Electric2011 Dahon Jetstream P8

  • Thread starter Deleted member 4366
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Deleted member 4366

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I won't insert photos of the bike just yet because it's the same as those that you'll see on any website. I decided to try my spare Cute Q100 rear motor that I bought from BMS battery. I have two: a 24v and a 36v. I'll use the 24v, but run it at 36v because they're both 201rpm versions for 26" wheels. A rough calculation says that at 24v it'll do about 12mph and at 36v about 18mph.

I laid it in place and it overlapped the drop-outs by about 5mm, but can easily be sprung in. I checked the alignment and it's about 2 to 3mm off centre.



Next, I assembled the free-wheel to check that it fits OK. I only have a 6 speed with 14T top gear. It's 32mm thick and there's enough room for 40mm. 14T is no good. On my mountain bike, my comfortable top gear pedalling is about 17.5 mph with 52/14T gears, so the Dahon with 14/52T would be about 13.7mph, which is a bit slow with electric assist. It's not that the bike would go slower, it means that I'd be pedalling a lot faster, which I don't want. A quick call to Cyclezee and hopefully he can provide an 11T 7 speed, which'll give top gear pedalling at 17.5mph, which is about the top speed of the motor. we think this free-wheel is 36mm thick, so I can shorten the spacer bush on the motor by 4mm so that I don't have to spring the drop-outs and the wheel will be more central (lucky that the wheel is off-centre the right way).



Now I need a rim and spokes. I need to talk to Catsnapper.
 

jerrysimon

Esteemed Pedelecer
Aug 27, 2009
3,292
112
Cambridge, UK
Excellent Dave I will be watching you build with great interest.

As I said recently, I feel spoilt in the forum lately with all these folding bike posts :)

Regards

Jerry
 
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wurly

Esteemed Pedelecer
Aug 2, 2008
501
9
Yeovil, Somerset
It doesn't have to be folders, i like the diy part of any ebike build.
Do you have a full time job d8veh? you seems to be constantly building ebikes.:)
 
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Deleted member 4366

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I only work two days a week teaching electronics at a secondary school, so I have a lot of time on my hands.
 

cwah

Esteemed Pedelecer
Jun 3, 2011
3,048
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www.whatonlondon.co.uk
Same, I'm following this thread with a lot of attention :)

Thanks for sharing this D8v3h

ps: Is CatSnapper a spoke and rim dealer? :confused:
 

Scottyf

Esteemed Pedelecer
Feb 2, 2011
1,403
-1
Catsnapper is Alan @ just1bikes based in Essex I believe.
Also has a keen interest with anything on two wheels.
 

cwah

Esteemed Pedelecer
Jun 3, 2011
3,048
179
www.whatonlondon.co.uk
Any news from this nice bike? Does it still roll once folded? Is it a bit big once folded? Maybe do it this way:
http://www.youtube.com/watch?v=1ySyzcRMLhQ

And enjoying your time with this bike? I'd love to jump from sidewalk to road and climb up/down the stairs on the street with this bike :D
 
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Cyclezee

Guest
Whilst searching my photo library I came across a Jetstream conversion with an eZee kit from last year.
It was a work in progress, I don't have any of the finished project, but some may find it interesting.
eZee Jetsream.jpg
 
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Deleted member 4366

Guest
I built my wheel today with a rim and spokes from Catsnapper (Just1bike.com). Everything went well and the spokes were spot-on lengthwise, just had to bend them a bit round the flange to make them line up with the holes in the rim, but I understand that this is normal. they're 14g spokes in a one-cross pattern.

A trial fit showed that the rim was a bit more offset than I thought, so I put a provisional dish in it to bring it close to the centre, but, when the gears come, I'll probably shorten the axle a bit to bring it the last couple of mm. I don't know the stack-height of the gears until they come, but I think 39mm and I have a gap of about 40mm.
Here's some photos of before and after dishing:



 

eddieo

Banned
Jul 7, 2008
5,070
6
Whilst searching my photo library I came across a Jetstream conversion with an eZee kit from last year.
It was a work in progress, I don't have any of the finished project, but some may find it interesting.
That rear motor looks a good fit, is that the standard Ezee wheel & motor? Also where did the battery end up? (wish I had kept my jetstream now:()
 

mxer125

Pedelecer
May 13, 2011
94
0
Love your builds d8veh propper stuff at fantastic prices you have sourced, This should have SOOOOO much torque :cool:

Nice wheel build, Never done one should emagine it's a bit of a nightmare :confused:
 
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Cyclezee

Guest
I don't know the stack-height of the gears until they come, but I think 39mm and I have a gap of about 40mm.
Here's some photos of before and after dishing:
Hi Dave,

Just to confirm, according to my 'very near gauge' the stack height of the 7 speed Freewheel is 39 mm and they will be delivered Tuesday.

