Lightweight Trekking Bike Build

[Deleted member 4366]

The motor will take any freewheel. I'd guess that it's 135mm with a 7 speed. Awol has it now, so you'll have to ask him what the width is. Normally, the whole thing becomes a bit wider with 8 speed, which is no problem in itself because the frame will spring a bit to accommodate it, but you need to think about the centrality of the rim. You can add a spacer to the left side, which makes it even wider or dish the rim, but both of those can bring other problems that need to be solved.

 

[awol]

d8veh does the rear motor take an 8 speed freewheel? Or rather does an 8 speed freewheel and that motor fit 135 mm dropouts?

I will do a separate post on the rear motor soon..

 

[Deleted member 4366]

I've made some good progress now that I have the build completely planned out.

I need to shorten the hydraulic hoses, so I ordered some new olives that should come on Monday, and I'm still waiting for the spokes to come so that I can build the wheel.

I spent all yesterday building the battery. I'm very pleased with the way it turned out. It's a 36v 6Ah battery that weighs 1kg, cost a total of £87 and it can deliver 30 amps. It's totally waterproof. I'll give more details when the bike is finished.

One problem I encountered was that there's no space in the crank for a pedal sensor. I haven't taken the crank off yet, but I'm guessing it's an Octalink type of spline. I wanted to change the cranks anyway to lighten them, so I ordered a Shimano FC-R565 Holotech one.

I can't remember if I mentioned it before, but these motors are sensorless, which means that you can't use the nice sine wave 48v KT controllers. Also, the main capacitor in the supplied Li Shui one is 50v, which might even be a bit dodgy for 12S (44V). I've run other controllers at 12S with 50v caps before, but they were a lot cheaper, so I didn't care about the risk. I think I would change the cap to at least 63V if I were going to use 12S.

Costs so far:
Donor: £250
Hydraulic brakes (used): £80
Motor kit: £125
Battery: £87
Rim: £20
Spokes: £12
Throttle: £7
PAS: £3
Handlebars: £10
Grips: £6
Crankset: £70
Sundries: £10

Total: £680

That's an absolute bargain for an electric bike with 9-speed gears and hydraulic brakes that weighs less than 12kg.

 

[Deleted member 4366]

Nearly finished now. Just got to tidy some wiring, but still waiting for the new cranks so that i can fit the PAS. Total weight is 12.7kg on my spring balance. It'll lose a bit more when I fit the new cranks. I think I need to find a black rim and spokes:

 

[Tabs]

That's looking neat,nice job.

 

[awol]

Nice.
Great battery idea hidden in the plastic tub, but where's the controller hidden?

 

[Deleted member 4366]

It's in the tub.

 

[bbqforce10]

Great looking bike, very tempted to try and build something similar for my commute.

 

[jerrysimon]

Dave,

Would love to see a pic of the controller/LCD. Also is it PAS only ?

Ah the controller is in the hub like the KeyDe one!

What about the rear motor I guess the controller is seperate ?

Sorry I really should read the thread properly all the pics are here

Jerry

 

[jerrysimon]

I think I need to find a black rim and spokes:

Dave nice Halo black spokes here on ebay and decent price. JE James do them for half this price but not all spoke sizes.

A nice black Mavic disc based rim would look good.

PS I checked with the supplier and they only do 36 hole versions at the moment.

Jerry

 

[awol]

Ah the controller is in the hub like the KeyDe one!

No, the controller is in the tub on the frame.

 

[jerrysimon]

The front one has the controller inside the hub though ?

Jerry

 

[Deleted member 4366]

The front one has the controller inside the hub though ?

Jerry

No' it's a normal controller as shown in the photo. Normally, I'd put it in one of those tool bags under the seat.

Dave nice Halo black spokes here on ebay and decent price. JE James do them for half this price but not all spoke sizes.

A nice black Mavic disc based rim would look good.

PS I checked with the supplier and they only do 36 hole versions at the moment.

Jerry

Bummer about the 36 holes only.

If I like this motor, I'll probably buy another to get a nice black wheel. I can't try the bike yet because I'm still waiting for my crankset to fit the pedal sensor.

 

[jerrysimon]

Yes the new controllers these days seem tiny compared to the old ones when we started!.

Jerry

 

[awol]

It's in the tub.

Hope you don't mind but I like your idea so much I'm already planning using it on a future build. Something like this, it means I can get my lipo battery pack in a saddle bag.

 

[Deleted member 4366]

Sorry, you have to pay for a licence if you want to copy my ideas. Come to think of it, it was my idea to get one of those tiny Xiongda motors, so you need to pay for a licence for that too. My legal department will contact you to sort it out.

BTW, if you want to copy my battery, that one is licence free. i donated the idea for the good of mankind. I have a spare base to fit the bottle if you want it.

 

[awol]

BTW, if you want to copy my battery, that one is licence free. i donated the idea for the good of mankind. I have a spare base to fit the bottle if you want it.

Thats good, I really like your battery idea it's amazing and it's definately on my todo list so may be in touch to see if you still have the base plate at the time.

 

[jerrysimon]

Have you got a welder for the cells ?

Been thinking of getting one of those for a while. Larger batteries are cheaper now but I still prefer something smaller for my conversions.

Jerry

 

[Deleted member 4366]

I have one of the cheap Aliexpress spot welders. It's great for welding the first nickel strip to the cells, but when you need to weld another on top, it seems to struggle.

There's a guy on ES selling hand spot-welders, powered from a lipo pack. They're relatively cheap and they seem to work OK.

 

[drummerian]

d8veh, interested to hear more about this motor once you get the bike up and running. Which motor exactly is it that you have? The website seems to ominously call the 'motor with high torque' etc. Any problems with delivery/import duty?

also interested in what controller you are using?