Electric Bikes – battery problem solved, but other problems rear their heads

The battery is charging again as I type, and all cells are charging at same rate, all rising nicely, so it looks like the problem was one bad cell, possibly two, but the first may have been making the second look bad. Unfortunately, the bike fell off its stand in the wind, cracking the battery case again, but it is easily repaired with some ACM, glue and screws! The next battery will be built inside panniers which are ex-NZ Post, so are light and built to last! When the new BMS arrive, the new battery build will begin.

Last night I was adjusting the front derailleurs of Lynn’s bike, and noticed some resistance and strange noises while turning the cranks. At first I thought it was something in the rear wheel, gears, chain or chain rings, but when I finally removed the chain from the front chain ring, it became very apparent that the bottom bracket bearings were a bit of a mess. After a few hours on the web, I now know I need a UN55 68-118 bottom bracket cartridge to replace the noisy/stiff bearings, and a BBT-22 Bottom Bracket 20 point cup removal tool. I also know the difference between a UN53, UN54 and a UN55 cartridge! Bought the tool this morning, found a bike shop with the bottom bracket in stock in Wellington, all could be good by this evening! I will probably check mine after I have finished hers.

By the time I get home at lunchtime today, the odometer will have clicked over 2000kms! I am using the bike for errands and shop work more and more, on Thursday, I took some signage and some tools down to the coffee cart at Aotea lagoon and applied the signage to the doors! Woo-hoo – signwriting from a bike! It’s possibly a few decades since that was last done!

Posted in Electric Bikes
One comment on “Electric Bikes – battery problem solved, but other problems rear their heads
  1. Dave says:

    I got the bottom bracket and fitted it, eventually. A couple of strange problems arose, mainly because the cranks seemed a couple of mm close to the bracket. When I finally got everything adjusted, I took my bike apart, and while the bearings on mine were OK, I remeasured the axle distance, and it was a 122.5 axle, not a 118. So I remeasured the one I took out of Lynn’s, and it was a 122.5 too! The lesson here is when the battery is low on your micrometer, don’t trust the measurement it gives you! Still we had a great afternoon visiting Burke’s Bike Shop in Kilbirnie – by far the best range of anything bicycle in the Wellington region!
    While working on my bike, I tightened up the front wheel bearings, and had a quick waggle of the back, which was when I found the loose gear cluster, with a couple of mm play side to side! So I took the wheel out, expecting to find the cluster loose on the splines, but instead found that the nut holding the freewheel and splines to the axle and motor was loose. Quickly tightened it up and reassembled! I was probably very lucky something didn’t get damaged.

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