Anyone got a spare frame?

[Jeremy]

I've been asked to have a go at building a super light folding ebike by one of my (ageing) aviating friends. He wants to be able to chuck it in the back of his microlight and use it for getting around when touring.

The chap's seen (and had a go) on my electric 'bent and was very taken with the low weight and performance of the little Tongxin motor. Try as I might I can't find a source for a nice, light (and very cheap!) donor bike. I want one with 20" wheels, and ideally an alloy frame, as the thing will get scratched to death heaving it in and out of the microlight, I'm sure.

As I can't find a suitable donor bike, I plan on having a go at building him a very light folder from scratch, with no gears. This means I need to source a cheap frame, then just add the bits I need. I have a couple of spare 20" rims, plus I most probably have enough brake bits around. If anyone knows where I can either get hold of a decent frame, or perhaps a suitable donor bike at a cheap price, I'd be grateful.

I will replicate the setup I have on my 'bent, I think, using a 36V, 10 Ah Ping LiFePO4 battery. Some ingenuity will be needed when it comes to the charging arrangements, as I will need a DC-DC converter to step up the microlight 12V supply for in-flight charging. Should be an interesting project, though (as if I don't have enough already!).

Jeremy

 

[keithhazel]

I've been asked to have a go at building a super light folding ebike by one of my (ageing) aviating friends. He wants to be able to chuck it in the back of his microlight and use it for getting around when touring.

The chap's seen (and had a go) on my electric 'bent and was very taken with the low weight and performance of the little Tongxin motor. Try as I might I can't find a source for a nice, light (and very cheap!) donor bike. I want one with 20" wheels, and ideally an alloy frame, as the thing will get scratched to death heaving it in and out of the microlight, I'm sure.

As I can't find a suitable donor bike, I plan on having a go at building him a very light folder from scratch, with no gears. This means I need to source a cheap frame, then just add the bits I need. I have a couple of spare 20" rims, plus I most probably have enough brake bits around. If anyone knows where I can either get hold of a decent frame, or perhaps a suitable donor bike at a cheap price, I'd be grateful.

I will replicate the setup I have on my 'bent, I think, using a 36V, 10 Ah Ping LiFePO4 battery. Some ingenuity will be needed when it comes to the charging arrangements, as I will need a DC-DC converter to step up the microlight 12V supply for in-flight charging. Should be an interesting project, though (as if I don't have enough already!).

Jeremy

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i for one will be just as interested as you as want something even lighter then my quando for getting on the bus with..power included

 

[flecc]

The discounters CycleKing sometimes have unusual items like this. I once saw an alloy 26" wheel derailleur bike in there which was incredibly light, and unbelievably at £120 complete. They often have folders of various sorts as well.

CycleKing

Here's their Folders page link.

Some of the 20" wheel alloy ones look quite decent.
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[Jeremy]

Thanks for the tip, Flecc, I'll follow it up.

The plan is to stick with 20" wheels, as the bike will be used to ride across grass airfields, where smaller wheels would be a disadvantage. Based on my experience with the Tongxin in a 20" wheel, I don't think that gears will be necessary, plus the bike will be used mainly around airfields, which are generally in relatively flat places (with a couple of exceptions I can think of).

Ideally I want a sub-10kg basic bike, to which the relatively high power Tongxin 36V set-up will add maybe another 5-6kg overall. If I can get a 16kg bike with the range and hill climbing ability of my 28kg 'bent, then I'll be well-chuffed. I might even build one for myself if it works!

Jeremy

 

[flecc]

Sounds good Jeremy, rather like a lightweight version of the Quando, that heavily built bike always somewhat hampered by it's 25 kilos with the huge battery.

My guess is that one of those folders illustrated on that webpage could come close to suitability.
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[keithhazel]

Sounds good Jeremy, rather like a lightweight version of the Quando, that heavily built bike always somewhat hampered by it's 25 kilos with the huge battery.

My guess is that one of those folders illustrated on that webpage could come close to suitability.
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is it me or is there no pictures of folding to see what it folds like, or weight either......probably me...

 

[flecc]

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is it me or is there no pictures of folding to see what it folds like, or weight either......probably me...

At their prices there's no spoonfeeding Keith. You just have to do the checking out yourself in one of their many showrooms. If my local one is anything to go by, you can spend ages doing that without being pestered by staff.
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[keithhazel]

At their prices there's no spoonfeeding Keith. You just have to do the checking out yourself in one of their many showrooms. If my local one is anything to go by, you can spend ages doing that without being pestered by staff.
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yes Tony agreed their prices seem good, however..showrooms we dont have..you lot are so lucky you have everything....showrooms, hills..just not fair.

 

[flecc]

Another possibility that might be worth checking Jeremy, since you're not too distant. The Avon Cyclery, aka www.foldingbikes.co.uk - The Uk's no 1 online folding bike store.

Normally quality stock, but there's a chance of old/damaged/second hand stock.

They are the rear of Bath Spa Railway Station.
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