Clutches That Can Launch?????? Need Info

[Colemanman]

Ive had enough time to play around with torque converters and centrifugal clutches to know that clutches are a very viable option. Most people seem to skip right to the converter. But lately ive been starting to play around with clutches, jackshafts and have realized their amazing benefits over a converter.

1. Once locked up they pull much harder than a cvt does
2. They dont have a belt to burn when they slip at high speeds.
3. They allow higher speed.
4. When locked up and geared right they dont slow down as much as a 30 series converter.

Sorry for the rant

Anyway i was wondering how to get a centrifugal clutch to launch hard off the line like a converter does. I tried a 3000rpm atall max torque clutch, but i actually lost acceleration and pull compared to the stock 18 or 2200 rpm one. Do i need to get a disc clutch to be able to have a harder launch? Can disc clutches be tuned to rev about to about 2800rpms for example and almost immediately lock up to obtain a launch? I dont like how much the drum clutches slip before lock up and i thinks thats prohibiting my launching idea. Does anyone know of a cost effective disc clutch thats decent but doesn't cost to much, id be putting it on a coleman ct200u with a stage 1 tillitson 212e electric start hemi.

Thanks to all who reply.

 

[SAS289]

I'm not sure how you would lose acceleration and pull with the higher engagement clutch, Once the bike starts rolling they should behave the same as long as the gearing is the same.

If you are engaging a clutch 18 to 2200 you may be using a clutch with a spring that is already going bad. Do "Stock" clutches not engage around 24- 2500 RPM? My stock Coleman clutch does.

If you wanted a reasonable compare between a clutch and TAV wouldn't you have to launch with identical gearing? Otherwise you are comparing 13.5/1 versus 10/1.

Did the clutch you had that slipped at high speed not slip at lower speeds where all the load and engine torque is? It should have. Are you sure it slipped? The evidence would be on the clutch drum. The full engagement part of the drum would look similar to the slip area of the drum.

Have you ever tried different gearing with the TAV on the bike with the Tillotson? Put the TAV back on with an 8 tooth and launch that. You should find it interesting. I did not like stock Coleman gearing with the TAV. I like the 8/50 or 9/60 gearing much better. I don't really "launch". The bike wants to wheelie too much with the 9/60 gearing. Other than that I like it.

 

[desert rat]

https://www.walmart.com/ip/Noram-Ch...=120813424&wl11=online&wl12=184401430&veh=sem

When money don't matter play with the big kids. Karts have more weight and horse power there for more clutch.

 

[Colemanman]

Idk exactly how i lost it but the 3000rpm slipped more before lock up. Every couple days i take apart althe clutch and sand the drum with 80, oil the bushing and slap it on. It wasnt high speed slipping. The clutch was 12t max torque, was a 60t. The high engagement seemed to slip more before full lock up. I think it has to do with the amount of time it takes to reach lock up. With the 3k clutch i had lock up around 25 mph and the stock was at id say 17 to 20mph lock up. My low stall clutch can lock up faster and therefore be accelerating harder than the 3k. My motor dont rev past 5200 so i think its just taking away my usable powerband.

I under stand what you mean by the identical gearing between the cvt and clutch for acceleration. I know in most scenarios you won't have the same gearing but my idea was if i rev to 3k the clutch slams in hard and almost immediately locks up to provide the jerk off the line, then it would would be similar to the cvt launch except no gearring changes. Provided it doesnt lug the motor down and stall it from lack of power Drum clutches gently slip into lock up. So i was wondering if discs can slam it to provide a launch Sorry if i didnt word that clear enough lol


Yea i played alot with the gearing. I havent touched the jackshaft sprocket but i have changed the rear. I have a 38t, 46t, 50t, 60t and 72t. One thing that boggles me is that the taller the gearing i throw at it, until a certain point, it takes off faster and makes a faster 1/8 and 1/16 mile time. The fastest time i did was a 11.5 in the 8th with a 46t. That was my tilly with a converter. The bigger sprockets definitely have more torque but as far as point a to b stuff, i got waaay more acceleration all the way through the range using a 46t rear sprocket. It seems to hold the low ratio longer and allow me to accelerate fast bc of it. I do change it out for more offroady situations to a 60t rear. Especially when i need to climb halfway up a hill and stop and have the torque to get moving on a steep incline with gear on the back. Thanks for replying guys.

 

[FOMOGO]

https://www.walmart.com/ip/Noram-Ch...=120813424&wl11=online&wl12=184401430&veh=sem

When money don't matter play with the big kids. Karts have more weight and horse power there for more clutch.

So that is OldMiniBikes Warehouse selling through Walmart. Interesting...

 

[Colemanman]

https://www.walmart.com/ip/Noram-Ch...=120813424&wl11=online&wl12=184401430&veh=sem

When money don't matter play with the big kids. Karts have more weight and horse power there for more clutch.

Wym big kids lol? If you mean being a big is having no money limit, Then thats not me lmao, im kinda limted in that aspect. Im talking about mini bike. Specifically a coleman ct200u with a tilly 212. I have a converter but lookin for other options as well. Is that clutch tunable? Like for stall speed and the engagement?

