FS offroad TSDZ8

[E-HP]

I've been trying to get motivated to fix my ebike, but every time I look at it and see broken parts and twisted metal, I get too depressed to start. Plus, I have junk piling up around it in the garage, so now I need to clear that to even begin the work.
But, over the last month, one of my buddies decided to build his first ebike, and after a bunch of back and forth, he decided on the TSDZ8. Well, his progress emails have pushed me over the edge, and I decided to finally convert my full suspension bike. I did some quick measurements for my battery options, then ordered the same kit, which will arrive next weekend.
I think I can get 14Ah in the triangle, in either a Hailong style pack or super shark. The hailong might require flipping my shock to get a little more clearance, but I'm leaning toward a super shark pack, like EM3EV uses. The issue with these sized packs is that I'd only get 13S4P to fit in case. 5P won't fit, but it can accommodate 14S4P, which will give me a little more range. The display in the kit can be set to display realtime voltage, so that's all I need.
The OSF for the TSDZ8 seems to be coming along, so that may be an option down the line, after the initial new ebike glow has worn off.
I think this build will satisfy my offroad riding needs, so I can dedicate my existing ebike to pavement and keep the slick tires on it, with good offroad knobbies for the new bike.
My full suspension bike is old school, with linear pull brakes, but it has some cool old decent vintage parts. Full XTR drivetrain, White Industries hubs that roll super smoothly, and other cool bits and pieces. I was thinking of upgrading the parts to something more current, but I kind of like it the way it is, so probably will only change out the seat.

My econo-e-bike

Rack for the FS: What about folding the rack rear supports more forward so they can attach to the seat tube instead of the seat stays? Wouldn't be as stable, but maybe enough? (something like this:) I like that Leaf 1500W motor also, want to use one for my next project. Did you order frewheel...

endless-sphere.com

I forgot how it feels to have new parts coming in the mail, especially a full kit. I need to yank my bike down since it's hanging from the ceiling now, and probably clear out some of the garage junk to get ready.
There's a hill near my house called Motorcycle Hill. I can climb it with my existing ebike, but there are some single track trails that I can't climb because of the steep switchbacks that require going too slow. The single tracks will be one of my first tests of the new build, since that's one of the main purposes of building the bike. The hill is no longer barren like it was a hundred years ago, so the vegetation has created several trails up the hill.

Motorcycle Hill History

What is “Motorcycle Hill”? Trailtrekkers have named their trail Motorcycle Hill Trail as a tip of the hat to the daredevil racers of a bygone era. Potrero Hill Climb by Mark Miner 90 years ago, our…

ectrailtrekkers.wordpress.com

 

[dgc]

You might like this, bafang killer, Google Search

 

[neptronix]

^-- above link references a video about a TSDZ8 from a channel called 'dude stuff'

 

[dgc]

Yep, I just like it where he tries to get up the steep bank.
Always ridden modified Tongsheng TSDZ2s and TSDZ2Bs hard-tail and full suspension bikes myself.

 

[neptronix]

ps, happy to see you back to building e-hp!

 

[dgc]

Not sure if it is old school but gathering the bits for new build based on the Specialized Epic frame I have in loft, lucky to have a spare rear shock as well and a set of RockShox 35 Silver Solo Air forks. Always usually gone for NOS frames, but like the space given in the triangle on the Epic.

 

[E-HP]

ps, happy to see you back to building e-hp!

Thanks. I needed something new to get motivated. I see the motor has shipped! I need to get on ordering a battery now.

 

[dgc]

I am old and retired, but get fed up mowing the grass and polishing the car.

 

[amberwolf]

I am old and retired, but get fed up mowing the grass and polishing the car.

If I was retired, I'd finally have some time and energy to do one or two of the ten bajillion projects I would like to begin, much less complete.

 

[dgc]

In reality when you retire you still never have the time, I worked as a Project Engineer, talking to customers all around the world, but time is still fly's past, what with e-bike building, up to 10 now, some for family and friends, into 3D design and printing. I do ride a e-bike nearly everyday for exercise, do weight training which is the shopping in the backpack.

