my first build: brompton at 30 mph

General Discussion about electric bicycles.

Re: my first build: brompton at 30 mph

Postby cwah » Fri Feb 24, 2012 11:36 am

I just went to the steel shop recommended by Dave (thanks ;)), they said they can do it. I have to meet them with my bike this monday.. I almost want to find another place to get it welded during the weekend lol.

I can't go directly with my wheel because it has not been laced yet. I have to contact alan to lace it. I'll just meet them with the motor.

And I'm not sure to keep this motor anyway, I'll just ask them to provide 135mm dropout symetrical on both side. So it will be easy for me to change motor if I want to.

So my request will be:
- 135 mm dropout wide
- Stronger forkend able to handle 150 nm torque
- Forkend alignment to handle the motor
- Symetrical alignment to the bike frame

The rim would probably not be central because my wheel is not laced yet.. is it a big deal or shall I get it laced first (send it to alan and get it back will take some time)?
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby cwah » Fri Feb 24, 2012 11:48 am

wesnewell wrote:
cwah wrote:I'm soo impatient to have my motor fitted... Do you think I can do it with my wood bar or shall I go buy the torch and the car jack?

Well, I've done 3 bikes using wood. Don't see why someone else couldn't do it too. Only takes a minute or two. It will spring back some, so you probably want to go to at least 150mm before knocking the wood out.


I'm not sure wood would work with my bike. The leverage area is not good:
Image

There is a central steel bar on the middle of the fork as main support. With the wood I'll mostly bend on the area with screws and not the fork itself.
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby joe tomten » Fri Feb 24, 2012 12:55 pm

Things to think about:

How big of a tire do you want to run?

Do you want that multispeed freewheel? and how will that affect the chainline?
User avatar
joe tomten
100 W
100 W
 
Posts: 286
Joined: Wed May 13, 2009 3:05 pm
Location: E. Mass., U.S.A.

Re: my first build: brompton at 30 mph

Postby cwah » Fri Feb 24, 2012 1:18 pm

As biiig tire as possible lol. But I think I'm going to be limited by the brakes.

And single speed freewheel is enough. Don't know how that can affect the chainline.
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby joe tomten » Fri Feb 24, 2012 2:34 pm

I have a Brompton front fork here, and the 16" * 1.95” hookworm won’t fit. A 1.5” Schwalbe marathon winter fits in there with room to spare.

If you want a fattie tire in there the flaring you have done will need to start far out from the axle - which might introduce it's own complexities. Probably best to stick with the least complicated bending and be happy with 1.5 to 1.75 tires.
User avatar
joe tomten
100 W
100 W
 
Posts: 286
Joined: Wed May 13, 2009 3:05 pm
Location: E. Mass., U.S.A.

Re: my first build: brompton at 30 mph

Postby cwah » Sat Feb 25, 2012 3:52 am

Ok, will stick to the inital tire then.

I just noticed that my motor dropout is 145mm and not 135mm as advertised for single speed:
Image

Shall I ask for 145 mm dropout or shall I shave the motor dropout shoulder?
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby Ykick » Sat Feb 25, 2012 8:43 am

Your method of measurement looks suspect to me so I'd go with the engineering drawings and request 135mm. Leave the file and axle alone. If you can take an absolute accurate measurement and it's indeed 145mm then maybe request 140mm and man handle it with a pry bar while installing.

I'm only looking at cut-off pictures but my eyes question if the body of that motor is gonna fit inside the frame dropout without some serious reshaping?
Internet Image experts...
User avatar
Ykick
1 GW
1 GW
 
Posts: 3485
Joined: Thu Nov 26, 2009 6:10 pm
Location: USA

Re: my first build: brompton at 30 mph

Postby cwah » Sat Feb 25, 2012 4:32 pm

I don't know either. If it need serious reshaping so be it.

I'll ask them to go for 135mm or 140 mm. I can still shave the dropout anyway.
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby wesnewell » Sun Feb 26, 2012 2:09 am

cwah wrote:I'm not sure wood would work with my bike. The leverage area is not good:
There is a central steel bar on the middle of the fork as main support. With the wood I'll mostly bend on the area with screws and not the fork itself.

