So I've pretty much worked out what I'd like for next winter:
Bike weight preferably less then ~30kgs,
Road legal (brake cutoff switches, etc)
Range >50kms with no human input, long-range pack?
Climb ~15%-ish grade at speed limit with no human input,
Has to be workable year round regardless of weather,
Low maintenance, low thief desirability.
So here's what I'm thinking:
Rigid alu mtb or touring bike, fat tires on wide rims. Clyte 409 run at 72v 60A, two EVtech 36v15ah packs.
Weight breaks down kinda like this:
6.25Kg for for the 409
1.25Kg for the 35A controller
9Kg battery packs
13.5Kg for the bike w/full fenders, racks, lights, etc. (yeah right!)
Just under 70kgs & 1m80 for the rider
At around 3.6kgs the BMC sounds good I guess, but I dunno.
I figure it should climb 15% at 32km/h sucking somewhere between 35-40A, and with 60A on tap it should be able to power through just about any snowbank. Local hills are steep but short, so I don't except to have heat issues. If it gets too steep I'll just get off and let it drag me up the hill, anyways.
I would have liked a front motor to benefit from the major plus in the slop, but I figure I can squeeze more weight two ways with a rear motor: I'll avoid having to add weight with a steel front fork, and it'll shave a good bit of weight off the drive train, as I'll have to run a single speed rather then hub gear with cable and such. I'm thinking about gearing it either 48/16 or 52/17, at 30/40 km/h that would yield 80/106 & 78/98 RPM's at the crank.
The one major hic about this project is that I can't/don't want to buy two of these EVtech packs, as they're pretty dear. Hopefully by winter I'll have found a solution for this, until then I'm thinking about lead & taking it easy.
I'd like to be able to strap on a longer range 72v pack made of 18Ah lead slabs or such, three on the rear and three in front would make for reasonably long range occasional use pack. Along with the Evtech packs, this would yield ~2Kw/h. Ample for commuting 150kms.
So that's my half-baked idea of what BikeII should be, as it stands.
Who says better?
Bike weight preferably less then ~30kgs,
Road legal (brake cutoff switches, etc)
Range >50kms with no human input, long-range pack?
Climb ~15%-ish grade at speed limit with no human input,
Has to be workable year round regardless of weather,
Low maintenance, low thief desirability.
So here's what I'm thinking:
Rigid alu mtb or touring bike, fat tires on wide rims. Clyte 409 run at 72v 60A, two EVtech 36v15ah packs.
Weight breaks down kinda like this:
6.25Kg for for the 409
1.25Kg for the 35A controller
9Kg battery packs
13.5Kg for the bike w/full fenders, racks, lights, etc. (yeah right!)
Just under 70kgs & 1m80 for the rider
At around 3.6kgs the BMC sounds good I guess, but I dunno.
I figure it should climb 15% at 32km/h sucking somewhere between 35-40A, and with 60A on tap it should be able to power through just about any snowbank. Local hills are steep but short, so I don't except to have heat issues. If it gets too steep I'll just get off and let it drag me up the hill, anyways.
I would have liked a front motor to benefit from the major plus in the slop, but I figure I can squeeze more weight two ways with a rear motor: I'll avoid having to add weight with a steel front fork, and it'll shave a good bit of weight off the drive train, as I'll have to run a single speed rather then hub gear with cable and such. I'm thinking about gearing it either 48/16 or 52/17, at 30/40 km/h that would yield 80/106 & 78/98 RPM's at the crank.
The one major hic about this project is that I can't/don't want to buy two of these EVtech packs, as they're pretty dear. Hopefully by winter I'll have found a solution for this, until then I'm thinking about lead & taking it easy.
I'd like to be able to strap on a longer range 72v pack made of 18Ah lead slabs or such, three on the rear and three in front would make for reasonably long range occasional use pack. Along with the Evtech packs, this would yield ~2Kw/h. Ample for commuting 150kms.
So that's my half-baked idea of what BikeII should be, as it stands.
Who says better?
I've read that a 10% grade is unpeddleable using just human strength. I'm just looking into calculating grades of the streets in my neighborhood and for one particular street its about a half mile stretch with a consistent climb. I thought this street had a decent grade but it only calculated to a 4.22% grade. Can someone look over my calculations to see if I got it correct.
