Anyone with 212cc Predator on a Shift Kit?

[5-7HEAVEN]

Ok. Theoretically, a 28t/14t in a 7-speed cassette calculates to 50mph on a 26-inch tire.
That's in high gear w/a 3600rpm governor.
An 11-tooth clutch chained to a 21-tooth on the jackshaft = 1.909:1.....
On the right-end of the jackshaft, a 9-tooth sprocket links to a 45-tooth driven chainring = 5:1.....
Finally, a 24-tooth chainring drives the 14t cassette = .583:1.....
1.909 x 5 x .583 = 5.57:1....in 7th gear..
Or with a 10t clutch, 2.7:1 TAV-2 converter, then a 10t jackshaft linked to a 36t chainring.
2.7 x (36t/10t) = 5.67:1.....in 7th gear.
Research on two MB websites says that a trimmed 212cc will fit in my Sixthreezero frame.

 

[5-7HEAVEN]

I just ordered a Harbor Freight Predator 212cc engine for $135 delivered.
That's a bargain for me. I paid $7.00 shipping.
All other vendors wanted $90+ for shipping costs.

 

[5-7HEAVEN]

Still waiting for the 212.

HF won't ship to Hawaii. I had it sent to a freight company in CA, then to be routed to HI(Extra shipping charges now).
I decided to try utilizing timing belts and pulleys, jackshafting it ala shift kit to the bike's bottom bracket.
I realized the TV2 w/2.7 ratio reduces to 1:1 while riding. That set me thinking not to use it. Instead, I'll try to try a clutch w/a 23-toothed cog, then connect to a 40t jackshaft pulley(5"OD). Jackshaft out w/a 17t pulley to an 83t timing pully(8.3" diameter) @ the chainring. With a 34-14 cassette, gear ratios will range from 4.95-12.03:1.
Maybe I'll get to utilize 4 or 5 gears, not all 7 w/ungoverned 212.

If I used a 5-speed hub, I'd have tried to use a belt from chainring to rear hub.

 

[5-7HEAVEN]

Well, Harbor Freight is out of stock; clerk said it's an "indefinite wait".
So I bought another 212cc clone from a CA vendor this past Monday. Since no one ships engines directly to Hawaii, the motor was delivered to a shipping company in Carson, CA.
The 212cc clone should arrive in a few days.

In the meantime, I believe I figured out the gearing, using either standard belts and pulleys, or timing chain belts and sprockets.
Belts and pulleys are cheaper than timing belts/pulleys, and readily available on the I-net. However, to get correct gearing, the driven pulleys have to be large.
I'm trying to keep jackshaft equipment small, and have a huge 10"-12" driven pulley at the bottom bracket.
So a small centrifugal clutch pulley is 3.7" outside diameter(OD). The connecting jackshaft pulley is 5" OD.
Gear reduction is 5"/3.7" = 1.351:1.....
The other jackshaft pulley is 1.75", and belts to a 12" chainring pulley.
12"/1.75" = 6.857:1.....
1.351 x 6.857 = 9.264:1…..
The drive sprocket at the bottom bracket is 24t.
The existing 7-speed cassette shows to be 28t/14t.
So First gear is 28t/24t = 1.167.....
Multiply 9.264 x 1.167 = 10.811.....
In Seventh gear, it's 14t/24t = .583:1.....
Multiply 9.264 by .583 = 5.4:1.....
So.....10.811 in First gear and 5.4:1 in final drive.
Using a gear ratio calculator, that's 51.5mph @ 3600rpm, or 35.8mph @ 2500rpm/max TQ.
In perspective, a bike with a 10t driver/54t pulley at the rear wheel = 5.4:1.....
Add a Trans Verter w/a 2.7:1 ratio = 5.4:1 x 2.7:1.....
5.4 x 2.7 = 14.58:1, which is awesome from a standstill!
When the TV reverts to a 1:1 ratio before midrange rpm, overall final drive reduces to 5.4:1.....
not so awesome.

 

[5-7HEAVEN]

Using timing gear items, I bought an aluminum 83t/8mm pulley. It is 8.32"pitch diameter(PD)with a 25mm width. I'm adapting it onto an SBP freewheel, which screws onto the right pedal. It will bolt onto a 24t chainring sprocket, which will chain to the 7-speed cassette.
Belting onto the 83t is the jackshaft's steel 17t timing sprocket. It is 1.7" PD/25mm width. Its bore is tapered from a 9/16" to a 7/16" inside diameter(ID). I'm unsure how it ever connected into the go kart's drivetrain. The strongest way to adapt it to my needs is to bore the pulley to 3/4" ID and weld it onto the 3/4" jackshaft.
On the jackshaft's other end will have a 4.41" aluminum timing pulley. It is 44t/8mm pitch and uses a 30mm belt.
It belts onto the engine's centrifugal clutch, which has a 21t(2.105"PD) timing sprocket.
Using these specs, I can calculate gear ratios for the 7-speed cassette:

Basic gear ratio from driven pulley to the jackshaft is 8.32"/1.7" = 4.894:1.....
Ratio from jackshaft to clutch = 4.41"/2.105" = 2.095:1.....
4.894 x 2.095 = 9.239:1.....
So, First gear is 9.239 x (28/24) = 10.779:1.....
and Seventh gear is 9.239 x (14/24) = 5.389:1.

