Converting old Raleigh 3 speed

Is the 250W motor adequate for hills and such? I cant decide between a 250 or 500w Tongsheng motor for my classic Raleigh. I am afraid of having too much power and going too fast on my rim brake bike but maybe with a larger motor I can limit the top end and have a more reliable cooler motor. Does a 250 w motor run more efficiently and have longer battery life?
It’s fine 95% of the time - it’ll put out a lot more than 250w in short bursts. I’m about 80kg, and the bike and luggage must be pushing 35kg, and when it struggles on a hill I feel its more limited by the gearing (can’t spin the pedals fast enough) than the motor power. It’s honestly great - I took it camping last weekend, did 70-80 miles over pretty hilly terrain with only a 2 hour top up charge, still had two bars of battery left when I got home
 
It’s fine 95% of the time - it’ll put out a lot more than 250w in short bursts. I’m about 80kg, and the bike and luggage must be pushing 35kg, and when it struggles on a hill I feel its more limited by the gearing (can’t spin the pedals fast enough) than the motor power. It’s honestly great - I took it camping last weekend, did 70-80 miles over pretty hilly terrain with only a 2 hour top up charge, still had two bars of battery left when I got home
Choosing a cog for the three-speed is a big factor. They range from 22-Teeth to 16-T. That is a 30% difference for either climbing ability or top-end speed in the trade-off. I tend toward the 16-T on my own IGH bikes because I like to go faster than most. 20-T is a good place to start. You can always shorten a chain and drop the cog to a faster one. 20-T will do climbs easily and will be fast off the line. See how you like it.
The following is from Sheldon Brown's Gear Calculator site. I put in a cadence of 80 for this example, a 42-T chainring and a 20-T cog. The top end would be 26Kph with 700x38 tires.

Gear chart using MPH @ 80 RPM​


For 700 X 38 / 38-622 tire with 170 mm cranks

With custom sprocket(s)

With Shimano 3-speed Nexus Inter-3 Rear Hub​


0.73 (Low)1.01.36 (High)

2010.0
42
2013.7
42
2018.6
42
 
Yes, rear cog size is important, but there’s only so far you can go before there’s too much torque going through the hub, I believe Sturmey Archer used to recommend no more than a 2:1 ratio, and that’s non electric. I’m back to a (standard) 18t rear with the 42t Tongsheng, which works fine for all but the steepest hills. Before this bike was electric I had a 22t on the rear with a 46t front, and I think that was working the hub pretty hard. I built a new 40 hole rear wheel with a NOS hub when I put the motor on. Oh the chain is a KMC ebike specific single speed chain too
 
I put oil down the hole on the clicker side of the three-speed Nexus with the bike on its side. I was doing jackrabbit starts and not lifting on the back stroke so I did burn up one un-oiled hub on that bike before I learned better. The lesson was still worth it considering all the miles and pleasure.
 
Thank you all for this information! So it looks like the 250 W will fulfill my needs. I do not need top speed but yes on then ability to climb hills.
My Raleigh Sport has a front sprocket with 46T and rear Sturmey Archer three speed with 18T. So JohnnyGee, do you think that a front 42T or smaller would be the ticket?
 
Thank you all for this information! So it looks like the 250 W will fulfill my needs. I do not need top speed but yes on then ability to climb hills.
My Raleigh Sport has a front sprocket with 46T and rear Sturmey Archer three speed with 18T. So JohnnyGee, do you think that a front 42T or smaller would be the ticket?
The Tongsheng comes with a 42t so I’d stick with that and see how you get on with the 18t rear. Means you can keep the chain too, although it will need shortening. I presume they’re not rod brakes? If so I’d strongly recommend Kool Stop Salmons too, much better stopping power. I wouldn’t worry too much about rim brakes vs discs etc by the way - it’s a bit extra weight you’ll be dealing with, not higher speeds.
 
By the way, mine is a 14 Ah battery that gives me 40 - 50 miles. Just to give you an idea of the size of battery you might need to give the range you want
 
Thanks Johnny!
I will start with 42T. Regular steel brakes. Thank you for the hot tips! It has New Cables. I will probably purchase the 250 or 350 watt version. Two reasons: Don't need a speed demon or long range and because the space between the upper and lower tubes is limited for the battery. I can probably fit I hope a Kettle style battery which seems to top out at 10 Ahs. The space is 110mm lower down and 90mm near the handlebars. The length of the area is approx. 325mm long. Any recommendations on where to purchase a motor and battery? I am consulting on Alibaba. Amazon seems to be sold out. They only have a "New" 500 W, 48 volt version available. Price is 585. w 48v 500w kettle battery.
 
Buying from AliExpress leaves most buyers with no warranty coverage or support. $585 for motor and battery can’t be accurate. Buyer beware.
 
This is what I have to work with.
 

