Rocky Mountain Element Conversion

[Deleted member 4366]

Thanks for your kind words.
Well, it's finished now and I've done a few miles on it. I'm lost for words because it's come out better than I was expecting. I can say that it's better than any electric bike that I've ridden before by a country mile - including the Haibike. The brakes are like those on a Suzuki GSXR with finger tip power and so controllable. The air suspension is about twice as good as my two Giants. It floats over bumps and steps in the road. I'm guessing that it's something to do with the ratio os sprung to unsprung weight. The balance and stability are superb - even when you stand up on the pedals free-wheeling down a steep hill at 30mph, it is steady as a rock - must be due to the low down weight or something.

The back motor is activated by the PAS sensor and the power is based on cadence, so it gives a very progressive power increase - just right for the what I wanted. Without throttle, power-wise, it's like many other 250w electric bikes with meaningful assistance to about 18mph with power finally stopping at about 20mph, but when a steep hill comes, open up the throttle and you can go up without pedalling. The motors are very quiet at normal speed, in fact so quiet you wouldn't know it's electric; however, at full throttle and low revs - like on a very steep hill - you can hear the motors.

The maximum amps I saw up a very steep hill was 26 amps.

So my final conclusion is that it was a very worthwhile project. You can't buy a bike like this, (which is a shame), so there's nothing to compare it with. It's not particularly fast, but it's so smooth, quiet and comfortable. Hopefully, I can get some efficiency data on a long ride tomorrow if it doesn't rain.

 

[bazwaldo]

Fantastic project d8veh and very skillfully completed.
The bespoke frame box looks terrific with the paint job.
I agree with Kenny if you could economically mass produce these designs you could go into business!
Great work and thanks for posting.

Barry.

 

[Cyclezee]

Superb and completely unique, even the paintwork looks totally professional.

Improvisation par excellence

That just has to be DIY kit bike of the year by a mile

 

[cwah]

Very very nice D8veh

I was the same battery caaaase

Mine is so ugly. Just seen you used wood board for that. How did you make it so clean at the end? Do you use some sort of plastic case and spray paint?

 

[funkylyn]

Wow....well done Dave that is really impressive......

just a thought.....Bristol next year with a stand selling a small collection of totally unique e-bikes for people who are looking for quality and something different, it would be a sell out I would think, and the perfect excuse for you to spend the winter building, experimenting and basically thoroughly enjoying yourself

Shall I save you space under the tree ?

Lynda

 

[flecc]

Superb conversion d8veh, professional in every aspect. It's a pleasure to see someone else use wood in casing construction, an option far too often dismissed despite it being possible to produce a match for any manufactured metal or plastic casings.

I can well imagine this being a very civilised e-bike to ride, while being very capable at the same time.

 

[Scimitar]

View attachment 4166Lovely casing job there, d8, unlike mine

 

[Deleted member 4366]

I was the same battery caaaase

Mine is so ugly. Just seen you used wood board for that. How did you make it so clean at the end? Do you use some sort of plastic case and spray paint?

After gluing the other side to it, the whole thing was planed and sanded to give the round corners. You can see balsa wood at all the corners and joints inside so that I could get it nice and round. Only the battery stopped me from rounding further. Finally, it was covered in Solarfilm, which you iron on with a special iron. The construction is the same as I used to use for radio controlled aeroplanes.

Lynda, would you save space for me under the tree even without bikes to sell?

 

[Cyclezee]

View attachment 4166

Sorry to deviate, but that is one hell of a side stand you have got there Scimitar, it looks like it is anchored into the ground

 

[jackhandy]

k

Wow....well done Dave that is really impressive......

just a thought.....Bristol next year with a stand selling a small collection of totally unique e-bikes for people who are looking for quality and something different, it would be a sell out I would think, and the perfect excuse for you to spend the winter building, experimenting and basically thoroughly enjoying yourself

Shall I save you space under the tree ?

Sounds idyllic - doing something you enjoy doing, are damn good at & getting paid for it; but people have a warped idea of value for money:
People are prepared to pay me more per hour for cutting their grass than for doing bespoke carpentry or making an heirloom rocking horse

 

[jackhandy]

AND, goes without saying, that really is a beautiful bike, d8veh.

 

[funkylyn]

k

Wow....well done Dave that is really impressive......

just a thought.....Bristol next year with a stand selling a small collection of totally unique e-bikes for people who are looking for quality and something different, it would be a sell out I would think, and the perfect excuse for you to spend the winter building, experimenting and basically thoroughly enjoying yourself

Shall I save you space under the tree ?