 

[desert rat]

Wym big kids lol? If you mean being a big is having no money limit, Then thats not me lmao, im kinda limted in that aspect. Im talking about mini bike. Specifically a coleman ct200u with a tilly 212. I have a converter but lookin for other options as well. Is that clutch tunable? Like for stall speed and the engagement?

Clutches are very tune able. You can change weights and retaining springs, you can change the cam leavers, you can change friction plates. but like I said that's big boy toys level and can be very expensive. I have seen them as much as $600.00 for a full kit. I only have one and that's on a 36 horsepower two stroke cart. That cart has no flywheel (9,000+ RPM) so clutch tuning is very important. I think it's max tork that sells spring kits for stall speed for their drum clutch. With a clutch your stuck with the gears you pick to run. A clutch is not good for hill climbing in my opinion. CVT is the only way to go for that type work I would think but I don't hill climb on mini bikes. If I trail ride I do it on BIG bikes, think baja 1000 type trails and rocks like razer blades here. A toat goat might make it here.

 

[Colemanman]

Lol right on thanks for the info. I have a few mini bikes for street riding with a clutch and a few to ride trails and offroad. I tried the 3k stall max torqure and it didnt seem to accelerate harder. It just made my usable rpm range smaller due to the increased slip. Can disc clutches be tuned to slam in instead of gently slippin in like a drum clutch?

 

[desert rat]

Lol right on thanks for the info. I have a few mini bikes for street riding with a clutch and a few to ride trails and offroad. I tried the 3k stall max torqure and it didnt seem to accelerate harder. It just made my usable rpm range smaller due to the increased slip. Can disc clutches be tuned to slam in instead of gently slippin in like a drum clutch?

yep. but blip the motor and your gone or the motor stalls

 

[ole4]

disc clutches like a bulley hit hard enough on modified motors to occasionally break the crank without a outboard bearing. They also do not last very long if you slip them. good for karts where once they lock up they rarely have to slip much. They are used a lot on drag race minibikes but for something you are going to drive around the neighborhood with lots of starting and stopping probably not a good choice. The number of discs depend on the power you are making. A racing converter will be faster than a clutch when set up correctly thats why you don't see many Jr dragsters with a clutch. Why drive in high gear when you can have variable gearing. Problem is when you do gear a converter correctly it will generally cause a minibike to flip right over. Either long wheelbase or wheelie bars are required.

 

[desert rat]

disc clutches like a bulley hit hard enough on modified motors to occasionally break the crank without a outboard bearing. They also do not last very long if you slip them. good for karts where once they lock up they rarely have to slip much. They are used a lot on drag race minibikes but for something you are going to drive around the neighborhood with lots of starting and stopping probably not a good choice. The number of discs depend on the power you are making. A racing converter will be faster than a clutch when set up correctly thats why you don't see many Jr dragsters with a clutch. Why drive in high gear when you can have variable gearing. Problem is when you do gear a converter correctly it will generally cause a minibike to flip right over. Either long wheelbase or wheelie bars are required.

Well said.

 

[Colemanman]

Right that's understandable. I if i were to get one id put in on my street bike. Its a azusa mini bike, 10 inch rims, 5 to 1 gearing, Stage one gx160, governor removed and lightweight flywheel. I only use it on pavement. The whole idea with this bike was to make a mold drag bike. I usally take long rides so stop and go wouldn't be to bad. Id thought of stretching the azusa and building a custom wheelie bar set and putting a 420 on it and make it a drag bike and keep the 10s for the looks and swap em to slicks whem need be. I was checking out the junior dragster set ups and there pretty dam expensive so thats why i was leaning toward a clutch. And the fact when the gearing is right, as soon as the clucth locks up, side by side one of my cvt bikes, i can out pull my other bike with a tilly 212 and converter all the way to valve float. I like the clutches because the feeling of connection of the hand and throttle. Its much more instant response and instant acceleration when your at speed compared to the 30 series. I do like the 30 series for offroading and taril riding and the versatility it has for riding conditions but i dont mind gearing my clutch bikes for a different riding style and environment. Clutches are cool to me lol Thats interesting about the disc clutches bending cranks, what kind of power does it take for that to happen? Would a mild engine be ok with a disc clutch? Im not taking this bike to drags or anything i just wanna have a little fun in my neighborhood and race some friends. Whats a decent disc clucth cost? I could always swap it for a drum clutch for stop and go driving. Thanks for the information guys. I appreciate yall taking the time to inform.