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This is what I have to work with.
Thank you for the photo. It is helpful. I see three placement areas for the battery. 1) the down tube - tight. 2) The top tube - ample. 3) The seat tube - higher center of gravity but ample with good weight distribution. Do you have eBay? With PayPal you will have some buyer protection. Use Topeak Versa Mounts. You will need three, so purchase two packages. Run the leads from the motor to the inside of the mounting plate cover. You will want a new chain that is strong. The half-links are nice but the pin can be tricky. Here is a 10.5Ah 36V on a seat tube with just two Versa Mounts.
 

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What a beautiful neat job of your bike! I have never seen that type of battery before but I think it would be perfect on my bike.
Please tell me the name of it.
I was planning to put the battery between the top and bottom tube but the one you have may fit perfectly on the seat tube.
I do have EBay. I will look there.
Thank you!
 
In about 15-days 3500mah premium cells will start to slowly enter the market. In another post I showed a photo of prune-o vs wine made from premium chardonnay grapes. Just to be redundant I will do it again. Starting with high end cells will make all the difference for your bike just like making wine with superior grapes. Wait about two weeks and you can have a small battery with long legs. Premium cells have not been on the market for all of 2021. The stuff that is available now is (mostly) junky. Do not be tempted to go the way of prune-o when you can have the real deal. It is all fun. Show photos of the completed job. Oh, and with the small batteries you just use the motor's wires and attach the connector under the battery. Shrink tube seals the wires. No ugly connectors will show.
1625010966882.png
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What a beautiful neat job of your bike! I have never seen that type of battery before but I think it would be perfect on my bike.
Please tell me the name of it.
I was planning to put the battery between the top and bottom tube but the one you have may fit perfectly on the seat tube.
I do have EBay. I will look there.
Thank you!
 
Whoopie Doo, That is swell! Thank you!
You have a 3 speed coaster brake bike that you want to convert, right?
China based recycles-ebikes sells a coaster brake version of the TSDZ2
I haven't purchased anything from them but their prices tend to be ~$100 less than eco-ebike which is US based
Contrary to other opinions, I would go for the 500w version rather than the European legal limited 250w version. Probably the only power based difference is that the 250w controller limits power more than the 500w version but you should ask a seller about any differences. The coaster brake version has a solid main/large reduction gear without a sprag clutch bearing so that is one less point of potential failure. It also has straight cut instead of spiral cut gear which may make the motor assist louder but I'm not sure of that.
The only other options are display/peripherals. The large VLCD5 display comes with an 8 pin controller connection which allows for throttle and brake inhibitor levers. I don't use these features so I prefer the smaller displays which come with a 6 pin connection off of the controller. I have a small XH18 display which I would not recommend because of very limited programmability. I also have a C3 display which I would recommend but have rarely seen offered for sale. Pedaluma's bikes I have seen images of use VLCD6 display which I do not have.


EDIT:
I saw the image you posted of your bike, it has a rear rim brake so maybe it isn't a coaster brake hub in which case you wouldn't need the coaster brake version of the TSDZ2
 
What a beautiful neat job of your bike! I have never seen that type of battery before but I think it would be perfect on my bike.
Please tell me the name of it.
I was planning to put the battery between the top and bottom tube but the one you have may fit perfectly on the seat tube.
I do have EBay. I will look there.
Thank you!
Your bike looks like a great choice for adding a TSDZ2.
Myself, I'd look for a rectangular battery that fits between the frame tubes like you were planning to do but the bottle type battery might be a great choice for you also. Depending on your planned use I'd stick to a 10ah battery - a 36v 10ah battery has lasted me 46 miles/3400 ft elevation gain with capacity left over - but I don't ride my bike like it's a electric scooter, which I see other ebike riders do.

EDIT:
If you don't mind the larger VLCD5 display recycles-ebike sells this kit including a 8ah seat bag battery for $500.

1625068500718.png
 
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Your bike looks like a great choice for adding a TSDZ2.
Myself, I'd look for a rectangular battery that fits between the frame tubes like you were planning to do but the bottle type battery might be a great choice for you also. Depending on your planned use I'd stick to a 10ah battery - a 36v 10ah battery has lasted me 46 miles/3400 ft elevation gain with capacity left over - but I don't ride my bike like it's a electric scooter, which I see other ebike riders do.

EDIT:
If you don't mind the larger VLCD5 display recycles-ebike sells this kit including a 8ah seat bag battery for $500.

View attachment 91854
Go for a battery that is low and centered. Ditch the cut off levers in the dustbin and chop off the speed sensor lead sealing the end and tucking it into the secret compartment behind the chainring. Throw away the throttle. Program the display for 100cm circumference wheels.
 
I almost forgot. This is important. The provided stainless 50mm bolt that goes between the chain stays is neither long enough nor strong enough. Upgrade it to a hardened 55mm or 60mm because the extra turns of thread will prevent it from sheering or from breaking the aluminum support. Tighten everything loosely at first, gradually tightening down in an even pattern. Blue thread-lock is nice to keep things secure. I shim the BB so it is also tight to prevent creaks.
 

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Hmm, this could solve the problem of removal in a tight space like between the upper and lower tubes on a girls Raleigh. Has anyone heard or used one of these?
 

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