E Bike Conversion

[Doofus]

Is a Bafang mid drive kit the answer?

Seems to tick all the boxes, but sounds like one of Amazon's made-up brands...

[dontlookdown]

Watching with interest as I have been thinking about this too. Ancient hybrid in the garage would make a great shopping ebike as it is already racked up etc. Hopefully not too nickable parked at the supermarket.

Mid drive seems best, but do you stay legal at 250w or go for a bit more shove? I am minded to stick to 250w as I do still want to do some pedalling but would like a bit of help lugging 20 kilos of shopping back up the hill on the way home.

Then do you need brake cutouts, cadence or torque sensing, those cranks with the pedal closer together etc. Lots to think about.

Sorry for the thread hijack op, I was literally going to post about this myself today;)

[Driver101]

Bafang mid drive kits are very popular. You need to order the right bottom bracket width to suit the frame. There can be issues with fitting, but often it's just modifying the gear cable guide.

There is plenty of guides of YouTube. It's not difficult if you have a little mechanical ability.

You need brake cut offs. You don't want the motor pushing when you want to slow down. The Bafang kit has them included. Either replacement levers if you have cable brakes, or magnets if you have hydraulic brakes. You have to choose which option.

750w is the most popular kit. Unless you're doing something silly you won't get noticed. It is illegal if you are caught.

I'd also recommend buying the cable to program the controller. The settings from the sellers are all over the place. Getting the settings right makes the bike better to ride.

[Doofus]

Driver101 said:

750w is the most popular kit. Unless you're doing something silly you won't get noticed. It is illegal if you are caught.

It would appear that the Bafang kits are supplied with "36v 250w"stickers.

[Driver101]

Doofus said:

Driver101 said:

750w is the most popular kit. Unless you're doing something silly you won't get noticed. It is illegal if you are caught.

It would appear that the Bafang kits are supplied with "36v 250w"stickers.

They do, but everyone knows that. The battery will also say 48 or 52v on it.

[Mammasaid]

Mid drive is best in terms of neatness, however it's the most expensive conversion, then rear drive, and finally front drive is cheapest and easiest to fit.

Front drive is fine if you're mainly on road or gravel tracks, it's simply a case of swapping front wheel, the mounting the battery, controller and wiring around the frame.

Here's mine with a front drive, liked the bike, so I thought a £500 conversion kit would be fine for my 12 mile commute. As I'm 50+ and with a little extra weight to shift, it works well for me.

[centralscot]

I have a Bafang mid drive set up on my converted Halfords Carrera ,brilliant set up for me,and they do come with the 250 watt stickers.

Edited by centralscot on Saturday 21st May 13:56

[dontlookdown]

All great stuff, tks. The other brand seems to be called Tongsheng. Any experience with those? Claim a bit more torque and lighter weight. But that could equal more flimsy too...

[dontlookdown]

I had a go on a hub motor conversion my neighbour bought made up from an lbs. Front wheel 1000w job. It road badly, a lot of torque steer and boneshaking ride. Easy to do but seemed a bit Heath Robinson tbh.

[monthou]

dontlookdown said:

All great stuff, tks. The other brand seems to be called Tongsheng. Any experience with those? Claim a bit more torque and lighter weight. But that could equal more flimsy too...

Of the two I've only used a Bafang.
Forum knowledge: Bafang is more robust / more powerful. Tongsheng is more like riding a bike - because it uses a torque sensor, the harder you pedal the more you get out.
On the bafang if you pedal harder the speed will stay roughly the same, but the motor will be doing less work. This sounds really odd but it feels fine. My wife has a carrera rear hub with a torque sensor and that feels quite different in use to the Bafang.

[Doofus]

monthou said:

Of the two I've only used a Bafang.
Forum knowledge: Bafang is more robust / more powerful. Tongsheng is more like riding a bike - because it uses a torque sensor, the harder you pedal the more you get out.
On the bafang if you pedal harder the speed will stay roughly the same, but the motor will be doing less work. This sounds really odd but it feels fine. My wife has a carrera rear hub with a torque sensor and that feels quite different in use to the Bafang.

With the Bafang, doesn't it depend upon which extras you buy as to how it behaves? Gear sensors etc. Is the torque sensor standard, or only a thumb throttle?

Thereseems to be a variety of kits available all with subtle differences. I don't want a huge screen, for instance, but it's very hard to find any dimensions.

[monthou]

Doofus said:

monthou said:

Of the two I've only used a Bafang.
Forum knowledge: Bafang is more robust / more powerful. Tongsheng is more like riding a bike - because it uses a torque sensor, the harder you pedal the more you get out.
On the bafang if you pedal harder the speed will stay roughly the same, but the motor will be doing less work. This sounds really odd but it feels fine. My wife has a carrera rear hub with a torque sensor and that feels quite different in use to the Bafang.

