29" e-bike for commuting - rear hub motor or TSDZ2 ?

Hi,

I commute regularly following 5.5miles long route through the forest to the train station :



As you can see it's daily almost 2 hours of healthy MTB training (mostly gravel road not suitable for city bikes). I would like to reduce time spent on the route (forth and back) under 50 minutes (as I have kids now :wink: ). That means I need at least double my average speed to at least ~15 miles per hour (25km/h).

From what I read here I really like TSDZ2 central motor with torque sensor but there are opinions that central motors are not so reliable in the long run. Rear hub motor could have problems in more steep sections is that right ? On the way back there's 3.5mile long section with ~7% average gradient (one short section just 0.2miles with 13% gradient). My weight is 210pounds (95kg) and I would like use motor on my 29" MTB (steel frame). What motor would you recommend ?

I think I don't really need strong motor 250w-350w should be enough for my needs as I will be pedalling as I am used to. Also legal limit of motor assistance is <=15miles per hour in my country and only <1kw motors.

I'd go with a middrive for that kind of terrain and speeds and wheel size and weight, etc. Which middrive...I don't have any direct experience with any of the commercial ones, but others will likely step in with opinions on them.

I like the tsdz2 system and I have 3 going at the moment. If you like to pedal go with the torque sensing you will be happier with it. I don’t mind to work on them a bit and its not hard, greasing or replacing parts. Some attention to using a stronger chain and smooth shifting makes a nice ride. You should be able to use a shark size pack 12ah or so on that commute.

Powers this along an avg of 20kph where I live its pretty hilly.

I own both a TSDZ2 that I have mounted on my steel 29"er mtb and I have a couple of front hub motor 700c drop bar bikes. In my experience either system would be more than enough to do your route with a 10ah battery averaging 15mph. The one thing I would say though is that the hub motor system is way more reliable than the TongShen given that it is a quality hub motor to begin with like the Bafang G31x series geared 350w one.

I have had some issues with my TS and at this time after 900 miles of use the bearings are shot so it is out of service and I am considering just getting another one instead of trying to source and replace them and the chance that even if I get the new bearings on successfully will the Torque Assist still work as I had issues with that once also....In comparison my hub motors with many more miles on them have been relatively trouble free, although I did replace the bearings on my 9c after 2500 miles but it was a pretty easy 1 hr job to do so and I was able to source the bearings easily of a much higher quality.

MartinW,

What country are you in ?
( With gravel Riding and Weather in you area the Tire Size is also a good thing to consider
)
What bike do you have now and the tire size ?

With a 320 Meter Altitude Gain at 3.5 miles you ... Are going to need a powerful motor.

Even a 100 Meter Altitude Gain can put allot of stress on a motor if you do not get the right motor . Especially on a 29 er.

I live near hills, and am going to be selling my hub motor that is rated for 350 watts the Q100c to someone who will only be riding mostly flat terrain riding , and now I am using only my Mac 6T motor , with 36-52 volt packs and running it at 25-30 amps . I am Using my 36 volt pack at up to 30 amps for days going up hills. and up to 20 amps with 52 volt pack for flat terrain riding .


What would work for you Besides a heavy DD hub motor, is a motor that has done allot of reliable miles/km's . for many people that is the Mac Motor, they are rated at 500-750 watt , but can use more for short bursts. A little motor you describe can only use 17-22 amps or so max . a 350 watt motor typically only up to 17-18 amps max.
For the 100 meters that would be barely enough. For 320 meters of climbing you are going to want a motor that can run on at least 25-35 amps for as long as it takes to climb up 320 meters / 3.5 miles.
( Check the Grin Motor Calculator site and test the motor at the % grade you will go up and look at the bottom right to see when/how long before the motor will overheat . )

For a Hub Motor that would be reliable and with your 29 inch wheels a Mac 10 T would be good with a 40 amp controller that is adjusted with a Cycle Analyst , or newer Blue Tooth Dongle . Or any other hub motor that has the same performance as the Mac.

For a Mid-Drive get at the very least a BBS02 ( with newer higher amperage controller 25 amps or better )
or a BBSHD, or Better yet a Cyclone 3000 watt, or a Lighting Rod's Mid or Big Block, or the not yet released X1 Pro.

Czech Republic, 30km from Prague.

As I state before I need just partial assistance to get 15mph speed. I have 29" MTB with steel frame - Front tyre is 2.25 Schwalbe Nobby Nic because I had defects with lighter tyre on rough gravel road + also it's safer/more stable when descending ~20 - 25 mph. Rear wheel has 2.1" Schwalbe double defense tyre (again because of defects). There's no snow except few weeks in winter but I will not adventure when weather will be very unhostile (will use my car).

