TSDZ2 and belt drive?

skestans

100 W
Joined
Jul 11, 2019
Messages
208
Location
Switzerland
New to all this and very excited to convert a regular bicycle.

I'm considering using a TSDZ2 because of its pedal assist capabilities and because of the open source replacement firmware.

One of the bicycles I'm considering is a belt drive with an internal 8 gear hub. Would the TSDZ2 work well in that context or am I better to stick with a conventional chain drive train?

And where to get the right "cog" to fit the belt rather than a chain?
 
I know that conversion has been done with other mid drives, but have not seen it done with this one.

SFAIK you need a custom part, if somebody makes it, you are in business, if not, you are SOL unless you have a machine shop.

There are SOME, as in a SMALL NUMBER, of IGH which have been reported to hold up under the power output of a motor. Don't recall what they are and don't know what you have. None I know of that will not void your warranty for using a motor for input to the hub.

Do you have a lot of hills to climb? Hub motors also have pedal assist available, and the right motor will climb any hill you want and leave your drivetrain components unstressed by several times the power they were designed to handle. Grin even has a hub motor with an IGH built-in. The motor does not drive thru the gears, just you.
 
Go with a conventional chain drive because bicycle chains are very quiet, durable with low power, easily available, easily replaced, etc. So there's no reason to use a belt. Chain wax is the way to go.
 
AngryBob said:
Do you have a lot of hills to climb? Hub motors also have pedal assist available, and the right motor will climb any hill you want and leave your drivetrain components unstressed by several times the power they were designed to handle. Grin even has a hub motor with an IGH built-in. The motor does not drive thru the gears, just you.

I live atop a 8-10% grade hill in a mountainous area (Switzerland). I am worried a hub motor will move the center of gravity too far from the middle of the bike, and that they don't have pedal assist but full on or full off with a throttle.

I'm not dead set on a belt, just saw a bike I like and the model only sells with a Nexus 8 belt drive.
 
Switzerland, yes, mid-drive likely a good idea.

However, almost all hub motors will accept a pedal-assist sensor, PAS, they do not affect the rest of the drive train, and are available in a wide range of power levels.

I have zero hills to deal with and have never really examined hill-climbing abilities with any real interest. Mid-drives involve a lot more maintenance issues.

Do you currently, and/or intend, to pedal, a LOT, or just occasionally and just want to go faster and/or farther?
 
I am used to riding a normal bike and do enjoy pedaling. The reason why I'm looking into an e-bike conversion is because my geeky side thinks it's pretty cool and because the hills are brutal where I live. I would also like to be able to ride 30-50 km easily.

Basically, I want a bicycle that helps me go further; not a moped.
 
skestans said:
I am used to riding a normal bike and do enjoy pedaling. The reason why I'm looking into an e-bike conversion is because my geeky side thinks it's pretty cool and because the hills are brutal where I live. I would also like to be able to ride 30-50 km easily.

Basically, I want a bicycle that helps me go further; not a moped.

That describes me and the TSDZ2 well I think. I'm already a bike commuter and got the motor for fun and to make the hot summer commutes less sweaty. It definitely expands the trips I'm inclined to do on the bike and makes everything low stress. On the other hand I still often find myself expending quite a bit of energy, partly through habit, but when it's really hot and unpleasant I can kick back on an easy cruise while still doing 20+mph, and steep hills can be made quite easy.

With the FOSS firmware on the default configured level 3 I feel like I have a lot of assist - a comfortable cruise on the flat is 22mph/~35km/h at 200W. I expend about 10Wh/mile (6Wh/km) but my area is fairly flat. As such a little mini-cube battery gives me a solid 20 miles / 30 km.

I pretty much never use more than 500W. My bike is geared so I spin out at 25mph/40kph and 500W gets me there in no time. With our road quality and traffic I'm happy with that as my top speed, but more is available.

I think the TSDZ2 is a good choice for you and me. With the small battery I only added 4-5kg to the bike and the weight balance is good. However, my range is limiting and I am considering getting a second battery - one bigger battery would have been more cost effective.

On the belt drive thing - while my IGH (3 speed) seems to have a good chain line, belts need it to be very precise and it might be tricky. I know it's been done, but I think it requires custom modifications. Personally I don't much like the Shimano 8 speeds and found them not very durable under leg power - I broke two in about 3000 miles each even though I was good to them and never shifted under load. A 3 speed is not a bad idea, if a bit limited in range.
 
Just a thought, and there are both pros and cons, BUT - A lightweight, low power, front hub motor will do most or all of what you want, and most importantly leave your current drivetrain unchanged, no extra power thru it, warranty not voided, and can be pedal assist only with no throttle.

IMO, this is the easiest install and leaves your bicycle more bicycle-like. Configuration of the front fork and proper torque arms are vitally important with such a choice.

Can you currently climb all the hills you want to take, unassisted, and approximately how long does it take and what is the lowest speed you reach?

Pay close attention to the post where the 8-speed IGH broke, TWICE, under leg power alone. Mid-drive is still a logical choice but there are complications.

