Dear all, thanks to the enthusiasm and discussion on here I've finished my build. It's a Raleigh 20 frame with a 7 speed rear hub, a Tongsheng unit and 17.5Ah battery. It's a lot of fun! The bottom bracket had to be ground back on the RHS by about 5mm (as was a welded prop stand attachment ), a DIY drop bolt was necessary for the rear brake and I've had to mount the twist grip on a handlebar extension as it wouldn't fit the bars themselves. The frame was powder coated locally. I mis-ordered the seat post years ago - it had hung around in the bike box and I was very pleased to find it fitted the frame perfectly. If I did it again I might go for front shocks and custom weld a rear brake support to avoid the need for a drop bolt. I'm wondering about the next project and considering an old recumbent in the bike shed which would benefit from a motor.

That looks really good. I have a Raleigh Twenty available to me as it happens. I bought one for my daughter in law a few years back and fixed it up for her, but it is unloved and unused in a car port. This gives me ideas.

Dear all, thanks to the enthusiasm and discussion on here I've finished my build. It's a Raleigh 20 frame with a 7 speed rear hub, a Tongsheng unit and 17.5Ah battery. It's a lot of fun! The bottom bracket had to be ground back on the RHS by about 5mm (as was a welded prop stand attachment ), a DIY drop bolt was necessary for the rear brake and I've had to mount the twist grip on a handlebar extension as it wouldn't fit the bars themselves. The frame was powder coated locally. I mis-ordered the seat post years ago - it had hung around in the bike box and I was very pleased to find it fitted the frame perfectly. If I did it again I might go for front shocks and custom weld a rear brake support to avoid the need for a drop bolt. I'm wondering about the next project and considering an old recumbent in the bike shed which would benefit from a motor.

 

Very nice ideed! Did you drill four rivnuts into the frame for the battery mount? What are those blocks under the mount?

Edited September 30, 20214 yr by guerney

Nice job.

With the right front chain wheel on, setting up the gear ratio, I'd imagine the original Sturmey Archer hub would probably have had enough range to work pretty well with the Tongsheng. I have a Bafang BBs01 conversion with 8 speeds, but most of the intermediate ones are redundant. I ride it on about three of the rear cogs and that includes some pretty steep gradients.

 

That looks like a really nice refurbishment of an old Twenty. Very smart.

Over the years there have been about a half dozen 20 builds on the forum d8veh aka vfr did a couple or so with pics.

Great bike Zelige, best looking Raleigh 20 i've seen.

Very nice ideed! Did you drill four rivnuts into the frame for the battery mount? What are those blocks under the mount?

 

Yes, 4 x stainless steel M6 rivnuts for battery mount. Despite getting flat head M6 screws for the rivnuts I still had to Dremel recesses into the battery mount so it was flush to take the battery. The black blocks are pieces of semi-rigid foam that I cut from the battery packaging. The idea was to slightly elevate the battery mount from the frame to avoid it scratching the powder coating.

With the right front chain wheel on, setting up the gear ratio, I'd imagine the original Sturmey Archer hub would probably have had enough range to work pretty well with the Tongsheng. I have a Bafang BBs01 conversion with 8 speeds, but most of the intermediate ones are redundant. I ride it on about three of the rear cogs and that includes some pretty steep gradients.

You're right. Pretty much all riding on the flat is in top gear. We've some very step gradients so am glad of the low gear, but yes the intermediate spread isn't used much.

 

One thing I'd point out to newbies (including a reminder here to myself) is that setting off in turbo mode in low gear can be risky as the brief but powerful acceleration can lift the wheel and/or accelerate the bike off course and into danger.

You're right. Pretty much all riding on the flat is in top gear. We've some very step gradients so am glad of the low gear, but yes the intermediate spread isn't used much.

 

One thing I'd point out to newbies (including a reminder here to myself) is that setting off in turbo mode in low gear can be risky as the brief but powerful acceleration can lift the wheel and/or accelerate the bike off course and into danger.

 

There might be a tweak for that:

 

https://www.pedelecs.co.uk/forum/threads/experiences-with-open-source-firmware-on-the-tongsheng-tsdz2.39384/

 

https://empoweredpeople.co.uk/2020/05/28/tongsheng-tsdz2-what-firmware-options-are-there/

 

I had the same issue with the Bafang BBS01b, but not after I set "Start Current" to 10% instead of the default 20%, now it feels much safer - also I have the motor shutoff speed set to as rapid as possible. I have no idea what the equivalents are in the Tongsheng firmware settings.

Edited October 1, 20214 yr by guerney

Great bike Zelige, best looking Raleigh 20 i've seen.

Thanks! I took a lot of inspiration from Jimmysmooth's Bafang Raleigh20 here

I had the same issue with the Bafang BBS01b, but not after I set "Start Current" to 10% instead of the default 20%. I have no idea what the equivalent is in the Tongsheng firmware settings.

Thanks - was your 'start current' adaptation with or without the open source software?

That looks really good. I have a Raleigh Twenty available to me as it happens. I bought one for my daughter in law a few years back and fixed it up for her, but it is unloved and unused in a car port. This gives me ideas.

 

That's exactly how I got going - I saw Jimmysmooth's fabulous conversion and thought, hmmm...

Thanks - was your 'start current' adaptation with or without the open source software?

 

There are Bafang firmware configuration tools out there, as far as I know none are open source - "start current" is an easily found setting (this is before changes):

 

 

 

 

 

This is after changes:

 

 

 

"Stop Decay" is as short as possibe. For the most part, I'm happy with the way my Bafang now works, but I'd love the option of a legal throttle (up to 6km/h) assisted start when you start pedalling (and press a button - I only want that throttle active in certain situations), because it'd be handy on hill starts and at traffic lights etc. Open Source gets better over time, might well be worth looking into if you think your Tongsheng needs tweaking, to make it feel safer in use. On the other hand, it might not be worth the bother and risk of making it inert, by trying.

Edited October 2, 20214 yr by guerney

Nice work ! I like the front disc brake setup, well done...