Scrapyard folding 12.5" wheeled ebike project - Big Tuna

I was going to put this in with my other general build thread, but really I think deserves its own thread due to being to rad.. Basically I picked up this ebike – if it even is that!!! For my brother to have a play with.. I have a fella who gets me old bikes off the scrap man, and sends me random Facebook messages saying do you want this? I sent onto my brother and he said yip.. Initial photo and conversation from supplier..

Basic plans are to strip back and max out power for cruising..

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Photos as bought. Idea is to strip, fit battery etc as needed and use for general messing about..

My brother for some reason has called it “big tuna” with no explanation, but somehow I think that works and therefore it will be known as that from now on.

I think it's got a dumb and dumber vibe going on..

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Existing wiring and all safety cut offs removed.. bodged battery pack installed with a BMS system, new throttle & key switch installed. current motor is 250w.. I think it is geared for about 12mph flat out, which in all honestly is ample.. although will push the boundaries to get maximum from motors, controllers, batteries etc..

Heading back down next week to fit new tyres. new BMS and Controller ordered.. should be capable of 400W...

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this is bonkers

I'm all up for this.

Should be a bit of fun.. there is talk of it being strapped to the back on a Mercedes and going to the Nürburgring in June.. from Belfast!!!! I think whatever we do power wise it will still top out at about 12-15mph.. but to be fair after a test ride is plenty!!! As long as it can do burn outs I'll be happy..

This looks like a hilarious deathtrap

Indeed, 12mph seems like 120mph!!!

Correct me if im wrong - but there's just one flimsy looking caliper brake on there?
Looks like a lot of fun at 12 mph!

Flimsy front caliper and rear drum!! for what it's worth..

And it folds too! Just brilliant.

dat wiring / connector box pic

Yeah YEAH.... This is my cup of tea! More intricate pics please. Get your brother to write shite down please. This is all sorts of awesome.
If you and your brother ever get rid of, give me a shout. Also what's the deal with the hard top MK1?

Holy shit I want one of these so badly.

That's the motor controller, currently being upgraded :-) and relocated to the rear.. The battery pack is a DIY 24v pack made from 18650 cells linked together in 3d printed housing.. then set into 1/2 a 5 litre brake cleaner container..

My Bro (twin) is into everything.. so he messes with all kinds of electrics / battery stuff.. Mk1 is an road legal, but used for autotesting / lanes rallies.. he also has a 1999 TDi polo saloon with 380 lb/ft!!!!

Cool this. Good work. What club does he do his autotests with?

Running the battery down..

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Bigger motor controller and bigger battery.. did not end well. no BMS on the battery so think it fried the new controller.. did give it more grunt though...

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Crazy project, can’t wait to see how it turns out

New battery update.. My bro managed to get a 36V battery off a fella so this have now been hooked up and provides extra voltage and speed!!! also looks like a bomb / rocket on the back..

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Down tonight for a test ride.. setup is now a 36v battery and 600w controller.. so it did 18.6mph top speed, which to be fair is pretty fast.. my cadence was mental on the mighty 105mm cranks.. also note the tyre rubber from successful burnout attempts..

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Looks fun (and dangerous)

Where do you find replacement tyres, when they inevitably blow up from excessive burn outs?

This is great! Moar burnouts! It needs a partner for drag races.