Lightest possible conversion

[Paultr]

I have recently completed the conversion of my hybrid bike to electric power using a rear wheel motor. This bike has front suspension, rack and panniers and virtually every other bike gadget going (including tinkling bell for pedestrians and a siren for cars !). Pic to be posted later.

The end result of all this is one heavy bike and I now quite fancy having a stripped down lightweight one also (I fear I am getting the e-biking bug !). I have a Peugeot racing bike dating from the 1970's but the frame is too big for me now so I am going to sell that and maybe buy similar from Ebay or else a new low/medium priced road bike (which idea is best do you reckon ?).

The point of this post is to ask what is the lightest option for e-power. Is it another rear hub and if so, any pointers as to models ? Or maybe a centre drive motor would be better and again, any tips to models please ?

Next is the battery. I now have 36V 17A but presumably as the bike would be lightweight I could survive with less amp hours. I would like a range of 35 miles minimum if possible. Again, any pointers as to types/models please.

Any other tips as how best to achieve a featherweight flyer wil be gratefully received

(I have only had my bike for a couple of weeks and already two people have pulled out on me so I want to do this not so much for getting high speed but rather having a machine that is easy to get in and out of the house. At the moment I have stone 5 steps to get up so I have built a ramp but nevertheless getting the bike out is a bit of a faff. A lightweight one would be good for quick trips to the offy etc and would stop me just jumping in the car).

 

[Woosh]

lightest CD kit is the Tongsheng TSDZ2 3.6kgs
Lightest suitable battery is in small water bottle with 10S3P 10.4AH capable of 20A maximum draw 1.7kgs
You still have to add the weight of the LCD, speed sensor and cables, about 300g.
Total weight; 5.6kgs
Lightest front hub motor: xiongda YTW-06 1.4kgs
(there are other manufacturers, Bafang, Aikema, Mxus etc for the same basic specs).
There is no integrated controller to the small water bottle battery, you will have to fit a seat post controller: 400g.
You still have to add the weight of the LCD, speed sensor, throttle and cables, about 400g.
Total weight: 3.9kgs

food for thought.

 

[awol]

d8veh did a lightweight bike with the xiongda YTW-06 motor but the smaller the motor the less power it will probably have.

http://www.pedelecs.co.uk/forum/threads/lightweight-trekking-bike-build.28276/

Also my build with a q100h (2.2kg) ended up about 14.5kg without the battery which feels very light compared to my heavy commuter bike.

http://www.pedelecs.co.uk/forum/threads/ebike-build-from-scratch.29930/

 

[Nealh]

Despite the nay- Sayers lightest bike possible would be a 8-11kg weight and 2 .5kg kit inc battery though range might be an issue with 209wh battery.
A friction drive you engage at will, no led/lcd and very little cable routing to hide.
This new Bristol venture works in the wet as well as it does in the dry, watch the vids. Designed for lightweight town/commute bike with help for those hills.

https://revolutionworks.com/collections/revos-2
https://www.kickstarter.com/projects/revolutionworks/revos-transform-your-bike-into-an-ebike?ref=nav_search&result=project&term=revos

Horses for courses there are needs to suit all options.
If you want a longer range bike then mid drive or hub bike with 13/15 ah battery means a 18 - 22kg bike.
For shorter journeys and a bike you need to carry sometimes go for lightest simplest available option.

 

[Woosh]

Despite the nay- Sayers

The useable power depends on how well the motor dissipates heat. It's like a thermostatic shower tap, it comes with weight.

 

[Paultr]

lightest CD kit is the Tongsheng TSDZ2 3.6kgs
.....
Total weight; 5.6kgs
Lightest front hub motor: xiongda YTW-06 1.4kgs
.....
Total weight: 3.9kgs

Thanks Tony . So it seems a centre crank drive is heavier but I do not fancy a front wheel motor so what is the lightest rear wheel option ?

.....
For shorter journeys and a bike you need to carry sometimes go for lightest simplest available option.

There is something elegant in the simplicity of this friction drive. There used to be something similar in France years ago but that was with a little petrol engine - can't remember their name but they became quite iconic.

 

[Jonah]

I’m fairly sure You can get a Xiongda ytw06 for rear wheel. There a several threads on Xiongda conversions. You get the motor from China and get your LBS to build it into the wheel of your choice. My front wheel motor seems as powerful as most other standard hubs I’ve tried.

 

[Richardab]

My recent build is now at a bit under 15kg. Base bike was 8.6kg, 11.6ah 48v battery inc controller about 3.5kg and q100c rear hub motor about 2.2kg, 0.5kg for LCD, wires and bag.

It averages 19-20mph and I did 34 miles using 60% of the battery although I am pedalling a fair bit.

http://www.pedelecs.co.uk/forum/threads/carbon-single-speed-commuter.31528/

I am sure you can build lighter if you reduce range or speed aspirations. I believe there is a Q85 motor also which I assume is lighter.

 

[flecc]

There is something elegant in the simplicity of this friction drive. There used to be something similar in France years ago but that was with a little petrol engine - can't remember their name but they became quite iconic.

That was the Velosolex. They make electric ones now which mimic the old petrol one's style in some respects, but no longer with friction drive. Link
.

 

[awol]

so what is the lightest rear wheel option ?

Xiongda do a rear freewheel version of the YTW-06 and it has good power for it's size.
http://www.pedelecs.co.uk/forum/threads/small-rear-xiongda-motor.28353/

 

[anotherkiwi]

Use a Q100C to keep a decent cassette and gearing and lose weight from the battery and elsewhere.