 

[delray]

Right that's understandable. I if i were to get one id put in on my street bike. Its a azusa mini bike, 10 inch rims, 5 to 1 gearing, Stage one gx160, governor removed and lightweight flywheel. I only use it on pavement. The whole idea with this bike was to make a mold drag bike. I usally take long rides so stop and go wouldn't be to bad. Id thought of stretching the azusa and building a custom wheelie bar set and putting a 420 on it and make it a drag bike and keep the 10s for the looks and swap em to slicks whem need be. I was checking out the junior dragster set ups and there pretty dam expensive so thats why i was leaning toward a clutch. And the fact when the gearing is right, as soon as the clucth locks up, side by side one of my cvt bikes, i can out pull my other bike with a tilly 212 and converter all the way to valve float. I like the clutches because the feeling of connection of the hand and throttle. Its much more instant response and instant acceleration when your at speed compared to the 30 series. I do like the 30 series for offroading and taril riding and the versatility it has for riding conditions but i dont mind gearing my clutch bikes for a different riding style and environment. Clutches are cool to me lol Thats interesting about the disc clutches bending cranks, what kind of power does it take for that to happen? Would a mild engine be ok with a disc clutch? Im not taking this bike to drags or anything i just wanna have a little fun in my neighborhood and race some friends. Whats a decent disc clucth cost? I could always swap it for a drum clutch for stop and go driving. Thanks for the information guys. I appreciate yall taking the time to inform.

your still right about how your clutch can work in some cases and out run a torque converter. i have been down that same path as you. for me i got good part on how to make a clutch work in some conditions over a torque converter. i run a clutch on my flattrack bike. everybody else runs a torque converter. some run the jugg and others run the 30. from a dead stop take off to the corner we out run a torque converter(TC) also when coming out of a corner the bike pulls much harder then TC. my opinion when running most of these type TC(30 series) units they like to spin the belt little. you may not feel it. but it is. on a clutch with the right set up your direct drive to the rear sprocket and there is no slipping at all. there is a LOT OF THINGS going on that you need right for a clutch to out run a torque converter,but it can be done. we even did little grass drags this last summer and we out ran all the torque converters at 175ft in are class....won it and at other place at 300ft we out ran all the small blocks with TC'S.

 

[bigkid]

There was the 3d manual clutch. Don't know that it's available anymore. I remember a lot of discussion about here on the boards. Might do a search if you're interested. IIRC seems it was kinda weak.

https://3dmotorsport.net/collections/manual-clutches

 

[Colemanman]

Yea know what you mean about the 30 series belt slip. My tilly 212 coleman with a converter and 46tooth does good until high rpm, high speed situations. At about 4500 its going 50 to 53 but if i give it the rest that it's got itll go to about 5200 and wont gain any mph. I also glazed a belt or 2 doing that lol. It would be cool to get a crank adapter and put a 40 series on it to get the benefit of the roller and spring clutch and the extra torque of the huge driven

 

[delray]

Yea know what you mean about the 30 series belt slip. My tilly 212 coleman with a converter and 46tooth does good until high rpm, high speed situations. At about 4500 its going 50 to 53 but if i give it the rest that it's got itll go to about 5200 and wont gain any mph. I also glazed a belt or 2 doing that lol. It would be cool to get a crank adapter and put a 40 series on it to get the benefit of the roller and spring clutch and the extra torque of the huge driven

i think you would create a balancing problem installing that large heavy driver on a small block clone with a light billet flywheel and it would take extra power to turn that heavy unit also. you would be better off getting that new gtc driver with a third bearing support ,thats if it can hold up to high stall launches and a 7inch 20 driven. but you need the room for it.
i ran this jr dragster unit with couple different tecumseh's i built and it felt more direct drive then a 30's series did. unit uses a 20 series 3/4 belt.
her is more info on it. https://www.oldminibikes.com/forum/index.php?threads/340-salsbury-series.168096/



even with me on laying down on the bike it still wanted to lift the front wheel off the ground for the first 5 feet or so and go....
no belt slipping in this setup.

 

[Colemanman]

Yea my gx160 is my street one that has the light flywheel, with the clutch. My colemans got a stage 1 tilly and the clone 30 series converter. Ive been happy with it other than the belt slip. Ive heard good things about the juggernaut limiting high speed belt slip but i havent picked one up to test it. I love the flathead and I really dig that extra crankshaft support bearing. It looks beefy like it could take some serious launches. Do the motor mount bolts run through the plate to keep it aligned or is adjustable?. I have a comet 7 driven from a manco go kart i was thinking about messing around with. But id have to buy some bearings to fit the 5/8 shaft bc the clone converter i believe is 16mm or 17mm shaft. And the ramp buttons are missing on it where the cam rests against. Is the 7 inch driven a symmetric unit or asymmetric. The one i have appears to be asymmetric

 

[delray]

yes,bolts go right through the plate. 7inch 20 series( symmetric v-style)are not that expensive to buy new and you really need them flip them around or you can try making the driven float so the belt is in line with the front when the driven is fully engage.

 

[Colemanman]

Right they run inboard the 20 series. Was that crankshaft support bearing hard to line up? How did you make? I think thats so cool.

 

[delray]

easy line up, mine was made for a jr dragster. it also came with the 4th bearing support for the flywheel that i don't use.

they are on ebay for sale. last one but they sell more.
http://rover.ebay.com/rover/1/711-5...0001&campid=5335845805&icep_item=222566171371

here something i stumble on awhile ago i thought was very interesting to see and looks easy to make and maybe make it better with a rear support for the jackshaft. that would depend on the minibike it's going on. as you can see it was design to have the driven pointed in. guy could extend the shaft little longer with a support bracket and mount a sprocket on the end of it and run it to the rear sprocket.