erian wrote: ↑
Dec 22, 2017 8:32 am
I have seen that many of you have actual experience with TSDZ2 Tongsheng mid drive. in my adventure to convert my first bike to ebike someone suggested that for my racing bike with dropbars and hydraulic brakes and the 25 miles one way trip i want to do daily this is an ideal motor.
Any thoughts of yours? will it last well? what batteries or what version of the motor, is it worth purchasing the one with the larger screen or the one with the revoshift type of handle? Does it need frequent servicing/greasing?
Any info from your experience would be awesome and will help me with the project.
I converted a bike that's a lot like yours in form, though not actually a racing bike, just a facsimile of one - it's far too heavy.
You can find the thread here:
https://endless-sphere.com/forums/viewt ... =3&t=88943
It's probably true that your "racing bike" won't be much of a racer when NOT using the electric assistance, but it'll sure fly with it - just get the gearing right!
I got a 12.76 Ah battery for a "48V" system, rated at 15A and 500W, and on my first trip out I did 22 miles of hard riding, up and down STEEP hills - hills I wouldn't want to walk up! And when I got back and charged the battery - I use a Grin brand "Cycle Satiator" battery charger (expensive but fantastic) - I found I'd used only about 1/4 of the battery capacity. I calculated the theoretical range at about 96 miles or thereabouts.
Gearing is crucial. I recommend reading this thread:
https://endless-sphere.com/forums/viewt ... =2&t=88711
As was already noted, there's a cadence limit of about 90 pedal RPM - you can pedal beyond that, but you lose all assistance.
I found that a dual (or even tripple) front chain ring is not only difficult to do (derailleur distance from bike centerline) but mostly unnecessary if you have the right gearing in back and a reasonable choice in front. I have two of these systems and I'm running dual 42T & 52T chainrings with 7 gear cassettes in the rear, 11T to 28T, on both of them, and find I seldom need as low as 20, nor higher than 15, but SOMETIMES I do need to get to 28 or, more rarely, 11. However, one bike has a 27" wheel and the other has a 700C with 2" diameter tires which make it a 29" (some claim 28" -shrug- ) And since I have both, I can tell you WHEEL DIAMETER MATTERS! The gearing I just gave is just about perfect for the 27" wheel and the bike stands up and cruises! I've had it up over 25 to maybe 27 miles per hour - this with a 48V 500W TSDZ2. The other, with the big tires, has a 48V 750W TSDZ2, but it's hard to get over 22 MPH or so since I have to use lower gearing to get it up to speed and then I run up against the 90 PRMP limit. Use the calculator provided here which has a 90 PRMP-aware feature to help with the calculations:
https://endless-sphere.com/forums/viewt ... =2&t=88719
If I recall correctly, the 27"-wheeled bike (with 1.25" tires) gets best speed with the 52T / 11T combo and easily climbs over 20 MPH, and can cruise on level ground at 25, or, if I really push it, I can get up to 27, while the 700C (with 2" tires) gets best speed with the 52T with either the 15T or 13T - don't recall which, and it's obvious there's more power but the gearing just isn't quite right to get it up to 25 mph, though I can cross 20 MPH reasonably easily with the 52T / 15T combo. I've only needed to go to the 42T and 20T or more setup a few times on damned steep hills, but think it's important to be able to take them.
I'm just about to try an experiment others have already tried but for which there are scant rider-reports: I'm going to modify a "48v" unit - either 500W or 750W (I own one of each) - by swapping out the motor for a "36v" motor - and ONLY the motor. By doing this, I intend to "over-volt" the motor in an attempt to increase the cadence. I'll probably do it on a new build using standard 26" wheels, but I MIGHT put it on a bike with 700C wheels - not sure yet. The big issue will be overheating, but then I live in a mild climate - the San Francisco Bay Area. ...I'm hoping this will help the 700C wheel equipped bike to get over 25 MPH more easily.
In my opinion, the "user interface" to get is the VLCD-5. It has more features (usb charge port for a phone / GPS, etc, and ports for e-brakes-cutoff switches and a thumb throttle) and has fewer reported problems. The display is removable from its base so you can easily put it in your pocket when leaving the bike - less eye-candy to attract a thief.
Also note that you cannot add a hand throttle after-the-fact because the wiring from the motor to the display is different!
So, if you think you MIGHT want it, order the unit with; it's use is entirely optional.
As for servicing, some units are known to have come with too little grease from new, but note that there's a nylon gear in there and so you MUST use the right type of grease - most greases eat plastics! AND, that reminds me; the only serious DO NOT DO THIS warning that may not be obvious is that you MUST NOT put a heavy load on the system without it ALREADY spinning at a good rate of speed
- a motor that's spinning too slow will get very hot and also that nylon gear can strip out - known to happen! I make it a point to only start out at the lowest assist level and only increase it as my speed increases.