New clutch in development

[jimmymc2286]

I got to have one of them. Please post as soon as he gets his web site up and running. This would be perfect for my vintage build. I'm sure my little 79cc HF would not cause it any problems. I can see a hand clutch lever on the side of the tank now. It
s going to be a long couple of weeks.

[16v4nrbrgr]

Any updates on this?

[chainmaker]

Here is his update from the mini bike site

Just to give a quick update, we've been working hard to really test the durability of the clutch and ensure that everything works properly with our prototypes. My brother and I are both engineers and we've been doing all sorts of testing to put the clutch through it's paces. That being said, we are very close to signing off on the final designs, and we expect our first shipment to arrive for assembly in mid-March at the earliest. We've registered our business/resell license with the state of California, and our official company name is Downs Brothers Racing. Our standard 3/4" unit will be called the DBR Type I (Pat. Pending 61/764,452). For mini bike applications, we have decided to also include the clutch lever assembly, as well as the clutch cable. Our website is almost complete, and we will update everyone when we are live (www.downsbrosracing.com). We have made a note of people who have verbally committed on this website, and we will contact everyone individually to prioritize these orders. If anyone has more questions/concerns/feedback about the clutch, please don't hesitate to ask!

[curtisfox]

Again AWESOME! i will have to have one. I had a disk clutch back in the 50's on a Monark twin. Loved it.............Curt

[Mr. Minecraft]

I am definitely going to buy one of these. The only thing is I'm guessing that these are not for the HS 49cc engines? I have the tapered shaft engine btw, but can probably buy a new crankshaft with the strait shaft.

[MotorizedEtc.]

Yes this would be awesome if it works with the HS 49cc.

[maniac57]

Originally Posted by chainmaker

I just wanted to start a post about a new manual clutch that is in development.
Here are some pics and specs.I am just sharing info here not my product or friends product. Just think a lot of guys would be interested in it. I told the guys building them I would start a thread over here .




Some specs.

-Completely bolt on unit
-Actuated by standard lever and brake cable
-Does not apply a thrust force to the crank shaft bearings
-3.25" diameter
-Needle bearings used throughout


Some bad specs:

-Sprocket center line is farther outboard than a conventional centrifugal clutch by about 3/4" (this is when the centrifugal clutch is mounted such that the sprocket is close to the engine). I can't figure out a way to get around this. This would require shifting the engine by 3/4" to account for it.
-Minimum sprocket size is 15 teeth for #35 chain. I MIGHT be able to get it down to 14 teeth but i doubt it. My thought, though, is that since launch RPM will be higher than a standard setup, this wont be as big of any issue as one might think. Still unfortunate.


Price would probably be comparable to a Comet TAV2.

Testing has been going better than expected and the clutch works exactly how you would want a manual clutch to operate! Burn-outs, donuts, power slides, fast starts, decompression braking, and clutch feathering are no problem with our 7 hp 212cc Predator Invader Kart. It really does add a new dimension to driving a go-kart, and our friends hate it when we pop the clutch out of turns and accelerate past them! We've also tested the clutch on a mini-bike with awesome results. After our provisional patent application was approved, we spoke with the some of the largest clutch manufacturers in the US (Horstman, Max Torque, Noram etc.) to gauge interest in the product. Since the responses were overwhelmingly positive, we have decided to pass on a licensing agreement with a larger company to test the waters in business for ourselves. In order to make the product at a larger company, the design would have to be mostly 'watered down' (stamped instead of machined etc.) to keep manufacturing costs down. Since our company is just myself and my brother, we do not have much overhead and we can sell these nicely machined and robust units at a competitive price. We have received quotes for manufacturing, and have established vendors for the internal hardware so now we have an idea of how much they will cost to make per unit in bulk. Currently, we are hoping to sell these units with a price tag of around $100 so that the average go-karter or mini bike enthusiast can afford to buy our product. Once our website is live within the next couple of weeks, we will be open to taking discounted pre-orders to the first set of people who want to try the manual clutch. In addition, we are in the process of filming videos of the clutch in use, and will have these on display on our website along with any testing data that we can come up with. I just wanted to update everyone on here and just get a sense of what our potential market might look like. Please comment if you consider yourself someone who might be interested in buying this product in the near future! We'd love to hear your thoughts, positive or negative.



Here is the thread http://www.oldminibikes.com/forum/en...ft-engine.html

I'm wondering how these will work myself...but don't call me, I'll call you.

[silverbear]

Signing on to this thread.
SB

[Dirt bag]

I want one or two!

[oldtimer54]

Ya I think this would go great with my new 99cc Lifan build. I want one two (or is it I want 2 lol).