Nice work Dave;)
 
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Cyclezee

Guest
That rear motor looks a good fit, is that the standard Ezee wheel & motor? Also where did the battery end up? (wish I had kept my jetstream now:()
Hi Eddie,

Yes it is a standard eZee 20" rear wheel and motor.
The battery went on a rear rack, there are a couple of options for bikes with rear suspension, the eZee MTB type or one made by Pletscher shown here Gebrüder Pletscher AG, Druckgusswerk and below.

battery carrier BCMT.jpgdahonquickrack1.jpg
 
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Deleted member 4366

Guest
I got my gears today. As I had to order them from Cyclezee, I decided to buy an Ezee motor at the same time so that I can do some performance comparisons. The Ezee motor is about 1kg heavier and should be a lot more powerful. It's also a couple of mm narrower than the Cute and sits nearly central in the frame. I'll describe the Ezee installation after the I've tested the Cute.
Next problem to solve is the rather shallow drop-outs. I'll have to make torque arms because there's no room for the tang of the anti-rotation washers that are usually enough to resist the torque. I'm also not that happy about the narrow axle shoulder on the inside of the drop-out that will soon bury itself in the alloy drop-outs and loosen the nut. Not so bad on the gear side because there's a big nut on the axle.
 
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Deleted member 4366

Guest
Noe that I've got my tax return out of the way I can get back onto my projects. Today, I completed the drop-out reinforcers and installed the first motor (Cute). The plate on the drive side is 2.5mm mild steel and the one on the other is 6mm. They butt up against the back of the chain-stay box section and both have a single screw to keep them in place. Sorry about the crappy photos. I don't know how these kit installers can do it for their price. It took me all day to do this.

 
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Deleted member 4366

Guest
Nearly finished now. I should be able to try it out tomorrow. The controller and the Speedict are in the black box. There's no throttle as such. Instead I have a cruise control that's activated by a switch on the left handlebar. The speed is selectable from the potentiometer on the top of the black box. Rather than use those ugly and heavy switched brake levers , i kept the originals and put read switches, which are activated by a magnet on the cable at the back and a magnet on a little bracket attached to the caliper at the front. the total weight including 5.4aH 44v lipo is 16.5kg.
Costs:
Bike £599
Battery £60
Motor and controller £150
Other stuff £5
Speedict £66
Total £881

After I've tried it with the Cute motor for a bit, I'm going to swap it for an Ezee motor for comparison.


 
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eddieo

Banned
Jul 7, 2008
5,070
6
Nice job! very neat looking motor...Is that the battery or controller on crossbar under seat?
 
D

Deleted member 4366

Guest
Nice job! very neat looking motor...Is that the battery or controller on crossbar under seat?
No, it's the controller. The battery will eventually go behind the rear suspension unit. I'm going to make a container and brackets for it. For now. it'll go in a bag.
 
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Cyclezee

Guest
Nice work Dave,

I'm looking forward to seeing the completed project and your opinion on the eZee motor in comparison to the Cute.
 

cwah

Esteemed Pedelecer
Jun 3, 2011
3,048
179
www.whatonlondon.co.uk
Nearly finished now. I should be able to try it out tomorrow. The controller and the Speedict are in the black box. There's no throttle as such. Instead I have a cruise control that's activated by a switch on the left handlebar. The speed is selectable from the potentiometer on the top of the black box. Rather than use those ugly and heavy switched brake levers , i kept the originals and put read switches, which are activated by a magnet on the cable at the back and a magnet on a little bracket attached to the caliper at the front. the total weight including 5.4aH 44v lipo is 16.5kg.
Costs:
Bike £599
Battery £60
Motor and controller £150
Other stuff £5
Speedict £66
Total £881
Really... really nice job Dave.

I didn't understand everything however:
- How can a cruise control replace a throttle? Cruise controle is fixed speed isn't it? You'll have to adjust the speed from the potentiometre below your seat when you use your cruise control?
- And I like the idea of using magnet. But not really sure how it works? I'd like to do the same thing for both the brake and light :) Do you have a link where you purchased it?