Stromer ST5: Is it reliable?

Back in July, I wrote about the excitement about getting a 2nd ST5 after the 1st ST5 failed the day I was to take delivery at Electric Bikes ZZZ. Between July and September, I experienced a lot of weird errors, I lost track of them. I was getting annoyed that the bike seemed to have been most of the time at the shop for diagnosing errors that were difficult to track down or reproduce.
It seems that my bad experience was unique among ST3/ST5 customers. The shop agreed with me that, somehow, I had received another defective bike.

At the end of September, I take delivery of a 3rd ST5 thinking that my problems should be over with this new bike. Forward to early November when a new pattern of errors emerges beginning with a transient error, E210208, when I turned on the bike for my morning commute. The error went away after power-cycling the bike only to show up again a couple of days later.

About 10 days later, I get a new error: E250103 (Torque sensor needs calibration). In all the years that my wife and I have owned ST2 bikes, we've never had this error before! Since I'm on a tight schedule for catching my vanpool, I switch to my old ST2. That evening, I perform the torque sensor calibration procedure and take the bike for a short test around the block. Everything seems fine!

Next morning, I take my ST5 for my morning commute. As I make a right turn into the side street where the vanpool parking lot is, the bike flashes lots of messages and I loose power assistance while Omni displays a flurry of messages too small and too quickly to read safely while trying to figure out what's going on. It turned out to be E250103 but I have to postpone troubleshooting until the vanpool returns later that afternoon. After turning on the bike and performing the torque sensor calibration procedure, the bike flashes E250103 as soon as I pedal. The difference now is that the subsequent procedure fails and the bike reports a new error about that. I tried power cycling the bike twice and the procedure a few more times; nothing. I ride the bike back home loaded with my stuff. On or off, there's a lot of cogging resistance. Riding that way at 20mph, the electric horn produces an unpleasant shrieking sound once in while.

At home, I leave the bike turned off. About 30 minutes later, I turn it back on -- no E250103! It's as if nothing had happened! I'm really frustrated. For the rest of the week, I used my old ST2. Then comes Saturday -- I need fresh bread (it's a French thing...) and take my ST5 to the bakery nearby. On the way back home, I turn right on my street and bam -- power assist goes off; E250103 again. Fortunately I only have a couple of blocks to go...

Up until I experienced the torque sensor errors, I was willing to deal with errors w/ the shop. The torque sensor errors -- and the effect they have on the bike -- are a completely different category for me: basically it means that I cannot rely on the bike to function as intended when I need it. This was the last straw for me and today I returned the ST5.

I really liked Stromer's design. Omni's screen is too small to be useful while riding the bike but it is nice knowing that the bike sent all the errors back to Stromer. What is not nice is the fact that customers are in the dark w.r.t. what is the actual reliability of Stromer's ST5 design. For $10K, the last thing I need is to feel anxious regarding my bike's reliability.

- Nicolas.
 

Robie

Active Member
My St2 is the best bike I will probably ever own. Pure magic for 5 yrs. Sorry your 5 is a flop.Hope The Mother ship gets you another ASAP .
 

Insider

Member
My ST5 had assist cut and error messages at ~750 miles. It got to a point where I couldn’t turn it on using the power button.

I discovered a few things:

I could only turn it on while plugged into the charger. As soon as I unplug, bike would shut down. This meant that power was not getting to the OMNI unless plugged in.

I Finally discovered one of the pogo pin (Rosenberger connector) at the bottom of the battery compartment had retracted into the body. This meant the battery was not supplying power to the OMNI = can’t turn the bike on.

My Stromer dealer ELV motors was able to order the wick connector and replace the connector under warranty. I ran another 750 miles and no issues!
 

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Insider

Member
Yup 1500miles on it now trouble free. I ride about 18 miles to work daily. I get a great workout on it, It’s my time machine.

The internet connectivity is poor. Metrics lagging. Since I upgraded my iPhone to the 11 pro, I cannot pair. I never cared for the seamless unlock mode.

just updated to the latest firmware OTA 2 days ago. (It included a battery firmware)

YMMV, I’m very hands on with my ST5, that’s why issues don’t get me down. (i.e figured out the wick connector problem without back and forth with the dealer.)

Brakes squeak like no bike I’ve ever owned. Sintered pads didn’t help. I spend probably 4 hours troubleshooting and fixing.
I went to great lengths - trueing the wheels and rotors - even lapping the brake mount posts so it’s squared up with the axles.
The brakes are awesome now.