Well, rethink how you are going to use the wood. And not like in your photo.:-) Stand the wood on end on the ground. Put it between the insides of the *forks* sideways. Take a sledge hammer and pound the wood into the forks spreading them apart. If you don't understand, I'll try and draw a picture, but I'm a lousy artist.
Mongoose 26" Ledge 2.1 mtb bike $99, yescomusa.com 48V 1000W rear hub kit $276, Hua Tong 72V 40A controller $35, 10ah 24s lipo $275=40+mph, range=45 miles @20mph
User avatar
wesnewell
10 GW
10 GW
 
Posts: 4459
Joined: Mon Jan 31, 2011 6:25 pm
Location: Wylie, TX, USA

Re: my first build: brompton at 30 mph

Postby cwah » Sun Feb 26, 2012 7:17 am

I don't know if I'll do it correctly with a wood bar. It's quite a lot to be widened. I'll see tomorrow with the metal guy.
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby cwah » Mon Feb 27, 2012 3:12 am

Just went to the metal shop. They said they can't do it because of the metal bar in the middle of the fork. The bar in the middle was added at the end.

They said I need to have a new fork with the right size... but there is no way I can have that. :( :( :(
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby adrian_sm » Mon Feb 27, 2012 4:22 am

What rear brake are you planning on using?

The reason I ask is that if you don't need a rear disc brake, and you are running single speed on the rear, can't you modify the axle and reduce the required drop out width?
Build #1 ~28kg ~ 700w Avanti Hardtail Crystalyte 408, 48V10Ah Headway. ~5500 kms to date. (retired)
Build #2 ~30kg ~2000w Giant AC Dually Crystalyte 408, 48V10Ah Headway + 6s10Ah LiPo = 70V. ~15000 kms to date [SOLD]
Build #3 ~13kg ~2000w Commuter Booster <1kg Friction Drive in Beta testing (www.commuterbooster.com)
Build #??? ~21kg ~1500w Adrian's Bafang BPM Hardtail MTB Bafang BPM code12, 15s LiPo, ~40kph, ~30kms
User avatar
adrian_sm
100 MW
100 MW
 
Posts: 2641
Joined: Mon Feb 23, 2009 12:54 am
Location: Melbourne, Australia

Re: my first build: brompton at 30 mph

Postby cwah » Mon Feb 27, 2012 4:48 am

I'm thinking about it. Will check later tonight.

but the hub may be too big for the fork
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby dogman » Mon Feb 27, 2012 6:37 am

Steel right? Cut the crossbar, bend the forks yourself, then have someting put back to restore the crossbar. Perhaps a bolted on piece of angle iron. The metal shop is just covering thier asses, so you are on your own.

Do what you can to the axle, so you just bend the forks enough to clear the motor shell.
THE LIPO RULES. NEVER ABOVE 4.3V NEVER BELOW 2.7V DON'T PUNCTURE

Ideal charging /discharging range for Lipo, 3.65v minimum 4.1v maximum

See battery technology section, FAQ thread at the top of the page for lipo noob info.

See the frankenbike longtail at the thread below.
viewtopic.php?f=6&t=28389&hilit=bouncing+betty
User avatar
dogman
100 GW
100 GW
 
Posts: 27552
Joined: Sat May 17, 2008 12:53 pm
Location: Las Cruces New Mexico USA

Re: my first build: brompton at 30 mph

Postby cwah » Mon Feb 27, 2012 6:44 am

Ok, you're right, I'm going to visit another steel shop. It shouldn't be that difficult :x
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby d8veh » Mon Feb 27, 2012 12:41 pm

I don't see what the problem is. A competent metal-worker, who has a hack-saw and welding set could make the frame do whatever you want. To me, it looks a small job to heat up the stays and bend them to the right shape. You could, like said above, cut that cross-piece and weld in an extension, but I don't believe that it's necessary.
d8veh
100 MW
100 MW
 
Posts: 2546
Joined: Fri Dec 10, 2010 10:45 am
Location: Telford

Re: my first build: brompton at 30 mph

Postby cwah » Mon Feb 27, 2012 1:21 pm

Just went to a frame builder shop... He said it was possible but may need to change the rear fork... And may cost 200 to 400£ or more :shock:

How come just widening the bike dropout could be that expensive.

