Off road beast bbs-01 750w :)

[st1vo]

I've just spent 20 mins composing a great thread and it just disappeared.... NOT HAPPY

I'll keep it short this time...

Plan:
1. Get 4x/jump bike with strong frame and good brakes 2nd hand
2. Get 48x750w bbs-01 from China
3. Merge the two
4. Go 30mph off road until dead

Good idea??

It'll cost about £750 in total... are there better alternatives??

 

[st1vo]

This is the bike in question

 

[trex]

the 8-Fun crank drive may not be suitable for a fun bike. Its integrated controller is a limiting factor.

 

[st1vo]

Alternatives??

 

[trex]

I don't know, just a guess. For a fun bike, a 48V 8AH battery that can deliver a big punch, bolted to the down tube or seat tube like Frank's bikes or the Neos, that a self build job, and a 500W GNG type crank drive.
I was thinking of building such a battery, without BMS, bringing all the balancing wires to charging port. That would allow highest discharge rate.

 

[Deleted member 4366]

The 750wBBS01 is new, and I haven't yet seen a review by anybody that has one. One should probably come within the next month. The GNG is probably the best for off-road, but not so good as a commuter because it takes frequent maintenance : Chain lubrication and adjustment. They have a high-powered 60v version with a chain primary reduction, so it's a bit noisy. The belt drive one isn't too bad. If you like DIY, there's lots you can do to improve it to handle high power. In standard form, it'll just about do what you want, but expect to replace a few belts. You can find these on UK Ebay
450W (brushless mud guard)

The higher powered one:
GNGELECTRIC---Electric bike conversion kitElectric trike kitHub motorGas bike kit - 60V650W (brushless)

How to improve it:
Endless-sphere.com • View topic - GNG, 1000W 48V BB-drive, $400

 

[103Alex1]

Are you intending to do much 'jumping' on the jump bike ? If so, your battery needs to be very well secured , protected and housed. Looking at the basic geometry of the bike in your photo (albeit there is no rear suspension) I'd take inspiration from the housing on this ...

Stealth Bomber Electric Bike - Escape Bike Shop

 

[st1vo]

OK.... thanks for the early input.
Don't like the sound of frequent maintenance, or mucking about with wiring... need plug and play!!
I didn't buy that bike.. it just ended on ebay for £185... didn't have bottle holder holes in frame.. more homework needed
Maybe I'll wait for the 48v750w bbs-01 reviews to appear b4 making a decision.
I've never had an ebike, but tried a Kalkhoff Impulse bike, big and heavy and not really 'fun', and a couple of low powered hub bikes, but again, not 'fun'... I get more kicks from my Merida T3 hybrid, light and fast and OK on a trail but I don't really want to mess about with electrifying it as it's cost me £800 to get it like it is.
Maybe a 29er would be the way to go...
Defo set on a crank drive.

 

[103Alex1]

Impulse is very good climber but those retail Bosch/ Impulse bikes are not nearly powerful enough to compare with a powerful hub motor for example 'fun wise'. You really should try one before making final decision if not looking to build immediately.

How much 'fun' are you looking for ? For plug and play you will struggle to get serious fun, because bikes with high powered kits on bikes that are going to be knocked about usually benefit from additional engineering / modding to get them robust enough for a proper off-road hammering.

Crank drives cause their own issues at higher power levels too due driving through the chain. The £9-£10k Stealth Bomber has a rear hub motor and it's in the "serious fun" category. So are all the hipowercycles bikes. Any reason why you don't want a powerful hub motor instead ? Unless you are planning on big drops and jumps, a bike with rear suspension should take out enough of the impact of rear wheel hitting ground for it not to be a worry using rear hub.

 

[Blew it]

I've just spent 20 mins composing a great thread and it just disappeared.... NOT HAPPY

st1vo, when you log in, put a tick in the square box to the right of your password and then hit "log in". That will stop the log-in timing out.
Remember to log out if using a shared PC.

 

[trex]

Crank drives cause their own issues at higher power levels too due driving through the chain. The £9-£10k Stealth Bomber has a rear hub motor and it's in the "serious fun" category. So are all the hipowercycles bikes. Any reason why you don't want a powerful hub motor instead ? Unless you are planning on big drops and jumps, a bike with rear suspension should take out enough of the impact of rear wheel hitting ground for it not to be a worry using rear hub.

I think the combination of crank drive + bottle battery is better for a fun bike because the moment of inertia is considerably smaller.
Furthermore, you can get a lot more torque in the 3-4 mph range for climbing stairs and 30mph for flat roads.

 

[Deleted member 4366]

I think that what you want, you can't have. If you want a powerful bike, it's going to be heavy. It takes about 1kw to sustain 30mph on a smooth flat road. In an off-road situation with bumps and hills, you'd need double that, which means 40 amps at 48v, so a 5kg 48v 10aH lipo pack will last 15 minutes. My next question was going to be about where you're going to attach the battery.

