Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
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ttgg   1 µW

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Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by ttgg » Mar 13 2017 11:38am

Hi, first post, been reading this forum for several years since I got back into biking [I'll be 61 this year]. I have a late 1960s Huffy with 20" wheels, 3 speed IGH with coaster brake and a caliper brake on the front.

The design makes for a good mini-cargo bike and I have some rack mods in mind. This bike easily rolls into my first floor tiny apartment, which is a must.

I've only been riding in about a 3 mile radius, mostly flat with some slight inclines, and my knees are sending me a message from the future. I'm 6'1" 170lbs. Would like to get electric assist set-up over the next couple of months.

I would like to increase the range to maybe a 10-20 mile radius, so occasional 20-40 mile round trips, [who knows maybe more] and lesser trips daily. That would introduce some longer and steeper inclines.

At times the bike would be heavily loaded [I've carried 12 gallons of water from the spring] and also plan to add a single wheel trailer.

Nothing but basic transportation/commuting and the pleasure and freedom of riding. I'm not a trail rider or anything like that.

Speed is not a critical concern, I want to pedal but have it always be easy. I'd think 20-25 mph under ideal conditions would be amazing, any speed up hill as long as I'm pedaling easy. As it is now I don't mind getting off and pushing a load up a hill.

The bike has 110mm rear dropouts and 93mm front fork. Early on I was looking at hub motors but not crazy about spreading my frame and losing the IGH [at least not for the first project].

Then I got excited about a powerful push trailer [single wheel only]. After some thought I realized I want electric every time I ride and definately don't want to have to hook up a trailer.

Recently I found the BBSHD, I had dismissed mid-drive earlier but now I'm all for it. However it kind of took the wind out of my sails when I learned the Bafang will not allow use of a coaster brake.

I found the TSDZ2 offers the coaster brake function. Although mentioned a bunch of times no one has reported actual personal experience with it. I read the 11 page TSDZ2 thread and others. There is also an older thread asking this question with no use reports.

I believe I'll be going with the BBSHD, it seems it may have evolved more than the TSDZ2 and also has more power. I found some info on bolt-on options for adding a caliper brake to the rear.

I'd love to have a cable actuated roller brake on the rear w/3spd IGH, but nothing is available with 28 holes. I did find some 28 hole options for a disc brake but as that involves spreading the dropouts I'd rather start off with the bolt-on rear caliper for now.

So, I have things to sort out like gearing questions and a bunch of other stuff, but at the moment just wondering is anyone using the TSDZ2 with a coaster. I saw they may be coming out with a 500w version, could be an option for the future.

thanks for your time and any info or thoughts on my build!

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Norton   10 W

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by Norton » May 28 2017 10:09am

Hey tt,

I too am interested in this mid drive kit in the 500 watt version.

First thing, as I understand it, the 'coaster brake' version only means it ships without brake levers with the built in switches that cut the motor.
With this mid drive as soon as you stop pedaling the assist stops, so using it with a coaster brake would work fine with any version of this kit.

I too am torn between going big (BBSHD) or going with a 500 watt TSDZ2 (with a higher tech torque sensing PAS system).
There is a throttle kit add-on for the TSDZ2 so you can ride without pedaling when you want to, just like the Bafang systems.
There is also a small display/controller option also. I'm still searching for info on those add-ons.

One note I might add: Do not go big with that antique 3 spd IGH coaster brake on the back.

Let's keep this thread alive!

rpgear   100 µW

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by rpgear » Apr 27 2018 9:38am

Just came across this thread regarding the coaster brake model. I have a couple of "non" coaster brake versions of the TSDZ2 here in my shop, and just tested whether your idea that any TSDZ2 would work with a coast brake. The pedals engage the chain ring normally in a forward rotation, but freewheels in a stopped or reverse direction. In other words, the pedals can NOT engage the coaster brake with this standard TSDZ2 model. I too, have a need for a coaster brake version for a customer's Raleigh TriStar trike, which is why I was searching the internet for sources. My normal sources do not carry the coaster brake version. May have to go directly to the factory for this one.

And, good point about not going too big with that drive train. The Huffy was built to a low price point target, even back then, so tread carefully when applying power to this type of chassis.

Since this thread is a year old, I would assume you have moved forward. Any updates?

jonga   1 µW

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by jonga » May 25 2018 3:48am

So the non-coaster brake version won't work with a coaster brake. How about the other way around? Will the coaster brake version of TSDZ2 work on a bike without a coaster brake? Or will it be an issue with the freewheel?

Drum   100 W

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by Drum » May 25 2018 4:26am

Hi,
I recently repaired a TSDZ2 motor unit and mounted it on my spare mountain bike to test it.

While I had it apart I noticed that the large steel output gear that the chainring is mounted on was solid and did not have the sprag clutch (one-way bearing) in the centre like all the disassembled motors I had seen photos of previously. I assume this motor was the "coaster brake" version. Without the sprag clutch, pedaling backwards DID run the chain backwards and would work just fine with a "back-pedal" coaster brake.

So I assume that if you order the coaster brake version of the motor, the solid gear will be installed and it will do what you need.

There is one very minor issue: the pedal shaft is now driven by the motor.. the pedals must rotate with the chainring, and if the motor is driving the chainring to rotate forward it is also driving the pedals.
When I suddenly stopped pedalling after pedalling hard, I could feel the pedals kick forward a bit before the controller caught up with the sudden drop in torque on the pedals and cut power to the motor.
This was noticeable but not dangerous.. got used to it very quickly.. but it means you should NOT use a throttle with one of these motors, and if you get one be prepared to live with this little quirk.