Sounds idyllic - doing something you enjoy doing, are damn good at & getting paid for it; but people have a warped idea of value for money:
People are prepared to pay me more per hour for cutting their grass than for doing bespoke carpentry or making an heirloom rocking horse View attachment 4168

Sorry OT.... but that is one impressive Rocking horse there Jackhandy......did you make it ?

Lynda

 

[jackhandy]

yuss, wiv my own 2 hands

 

[funkylyn]

yuss, wiv my own 2 hands

Congratulations then, because that is really beautiful, you are very talented.....stand at Bristol next to Dave then maybe ? (you could always put it on wheels and add a motor lol )

Lynda

 

[Cyclezee]

k

People are prepared to pay me more per hour for cutting their grass than for doing bespoke carpentry or making an heirloom rocking horse
View attachment 4168

That is a work of art Jack, didn't realise IKEA sold rocking horses

Sorry, it's Sunday and I couldn't resist

 

[cwah]

After gluing the other side to it, the whole thing was planed and sanded to give the round corners. You can see balsa wood at all the corners and joints inside so that I could get it nice and round. Only the battery stopped me from rounding further. Finally, it was covered in Solarfilm, which you iron on with a special iron. The construction is the same as I used to use for radio controlled aeroplanes.

Thanks for the insight.

I just purchased Fablon sheet for my battery box. But I'm going to look at these solarfilm, it may be better adapted.

BTW, why did you choose wood over plastic? Is it for the cost? Because with plastic you would be able to haver thinner and stronger case I suppose?

 

[Deleted member 4366]

BTW, why did you choose wood over plastic? Is it for the cost? Because with plastic you would be able to haver thinner and stronger case I suppose?

I thought it would be easier to get a nice clean shappe with wood. I was also thinking of making a fibreglass or carbon fibre one by making a wooden one first and then taking a mould off it, but in the end I thought wood would be quicker.

 

[Deleted member 4366]

I took the bike out for a ride with Steve today. We went down Ironbridge gorge and back, which was 15.5 miles with a good couple of miles steep hills in each direction - downhill going and uphill return. The hills were no problem at all using both motors. I used 5.8aH at 14.6wh/mile, which is about 80% of what my BPM motors will do with the same pedal effort and the same speed. While going up a medium inline at 9mph, I was using 13.3 amps (the max for one motor) with just the back motor, but when I used the throttle to bring in the other motor, the current dropped to 8.5 amps for the both of them at the same speed. Therefore I can categorically say that for hill-climbing, two small motors usev less power than one - as I had hoped/expected.

 

[Scimitar]

Sorry to deviate, but that is one hell of a side stand you have got there Scimitar, it looks like it is anchored into the ground

I only had to resort to a Napoleonic cannon because the original sidestand busted (cheap crap).
I have a decent mid-stand, but the space behind the BB isn't quite long enough.

People are prepared to pay me more per hour for cutting their grass than for doing bespoke carpentry or making an heirloom rocking horse View attachment 4168

Tell me about it: a few years ago a woman (who owns a bleedin' castle) asked me to quote for refinishing a large dining table (it wasn't an antique, just a bit knackered on top) and she baulked at €150. The same woman happily paid me €200 to fix her PCs.
I don't get it - I'd have spent much more time on the table and from my point of view she was getting a bargain.

 

[cwah]

I took the bike out for a ride with Steve today. We went down Ironbridge gorge and back, which was 15.5 miles with a good couple of miles steep hills in each direction - downhill going and uphill return. The hills were no problem at all using both motors. I used 5.8aH at 14.6wh/mile, which is about 80% of what my BPM motors will do with the same pedal effort and the same speed. While going up a medium inline at 9mph, I was using 13.3 amps (the max for one motor) with just the back motor, but when I used the throttle to bring in the other motor, the current dropped to 8.5 amps for the both of them at the same speed. Therefore I can categorically say that for hill-climbing, two small motors usev less power than one - as I had hoped/expected.

very very nice again D8veh. Very different to the bulky battery case I used to see in most ebike setup... but I understood it's a 36V12AH battery? So it's only 432wh? My brompton battery has 3 times more energy with a 20S 123 20 AH pack (66V20AH). Just wondering if you would be able to fit 3 times more energy in it lol.

With 2 motors, do you have 1 or 2 controllers? I haven't found where you mentioned about it.


This set up is clearly a breakthrough as this dual motor is lighter than using only 1 BPM! And if it's more efficient, with the same torque, that's really great to know.

Looking forward to hear more about the dual drive efficiency stats, especially on flat road and if the drag isn't too much