OK, I've been to five bike shops now. Most of them don't do any repairs on electric bikes, the one that did sort of shuddered when he saw my front wheel. I'm thinking that this is definitely a roblem with the main bearing of the front wheel, and it can't be fixed, not by me, and not by most bike shops. So, the short term answer is to use the other bike, not a problem. The longer term answer is to buy a new front wheel.
So I've ordered a 24 volt motor front wheel from Hong Kong, and I'm thinking it'll take a few weeks to arrive. When it does, I'll try to use it with the same bike, and with my existing 24 volt batteries. The cost was £180 (I hope, there might be some custom duty to pay) which is pretty cheap, considering in includes the motor, the wheel, the controller, the throttle and other bits and bobs.
In other news (as they say), the toner refill kit arrived, which consisted of a bottle of toner and an incomprehensible and ambiguous sheet of paper. But I think I worked out hw to use it, it wasn't difficult, and I now have a cartridge ready to use when my existing one runs out.
Yet more news - I now have two finger splints (small and medium) and three mallet finger supports (small, medium and large). The small one is hopeless, the medium one is *almost* big enuogh for my little finger, and the large one is a fraction too large. The sizes on the things are 2, 3 and 5. I don't know how come I didn't get a 4. The finger splint makes me look like I have a bionic finger; the mallet support, worn in conjunction with a black finger stall, makes me look like a pirate. I'll be seeing thedoctor on Wednesday; he'll have a good laugh.
And then I decided to have a look at my older non-electric folding bike. Could I use that as the basis for the new bike? Advantage - it has disk brakes. Disadvantage - I don't see a way to put a back rack on, which would be needed for the battery etc. So scrub that for now, but maybe I'll have some thoughts later.
Then I decided to have another look at my old 24 inch wheel folder. I'd stopped using it because the bottom bracket bearings (that's what the pedal cranks are attached to) were very wobbly, and the bike shop said that the bearings couldn't be replaced because they were a funny size. So - step one - remove the bottom bracket. That was VERY DIFFICULT INDEED, and involved a lot of time spent bashing at it with a big spanner to get the right side off, then a LOT of time bashing it with a hammer and chisel to get the left side off. Any engineer will tell you - when in doubt, use a bigger hammer. But eventually, it yielded - must have taken me a few hours altogether, bashing away with my biggest hammer as hard as I could, because there really was nothing to lose, if I couldn;t get this off, then the bike would remain unusable. I pulled the crank out. The ball bearings, and the remains of the cage holding them, fell out, all over the floor. No problem, I wasn't planning to reuse those.
So, then on to Ebay. The crank shaft is 160 mm long, and there weren't any of that length. The best I could find was 131 mm. But the crank shaft looks pretty good to me, it feels like it hasn't worn. So I bought a set of ball bearings, the races and the thing that screws in to keep everything in place. Cost, £6. Bike stuff is *so* cheap, especially compared to car stuff. I also bought a 131 mm sealed unit; maybe it'll be long enough (I don;t see why the existing one is 160 mm), and it'll only cost £12 to find out.