 

[E-HP]

I don’t ever recall getting ebike parts a week ahead of the estimated date!!! Now I’m way behind in getting a battery. I may need to run it off a bunch of lipos until I get a real battery.



EDIT: Interestingly, tracking shows that it just shipped yesterday, and is on track to be delivered next week/weekend.
EDIT 2: I received a message that my order is being shipped in two parts. The display is on track for next week. I'll need to check if they substituted magnetic brake sensors instead of levers per my request.
EDIT 3: brake sensors were included per my request!

 

[E-HP]

The display is on track to get here this weekend. I put a new chain on the bike and rode it around a little. I'll need new brake pads, and I may have some chain alignment issues, but not sure until I fit the the motor. I'm looking at alternatives for chainrings just in case. My large chainring has the same tooth count as the stock TSDZ8 chainring, and it looks like with the right shimming, it will be a few millimeters further out than where my middle chainring is now. I'd need to go with a smaller chainring to move it inboard to where the middle chainring aligns. I may just get it as close as possible, and maybe restack my cassette if necessary. Luckily I was able to find my shock pump, since I haven't used it in 10 years. I'll need to take it on a test ride to make sure everything shifts smoothly and adjust if necessary. I forgot how light my bike is; almost a shame to bolt a bunch of weight on it, but at least it will be back on the trails instead of collecting dust.

 

[E-HP]

I took one more pedal bike ride down the hill and back, and decided that's probably the last unassisted ride I'll be taking. After not being on my bike for 9 months, pedaling up the hill was pretty tiring. I got back, located my tools, and in about 20 minutes the motor install is done. The earliest the display will arrive is Saturday, but looking at the tracking, I'm guessing it will arrive by Tuesday or so, so I have plenty of time to install the brake cutoffs and speed sensor. Unfortunately, the chain line is exactly the same as the big chainring had, so 1st gear sucks, 2nd gear sucks but works. Looks like I'll be reordering the gears on the cassette, so not a big deal. I think I'll only need 5 good gears. The brake pads arrive tomorrow, which will be a requirement before riding, based on today's pedal ride down the hill.
The motor has good ground clearance, and doesn't hang down lower than the chainring, but the cables do. There's plenty of ground clearance, but I'll think about whether to add some protection for the cables.
I did a few more measurements and I'm not sure I can get a shark style battery pack in the triangle, even if I flip the rear shock. It looks like a Hailong G56 case would fit well, since it's pretty low profile (90,mm vs 110mm). That can hold about 14Ah at either 48V or 52V. I'm have a challenge finding one with decent cells. In the mean time, I have a couple of 6S 12Ah lipos I can run in series, for short rides, and just monitor voltage. If the TSDZ8's LVC is something like 41V, then that would be cutting the 12S lipos at 3.4V/cell, so that should be fine.


EDIT: I found a bunch of spacers in the parts box. I recall I used a couple to shim between my freewheel and motor, but they are also used for cassette spacers with the same inside diameter. I'm just going to remove one cog, and won't have to do anything else, but adjust my derailleur.

EDIT 05-06-25 Battery shipped and should arrive in a few days; but, the display is stuck in customs! Ugh. I may need to look for alternative displays.

EDIT 05-08-25. Pack is out for delivery, and the display finally cleared customs!

 

[E-HP]

Battery just arrived. Looks like it will fit perfectly.
The display made it by the customs log jam, and looks like the last leg of the trip is by USPS, although they’re not explicit (says “through Post network”).

I’ll mount the battery and swap in new brake pads, and the sensors tomorrow. I’m still deciding on my shifter and throttle. I’ll try the kit thumb throttle first, but will eventually just mirror my other bike with a half twist throttle on the right, and grip shifter on the left, for consistency.

