine were bolted to the support frame. The support frame mounting holes were slotted to allow for engine alignment left and right. The CVT is mounted to the engine with 4 bolts inside the black cover. Also a brace was added to the mounting hole for the CVT. These holes have a rubber insulator inside the hole, although I don't notice any vibration out of the engine to worry about.
It was about this point that I was looking at the engine/rack assembly and thinking I hated it! It just seemed to subtract greatly from the classic cruiser look that I like so much. I was this close to going to a pusher trailer or pusher side car. The side car actually will probably be my next project. I already have the 2.5HP engine I plan to use. I got it in December and have been running it a little each week to break it in. That will also use a CVT. Most likely a Comet brand. But another project for another time.
I digress. Anyway, I decided to see this thing through to completion. After all, I could always take it off and go in another direction later. I just hate to cut that rear fender to make room for the chain. But it must be.
I am glad though that I kept at it. I really like the CVT and the bike has more power and speed than my old one did with the friction drive. AND this bike is alot heavier.
Also a note on the tensioner. I thought the pivoting rack would provide all the chain tension I needed. WRONG! In practice, I guess due to the long chain run, the chain was bouncing all over the place. You may be able to detect the scuff marks on the whitewalls. A trip to Tractor Supply solved that.
Try to look beyond the raw rack and welds. It will be painted to match the bike.

Some shots of the chain tensioner and chain alignment.

DT, the chain tensioner kept the chain line straighter than the previous pics show. Also, I moved the front cross brace in the rack to make more room for the chain slap, which is now almost non existant.

Very Nice. I like it. I'll be using some of your ideas.

please, what size chain and sprockets?

Chain and Sprocket info

Stude13,
The chain is #41 from Northern Tools. The rear sprocket is a standard HT 44tooth I got from BGF. Yeah, I went there. LOL Truth is, it was cheap and fast. 3 days from Calif. to FL! He must have shipped 5 min after I placed the order.
I had to get creative on the front drive sprocket. The CVT comes with a 18T (if memory serves) BUT, it is for metric 8MM chain and the shaft is splined. I hunted every scooter and gear supplier I could think of for something more substantial, yet with splined hole. No dice. Many LOOK like they'll fit but bore size is wrong. I took the CVT to a machine shop to see what they could do. Everything they suggested was twice what I paid for the CVT! I asked if I got a sprocket with the right pitch and number of teeth and with SET SCREWS, could they just bore the shaft to the right size. Well, that they could and sprockets were about $15. And another $40 to bore it out! SHEESH! Why couldn't I bore it out. So, that's what I did...sort of. Couldn't find a sprocket with the proper # of teeth that I wanted AND #41 chain, AND a close dia. bore. So I settled for a 12T 5/8" bore but for 40 chain. It took a 9/16" drill bit to open the bore to the proper size and about an hour with the grinder cutting down the teeth to fit the 41 chain. But I succeded. I'm sure there has to be something out there with a closer fit but I wanted to get the thing DONE. I also ordered a 14T with the 12 in case I wanted a little more top end but haven't machined that one yet and don't know that I'll need it. I'm happy with the performance and speed I get out of the 12. (yeah, right. temporary condition, I'm sure)
Also, the sprockets have 2 set screws. I can turn the sprocket to the inside or outside for best chain alignment, However, the BOTH set screws DO NOT line up with the splines in the shaft. So I drilled and tapped another hole so that BOTH set screws seat in a spline groove.
In the end then, the CVT is supposedly 7:1 ratio. I added 12T to 44T. And using one of the gear ratio calculators I 'think' I got on this site, was able to plug in the numbers and get what I thought were the right gears. Seems I did get it right. The bike will move from a dead stop without pedals (although I do pedal anyway). I guess old habits die hard, as they say. Don't get me wrong here. Its a slug off the line; but it goes. And I top out at 30. It pulls the mild hills around my house without pedaling and even picks up speed along the way. Something my friction drive couldn't do and I had to help that up these same hills or it would bog.
All from a 35cc 4 stroke. CVTs RULE!

Did you check here or here? They're #25 chain though...

Nuttsy,

you have 6.56:1 at the output shaft in "low" and 3.15:1 in "high"

you are going to have to add 6.5-7:1 from there to the wheel. you can go HUGE on the wheel sprocket OR add a jackshaft to your mount rack just under the output shaft.

you don't have enough reduction yet. that's why it's a dog taking off, it may be you will also get some more topend too if the engine can rev freely up top.

i had the same lateral slop and flop with the chain on my Staton setup, a good tensioner/ guide makes all the difference.

steve