One of the beauties of the TSDZ2 is the wide availability of parts at relatively low cost. I have a 1970s Sears 27" 10 speed that years ago I converted with a 26" 3 speed coaster hub, on and off I've thought about a Tongsheng assist but don't want to buy another motor kit since I have two already. The TSDZ2 is simple to work on and easy to move from bike to bike so I ordered up a coaster brake main gear along with a straight cut reduction gear to match. The reduction gear is coming from China and has a wide delivery estimate from a week to a month and a half so it might be a while before I get to it but I'm looking forward to giving it a try on this bike. $75 in parts instead of over $400 for a complete motor kit. It should work, I think.
Converting a TSDZ2 to a coaster brake version
- Thread starter EMGX
- Start date
I'm aware that not many, or any, tsdz2 owners are interested in converting their standard model to a coaster brake version but I can say that it can be done fairly easily with two parts. One being a solid main gear (that doesn't have the sprag clutch bearing) as shown in the post above and because that main gear is straight cut instead of spiral cut you also need a matching straight cut reduction gear. Replace those and you have a coaster brake compatible tsdz2. There is a very short delay in power delivery cut out when you stop pedaling so there is a slight bump when going immediately from pedaling forward to pedaling back to actuate the coaster brake. I used a vlcd5 display along with a brake cut out lever for a front brake so if I apply the front brake along with pedaling back for the coaster brake the lag isn't present. I had read that the stock coaster brake version of the tsdz2 does the same thing. Anyway it works great, the straight cut gears don't seem noticeably louder than the spiral cut gears were and the lack of a sprag clutch bearing is one less thing to fail so I don't think that I would bother to convert it back even if I decide to put the unit on another bike at some point.
Hi! Thank you for sharing your project. The coaster brake version of the TSDZ2 isn't too common so it's nice to find some stories about it!
Where did you buy that coaster compatible main gear? I have been looking for info about it but I haven't been able to find anything. I'm planning to do the conversion to another direction: I have a coaster brake version but I'd like to get rid of it because my motor has quite resonable delay in power delivery cut for some reason. I'm wondering if the coaster main gear is fully solid metal or if the inner part is still removable with hammer and force.
Where did you buy that coaster compatible main gear? I have been looking for info about it but I haven't been able to find anything. I'm planning to do the conversion to another direction: I have a coaster brake version but I'd like to get rid of it because my motor has quite resonable delay in power delivery cut for some reason. I'm wondering if the coaster main gear is fully solid metal or if the inner part is still removable with hammer and force.
I am just getting ready to take this bike for a ride when I saw your post. The coaster brake version of the main gear is fully solid so the sprag clutch bearing cannot be added to it. There is a delay in motor cut off when pedaling backwards to brake and I found it slightly annoying so I added a brake cut off lever and a front brake. When I squeeze the front brake the motor cut off is immediate. Still, I don't prefer the coaster brake because I ride curvy roads where I want the pedal to the inside of the curve up to avoid pedal strikes. That is harder to achieve when you can't pedal backward to just change the position of the pedal.
I bought my solid coaster brake main gear from eco-ebike which is a US based reseller but the sprag clutch gear are on US ebay for as little as $40 with free shipping from China. You would also need a compatible spiral/helical cut reduction gear (~$20) to match the main gear since the coaster brake versions are straight cut. And of course you wouldn't be able to use your coaster brake with the sprag clutch gear.
I bought my solid coaster brake main gear from eco-ebike which is a US based reseller but the sprag clutch gear are on US ebay for as little as $40 with free shipping from China. You would also need a compatible spiral/helical cut reduction gear (~$20) to match the main gear since the coaster brake versions are straight cut. And of course you wouldn't be able to use your coaster brake with the sprag clutch gear.
Thank you for your reply, it's nice to hear your thoughts about it! That brake cut off lever is good idea and would propably help a bit.
My problem is that it's hard to stop pedaling because the motor pushes the pedals forward so hard. That happens even if I'm not trying to break, I just wanted to stop pedalling. Sounds like every coaster brake version has that effect in some level but for some reason the effect is much stronger in my motor. It feels like the motor would have difficulties to recognize when I'm going to stop pedalling. I have installed Open Source Firmware and it should make the motor more sensitive but it doesn't. I hope converting the coaster brake gear to sprang clutch would help...
My problem is that it's hard to stop pedaling because the motor pushes the pedals forward so hard. That happens even if I'm not trying to break, I just wanted to stop pedalling. Sounds like every coaster brake version has that effect in some level but for some reason the effect is much stronger in my motor. It feels like the motor would have difficulties to recognize when I'm going to stop pedalling. I have installed Open Source Firmware and it should make the motor more sensitive but it doesn't. I hope converting the coaster brake gear to sprang clutch would help...
I've sort of given up on the coaster brake bike. It was a nostalgia thing since I've had that bike since I was 13,originally a 10 speed. Rode it from Inkster to Cedar Point (over 100 miles) with two junior high school friends (one of whom passed away a couple years ago). Several years ago I replaced the 27" wheels with 26" including the 3 speed coaster hub, switched out the crankset and drop bars and rode it around here quite a bit, including thru the Columbia gorge where the first picture in this thread was taken. But now it just isn't as fun riding a 3 speed coaster brake bike around here anymore, even with assist. The shimano nexus 3 speed has a very limited ratio range and I have a large rear sprocket for hill climbing but that really limits speed in 3rd without spinning ridiculously fast. Areas I ride don't lend themselves to a single speed or even a 3 speed and the coaster brake has become more of an annoyance than it is worth. I'll be pulling the tsdz2 from that bike and put it on something else. Maybe back on my Cadillac cruiser bike with the nuvinci n360 hub again, or maybe something else.
mikeschn
Well-Known Member
- Region
- USA
- City
- SE Michigan
That's how it started for me too! I haven't built up a cruiser ebike though. I restored a red vintage schwinn, and then bought an e-cruiser (shown in avatar). I still toy with the idea of building a cruiser, but really, the Vado is so much fun, I can't see how the cruiser(s) can compare. 
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