 

[dgc]

Consistency is the key, I build my bikes all the same TSDZ2(B) with the OSF firmware, hybrid on, then 180mm f / 160mm r hydraulic brake combo, 9 speed rear cassette, as I use mostly NOS frames so I am using a mullet setup to modernize the head-stock angle, with a 27.5"f / 26"r or a 29"f / 27.5"r combos, which is my current fad.

 

[E-HP]

There’s more clearance than I expected, so there may be a chance the next larger hailong pack might fit (I haven’t measured yet). This one has a height of 90mm and the standard size case is 110mm.

 

[Zambam]

What size (V and A) battery did you end up getting? Did you ask for A grade cells (Samsung, LG etc). How would you verify if you got what you asked for? Will you do a capacity test?

 

[E-HP]

I already opened it up but didn’t peal back the wrapping enough to see the cell info.. Not great construction, but it’s just something cheap to get it running for now so I can ride it while I fix my other bike. Supposedly LG cells. Not high output though, but should be OK with the TSDZ8.

LG INR21700M48F 4800mAh 21700 M48F Li-ion Battery

100K in stock, LG 21700M48F Lithium-ion Cells, fast shipping by air or sea with MSDS UN38.3 RoHS BIS CB IEC62133-2 UL1642.

ancoo-battery.com

If I like the mid drive, I’ll upgrade the battery later.

EDIT 05-10-25. Display is out for delivery!!

 

[E-HP]

Despite not connecting the speed sensor or brake switches, and with only the storage charge the battery delivered at, I took my bike out for a short ride up the hill. It was ok, but not impressive. I haven't done anything in the setup or connected the bluetooth yet, so maybe there's some settings that might help. On the other hand, I'm just used to going up the same 15% trail at 20 mph, so going half that feels sluggish. The throttle sucks. It feels like it has a 5 second ramp. Hopefully at some point, OSF might help.
The bike feels good. The weight distribution feels good. I'll be swapping out the handlebar, brake lever, shifter, and thumb throttle, and swap the seat for the one I was using on my other bike, before it's current saddle. It has more cushion, but not too much wider.
The torque sensor works pretty well, or at least better than the throttle. It's actually more responsive than the throttle, and seems to apply more power to the rear wheel (although pedaling has something to do with that too lol).
I'm pretty sure the next size up Hailong case will fit if I flip the shoch around, but I'm already thinking about just building a 14S3P pack in the same size case out or something like Molicel P50B 21700 cells. If I'm only running 20-25A, I think I won't have any voltage sag with a pack that can do 150A continuous. I may just test 14S using lipos first to see if it's even worth it.
I'm 50% sure I'll be converting to 24" wheels and disc brakes in the future. Using the tires I was using on my other bike, that would drop the stand over height by about and inch or so, which would be just about right.

 

[dgc]

Looks great, like my 48V TSDZ2B needed the OSF and a good tune up as originally my 36V TSDZ2 with OSF had a better performance.

 

[E-HP]

I installed the speed sensor and adjusted the parameters in the display, none of which really changes performance, and went for a test ride, out a few miles and back. My impression is that the controller limits phase amps pretty low, so acceleration is weak under throttle when not pedaling, and the power is limited at something just over 1000W. With pedaling, the bike accelerates better. I had hoped that the thumb throttle could help when starting from a stand still, but it doesn't really help much, and assistance is much greater when applied via the torque sensor. For now, I'm skipping the plan of using a half twist throttle, and will revisit that if/when I switch to the OSF to see if it's even worthwhile. Even without the OSF, the torque sensor is a nice improvement over just cadence sensing PAS, and after 9 months off the bike, I'm counting on it to get me back in shape.
Although I did ride on throttle only for a couple of blocks, the system is really meant to work with pedaling, so I got a lot of exercise while testing. The bike was way less comfortable than my other bike, even after putting on a more cushy seat. The handlebars need to be swapped out; I think my days of riding with a straight bar are over, so I'll probably put the same bars on as my other bike since the rise and the sweep work great for me (after trying several bars).
I used the koolstop pads that are the combo salmon and black compounds and forgot how powerful the linear pull brakes are with new pads (I almost went over the bars when I first applied them at the bottom of the hill). The test reset my expectations about the system, but it's still had fun, but the bike won't be enjoyable until I can get more comfortable with the cockpit.
Full suspension hasn't really produced the benefits that I had anticipated. The rear suspension works OK, and I'm sure will be safer when hitting a big pothole, but from the seat of the pants feel under normal riding, the thudbuster with the cloud 9 seat is a lot more comfortable soaking up the medium sized bumps. I haven't adjusted the compression and rebound dampening for the rear shock yet, but I have enough seatpost length to put a Suntour suspension post on the bike, if I can't get it dialed in for a smoother ride.
Shifting is really smooth and precise with the XTR drivetrain, but having to shift again sucks and something I'll need to get used to again. I'll need to remove one rear cog from the cassette and add a spacer to help with the chainline, since when shifting to 1st has a tendency to drop the chain off the front chainring.