- Q100C
- wide range cassette and single chainwheel = weight savings
- Magura HS11 front hydrualic brake, Avid digit rear = weight savings over disk brakes. Get a bike with V-brake fork of course, not cantilever.
- 2P10S custom battery with Sanyo 20700 cells - +4 Ah and 15 Amp discharge so the battery will be +8 Ah, 30 Amp peak discharge and 1.4 kg weight with BMS
- Eggrider display instead of LCD and buttons - 31g plus wiring to controller
- PAS

Have I forgotten something?

 

[Paultr]

That was the Velosolex. They make electric ones now which mimic the old petrol one's style in some respects, but no longer with friction drive. Link
.

Yes, that was it - with the little infernal combustion engine over the front wheel. When I was 14 the family had a holiday in Brittany and I really fancied one of those. I have looked at their site and they now sell the E-Solex with the motor in the same place but it is rated at 500W. It must come into a different category as I assume our 250W limit is European wide (ashamed to admit I have not read up on the law that governs our bikes ) Nice looking bike though.

 

[Richardab]

- Eggrider display instead of LCD and buttons - 31g plus wiring to controller

Oooo, I just googled the Eggrider, that looks interesting, do you have any experience with it. I really hate the KT-LCD controller on my bars as i already have a Garmin GPS telling me speed and distance and much more, although I wouldnt want my phone on the bars either. Do you know how this thing works, do you need the phone or is that just for advanced settings.

 

[Paultr]

Xiongda do a rear freewheel version of the YTW-06 and it has good power for it's size.
http://www.pedelecs.co.uk/forum/threads/small-rear-xiongda-motor.28353/

Found this thread about someone using this motor in a lightweight build
https://endless-sphere.com/forums/viewtopic.php?t=93843

Is it bad form or even not allowed to post links to competing forums ? If it is, would someone please tell me and I will delete the link .....

 

[flecc]

Yes, that was it - with the little infernal combustion engine over the front wheel. When I was 14 the family had a holiday in Brittany and I really fancied one of those. I have looked at their site and they now sell the E-Solex with the motor in the same place but it is rated at 500W. It must come into a different category as I assume our 250W limit is European wide (ashamed to admit I have not read up on the law that governs our bikes ) Nice looking bike though.

The EU law is 250 watts, but a couple of countries also have the S high speed class allowing up to 500 watts and 45 kph (28 mph) assist. Not in the UK though, unless registered as a moped.
.

 

[flecc]

Found this thread about someone using this motor in a lightweight build
https://endless-sphere.com/forums/viewtopic.php?t=93843

Is it bad form or even not allowed to post links to competing forums ? If it is, would someone please tell me and I will delete the link .....

That's perfectly ok Paul, all links welcome. Some of our members also post on ES.
.

 

[anotherkiwi]

Oooo, I just googled the Eggrider, that looks interesting, do you have any experience with it. I really hate the KT-LCD controller on my bars as i already have a Garmin GPS telling me speed and distance and much more, although I wouldnt want my phone on the bars either. Do you know how this thing works, do you need the phone or is that just for advanced settings.

Apparently the mode switching doesn't work with the KT yet. You plug it in to the LCD socket on the controller and the phone app gives the setup stuff plus statistics. I am writing to them again about the KT version and if the reply is satisfactory will buy one next month.

 

[Richardab]

Apparently the mode switching doesn't work with the KT yet. You plug it in to the LCD socket on the controller and the phone app gives the setup stuff plus statistics. I am writing to them again about the KT version and if the reply is satisfactory will buy one next month.

Interesting so your phone can just live in your pocket. What mode switching is that, I only have PAS levels on my KT-LCD3...i think

 

[Paultr]

Warning - long post !

I am learning a bit more each day and can see how people can get sucked into this e-bike world and it can become a real hobby. There are so many variations of hardware and you can delve as deeply into the technology as you want. At the moment it is a bit overwhelming and I know I will never get as expert as some on here but I guess as time goes on I will understand more.
it is a shame I am now retired as I have spent my whole working life trading in HK and China and in the latter years I used to live for around half the year there to cut down the number of long haul flights. It would have been so easy to visit the factories and to put stuff into one of our containers. Not that I would have saved much money as one thing I did learn is that their attitude to pricing is very different to ours. There are no juicy margins like EU importers have traditionally had (I am not criticising this practice, far from it. Importing is a cash intensive process with VAT & Duty & shipping up front and if you have no track record you can find it hard to get credit terms. This is also not taking into account currency movements. Importers need every %age markup they can get ) Getting back to China though and it used to tickle me that if you got a price of say 500RMB for an item and you had to buy say 5 and if you then said how much discount for 500 they would say 2% !! Everything is just so incredibly competitive. Then if you have a cracking product it is just a matter of time before one of your QC/production managers leaves to set up his own factory making a clone of your product. You also have to keep in with your local party officials or else you won't get permission to do anything. Anyway, I am not there now so just have to rely on the merchants websites. If anyone is still reading this post and has imported a motor etc from China did you get stung for VAT and what do the suppliers put on their invoices ?
If I do import a lightweight motor it will definitely not be something that Woosh could supply as I feel like a bit of a traitor as Tony has been so helpful I think the premium I likely paid for my kit (I have not checked ex-factory prices) was the best value money I have spent for a long while. The level of support from them was awesome and worth a fortune if you costed the time it took to write all the email help he gave me.
Anyway diatribe over - time to do some more research with the help of this excellent forum !

 

[anotherkiwi]

They are working on having two different cut off limits, one for "off road" as well as the standard road legal 25 km/h.