2 Manual Clutches for two speed trans

[Grape Ape]

Friend of mine has the 3d Motorsport Manual Clutch on his go kart and I was thinking about using two on a jackshaft with a actuation lever to select from clutch #1 to Clutch #2. Anyone see an issue with my thought pattern?

212cc Predator with 12 tooth sprocket
Jackshaft with input sprocket 12 tooth
Clutch #1 12 tooth
Clutch #2 17 tooth
Live Axle Sprocket for #1 Clutch being a 90 tooth
Live Axle Sprocket for #2 Clutch being a 90 tooth
13" rear tires

1st gear ratio 7.5
2nd gear ratio 5.29

http://3dmotorsport.net/

 

[Poboy kartman]

Actually...I kinda just skimmed this...(I'll go back and look....) but...I think your idea is more than doable....but wasted with those gear ratios....

You could probably run your final ratio with just a good centrifugal clutch.

 

[Grape Ape]

What would you recommend for gear ratios, all my buddies are running 6:1 or 6.6:1, I think 1 is running 7:1. I did not want to go to aggressive but want good hole shot and good top end. We are running a dirt track road course with at least 4 90+ degree turns.

 

[bob58o]

I like it!
I think I'd like around 4800 to sync with around 3200?
Depending on the engine mods you may want 5400 to sync with 2400 RPM????
HP is near max 3200 to 5200.
TQ is near max 1600 to 3200
Torque curve for stage 1 Predator with stock springs.

I think 7.5 and 5:1 is pretty good.

 

[bob58o]

I don't know jack about racing - or on dirt. I'm sure there is such a thing as TOO MUCH low end for dirt?

 

[Grape Ape]

So you think I'm pretty close on ratios, I did not want to have too hard of a shift but aggressive enough to be felt.

 

[mckutzy]

Wow they sure came down in price.... Id almost be thinking about another next to my MK1....
thatll make a two speed for sure.... "Clutching" between the 2, I imagine will be difficult to rig up.

 

[ddowns46]

If i were set on building a 2 speed kart, instead of using 2 manual clutches, i would use a centrifugal clutch, a one way sprocket, and one manual clutch.

The centrifugal clutch would be installed on the engine shaft. It would be chained to a direct drive sprocket on the jackshaft.

First gear would be a one way sprocket on the jackshaft chained to a sprocket on the rear axle.

Second gear would be the manual clutch mounted on the jackshaft running to a sexond sprocket on the rear axle.

First gear would be with the clutch lever pulled in. Second gear would be with the clutch lever released. Perfectly smooth shift whenever you want.

I would make sure that the jump between first and second gear wasnt so large that it reduced engine rpm to below the centrifugal clutch stall speed.

 

[bob58o]

Wow they sure came down in price.... Id almost be thinking about another next to my MK1....
thatll make a two speed for sure.... "Clutching" between the 2, I imagine will be difficult to rig up.

$170? Weren't they just like $350?

 

[Flyinhillbilly]

I'd put a lever between the two clutch cables so when one is pulled, the other is released. As illustrated by the state of the art rendering.

 

[firemanjim]

Why not just use a tried and true, old school 2 speed set up like I put on my Roper mini bike? 2 clutches and a one way sprocket...... ? I figured I could adapt it to a kart with no problems, and I KNOW I works great on my mini. Can pop and ride a wheelie in first gear with little to no effort. Second gear runs me up to 55mph..... (@6400 rpm)

 

[mckutzy]

Bob- ya they were just about $250-$300... In that range...
With almost the same if not more versitality(except the on/off ability, I'd would have got a 2,3,4 plate racing clutch.

 

[ddowns46]

Bob- ya they were just about $250-$300... In that range...
With almost the same if not more versitality(except the on/off ability, I'd would have got a 2,3,4 plate racing clutch.

The original launch price was $229.99. We dropped the price to 169 in order to attract a wider market and have sold a few hundred clutches so far at that price point.

We have customers using this clutch on everything from 50cc motorized bicycles to built CR 500's. One guy is even winning races using it on a twin cylinder 500cc sled engine that is advertised at 80 horsepower and 11,000 rpm. We designed it to be as versatile as possible.

Another customer running a stock bore/stroke predator 212 smoked a TAV equipped big block predator 420 in 400' drags. There is a video of it on youtube.

 

[Jfive]

I think it would be like shifting a semi with no clutch. Matching Rpms harder with gas then diesels do to wider range of rpms. Maybe a shifter like f n r but it would be 1st N 2nd that way you could push the shifter into first then allowing it to go into n to allow rpms to drop then into 2nd.

 

[bob58o]

The original launch price was $229.99. We dropped the price to 169 in order to attract a wider market and have sold a few hundred clutches so far at that price point.

We have customers using this clutch on everything from 50cc motorized bicycles to built CR 500's. One guy is even winning races using it on a twin cylinder 500cc sled engine that is advertised at 80 horsepower and 11,000 rpm. We designed it to be as versatile as possible.

Another customer running a stock bore/stroke predator 212 smoked a TAV equipped big block predator 420 in 400' drags. There is a video of it on youtube.

So you are the guy to talk to about these?

 

[landuse]

So you are the guy to talk to about these?

He is the inventor and distributor of the clutches

 

[Jfive]

Where is the 1" shaft version?

 

[Grape Ape]

I have tried the centrifugal clutch design and also the of comet style and does not do much with no control and when the sprag bearing goes out it get nasty quick with no warning. To get a good sprag bearing and the machining of the hub cost gets up there and still no control. If you do a shifter like Flyinhillbilly showed you would have to go past a point where both clutches are disengaged (eliminate need for sprag bearing all together) which is the weak link in the centrifugal clutch design)

 

[Poboy kartman]

Just have ddowns46 send me two and I'll figure it out for ya.

 

[ddowns46]

I have tried the centrifugal clutch design and also the of comet style and does not do much with no control and when the sprag bearing goes out it get nasty quick with no warning. To get a good sprag bearing and the machining of the hub cost gets up there and still no control. If you do a shifter like Flyinhillbilly showed you would have to go past a point where both clutches are disengaged (eliminate need for sprag bearing all together) which is the weak link in the centrifugal clutch design)

I would love to see this working simply because i've never seen it done before. Send us an email at sales@3dmotorsport.net and we'll send you a $50 discount coupon if you purchase 2 clutches needed to make this happen.