Kona Ute tsdz2 conversion

[peter.c]

A quick read shows the steel is soft enough to work/cut on a home lathe
and even welding does not work, one guy has even had a replacement machined from scratch and re designed the bearings it seems a lot of effort

 

[guerney]

Interesting... then maybe the metal is too soft? Is that a stepped shaft ie one piece of metal, or a shaft through a collar? If it's one stepped piece, there would be more twist at the thinner end. Before I bought the BBS01b, I did read about snapping shafts somewhere, but Bafangs don't appear to have that problem - just the controller tax every thousand or so miles, maybe.

How does the torque sensor on the Tongs work anyway? Would the bike go speeding full pelt, if one stood on both pedals?

 

[peter.c]

In turbo mode the 300% assist does make for fun hill starts
But still not as much as a bafang on level 9

 

[Nealh]

The steel used is soft but the main issue is the breakage is always on the drive side approx. 2cm in where there is a groove for a circlip which I believe holds the bearing in place, the extra bearing use dis to try and stop any axle flex but isn't the answer to prevent axles snapping.

 

[guerney]

Does the torque sensor work by detecting shaft twist? If so, there's a limit to how hard they can make the shaft, before torque sensing becomes less accurate. Also if it works by detecting shaft flex.

What's the problem with the blue gear? Tongs do seem to have a lot of design problems.

 

[guerney]

The steel used is soft but the main issue is the breakage is always on the drive side approx. 2cm in where there is a groove for a circlip which I believe holds the bearing in place, the extra bearing use dis to try and stop any axle flex but isn't the answer to prevent axles snapping.

Look at this Bafang version, why not electrify your Kona Ute with Bafang nealh?

 

[Nealh]

I've got one and have blown two controllers and have had PAS issues, it also has its issues. I really need to dig it out again and try the KT on it again.

 

[guerney]

I've got one and have blown two controllers and have had PAS issues, it also has its issues. I really need to dig it out again and try the KT on it again.

Do you have the BBS01? The BBS01b is supposed to have design improvements, somewhere or other. Have to say, I'm very pleased with my BBS01b. Despite my soldering sabotage and demanding carriage of heavy pumpkins, it still flies. Hoping Bafang's controller tax is not too steep - if each controller lasts at least 2000 miles, it'd find that borderline bearable. Might you be flogging a badly designed horse, attempting resurrection of your BBS01? Wasn't there some PAS/magnet problem with yours anyway?

 

[guerney]

I've got one and have blown two controllers and have had PAS issues, it also has its issues. I really need to dig it out again and try the KT on it again.

Greenbike kit sell bare BBS01b motors, supposedly an improvement over the BBS01?

Bafang bbs02 48v/36V 500w/750w bare motor-Greenbikekit.com BBS, ebike batteries, Bafang M620, Bafang M600, Bafang M500, Bafang M510, KT controller with display-GreenBikeKit.com

Bafang 48v750w/500w bbs02b bare motor for replacement

www.greenbikekit.com

 

[potato]

Back on topic about my ute build! Test ride using the original ill fitting bullet connectors from motor to battery was mostly successful. Motor is perfect, so I snipped off the bullet connectors, soldered the wires with heat shrink around everything so that's sorted.

The thing that didn't go so well is that the pedals feel incredibly wonky. I threaded them by hand to avoid cross threading them and just nipped them up at the end, so I haven't cross threaded them. Took them off just to make sure and checked the threads, which are fine, so either the cranks haven't been drilled square, or the pedal axles are bent.

Next step, try swapping for a known good set of pedals!

 

[guerney]

During a sudden thunderstorm, the motorand half my bike were completely submerged in a deep rain puddle/small pond a few months ago, and I worried that the self amalgamating rubber waterproofing tape around the battery bullet connectors, hadn't kept the water out... it did, but since then I've soldered the battery wires to the controller directly, and used marine 4:1 heat shrink plus self amalgamating rubber tape, just to be sure - my bike and I sometimes seem to be forever in hours and hours of heavy sustained rain:

4:1 Black Adhesive Heat shrink Waterproof HeatShrink Glue Lined Tubing Sleeving | eBay

Its high shrink ratio makes it ideal for sealing large components and irregular shapes. NOT the lay flat width of the heat shrink. As a guide, the lay-flat width of our heat shrink is below Shrink Temperature: 90 °c.

www.ebay.co.uk

 

[potato]

Half an hour spare this morning - thermal pads and grease arrived yesterday, so lets crack on..

