Help! Lightweight e-kit for coaster brake bike - alternate e-bike and 'normal' bike experience.

guerney

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What if your cable breaks or you drop your bike and the lever snaps off?
It's reassuring to have a secondary or tertiary braking method however flaky, brittle and low quality... which isn't your foot or some other human body crumple zone. At least I think so.
 

saneagle

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It's reassuring to have a secondary or tertiary braking method however flaky, brittle and low quality... which isn't your foot or some other human body crumple zone. At least I think so.
You have two levers, two cables and two brakes. OP has a hand lever plus afoot lever, a cable and a chain, and two brakes. Which is the best?
 

guerney

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You have two levers, two cables and two brakes. OP has a hand lever plus afoot lever, a cable and a chain, and two brakes. Which is the best?
I don't know, why don't you tell us? Spill the beans!
 

saneagle

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I don't know, why don't you tell us?
It comes down to whether a foot lever is better than a hand lever, a cable is better than a chain or a hub brake better than a rim brake. I reckon that the coaster brake wins by a head, which is probably why our Dutch friends like them so much. Personally, I wouldn't want to use either as they're both a very long way behind hydraulic disc brakes.
 
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guerney

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It comes down to whether a foot lever is better than a hand lever, a cable is better than a chain or a hub brake better than a rim brake. I reckon that the coaster brake wins by a head, which is probably why our Dutch friends like them so much. Personally, I wouldn't want to use either as they're both a very long way behind hydraulic disc brakes.
The Dutch don't have to tackle many hills - a chain break is far less dangerous in a country that's as flat as a pancake. I cracked a tooth on tarmac the last time my chain broke uphill, admittedly with rim brakes.





Personally, I wouldn't want to use either as they're both a very long way behind hydraulic disc brakes.
Who knows? Perhaps the OP's other bike has those.
 
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LauraEG

Finding my (electric) wheels
Apr 5, 2024
11
1
@peterjd My mechanic partner says I'd better get an e-bike instead of converting mine - maybe to avoid the extra work that seems to be piling up for him (special sensor etc)? ; )

@Tony1951 Agreed about other drivers when it comes to safety concerns. Especially in Barcelona where there's not a long urban biking tradition. That's why I never take heavy-traffic streets (with or without kids), only bike lanes whenever possible, and if necessary I just step on the sidewalk and walk a bit.

@saneagle @Benjahmin @Nealh @matthewslack @guerney Thanks for all your contributions. I'll have a look at the different sites and models you're suggesting (and maybe I'll re-look the Swytch option), but the general sense I get is that converting a coaster brake, especially if one is taking extra weight, is not the best option in terms of safety and convenience. Which is a pity, because I do love my current bike : (

Suppose I go with converting my other bike (btw, not disc brakes but v-brakes, I made a mistake). Is there a particular kit (or motor, or battery) you'd recommend for being very light and suiting my need of having powered assistance only in some parts of my rides (the climbs)?

Thanks again for all your thoughts!!
 
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Benjahmin

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Rear hub, something like an AKM100, 2.1Kg. Kt controller with LCD3. Display can sit on your handlebars with the control buttons right next to your fingers so you can turn assist on and off as you please. Pas sensor to suit your bike. Brake switches optional but do allow to ride with assist on but cut by slightly pulling the brake lever. So if you are on an undulating road the assist can come and go by just moving the brake lever. Battery can be as small or large as you like.
All can be got from Topbikekit and lots of help here to pick and choose.
Woosh would be able to advise and supply a kit to suit, but they are in the UK. Don't know if it would work for you exporting to Spain.
 
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saneagle

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@peterjd My mechanic partner says I'd better get an e-bike instead of converting mine - maybe to avoid the extra work that seems to be piling up for him (special sensor etc)? ; )

@Tony1951 Agreed about other drivers when it comes to safety concerns. Especially in Barcelona where there's not a long urban biking tradition. That's why I never take heavy-traffic streets (with or without kids), only bike lanes whenever possible, and if necessary I just step on the sidewalk and walk a bit.

@saneagle @Benjahmin @Nealh @matthewslack @guerney Thanks for all your contributions. I'll have a look at the different sites and models you're suggesting (and maybe I'll re-look the Swytch option), but the general sense I get is that converting a coaster brake, especially if one is taking extra weight, is not the best option in terms of safety and convenience. Which is a pity, because I do love my current bike : (

Suppose I go with converting my other bike (btw, not disc brakes but v-brakes, I made a mistake). Is there a particular kit (or motor, or battery) you'd recommend for being very light and suiting my need of having powered assistance only in some parts of my rides (the climbs)?

Thanks again for all your thoughts!!
Rear motor gives a better ride than a front one. Q100 or AKM100 (same motor) would be suitable as long as you get the 201 rpm version. KT controller to go with it is very good. It has a nice pedal assist function, and you can legally add a throttle to get an instant power boost. That will make more sense when you try it.