 

[trex]

for a fun bike, range does not matter, you can always keep a spare battery in your rucksack if it comes to it. I thought 48V 8AH should be plenty and weighs probably around 3.5kgs for a home built.

 

[st1vo]

Thanks for everyone's input...

I went to a bike shop today and explained my plan, they said forget it, I'd just break everything!!

As for your replies, ideally I'd want a bike that could do most things (I'm not into jumping)
i.e it would be good and fairly stealth on the road, it could handle tracks and bridalways, it would be fast and it would have a half decent range (30-40miles assisted) and be fun, how much fun is like asking how long is a piece of string... And be reliable..

What I don't want is a stodgy boring heavy ugly slow piece of junk with bad brakes and a 10 mile range....

I realise that people have multiple bikes because one bike can't do everything, but I was hoping the electrical assist would overcome issues like suspension and knobbly tyres which are no good for road use because they tire you out too much, and I don't want to bundle a bike into the car to take it somewhere to ride... seems daft to me!

 

[banbury frank]

Hi st1vo where are you in the uk

It will be worth you coming to banbury for a chat and a test ride we are open 7 days a week



Frank

 

[103Alex1]

Thanks for everyone's input...

I went to a bike shop today and explained my plan, they said forget it, I'd just break everything!!

As for your replies, ideally I'd want a bike that could do most things (I'm not into jumping)
i.e it would be good and fairly stealth on the road, it could handle tracks and bridalways, it would be fast and it would have a half decent range (30-40miles assisted) and be fun, how much fun is like asking how long is a piece of string... And be reliable..

What I don't want is a stodgy boring heavy ugly slow piece of junk with bad brakes and a 10 mile range....

I realise that people have multiple bikes because one bike can't do everything, but I was hoping the electrical assist would overcome issues like suspension and knobbly tyres which are no good for road use because they tire you out too much, and I don't want to bundle a bike into the car to take it somewhere to ride... seems daft to me!

For a 30-40 mile range (realistic) and 30mph assist you are looking at a 25-28kg bike in order to get one strong enough with enough power/battery unless you go LiPo to save weight - in which case you won't get anything off the shelf and it's a lot of work to set up from scratch. Also forget about 10Ah batteries with a bike that has more grunt - for that sort of range, and high assist speeds you need some very serious battery power (likely close to 1000 W/h which is a 7kg battery alone at 48V).

This wouldn't be great on rougher tracks off-road unless you built battery into the frame which means compromise on stealth. And I doubt a 1000W/h battery would fit into frame unless you had a battery custom made to fit in any case. So some things need to give.

The faster you want to go on a heavy bike the more you need full suspension. The elec assist overcomes the downside of big / knobbly tyres on the road. If you are not tall (5' 9"-5'10" +), 29ers are all very well but couple these with decent battery power and motor and if you are not you may well find the resulting bike too unwieldy.

If you can, go try one of Frank's 48V kits - the closest thing you'll get to what you want without doing all yourself off the shelf here. But don't let him talk you into fitting a big battery on a seatpost rack .

 

[trex]

that's not a fun bike.
this is a fun bike:

but with a crank drive that lets me climb stairs

 

[Deleted member 4366]

Thanks for everyone's input...

I went to a bike shop today and explained my plan, they said forget it, I'd just break everything!!

As for your replies, ideally I'd want a bike that could do most things (I'm not into jumping)
i.e it would be good and fairly stealth on the road, it could handle tracks and bridalways, it would be fast and it would have a half decent range (30-40miles assisted) and be fun, how much fun is like asking how long is a piece of string... And be reliable..

What I don't want is a stodgy boring heavy ugly slow piece of junk with bad brakes and a 10 mile range....

I realise that people have multiple bikes because one bike can't do everything, but I was hoping the electrical assist would overcome issues like suspension and knobbly tyres which are no good for road use because they tire you out too much, and I don't want to bundle a bike into the car to take it somewhere to ride... seems daft to me!

This one is pretty close to what you want. It does about 24mph. It cost about £1100 to build including the cost of the donor bike. The one behind cost about £700 including the donor. It has the same performance, but isn't so suited to off-road. If you can't DIY, have a look at Frank's Xipi stuff.

 

[103Alex1]

that's not a fun bike.
this is a fun bike:

but with a crank drive that lets me climb stairs

My CST will climb stairs at low speed if the tyre pressure is taken down ... it just uses a shed load of W/h doing so !!! It also races up deep ruts in ridiculously steep dirt tracks ... all by itself I'm pretty sure I couldn;t nurse a crank drive up there with part-crank rotations without coming off. Just depends exactly what sort of fun you want to have .

 

[trex]

these two are nearer to the mark:

[video=youtube;2snkc7sCOXM]http://www.youtube.com/watch?v=2snkc7sCOXM[/video]