Have you looked into regen braking? Could be a game-changer for your situation.
 
I haven't tried climbing the hill with a bicycle as I sold my previous one and don't have one at the moment.

Judging from other cyclists I pass by, they're going 6-7km/h up the hill on the lowest gears. It's very steep.

Would a front hub also let me feel like I have "bionic legs" and amplify the amount of watts I generate with my legs? i.e. not a constant torque but rather based on my own pedaling?

This is all a bit confusing because I'm still fairly new to it.

edit to add: I'm not set on a belt drive and it seems to be more trouble than it's worth. The mid-drive seems easy enough to install and doesn't shift the center of gravity, what's not to like about it in your opinion?
 
I'll start at the bottom, the cranks, gears, chain, and bearings, will need much more frequent replacing due to several times the power input they are designed for. The install requires completely replacing cranks and bottom bracket, and the center of gravity issues do not really depend on the motor at all, battery placement is generally much more weight and is the same for all types. Only a few mid-drives have true torque-sensing, though this may be one of them. This can be added for hubs, though most find the standard PAS sufficient for much less money. The standard is simply RPM and not true Torque sensing. Also note that if part of your drivetrain breaks, you walk the rest of the way. Oh, yes, there is also additional offset to the cranks which for some people with knee issues has been a deal breaker.

Power thru the gears seems like such a good idea, most people however just do not need it, it is a gimmick and unnecessary complication. Most hub users will state that multiple gears really are no longer needed.

However, your situation is not common and your hills are extreme. The rule of thumb is you need to keep your speed from dropping below 50 percent maximum for a hub motor, though using partial throttle or PAS reduces the overheating problem. Long times at slow speeds with hi power demands will severely overheat most hub motors, though there are multiple cooling solutions available. The mid-drive thru the gears keeps the motor spinning at a high speed even when the bike is slow, and gets around much of this.

But, it does this thru reduction gearing which for many units has been somewhat problematic. Meaning a small plastic gear which breaks a lot, or a metal one which lasts but can be quite noisy. Obnoxiously so for some folks. Most hub motors are very quiet, and DD units are near totally silent.

Yes, it can be confusing and there is a lot to absorb. What I would recommend is to search out actual user reports, from people who have had their kit for significant periods of time, get their opinions and ask about their conditions. Be alert for salespeople and their hired shills, these are quite common on some sites and the mid-drive kits frequently have higher profit margins, some of the more aggressive vendors tend to specialize in such products.

I changed my mind several times before I bought my kit, there are many factors to consider and each type has its own pros and cons. What is best for your needs is something only you can answer, but you must define what those needs are, what is important to have, and which type of kit, and specific hardware, best meets those needs. There are questions you have not even thought of, yet.
 
AngryBob said:
Just a thought, and there are both pros and cons, BUT - A lightweight, low power, front hub motor will do most or all of what you want, and most importantly leave your current drivetrain unchanged, no extra power thru it, warranty not voided, and can be pedal assist only with no throttle.

IMO, this is the easiest install and leaves your bicycle more bicycle-like. Configuration of the front fork and proper torque arms are vitally important with such a choice.

Can you currently climb all the hills you want to take, unassisted, and approximately how long does it take and what is the lowest speed you reach?

Pay close attention to the post where the 8-speed IGH broke, TWICE, under leg power alone. Mid-drive is still a logical choice but there are complications.

Have you looked into regen braking? Could be a game-changer for your situation.

I, too, came to the same conclusion about the belt drive. Front hub motor is simplest option if you want to go that route.
 
My Wife's Genesis shopper has 8speed internal gear Shimano hub with a custom firmware TSDZ2 plus 52v shark battery
 
It's been done:

https://m.facebook.com/story/graphql_permalink/?graphql_id=UzpfSTczMjA3NTM3NDpWSzo0NDMzMjc0NDYxNjU3OTM%3D


You need spider interface for the crank, which is 130bcd.

The trickiest bit is making the perfect chainline, if it's not perfect, it will come off.

This will only work with a rear sliding drop out.
 
I put a TSDZ2 on a BMC Alpenchallenge Alfine 8 belt drive bike. For belt drive you need to verify the frame setup around the eccentric BB. I had to grind a little of the frame in order to get enough clearance for the motor to fit. If your frame has the pinch bolts at the bottom bracket to tighten the eccentric BB, then the TSDZ2 will not fit. Ill post a pic later.
 
pbert said:
I put a TSDZ2 on a BMC Alpenchallenge Alfine 8 belt drive bike. For belt drive you need to verify the frame setup around the eccentric BB. I had to grind a little of the frame in order to get enough clearance for the motor to fit. If your frame has the pinch bolts at the bottom bracket to tighten the eccentric BB, then the TSDZ2 will not fit. Ill post a pic later.

I also have a BMC AC with 8speed hub. Can you please post a picture of your setup? Do you still ride your rig from 3 years ago? What are your experiences? Thanks!
 
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