I also self installed the factory Wen suspension forks. Bleeding the TRP brakes was a bitch until I figured out that these TRP brakes are not configured in a sealed system. If you push fluid from the calipers side, fluid will leak out of the breather hole in the master cylinder top cap. You can’t bleed from the top at all. Tip: you can try cheap organic pads in Amazon for as low as $10 (Pads for Shimano Saint M810 M820 ZEE TRP)

I’m not a professional bike mechanic, but being a motorcycle rider for +20 years, gives me a lot of understanding of how a bike works generally.
 
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Ebiker01

Well-Known Member
Yea being a DIY person is best approach when owning an ebike wether is a very high end one or less then that.
With the pin not sticking out , it’s an issue underneath the connector b/c there’s not enough space due to the movement of some wires there.
The pins retract and best way i did on mine is using a dentist tool i position the wires underneath perfectly and put them in a fixed position so that The pins have ample movement up and down.
This is on a similar battery not on a Stromer ebike.
An ebike repair charges 125$ just to fix something like that. But is not even the money, is about the time wasted going back and forth with a dealer, etc..
 
Yup 1500miles on it now trouble free. I ride about 18 miles to work daily. I get a great workout on it, It’s my time machine.

The internet connectivity is poor. Metrics lagging. Since I upgraded my iPhone to the 11 pro, I cannot pair. I never cared for the seamless unlock mode.

just updated to the latest firmware OTA 2 days ago. (It included a battery firmware)

YMMV, I’m very hands on with my ST5, that’s why issues don’t get me down. (i.e figured out the wick connector problem without the dealer back and forth with the dealer.)

Brakes squeak like no bike I’ve ever owned. Sintered pads didn’t help. I spend probably 4 hours troubleshooting and fixing.
I went to great lengths - trueing the wheels and rotors - even lapping the brake mount posts so it’s squared up with the axles.
The brakes are awesome now.

I also self installed the factory Wen suspension forks. Bleeding the TRP brakes was a bitch until I figured out that these TRP brakes are not configured in a sealed system. If you push fluid from the calipers side, fluid will leak out of the breather hole in the master cylinder top cap. You can’t bleed from the top at all. Tip: you can try cheap organic pads in Amazon for as low as $10 (Pads for Shimano Saint M810 M820 ZEE TRP)

I’m not a professional bike mechanic, but being a motorcycle rider for +20 years, gives me a lot of understanding of how a bike works generally.

You're impressive! Have you changed the torque sensor on your ST5? I learned from electricbikezzz that my ST5 had indeed a failed torque sensor, barely a month after I had purchased it. When one of the previous ST5s had a failed light assembly, I saw how tightly packed the electrical wiring is in the front handlebar. These two events convinced me that fixing an ST5 on my own would have been well beyond my limitations. As Clint Eastwood's Dirty Harry said: "A man's gotta know his limitations!" The ownership of an ST5 was well beyond mine. I hope it will be within yours.

- Nicolas.
 

Insider

Member
You're impressive! Have you changed the torque sensor on your ST5? I learned from electricbikezzz that my ST5 had indeed a failed torque sensor, barely a month after I had purchased it. When one of the previous ST5s had a failed light assembly, I saw how tightly packed the electrical wiring is in the front handlebar. These two events convinced me that fixing an ST5 on my own would have been well beyond my limitations. As Clint Eastwood's Dirty Harry said: "A man's gotta know his limitations!" The ownership of an ST5 was well beyond mine. I hope it will be within yours.

- Nicolas.

Have not had to replace the TMM sensor. Luckily. The fork install was a doozy. Very tightly packed inside the custom handlebar.

I talked to Tektro and they make the TRP brakes. The replacement line are thicker because they claim the lines move more fluids needed for the 4 piston calipers.

Tektro Brake Systems Brake Disc Tektro HYD Hose Kit Draco/Auriga Comp-Ws 1800Mm

Took a lot of photos.
The local Stromer dealer wanted $300 to install. (No freaking way I’d let that happen. )
The forks cost $1327 and they are not adjustable beyond preload... fairly, they are nicely tuned and the bike now rides $1327 better.

Maybe I’ll do a write up. Some tools and creativity needed. (Need to drive the crown race on to the forks properly, brake bleed kit...etc. )
 
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bluecat

Well-Known Member
The forks cost $1327 and they are not adjustable beyond preload... fairly, they are nicely tuned and the bike now rides $1327 better.

OK, in Switzerland part #402406 for 1'199 CHF, so pricing seems to be correct.

I guess, you've read the instructions for the upside-down fork. I would not change anything - but being happy having the sole suspension which does not change the bike geometry.
 

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