Thoughts on my new ebike - crank-drive vs hub-motor - review of TSDZ02 48v

saneagle

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Today, I did the shakedown ride - about 35 km at an average speed of 20km/hr. It was down Ironbridge Gorge and back, mainly on trails, some exceptionally steep bits. Here are my thoughts, but please bear in mind that I'm comparing it with my normal bike, which is the best legal ebike you can get for normal riding on roads and trails.

The lasting impression is that it's underpowered compared to my hub-motor bike even though my hub-motor bike has a 14A controller and this one has 15A. The main difference is getting access to the power. The hub-motor bike gives the power you want whenever you want it. This one requires you to pedal harder to get the most power. You can see the difference in the battery usage. After 35km, the 20ah battery was showing 51.4v. That's about half the consumption of my other bike. The reason is because when I relax the pedal effort on my other bike, the motor still gives the same power and keeps the same speed, while as this one immediately slows down because the power goes right down. The end result is that I used more of my own energy and went a bit slower.

Hill-climing: Bear in mind that I'm 100kg and not too sporty, but am generally cycling fit. Somebody, who is generally unfit and not pedalled a bike for years would struggle with this crank-drive motor system. The hub-motor can manage all the steepest hills in this journey, of which a couple of short ones are around 30%. Again the crank-drive bike was noticeably slower for the reasons above. The main difference is that on the very steep ones in bottom gear required less pedal effort than the other bike, but on gentle hills, it required more pedal effort to keep up a reasonable speed. If I pedalled in cruise mode, I found that I had to keep shifting down until I ended up too slow compared with what I'm used too.

Gear shifting wasn't too bad. I expected worse compared with other CD bikes I've ridden, but this bike does have Shimano XT gears. Maybe that makes a difference or maybe its the way it delivers the power that makes a bit of the difference.

The noise was a bit annoying for me. It wasn't excessive, and I think it's below most people's expectations, but my other bike is silent by comparison. On the uphill paths, people were getting out of the way without me having to do anything. That never happens on my other bike.

There is a slight surge from the torque sensor. You can feel a threshold of pedal pressure that steps up the power. It's not a linear relationship. That's not so noticeable on other torque sensor systems that I've tried. The disadvantage is that you can feel the power switching up and down when you think you're pedalling constantly at constant speed. The advantage is that you can easily step up the power, probably to maximum, by pedalling a bit harder.

I didn't notice the 25km/hr cut off. It was very smooth.

In summary, I think this motor system is very well suited to people, who have some cycling fitness. If you have ridden a normal bike a lot and this was your first ebike, you'd love it. You hardly notice it's there, you just feel a bit of extra power from your pedalling. None of the things I've mentioned are deal-breakers. I only see it because I'm comparing with the best. IMHO, the hub-motor at 48v with a KT controller trounces it for general riding around, mainly because everything is smoother, more relaxing and less effort. The hub-motor with cadence sensor can make you a bit lazy, but sometimes you want lazy. It gives you more choice. You're always in control of how hard you want to pedal. The penalty is more battery consumption. The crank-drive bike will now be my main bike for the forseeable future until it completes its special purpose, so it can't be that bad.

I can see why people want to use the improved (for them) open source software. I need to do a lot more miles and think about it more before I go down that route.
 
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Az.

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How are first two assist modes on your motor? I find them really poorly calibrated on mine. Like they were almost non existing.
 

Peter.Bridge

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You can see the difference in the battery usage. After 35km, the 20ah battery was showing 51.4v. That's about half the consumption of my other bike. The reason is because when I relax the pedal effort on my other bike, the motor still gives the same power and keeps the same speed, while as this one immediately slows down because the power goes right down. The end result is that I used more of my own energy and went a bit slower.
On hilly rides my cadence sensored crank drive bike is significantly more economical than my torque sensored hub drive using exactly the same battery over the same route, taking approximately the same time. Not sure why, the hub drive is a 26" wheel with more "roadie" tyres - it does have panniers though and is heavier, the crank drive is a lighter 29 er with MTB tyres. I suspect the crank drive (BBS02) is rotating at close to its optimum efficiency whereas the hub drive is probably running a little slow on climbs. (probably still prefer the hub drive for normal usage though)
 

saneagle

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On hilly rides my cadence sensored crank drive bike is significantly more economical than my torque sensored hub drive using exactly the same battery over the same route, taking approximately the same time. Not sure why, the hub drive is a 26" wheel with more "roadie" tyres - it does have panniers though and is heavier, the crank drive is a lighter 29 er with MTB tyres. I suspect the crank drive (BBS02) is rotating at close to its optimum efficiency whereas the hub drive is probably running a little slow on climbs. (probably still prefer the hub drive for normal usage though)
That's interesting. I think it's probably more to do with your riding style, but you need to eliminate other variables or repeat the rides with different riders to be sure.