I'm about to give up and just buy the Crystalyte G209... Will check other metal shop tomorrow
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby cwah » Thu Apr 05, 2012 12:54 pm

News from my e-brompton build:
I'm now adding all the torque arms to my bike. I've 2 anti-rotation washer and:
- Conhistmotor torque arm (thinner) on the gear side:
Image
- Cyclezee torque arm (stronger) on the other side:
Image

This configuration should be enough to handle some torque :)

I'm trying to put the chain tensionner on top of the torque arm:
Image

The chain tensioner is not yet aligned with the chain:
Image

I'll have to keep filing the chain tensioner inside to allow it to go closer to the bike..

Now my biggest problem is that I've put too much strenght when I tried to tighten the motor shaft bolt. Now it's getting loose and I may need to change the shaft... but for that I'd probably need to purchase a new motor :(
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby d8veh » Fri Apr 06, 2012 3:53 am

Cwah, I think that chain tensioner's going to cause a lot of problems. The way I understand it, all it does is keep the chain tight when you fold the bike to stop the chain falling off. As an alternative, couldn't you just carry a a bungee strap and hook it round the chain or between the chain and the frame just before you fold, and then remove it after you've unfolded.

I'm looking at your torque arms and the installation isn't the best. The axle will try and turn in the opposite direction to the wheel, so try and imagine what happens if they turn a bit. The one on the opposite side to the tensioner is too straight and the first bolt will slip. Ideally you need a right angle between the first two (from the motor) parts. Alternatively you need to get someone to weld the first joint so that the bolt can't slip.

I'm looking forward to seeing what you can get out of that motor.
d8veh
100 MW
100 MW
 
Posts: 2546
Joined: Fri Dec 10, 2010 10:45 am
Location: Telford

Re: my first build: brompton at 30 mph

Postby cwah » Fri Apr 06, 2012 5:44 am

The chain tensioner allow me to keep the chain tight when I fold the bike, but also to keep the chain on the gear when I'm pedaling. If I remove the chain tensioner, the chain would just fall off the bike.

I corrected the torque arm angle in the opposite side of the tensionner:
Image

Is it better? :)
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby cwah » Fri Apr 06, 2012 9:36 am

Now I've put my 4 lipo in a carton box:
Image

When it's closed, just the cable is reachable:
Image

For a total weight of 4.5kg:
Image

I'll for now put that on my brompton front bag :)
Image
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby d8veh » Fri Apr 06, 2012 2:26 pm

I've been reading your Saga on Pedelecs, but i won't post there, so I hope you see this.
Am I right that it's nominally a 250w motor with hall sensors? If so, It may be that you've cooked a hall sensor. Do you have another controller to try - even a low powered one that you can run with 36v or whatever just to test the motor?
d8veh
100 MW
100 MW
 
Posts: 2546
Joined: Fri Dec 10, 2010 10:45 am
Location: Telford

Re: my first build: brompton at 30 mph

Postby cwah » Fri Apr 06, 2012 4:27 pm

Great thought Dave.

I have my initial bike controller.

Going to remove it and test it now.

Thanks
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby cwah » Fri Apr 06, 2012 5:53 pm

Just sawped with my other controller... And it worked.

It's definitely a problem with the controller :(
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

Re: my first build: brompton at 30 mph

Postby cwah » Fri Apr 06, 2012 7:54 pm

Here is inside the controller:
Image

Not sure what to look at to fix however
Help me find my stolen electric brompton: http://bit.ly/1a0vbBC and Bosch Sinus B3 http://bit.ly/1eV0WQz
cwah
100 MW
100 MW
 
Posts: 2737
Joined: Sun Jul 24, 2011 5:42 am
Location: Between paris and london

PreviousNext

Return to E-Bike General Discussion

Who is online

Users browsing this forum: Bing [Bot], DrkAngel, Spacey, stiffi, Yahoo [Bot] and 14 guests