Legal limit for public roads is 250w and 15mph in our country (of course in 'offroad' mode in the forest I could have a switch but legally it's hard to claim that I did not used offroad settings on public road in the moment if something will go wrong).

I will maybe borrow such bike for one day just to try whether 250w is reasonable or not.

If you can test out 1 or better yet more bikes for 1 or 2 days on your route that will tell you allot.
Some important things to remember.
You can always run/use a more powerful motor at a lower power setting.
I do this all the time with my Mac 6T motor, when on the flat areas I am using only 250-400 watts when traveling under 19 mph, however when I need more power ( hills ) that more power of the Mac motor is there for me to use.
Also
You can always adjust down the power when you have a controller/display system that can do the adjustments on the bike without the need for a computer and programing cable.
To do this I use my Cycle Analyst 2.3 to adjust the power settings. It is so easy you can do this each ride , adjust when entering the off road area and adjust again when back on the public road. Very easy with the Cycle Analyst.
Also I have read here on E.S. it is doable on a Blue Tooth Dongle/Controller when paired to a modern smart phone.

My 29" mt bike with 1000w 20amp 48 volt will make about 40 miles on a full battery. This is at 14-15mph any faster will drop that range and lower to 10mph will get me a lot more. My bike is 4 years old and this motor / battery has done 7,000+ miles and shows no sign of drop off. Most miles on pavement and some 10% on beach.

I have a TSDZ2 mid drive MTB with Nuvinci rear hub and Gtech hub drive ebike as well.

They are like chalk and cheese really, use the Gtech for my commute to work, nice and smooth single gear plodder.

The TSDZ2 is quicker and more involving to ride but you have to be up and down the gears (not recommended to stick it in high gear and set off on full power due to the load on the gears).

For your run I'd chose the TSDZ2 I think, for road commuting the hub drive is a more relaxing ride I think.

Noise wise the hub drive is quieter.

Mid drive for the best off road bike, that's able to climb steep hills. With a large 29" wheel, a hub motor may work ok if its 1000w, but not as good as a 350w mid drive would, on the steeper stuff.

However, Can the trail be rode at 15 mph the whole way? Seems like the downhill leg should be much quicker if the trail can be run fast. On a commute, not wrecking along the way and going to the e room for a collarbone is important. Fun riding you might have more time for that hospital detour.

In any case, you will do the trip much faster with a mid drive e bike. You'll get back to speed much quicker on the fast sections, and do the uphill run on it a LOT faster. So yeah, go for it. Just stay within sensible limits so you aren't late after crashes.

I also agree, a hub motor for road commute, unless its san Francisco steep roads. Geared hub motors ideal for most road commutes.

Thank @dogman dan, I agree with you. I will be faster when descending so even 12mph uphill should be fine - and motor will be actve only first 2km at the morning and 6km afternoon - but afternoon there's no real "time pressure" so I guess it will be fine.

Also I got quite important advice from ebike serviceman who lives nearby - approx. 10% - 15% motors with torque sensing have problems and are more often repaired/serviced (not sure if it's TSDZ2 : https://ekolo.cz/elektrosada-se-stredovym-motorem-ts250) so service man recommended me classical Bafang 8fun motor 250w/350w - it should be more silent and more reliable (of course there's compromise in the "feeling" when pedaling without torque sensor but I can live with it).

Quick update :

I borrowed 250w bike yesterday (bafang BBS01 250w) and it really shaves off 50min of traveling time as I originally planned (with active pedaling). I had problems only in steeper sections >7% where my speed was sometimes under 7mph (10km/h) with active pedaling (~140 heart rate). It's still good enough (without motor in those sections I had really doing just 4mph with 160 heart rate) but I have feeling that I could save even more time when I will add few more power to the motor. Luckily that bike had some kind of off road/BOOST button which released full power ~ 350w for a while and that was good enough to get ~ 9-10 mph (15km/h) in steeper sections and that's fine for me.

I will buy Bafang BBS01 250w kit but I will need some kind of 'turbo' for steeper sections - I guess it will be doable to setup last level of assistance above 100% (250w) threshold to 150% or so.

Rider weight : 210lbs, bike 44lbs, bag 10lbs = 264 in total.

Buy the BBS02 instead of the 01 .

martinw said:

Quick update :


I will buy Bafang BBS01 250w kit but I will need some kind of 'turbo' for steeper sections

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