Years ago, as an experiment, I installed two identical motors in two similar bikes, one as a hub-motor and the other driving the crank. Both had the same controllers. There were no torque sensors in those days, so one had a cadence sensor with throttle, the other throttle only. The bikes were ridden side by side during their journeys and swapped between the two riders, who normally get the same consumption from the same bike. The consumption on the two bikes was approximately the same with some small differences on some types of journey, but overall averaged out to be the same. Obviously, the experiment was to see if there was a difference in efficiency. It showed there wasn't one.

The controller's then were all or nothing from the cadence sensor, so a throttle was virtually essential to regulate speed or power. The throttle took precedence, so as soon as you operated it, it would reduce the power/speed if you were pedalling unless you twisted it to maximum.
 

soundwave

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you wont go very far tho but you will nuke everything on the road hit a wall and end up in a bucket :eek:
 

saneagle

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I'm intrigued what the best hub motor is.
There's not a lot of difference between them. Any geared one is OK. The important thing is to get one that has a maximum speed of about 1.3 times your modal riding speed. The ones with high reduction ratio are a bit more versatile. I use an AKM 128 that can handle double the power I give it. It's smooth and quiet with a sinewave controller, and it's lasted me 10 years and 10,000 miles so far without any maintenance. You need 48v if you weigh more than 80kg.
 

AndyBike

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you wont go very far tho but you will nuke everything on the road hit a wall and end up in a bucket :eek:
Some people are destined not to be able to think something through.
 

Nealh

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With a hub motor the internal gearing is a factor , the higher the gearing reduction ration then the better it will ride with no power and on flat or slightly rising terrain if one has forgotten to take the bike out of PAS 0 then one will hardly notice .
An advantage of a higher gearing ratio is on longer day rides , one can extend the range to whatever one wishes and just save the battery energy for ascents and the final slog home.
 

harrys

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I have front/rear drive cadence sensor bike conversions, a Bafang BBS02 mid drive, and a Tsdz2 48V. The latter is my favorite to ride, but it's probably because the bike is a very smooth 10 speed.

My TSDZ2 originally had no feel of assist in the first two levels and would surge in Turbo because of unbalanced force from my legs. I was not pedalling hard enough, Seven years of cadence sensor ebikes will soften you up. OSF/embrusa allowed me to have more assist at lower pedal pressure. I also resolved to ride my unpowered bike more often. AFter a year with the TSDZ2, I feel stronger. With the original firmware, my top speed was 18 mph in turbo, but today, I can approach 20-22 mph in Eco.

I set up a TsDZ2B in cadence mode for my wife. She finds it "effortless" riding, even easier than her 20" folder with a 20A KT controller.

I use a wattmeter to check my battery usage, MY TSDZ2 consistently uses 20% less battery ober the same distance. between 6-8WH/mile vs 8-10WH/mile on my hubmotor bikes. That doesn't mean it's more efficient. I think it means I'm pedalling harder.
 

guerney

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I set up a TsDZ2B in cadence mode for my wife. She finds it "effortless" riding, even easier than her 20" folder with a 20A KT controller.
Would be even more effortless on 20" wheels, like my cadence sensored 20" wheeled BBS01B folding bike conversion perhaps.


I set up a TsDZ2B in cadence mode
How did you set your TSDZ2 to cadence mode? Did you zero the torque assist mode values?





EDIT: Sorry, you enabled one of the 5 modes for startup doh!
 
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saneagle

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You are forced to pedal harder with this motor than one with a cadence sensor. It feels that whatever level you set on the LCD, there are two power levels with each one. When you pedal lightly, you get one power, and when you press harder, the power steps up to a maximum for that level. Normally, I leave it in level 3 and get a small amount of assistance when I pedal along the flat or downhill with my effort at about 60 - 100w, but when The road starts to go uphill, the bike slows down a bit, so I respond by increasing my effort to about 120- 150w and the motor steps up to the maximum for that level and I can go up the hill with that pedal effort. As soon as I get to the top, the pedal effort goes down and the motor power steps back down to the much lower level.