The 212 engine will be ungoverned for now. HP @ 7HP/3600rpm and max TQ @ 2500rpm.
Using a gear ratio calculator, top speed of 51.7mph @ 3600rpm....
or 35.9mph @ 2500 rpm/max TQ.

 

[5-7HEAVEN]

Yes. The 7hp 212cc clone arrived yesterday. It fit easily and lay flat inside the Sixthreezero's midframe, once I removed air filter, muffler and gas tank.
The shift kit and drivetrain are progressing. Working backwards, there's a 24t chainring connected to the 7-speed cassette. An 83t timing sprocket at the bottom bracket will link to the 17t cog welded to the jackshaft. On the left side, I bought a 44t timing gear for the jackshaft. It'll belt to the 23t cog clutch on the engine.
Gearing for First and Seventh gear will be 10.9:1/5.45:1.

There's tons of room in the midframe. I'm gonna try to install the jackshaft and timing sprockets in front of the engine.

 

[darwin]

Well, Harbor Freight is out of stock; clerk said it's an "indefinite wait".
So I bought another 212cc clone from a CA vendor this past Monday. Since no one ships engines directly to Hawaii, the motor was delivered to a shipping company in Carson, CA.
The 212cc clone should arrive in a few days.

In the meantime, I believe I figured out the gearing, using either standard belts and pulleys, or timing chain belts and sprockets.
Belts and pulleys are cheaper than timing belts/pulleys, and readily available on the I-net. However, to get correct gearing, the driven pulleys have to be large.
I'm trying to keep jackshaft equipment small, and have a huge 10"-12" driven pulley at the bottom bracket.
So a small centrifugal clutch pulley is 3.7" outside diameter(OD). The connecting jackshaft pulley is 5" OD.
Gear reduction is 5"/3.7" = 1.351:1.....
The other jackshaft pulley is 1.75", and belts to a 12" chainring pulley.
12"/1.75" = 6.857:1.....
1.351 x 6.857 = 9.264:1…..
The drive sprocket at the bottom bracket is 24t.
The existing 7-speed cassette shows to be 28t/14t.
So First gear is 28t/24t = 1.167.....
Multiply 9.264 x 1.167 = 10.811.....
In Seventh gear, it's 14t/24t = .583:1.....
Multiply 9.264 by .583 = 5.4:1.....
So.....10.811 in First gear and 5.4:1 in final drive.
Using a gear ratio calculator, that's 51.5mph @ 3600rpm, or 35.8mph @ 2500rpm/max TQ.
In perspective, a bike with a 10t driver/54t pulley at the rear wheel = 5.4:1.....
Add a Trans Verter w/a 2.7:1 ratio = 5.4:1 x 2.7:1.....
5.4 x 2.7 = 14.58:1, which is awesome from a standstill!
When the TV reverts to a 1:1 ratio before midrange rpm, overall final drive reduces to 5.4:1.....
not so awesome.

This is an ENGLISH only website please! Above looks like a message from Krypton that needs to be deciphered.

 

[5-7HEAVEN]

Too much technical information, I guess.

FYI, In a large nutshell, a 212cc engine fits easily(horizontally) in a Sixthreezero extended cruiser bicycle, with shift kit & 7-speed cassette.
Using timing belts and cogs to transfer power, not chains and sprockets.
A jackshaft is positoned up front, under the engine.
Gear ratios from 10.9 First gear to 5.45:1 Seventh gear.
Engine is governed. Cruising speed should be 32mph. Top speed maybe 50mph.

 

[5-7HEAVEN]

Epiphany.....
The best ways for a bike to survive 212cc engine’s power, especially with a shift kit.....
Correct gear ratios.
Pedal from a standstill.
Smooth application of power.
Smooth, slow shifting.
Belt drive instead of chain drive.

 

[5-7HEAVEN]

Parts are almost all here, for my 212cc build.
I'm waiting for my steel motor mount plate. My bike"s midframe is VERY wide. When they extended it, the manufacturer left 10" of the bottom of the seat tube. They used that as a post for the front derailleur. Removing that derailleur allows me to use the post as the welded "third point attachment" for the motor mount.