With the Bafang, doesn't it depend upon which extras you buy as to how it behaves? Gear sensors etc. Is the torque sensor standard, or only a thumb throttle?

Not really, no. You can tweak, but the basic characteristics stay the same. There's an extra cable to buy for that, Not expensive and worth doing. The gear sensor stops the motor when the gear cable tension changes, so as to make for smoother changes. There's no torque sensor included or available for the Bafang, you can fit a throttle to them (which is not strictly legal).

Doofus said:

Thereseems to be a variety of kits available all with subtle differences. I don't want a huge screen, for instance, but it's very hard to find any dimensions.

If it helps I have 2 screens... an all-singing all-dancing dpc18 (98x63mm) and a teeny tiny sw-102 (63x23mm).

[dontlookdown]

Also, batteries. Seem to vary a lot in price. Stick to Samsung, or go cheaper? And how much capacity for reasonable range - maybe 30 or 40 miles?

[Doofus]

monthou said:

If it helps I have 2 screens... an all-singing all-dancing dpc18 (98x63mm) and a teeny tiny sw-102 (63x23mm).

Thank you. Do the screens affect functionality? Pedal assist level, for instance.

[colin_p]

I've been running a Bafang BBS02b 750w / 48v for coming up to two years now.

I down-tuned it a bit at the time I fitted it for a long life as per this link...

https://edrivenet.com/bafang-programming/

Yes, you can DIY re-map your bike, the cable to do so is (or was) about £15 and the software is free.

Absolutely amazing piece of kit and easy to fit, although I fitted an additional rivnut on the downtube in addition to the two stock bottle bosses on the downtube although this isn't strictly neccessary.

[Houndlegs]

I've just fitted a Tongsheng to an old Carrera Fury for my 5 mile commute. I got a 500w 48 v kit, Samsung batteries.
I did a lot of forum reading before opting for this, but so far it's fantastic, only covered 60 miles though.
They reckon with the Tongsheng, there is only actually 2 versions, 36v and 48v and it don't matter what power they claim, that's it, just 2 versions.
They also say the battery lasts longer because you're doing the work as well.
Very happy so far.

[Driver101]

The throttle is with the kits normally, or a really cheap add on. It's 100% worth it. When your legs are gone or you're on a tricky trail or soft ground push the throttle and you can power through it.

You do have to think about the battery. If you have a small frame make sure it will fit. Also think how you're going to mount it. Some people drill extra holes in their frame or velcro straps take the stress off the water bottle mounts.

Also watch for the batteries. They aren't all the same. They have different terminal connections and aren't interchangeable.

[monthou]

Doofus said:

monthou said:

If it helps I have 2 screens... an all-singing all-dancing dpc18 (98x63mm) and a teeny tiny sw-102 (63x23mm).

Thank you. Do the screens affect functionality? Pedal assist level, for instance.

They do. You'll have to google for comparisons, but off the top of my head some will give more levels (DPC18 gives 9, which is more than you'll ever need, others give 5). Some will have lower max speeds. There's one which looks identical to the sw102 - the name escapes me - that has an 'off-road' function, so you can switch between maximum speeds. Again, not strictly legal.
I've yet to try my sw102, so I can't give you a comparison. I'm not even sure my eyes will be up to the screen size tbh, but it is very discreet.

[Doofus]

monthou said:

Doofus said:

monthou said:

If it helps I have 2 screens... an all-singing all-dancing dpc18 (98x63mm) and a teeny tiny sw-102 (63x23mm).

Thank you. Do the screens affect functionality? Pedal assist level, for instance.

They do. You'll have to google for comparisons, but off the top of my head some will give more levels (DPC18 gives 9, which is more than you'll ever need, others give 5). Some will have lower max speeds. There's one which looks identical to the sw102 - the name escapes me - that has an 'off-road' function, so you can switch between maximum speeds. Again, not strictly legal.
I've yet to try my sw102, so I can't give you a comparison. I'm not even sure my eyes will be up to the screen size tbh, but it is very discreet.

Thank you, again.

[monthou]

Driver101 said:

Also watch for the batteries. They aren't all the same. They have different terminal connections and aren't interchangeable.

They certainly aren't all the same in terms of quality, but not sure what you mean re the terminals. As long as it has 2 terminals the connections can be changed, they're just on the end of 2 wires.
FWIW my battery came from pwspower (samsung 13Ah I thinkbbb) and is fine after 18 months use. I'd use a 'known' seller rather than ebay / amazon. Eclipse sell the highly regarded EM3EV batteries, but they're out of stock atm. My next battery will probably be one of theirs, whether direct or from Eclipse.
Mine is one of these...
https://pswpower.com/products/eu-no-tax-electric-e...

I had a good root around the pedelecs forum before I started, loads of good info there:
https://www.pedelecs.co.uk/

Edited by monthou on Saturday 21st May 19:31