First E-bike build - eZee Giant CRX-1 (FB Road)

[sparkcrx]

Hello All,

I have been lurking in the shadows for some time now... Reading up on the various combinations people have trialled.
It makes for very interesting and informative reading... I have learned a lot, but have some questions about my specific setup.

I would like to convert my Giant CRX-1 FB Road Bike to electric-assisted power. The bike is used for a 21-25km each-way commute (42-50km's round trip).
I am not shy of using pedal power, but like the idea of riding to work without sweating too much and being able to get a workout on the way home.
I'm not against the idea of having a charger at work and at home to save lugging a huge ah battery on the back.

While i'm not locked into the CRX for an ebike donor, I like that it's light weight and has plenty of good bits that make it a nice riding bike "as is".

I managed to find a really cheap Giant CRX-4 (smaller ladies frame) to pull some parts and swap into the CRX-1 to make it more ebike ready.
(This would work out well as I could then build up the CRX-4 as a normal pushy for my GF using some CRX-1 parts! Carbon forks and seat post....)

Anyway, this is what I had planned. I would appreciate thoughts and advice from any of the experienced campaigners here!
I thought front wheel drive, as I get to keep my 105 drivetrain (10 speed cassette) and should I get a flat, it's more easily rolled out and changed.

- FWD Ezee Geared Motor Kit (700c) with controller
- CRX-4 Chrmoly Fork (remove the carbon fork)
- Torque Arms
- 36v 10ah or 48 15ah (Ping LiFePO4) either rack or in frame mounted
- Suspension seat post
- Cycle analyst

I have some reservations about using a 700C rigid frame bicycle for this purpose (with the added weight), but then the 700C wheels "roll" quite well over small bumps compared to a 26" wheel.
Never used a suspension seat post before, but the CRX-4 I bought came with one and is pretty comfy to ride!

In reality, is a 26" wheel MB more appropriate for a real-world commute that may include the odd squared-off concrete driveway ramp, pothles etc? (no gutter hopping!)
Or is a 700C rigid alloy-framed bike up to the task? I am mostly riding on road and bicycle paths.

The CRX-1 is the first "good" bike I have bought new (in 2010), so I don't reeeeaaaaally want to sell it for half what I paid for it!

My thoughts were eZee to keep the weight down, torque up and freewheeling which is a huge benefit.
Perhaps even keep it down to only 36V 10ah - 15ah? To keep weight down and power within the constraints of a FWD non-suspension lighter weight bike.

I am looking for a commuter that is still a bicycle, not a twin 1000W monster... Who knows that may come later!

Thanks all

 

[wineboyrider]

The radical environmentalists have been doing this to Nuclear power plants for decades. Some "environmentalists" really want humans to die and exit the environment so the birds and the bees can live without us.

 

[torker]

The radical environmentalists have been doing this to Nuclear power plants for decades. Some "environmentalists" really want humans to die and exit the environment so the birds and the bees can live without us.

I think you hit the wrong thread Wineboy

Spark, I think you are on the right path. Keep a rigid bike to 15-20 mph. and you should be fine. Also you say you don't mind pedalling so a small Ping battery should be good. I would go with 15 ah. just to better match most controllers 20 amp draw.

 

[sparkcrx]

Hey Torker,

Thanks for the reply, yes hopefully i'm on the right track. Ill have a think on it some more and hopefully in the mean time some others can chime in with their thoughts.

If I buy the 700C front Ezee kit, am I able to re-lace the hub into a 26" if I wanted to try it? Or is the hub itself different in some way for a 26" wheel?

The Ping batteries seem to have a reasonable reputation.

Is there a source for a ready-made neat looking cases to suit the Ping batteries?

I can make something up that will look okay, but the lockable alloy cased units look the business.

 

[torker]

No problem, With a charger at both ends and with some pedaling you "might" get by with one of the aluminum case batteries but I am not sure if any of those are more than 10 ah. If you went with one that size you would have to stick with a stock 20 amp controller. Not sure what kind of riding/hills you have.

 

[lawson415]

hey sparkcrx

I recently (last week) put an ezee 20" front hub with the 9 amp hour battery on my dahon mu xl . It works great, however, I wish I had spent the extra $ and got the 14 amp hour battery for the extra range. I can go 16 miles on this system, pedaling the whole way. With the 14ah battery, i could go 24 miles.

I have a 2.5 mile hill just before i get home so I want electricity to the end.

you could re-lace the wheel- no problem. it does use thick spokes.

Robert

 

[torker]

Going from a 26 inch wheel to 700c shouldn't be much problem. Going from a 20 inch and putting in a 700c might be. Most hubs are wound for the size wheel. A hub designed for a 20 inch would be wound for a lot faster rpm. Also most hubs are 36 h. You might count your spokes first.

 

[sparkcrx]

hey sparkcrx

I recently (last week) put an ezee 20" front hub with the 9 amp hour battery on my dahon mu xl . It works great, however, I wish I had spent the extra $ and got the 14 amp hour battery for the extra range. I can go 16 miles on this system, pedaling the whole way. With the 14ah battery, i could go 24 miles.

I have a 2.5 mile hill just before i get home so I want electricity to the end.

you could re-lace the wheel- no problem. it does use thick spokes.

Robert

Interesting.... I may go for a 36V or 48V 15ah ping by the sound of it then + make a nice case to suit. I'm not too happy with the idea of running a softcase as a long term solution.

I have access to a TIG, so will look at making a box out of thin gauge, ribbed ally mounted either to inside the frame triangle or onto a rack

Good to know that the hub can be relaced onto a 26" too.. Cheers guys

Lawson, do you have any vid footage of your machine in action?

 

[lawson415]

probably will not get video. will post pics after I get new battery and clean up the wiring.