Jack shaft vs torque converter

[Fang]

So i'm torn at this point,
making my own custom jack shaft set up or a torque converter
putting it on a 6.5hp 212cc predator, I've heard the torque converter tends to slip while going up hills but I really like the fact that it's variable speeds!
The jack shaft looks really simple to set up and will probably be cheaper though.
Anyone willing to chime in and school me on transfer cases is more than welcome, I just got a grasp on my 66cc before I took it off my bike wanting more power

 

[Sidewinder Jerry]

I personally use a LandRider derailleur with a shift kit. My bike shifts 5 gears automatically. I've been riding the bike for three years now and have had no problems with it.

 

[silverbear]

Signing on to this thread as I'm also trying to learn more about the torque converters. Initial outlay seems kind of high, but having in effect gears that brings the price way down. Also the fact that it bolts right onto the engine and looks pretty simple to me. That's assuming the final drive to the rear wheel lines up. I'm wondering if the shaft at the rear of the converter is long enough for some lateral adjustment of the driving sprocket going to the rear wheel. Also wondering if need be the shaft can be replaced with a longer one.

I hope that those with some direct experience with torque converters will weigh in on this thread.
SB

 

[magna_503]

I have one sitting in my room somewhere, and it looks like the rear shaft can be replace with a longer one to line up with the rear wheel, or even run an 12" shaft to the crank for shift kit???..

But I would think the gear ratio from the output of the CVT to the rear wheel would need to be around 7.5:1 ratio. Can't do that without another jackshaft setup though.

 

[chainmaker]

I'm signing on as well, I'd also like to find out more pros/cons.

 

[scotto-]

If you don't mind reading for a couple of days, my build went from CVT w/jackshaft to just a 2-disc clutch and jackshaft and some reasons why. Mind you I built this bike to race....not to putt around on.

The read: http://motorbicycling.com/showthread.php?t=32789

this:



to this:


I do like both set-ups very much and for different reasons. The main reason for switching from the CVT is that it robs the engine of the higher rpm's needed for racing and I was smoking too many belts with the power I am running now.

 

[mirage]

hi, all. converters would be nice. but in the uk we are not allowed gears, in fact anything is illegal, well you are allowed to breath air lol. well i have recently made a new drive system for my huasheng, it came with the long reduction box, inside chain driven, the is no choice drive sprockets from the 11 tooth normally in the kit. so first i used a 14 tooth bmx freewheel, modified using the original bush from the 11 tooth as i needed the key way ect, worked great for nearly 2 years, but i decided a little more speed to bring the revs down a bit for cruising. PS. i use a 75 tooth cnc rear sprocket. it,s hilly where i live. so i hit on the idea of using a shimano rear bicycle hub fitted to the gearbox shaft. it fitted almost perfectly driving the correct way, when fitted on the shaft, this allows a few choices when using bmx single shimano sprockets. i chose a 15 tooth, now the problem was getting it to drive from the drive shaft, i ground a slot in the hardend internal bush of the standard shimano hub with a dremel, the next problem was the drive from the outer end where the bolt holds the sprocket onto the shaft. i ground a hole in the hardend shaft very difficult. to fit a drive screw or pin through it. i used the old wheel hub that i got the shimano hub off. cut the hub in half well about inch and a half. as i wanted the drive molded teeth that fits into the end of the shimano hub, then drill a hole tthrough

 

[oldtimer54]

For my builds I use a CVT for the big engines. I use a jackshaft as a shifter with my rear derailer for 3hp or smaller engines. Derailers cant take the power of a big engine. To help my engines last and to get me up these hills I need different gear ratios, CVT's and derailers give them to me. So to sum it up CVT for the big engines jackshafts for the small ones.

 

[silverbear]

For my builds I use a CVT for the big engines. I use a jackshaft as a shifter with my rear derailer for 3hp or smaller engines. Derailers cant take the power of a big engine. To help my engines last and to get me up these hills I need different gear ratios, CVT's and derailers give them to me. So to sum it up CVT for the big engines jackshafts for the small ones.

Do your belts hold up well for you? I've never used a cvt before,but I'm thinking about a cyclecar project with a much bigger engine, a 420cc Predator. It sounds like just the thing for it.
SB

 

[oldtimer54]

Do your belts hold up well for you? I've never used a cvt before,but I'm thinking about a cyclecar project with a much bigger engine, a 420cc Predator. It sounds like just the thing for it.
SB

Ya the belts hold up fine. I only use Kevlar belts. I get them on amazon for about $15 delivered. I just rebuilt my CVT. I installed new bearings, cleaned it and lubed the one spot you lube a CVT. It took about one hr and is very easy to do. A CVT is great for getting me up these little 10000 foot hills. If kept clean I don't get any slipping. By the way Iam using a jackshaft with my CVT so I can get a careful chain alignment to the rear sprocket and a power take off for a generator. Chain alignment is very important and kind of tricky.

 

[KCvale]

I'll know soon enough how this torque convert works on a 212 Pred.

It is actually the TC2-1002P from gokartsusa.com, the P just indicates it has the spacer bushing needed for the 212 Pred.

