I am DETERMINED to build a bike that can do this!

[johnrobholmes]

On topic to the post, I think it is totally doable under 50lbs. I just don't think you can get many runs back up the hill on a decently light pack, like a 72v 10ah lipo or similar. The best way to build it WILL involve a divorced motor and not a hub motor. There just isn't a hub motor out there that will take the abuse, not to mention how badly it would handle with the unsprung weight riding it hard downhill. I rode my Santa Cruz Bullit with a Puma motor in it for a while, and it bucked hard at speed when hitting stuff.

It seems we have the same goal. I want the exact same thing for myself!

 

[Whiplash]

Yeah, I figure if you can get up once or twice on a good sized hill, its enough to have fun with, also, I was thinking, if you had a good regen setup on an RC motor drive, you could likely gain back quite a bit! Would need a cool clutch though.. Could even be mechanical..

 

[Whiplash]

On topic to the post, I think it is totally doable under 50lbs. I just don't think you can get many runs back up the hill on a decently light pack, like a 72v 10ah lipo or similar. The best way to build it WILL involve a divorced motor and not a hub motor. There just isn't a hub motor out there that will take the abuse, not to mention how badly it would handle with the unsprung weight riding it hard downhill. I rode my Santa Cruz Bullit with a Puma motor in it for a while, and it bucked hard at speed when hitting stuff.

It seems we have the same goal. I want the exact same thing for myself!

Hey I need to get a front wheel like the ones you did for Lyen on the MAC motor, in black... let me know how much with a decent hub up front for disk...

 

[Seriousknot]

Yeah, I figure if you can get up once or twice on a good sized hill, its enough to have fun with, also, I was thinking, if you had a good regen setup on an RC motor drive, you could likely gain back quite a bit! Would need a cool clutch though.. Could even be mechanical..

You mentioned something interesting, mechanical clutch. You might have meant manual clutch. I have been thinking about a small manually actuated clutch for some time. It could have a small pressure plate and flywheel just like a car. Easily adaptable to various projects. Manual lockout like the pedal to start two stroke engines from China.

 

[Whiplash]

Yep I would bet something like that would be good...

 

[etard]

No, something like that would be bad!! Now your adding weight and unnecesary complexity. Besides, who would want to fiddle between regen and BRAKES!! Before you hit that tree or go over that drop... not the guy in the video. If you are going to be successful as a business you have to make the guys in the video happy. That's why bike guys laugh at Ebikers. Either they ride contraptions with shit draped everywhere, or it's a heavy ass comfort bike. You have to convince one of these guys to go down the mountain on your design, or better yet, to be seen in public riding your contraption. It's as much about impressing your friends as it used to be at the skatepark when you were kids. Mtb not cheap, especially DH, so if you build a super lightweight bike, with bombproof components that gleam in the sun 8), and will get you up that 2000ft elevation change twice, it would definately be worth that 15 pound weight penalty on the downs.

Having said that, I wish you all the luck in the world. If you ever need any testers....

 

[Whiplash]

I agree the design needs to be streamlined and beautiful, it has to be functional but not lame looking....