Bit of paper trimmed to size as a trial formed the template for the shape to cut the 2mm sheet into - 5 sections, there technically could be a 6th but it looked like a mare to get to the back by the controller.



Slap the remaining thermal sheet into the casing as a guide and mark round it.. trim it to size and slap it on top of the last pads to continue to close the gap



Trial fit the casing showed there was still a smidge of room, this is where the grease comes in



Close it up



Presto.

I've not done anything sensible like taking a baseline measurement of temperature, but I'm confident enough based off the endless sphere threads that this'll proof the motor against overheating.

No luck with the crank arms though. I tried running the opposite pedal in from the other side as a tap to clear the threads. They ran in straight and true, without needing tools, and yet running in the pedals from the proper side just ends up with a wonky pedal. Have ordered some shimano steps cranks for £30 as an alternative and seeking a partial refund on the tsdz2 cranks.

I might gorilla up the pedals flat to the tsdz2 cranks as a stopgap, destroying the pedal threads in the process, we'll see.

 

[Nealh]

An internal sensor although optional is handy to have installed to monitor temps when in use (esp on the winding side), a sub 60c temp can be kept to by selecting gearing or PAS modes. Over heating the windings means loss of power and poss future failure. The plastic drive side cover (frontal area) is a good place for a sensor and is also a heat trap as the void behind is just air space and air is a poor heat conductor having a paltry 0.24 w/mk conductivity or worse, the use of the 6 w/mk thermal pads will aid heat transfer away.

 

[potato]

Replacement shimano steps crank arms arrived today from Bikester, so popped them on along with new pedals and off we go. Plenty of clearance to the motor, and even on a short test ride it feels amazing, feels more stable than before on downhills with the extra battery weight. Putting in the extra effort to go beyond the 15mph cut off feels like a fools errand though when I tried that Whilst it's all configurable I intend to keep this fully legal.

Over the weekend I'm going to see if I can do anything to restore the sun faded panniers and have a look at the yepp bike seat and mount to see what's next with that.

 

[potato]

Tiny cosmetics.. panniers didn't respond to attempts to revive them so they'll have to soldier on as is. Yepp seat mount got a going over with paint stripper, wire brush and eventually sanding with a dremel to get rid of rust, then repainted in copper rattle can to at least superficially match the bike. Need to repeat the process on the seat base itself but no rush



Range test ride today - sans child.

Starting off with a almost fully charged battery I went from Bristol to Bath in 'Speed' setting, which saw me arriving in Bath just as the first battery bar blinked out - which is good because I thought it was stuck on full!

Seeing as we'd covered .. 23 or so miles with seemingly very little impact after a bit of a potter round Bath, I turned it up to turbo for the ride back, which promptly set about absolutely rinsing the battery. I know lithium ion batteries tend to drop off rapidly after getting below say 80% but wow by the time I got to the outskirts of Bristol it was between half + a third battery so I turned it down to 'Speed', but even then by the time I'd gotten through the city centre and needing to do the remaining couple of miles to the house it was down to about 25%. Out come the 'Tour' mode, less a short burst of turbo for a hill at the end, and arrived home with the battery alternating between 1 and 2 bars - guess that's about 10-15%.

Very happy with that range - 45 miles including about 10 miles of turbo, in temperatures around 2 degrees celsius. Sensible usage in these temps should see an easy 50, and warmer weather I would expect to see more again - perhaps 60-65.

The odds of me going on any 60 mile rides with a baby on the back? slim to none but hey ho it's good to have it.

 

[Nealh]

How are you monitoring internal temperature ?

 

[potato]

Simple - I'm not the ES folk have done plenty of harsh testing after the same cooling mod as I've done and found the cooling improvement to be ample

 

[Nealh]

Sensible usage in these temps should see an easy 50, and warmer weather I would expect to see more again - perhaps 60-65.

One then is only guessing/surmising it is running cooler then, for about a fiver one can be sure instead of guessing.

 

[guerney]

Simple - I'm not the ES folk have done plenty of harsh testing after the same cooling mod as I've done and found the cooling improvement to be ample

I worried about my bbs01b overheating in summer, but it seems fine, even with much hill climbing carrying heavy weight - judging by forum comments, the Tongsheng blue gear seems to have a habit of melting?!?? I don't think Bafang BBS01b's white nylon gear suffers from the same sort of issue.

 

[sjpt]

seemingly very little impact after a bit of a potter round Bath

I guess you left the race course and the university out of this potter?