 

[Zambam]

Sounds like you are slowly getting it dialed. Shifting takes time, it will never be as quick as your direct drive rear hub under throttle. What's the weight of the bike currently?

 

[E-HP]

Sounds like you are slowly getting it dialed. Shifting takes time, it will never be as quick as your direct drive rear hub under throttle. What's the weight of the bike currently?

I think it's around 45 lb, although I haven't weighed it. Without the E stuff, it started at maybe 24 lbs, give or take. The throttle behavior is odd, although I haven't figured out what it's actually doing. It definitely overrides the PAS, and applies less power than PAS outputs at any given assist level, so letting off the throttle while pedaling will cause a surge. Hopefully the OSF can fix that because I really don't trust using PAS for the narrow single tracks, and would prefer to have all of the power available via the throttle. Right now, there isn't an option of throttle only, since level 0 cutoff both PAS and throttle. Using PAS on a wider fire trail worked fine, but when I started down a narrow steep single track, I turned around since I want to be very familiar with how the bike applies assist. I think I trust this battery for about 20 miles of mixed riding, based on where it ended up after charging to around 90%. It's sagging a couple of volts at 1000W, which I'd expect from a high energy cell.
I felt the benefit of the rear suspension working when off road, on some small dropoffs, but still considering a suspension seat post. The wider seat helped.

This single track is pretty grown over, so you wouldn't notice it if the sign wasn't there. I rode about 50 yards down it, then decided not to risk injury until I get used to the bike.

 

[Zambam]

24 lb for a FS is very light! My Raleigh M80 hardtail was 27-28 lbs before TSDZ2 conversion. Afterwards 41 lbs w/o any accessories. With rack, pannier, bluetooth speaker, cable lock, it's 44 lbs as in pic. I only use throttle if I need to get off the line quick. The motor sounds different throttle only and noisier than pedaling in torque mode, which is proportional to pedal input and quiet.

Have you tried a leather saddle. It yields and conforms to the shape of your butt and is the most comfortable saddle for pedaling I've tried so far . Mine is a Brooks copy from aliexpress around $32.

 

[E-HP]

24 lb for a FS is very light!

Have you tried a leather saddle. It yields and conforms to the shape of your butt and is the most comfortable saddle for pedaling I've tried so far .

It was an expensive hobby, with lots of titanium pieces, so it’s sort of sad bolting on stuff that weighs more than the bike itself, but at least it’s getting ridden now.
I’m past being able to ride any saddle without a good cutout, or I wouldn’t be riding at all. Maybe when I was younger.

I did around 15 miles this morning, and I can feel my body getting used to pedaling again. This bike requires pedaling the whole time I’m riding it, so it will be a while before I’m doing more than 20 miles a day. Charging really sucks at 2A, since Im spoiled by charging for an hour before a 20 or 30 mile ride. I need to get another pack with cells that can take a faster charge!

Turns out my rear shock’s compression dampening was set close to lockout, so I flipped the lever and it’s pretty plush now, even on smaller bumps.