The price says under $200 but that is far from delivered price with cover, chain guard and shipping, $270.66 delivered to me and it's on it's way.

It is going on this 29" Macargi 'Fatal Love'

It is just a coaster brake cruiser so it is also getting a pair of C brakes as well as HD tubes and liners.

I expect I will have plenty of room for 212 as a 49cc HS fits in with room to spare.

This my first torque converter and really big engine so I guess I'll see when it makes it to the bay.

 

[culvercityclassic]

Ya the belts hold up fine. I only use Kevlar belts. I get them on amazon for about $15 delivered. I just rebuilt my CVT. I installed new bearings, cleaned it and lubed the one spot you lube a CVT. It took about one hr and is very easy to do. A CVT is great for getting me up these little 10000 foot hills. If kept clean I don't get any slipping. By the way Iam using a jackshaft with my CVT so I can get a careful chain alignment to the rear sprocket and a power take off for a generator. Chain alignment is very important and kind of tricky.

I have to agree with oldtimer. I have used both and still do. Built a BTR for my son with a jack-shaft and he blew the motor up with hi-rpm runs. Switched over to a CVT and the bike runs great. The only issue I have is chain alignment to the back wheel while keeping the motor centered. This bike show how I solved that issue:
http://motorbicycling.com/showthread.php?t=39900&page=5

 

[oldtimer54]

I have to agree with oldtimer. I have used both and still do. Built a BTR for my son with a jack-shaft and he blew the motor up with hi-rpm runs. Switched over to a CVT and the bike runs great. The only issue I have is chain alignment to the back wheel while keeping the motor centered. This bike show how I solved that issue:
http://motorbicycling.com/showthread.php?t=39900&page=5

I use these so I don't take the chance of doing what your son did and the price is the best you can find well the best I can find anyway: http://www.tomtop.com/digital-engin...ble-inductive-for-racing-motorcycle-k934.html
That plus heavy duty valve springs and you should be set. I would not want to run a stock engine if the governor has been removed with out heavy duty valve springs.

 

[Dan]

Thanks for posting OldTimer. Awesome price.

http://www.tomtop.com/digital-engin...ble-inductive-for-racing-motorcycle-k934.html

 

[scotto-]

Ya the belts hold up fine. I only use Kevlar belts. I get them on amazon for about $15 delivered. I just rebuilt my CVT. I installed new bearings, cleaned it and lubed the one spot you lube a CVT. It took about one hr and is very easy to do. A CVT is great for getting me up these little 10000 foot hills. If kept clean I don't get any slipping. By the way Iam using a jackshaft with my CVT so I can get a careful chain alignment to the rear sprocket and a power take off for a generator. Chain alignment is very important and kind of tricky.

I've only used the Kevlar belts on the GTC (Comet TAV 30) CVT and with my 15+HP engines was smoking them frequently. Chain alignment was perfect as well.

Just a heads up. But talk about "holeshot" at the races And wheelies on take off!

 

[oldtimer54]

I've only used the Kevlar belts on the GTC (Comet TAV 30) CVT and with my 15+HP engines was smoking them frequently. Chain alignment was perfect as well.

Just a heads up. But talk about "holeshot" at the races And wheelies on take off!

LOL well at 9000+ feet even with a racing carb and a good header Iam probably only making 6HP so I should be ok. With that much power I would try the TAV 40.

 

[scotto-]

I'll know soon enough how this torque convert works on a 212 Pred.

It is actually the TC2-1002P from gokartsusa.com, the P just indicates it has the spacer bushing needed for the 212 Pred.

The price says under $200 but that is far from delivered price with cover, chain guard and shipping, $270.66 delivered to me and it's on it's way.

It is going on this 29" Macargi 'Fatal Love'

It is just a coaster brake cruiser so it is also getting a pair of C brakes as well as HD tubes and liners.

I expect I will have plenty of room for 212 as a 49cc HS fits in with room to spare.

This my first torque converter and really big engine so I guess I'll see when it makes it to the bay.

I hope you have really thick soles on your sneakers.....you're gonna need them doing the Flintstones back-pedal braking with that set-up

Don't worry KC, you're only about 2 years behind many members on this site with this type build.. others will catch on, eventually!

 

[scotto-]

LOL well at 9000+ feet even with a racing carb and a good header Iam probably only making 6HP so I should be ok. With that much power I would try the TAV 40.

I was actually thinking bigger than a TAV 40 and perhaps a symmetrical belt type as well. I'll get around to it one day lol

 

[silverbear]

Oldtimer said,
"By the way Iam using a jackshaft with my CVT so I can get a careful chain alignment to the rear sprocket and a power take off for a generator. Chain alignment is very important and kind of tricky."

I was thinking about running a generator or alternator off of the jackshaft and was wondering if you have pictures and commentary about what you did and how you did it. Thanks,
SB

 

[oldtimer54]

I was actually thinking bigger than a TAV 40 and perhaps a symmetrical belt type as well. I'll get around to it one day lol

When you do it let me know Ill want to see pics.