Apart from that "kick", the bike rode very well. The torque sensor is "double sided" so "sees" torque from either pedal. The assistance kicked in smoothly within half a rotation of the pedals, then increased assistance smoothly with increase in pedal torque. MUCH nicer and more natural to ride than any bike I have tried with cadence-sensing PAS control.

If I did not specifically need the backpedal brake function I would prefer one of the units with the sprag clutch, however there is an advantage to the solid gear: one less thing to fail. There have been a few people who have had to replace the sprag clutch after it started slipping, allowing the pedals to rotate forwards without reliably driving the chainwheel forwards... not an issue with the solid gear!

Hope that information helps,
Dave

casainho   100 MW

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by casainho » May 25 2018 9:50am

TSDZ2 motor controller can drive the motor at max of 18 amps!! so on 52V battery it is 936W and not 500W.
Developer of the Flexible OpenSource firmware for EBike motor controllers (TSDZ2 and KT) and LCDs (KT-LCD3 and Bafang 850C color LCD).

If you like my work, please consider making a donation. I am being using the donations to buy needed resources for my developments. My paypal: casainho AT gmail.com.

ions82   100 W

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by ions82 » May 28 2018 2:24pm

With 96 pounds of water (12 gallons at 8 lbs per gal), I'd definitely put some thought into the kind of bike you'll be using for such an endeavor. That's a heck of a lot of extra weight sloshing around. Might want to settle on the bike before considering the motor options. Honestly, an antique Huffy with 20" wheels (no idea how someone 6'1" fits on such a bike) doesn't sound like the ideal machine.

Max_Headroom35   1 µW

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by Max_Headroom35 » Jul 12 2018 12:19pm

Drum wrote:
May 25 2018 4:26am
Hi,
I recently repaired a TSDZ2 motor unit and mounted it on my spare mountain bike to test it.

While I had it apart I noticed that the large steel output gear that the chainring is mounted on was solid and did not have the sprag clutch (one-way bearing) in the centre like all the disassembled motors I had seen photos of previously. I assume this motor was the "coaster brake" version. Without the sprag clutch, pedaling backwards DID run the chain backwards and would work just fine with a "back-pedal" coaster brake.

So I assume that if you order the coaster brake version of the motor, the solid gear will be installed and it will do what you need.

There is one very minor issue: the pedal shaft is now driven by the motor.. the pedals must rotate with the chainring, and if the motor is driving the chainring to rotate forward it is also driving the pedals.
When I suddenly stopped pedalling after pedalling hard, I could feel the pedals kick forward a bit before the controller caught up with the sudden drop in torque on the pedals and cut power to the motor.
This was noticeable but not dangerous.. got used to it very quickly.. but it means you should NOT use a throttle with one of these motors, and if you get one be prepared to live with this little quirk.

Apart from that "kick", the bike rode very well. The torque sensor is "double sided" so "sees" torque from either pedal. The assistance kicked in smoothly within half a rotation of the pedals, then increased assistance smoothly with increase in pedal torque. MUCH nicer and more natural to ride than any bike I have tried with cadence-sensing PAS control.

If I did not specifically need the backpedal brake function I would prefer one of the units with the sprag clutch, however there is an advantage to the solid gear: one less thing to fail. There have been a few people who have had to replace the sprag clutch after it started slipping, allowing the pedals to rotate forwards without reliably driving the chainwheel forwards... not an issue with the solid gear!

Hope that information helps,
Dave
Hi there!
I recently ordered a TSDZ2 motor with coaster brake. Unfortunately my chinese was probably as good as Aliexxpress english, so I wound up with one with a sprag clutch. & since I had to save up money for a battery as well, I didn't notice it until today (3 weeks after delivery of the motor) when I put everything together.

So, my question is; what do I need to rebuild the motor with coaster brake capability?

Ideas anyone?


Cheers/Magnus
Stockholm/Sweden

KD5ZXG   10 W

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by KD5ZXG » Jul 13 2018 10:09pm

https://www.youtube.com/watch?v=u-SY0rGMEMo

This video (not mine) appears to show the relevant sprag.
Maybe flush out all the grease and re-pack with JBWeld?
Buy a spare first, just incase the experiment goes wrong.

Instead, I've ordered a Sturmey Archer RXL-RD5 to deal
with the braking issue. The cable operated 90mm drum
should solve it.

Unfortunately, I bought an "in stock" hub from a fake US
warehouse with communcation and timely delivery issues.
May have to write it off as a lesson learned.

Drum   100 W

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by Drum » Jul 14 2018 6:59am

Hi Max H.. Another ES user told me that the lack of a sprag clutch was only one of two differences between the standard and the coaster brake version of the TSDZ2 motor: he thinks it has a different controller as well.
With no sprag clutch, it is really important that the motor stops immediately you stop pedalling, so the "BK" (coaster brake) version of the motor also has a "BK" version controller which is programmed to drop output to zero as soon as pedal torque drops to zero.
A longer "run-down" time would force the pedals to continue rotating, which would not be safe.
I haven't been able to confirm this, but he seemed to have experience with the motors.
If correct, locking the sprag clutch might not be the only change needed to convert to a full coaster brake spec.
The best way would be to buy the solid gear and a "BK" controller, but that might not be easy or cheap.
Dave

malski   1 µW

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by malski » Sep 06 2018 9:29am

Hi Magnus, Drum,

I just made the same mistake and got the motor with a sprague clutch for my coaster brake only bike. Have you made any progress converting the motor to a coaster brake version?
Maybe there is a way to reprogram the controller in addition to freezing the sprague clutch?

vadda   1 mW

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Re: Hi, TSDZ2 any coaster brake users? BBSHD build thoughts

Post by vadda » Sep 18 2018 6:57am

I can't find any BK controller as spare.
Perhaps with OpenFirmware it might be possible to optimize some parameters to achieve the same behavior

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