Overall, I got about 52 miles from my 20ah 48v battery, which is nothing special. That's about the same as my hub-motor. I was expecting more than that.

The place I noticed the difference the most is on the long shallow climb back to my house. If I get tired, I can turn the power up on the hub-motor and get a break from the relentless pedal effort. With the crank-drive, it was either select bottom gear and crawl or select a higher gear and keep pedalling hard. Either way, there was no respite for about an hour of continuous uphill pedalling.

Overall, the cadence hub-motor is much more versatile for normal cycling, but I need this bike for its special purpose that my hub-motor can't do, unfortunately.
 

saneagle

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Did the consumption gets worse ?
Maybe it's something to do with the battery discharge curve. I didn't expect it to be that high. I had to measure twice to be sure. Also, the first journey was basically continuous down, then continuos up, while as the later ones that went to the same half-way point were constant up and down with steeper climbs.
 

guerney

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In my view, one must always adjust a ready made pizza to make it taste better. Cameras produce their absolute best results when manually set.

Either way, there was no respite for about an hour of continuous uphill pedalling.
I don't know why you're putting up with this torque sensing lark! I wouldn't, even if someone gave me a TDSZ2 for free. I reckon you should make firmware adjustments, set it to cadence sensing instead. There are TSDZ2 firmware fiddling owners on this forum. But as with pizzas and cameras, you risk making things worse. Your TSDZ2 could become inedible or blurry.
 
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saneagle

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In my view, one must always adjust a ready made pizza to make it taste better. Cameras produce their absolute best results when manually set.



I don't know why you're putting up with this torque sensing lark! I wouldn't, even if someone gave me a TDSZ2 for free. I reckon you should make firmware adjustments, set it to cadence sensing instead. There are TSDZ2 firmware fiddling owners on this forum. But as with pizzas and cameras, you risk making things worse. Your TSDZ2 could become inedible or blurry.
You're right. If I could go back in time, I'd be thinking about a 48v 250w Bafang BBS01B. I just don't get why anyone would want a torque sensor unless they're into self-flagellation and that sort of thing.
 

guerney

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You're right. If I could go back in time, I'd be thinking about a 48v 250w Bafang BBS01B. I just don't get why anyone would want a torque sensor unless they're into self-flagellation and that sort of thing.
People have reported being unable to increase the current limit of some 750W BBS02 controllers on this forum, including @peter.c. I don't know if the current limit of 48V 250W BBS01B controllers can be increased. Haven't yet heard of that being an issue with the 36V 250W BBS01B version. That being said, my controller didn't change for the first two write attempts, then threw a wobbly when I increased the current limit to 20A, to see if I could - other firmware parameters were replaced with weird values. All subsequent changes have gone smoothly.

Now that a TSDZ2 is on your bike, perhaps you could go the OSF route? Make it cadence sensing?
 
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saneagle

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People have reported being unable to increase the current limit of some 750W BBS02 controllers on this forum, including @peter.c. I don't know if the current limit of 48V 250W BBS01B controllers can be increased. Haven't yet heard of that being an issue with the 36V 250W BBS01B version. That being said, my controller didn't change for the first two write attempts, then threw a wobbly when I increased the current limit to 20A, to see if I could - other firmware parameters were replaced with weird values. All subsequent changes have gone smoothly.

Now that a TSDZ2 is on your bike, perhaps you could go the OSF route? Make it cadence sensing?
750w is illegal. I'd only consider the "250w" version.
BAFANG BBS01B 48V 250W Mid Drive Motor Electric Bike Conversion Kit With Battery | eBay
 

guerney

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Why not make the best of the present situation? @Nealh can show you how to make a gizmo, to replace stock TSDZ2 firmware with OSF. It might all go swimmingly well. On the other hand, even after you've set your newly installed TSDZ2 to cadence sensing, I fear it won't last for long using it as you have been, and you might end up buying a BBSXXX anyway. Rightly or not, I get robustidy anxiety at the mere mention of a TSDZ2.

For more climbing power, you could install a BBSXXX onto this brand new full suspension 20" wheeled Dahon Jetstream, custom built by CH White, the Dahon expert dudes. I don't know if the Jetstream's suspension is any good for whatever your Special Purpose is (I suspected it was to get mad cycling fit), but as a former owner you do.