I think there's also a case for a crank motor - either BBS01 or TSDZ02. If you're going to use a different bike, get one with disc brakes. As already mentioned, you could fit the coaster brake version of the TSDZ02 to your present bike, which is a fairly simple solution. You didn't mention which hub gears you have, though. Some might not be strong enough for the additional power of the motor.
 
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Az.

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Laura, I advice against going back and considering Swytch as an option. It is really one of worst choices available out there.

Buying e-bike is a lazy option. I don't like business model of market leaders like Bosch, Brose, Shimano etc. They don't make products to last. They don't want customers to repair their products, they want us to buy new stuff every few years. Don't like this approach.

Your bike looks like an easy job to convert. My wife has an e-bike with front hub motor, coaster brake and nexus hub gears. Similar to yours, but step through. If you like your bike, convert it. Check PSW, they have very competitive prices and very good batteries. They ship from EU warehouses, so delivery should be quick.


I asked about your budget, because there are bikes on the market designed to carry children. Yours is not. Have a look:


 
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saneagle

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Laura, I advice against going back and considering Swytch as an option. It is really one of worst choices available.

Check PSW, they have very competitive prices and very good batteries. They ship from EU warehouses, so delivery should be quick.
The latest Swytch kit is different in that they've eliminated most of the problems that affect reliability. It's basically the same as any other kit, only it's a ready made lightweight one. The only probable problem is that the motor speed is too high. Details are lacking at the moment. It's always possible that they'll list a low speed version for 700c wheels.

PSwpower only have higher speed hub-motors, which wouldn't be suitable, and they don't have lightweight ones. They sell TSDZ2 motors, but don't list the coaster brake version.

Having considered everything, I think it comes down to two choices. The ready-made solution is a coaster brake TSDZ2 with a 30 or 40 cell 36v battery. The alternative is a 201 rpm Q85 type front motor with KT controller and the same battery from any of the established Chinese resellers, like Topbikekit, Greenbikekit, BMSbattery, etc.
 
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harrys

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No one has mentioned the Tong Sheng TSDZ2 mid drive kit with coaster brake option yet? I will. It's almost the same price as most hub motor kits. It doesn't need brake levers or throttle. Doesn't have the risk of snapping the forks like a front motor.

I think it is very simple to install too. Everytime I have to file a 10mm dropout to lower the axle on a hubmotor, I know it's simpler for a first time installer.

We have two bikes with the TSDZ2/TSDSZB and also bikes with front/rear hubs. The middrive kits feel the most natural.
 
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flecc

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Oct 25, 2006
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No one has mentioned the Tong Sheng TSDZ2 mid drive kit with coaster brake option yet?
Nealh did first in post 16 on page one of the thread. Saneagle did also in posts 28 and 32 on this page.
.
 

LauraEG

Finding my (electric) wheels
Apr 5, 2024
11
1
Lots of ideas...! I have checked the coaster brake TSDZ2 and while I like the idea of using a product for what it is intended, the weight of only the motor appears to be 3.6 kg. I fear then that if I install this, plus the battery and other components, the total added weight will make me miss the whole point of having electric assistance only at some parts of my ride :confused:

As some of the motors recommended here are quite lightweight (1,4-1,6kg) I was looking at the possibility of buying only the Swycth battery (700g for the 90Wh one, and 1,1 kg for the 180Wh one). It seems however that this option is only for previous customers (replacement battery). Would you have other ideas for lightweight batteries in mind?

@saneagle my current bike has a 3-speed internal gear-hub. Would that change your recommendations?

@Az. thanks for your thoughts! I'm familiar with these different kinds of family bikes (I lived in Malmö, the paradise of cargo bikes ; ). My original idea is to keep using my bike but if that doesn't work those are options to consider for sure.
 

saneagle

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@saneagle my current bike has a 3-speed internal gear-hub. Would that change your recommendations?
I think they'll be OK. I've heard of slight run-on from the motor, so you'd need to use a front brake with a cut-off switch. the brake cut-off is instant, , so the back brake will always work as long as you use the front one at the same time.

Your present bike isn't the best for conversion. Whatever you do will be a compromise. As we said before, a different one with disc brakes would be better.
 
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Az.

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I fear then that if I install this, plus the battery and other components, the total added weight will make me miss the whole point of having electric assistance only at some parts of my ride :confused:
Conversion of a bike is always a compromise. I think it will be very difficult to achieve what you want. After conversion your bike will be different. I very much enjoy riding my bike, but for sure I wouldn't enjoy it without assistance. I still can have as much work out as I want by simply changing assistance levels and gears.
Did you ever try to ride electric bike? I think best way is to embrace change in full with extra power, but also with added weight and different handling.

BTW nice avatar.
 
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guerney

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Sep 7, 2021
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As some of the motors recommended here are quite lightweight (1,4-1,6kg)
You won't notice the extra weight while there's a good level of electrical assistance - I don't.

I'd like to see photos of your other bike with the V-brakes. Let the hub motor kit experts get properly stuck in.