From ST5 to Supercharger 2

Johnny

Well-Known Member
Since I gave up on owning a Stromer ST5, I had considered several options that I could try at a local LBS:

- Trek Alliant+ 9.9S at Helen's Cycles
- Specialized Vadoo 5 at Cynergy Cycles

I noticed that both bikes have the same derailleur as the Stromer ST2: Shimano Deore XT.
However, unlike the ST2, both bikes shift with a noticeable klunk -- as if someone is hitting the bike.

At Cynergy, the salesman told me that one can learn how to shift smoothly by releasing the pressure on the pedals before shifting.
Although I understand the physics of it, I've grown leery of getting into a situation where the motor power goes through a chain & cassette drivetrain.
So, I decided to look for an ebike with an internal hub.

There are several that I considered; many have unique and attractive features:

- Wattwagons
- Calamus
- Cheetah E-Bike City

The first two feature the powerful Bafang motor; however, the lack of synchronization between the motor and the shifting turned me off.
The Cheetah can be configured w/ a Pinion hub; although the Neodrive Z20 250W is clearly not as powerful as the ST5's 850W motor,
it is hard to make an evaluation without experiencing the bike firsthand.

The problem with these 3 bikes is that there is no LBS nearby. Given that I'm not signing up for servicing my bike, I looked for other options.

And last but not least, I looked at R&M. Since it is clear that Chris Nolte is a big fan of R&M, I visited him at his shop
and really like the advice that I received there regarding the different R&M models. For my needs, I chose the Supercharger2 GT Rohloff HS.
I've had the bike for a few days and tomorrow will be my 1st commute. Already, I'm really glad that I chose the combination of the Bosch motor
with the E-14 Rohloff -- it's really nice to know that the system will optimally shift the Rohloff and decrease motor power.
This is by far the most important feature from the ST5 that I wanted to have on my new bike.
Although the Bosch Performance Line Gen4 with E-14 Rohloff is clearly not as powerful as the ST5 w/ Shimano DI2 drivetrain,
I think that after a while, I'll master pedaling at a high cadence and shifting like a Rohloff ninja.

There is only one accessory missing on the R&M that I purchased separately: a loud horn.
The ST5 horn was nice in that it was integrated but it was not very loud.
I haven't received the Loud Mini horn yet but I like the fact that it was designed with a theft-proof option.
Theft-proofing the bike is another factor that I really like about Chris.

So far, I'm happy to have switched from ST5 to the Supercharger 2 GT Rohloff HS.
The air suspension fork is really nice too! I look forward to riding this bike safely without maintenance worries.

- Nicolas.


Hope you are enjoying your bike.

I think you have had the bike for around a couple of weeks now. Do you mind sharing your experience a bit?


How is the acceleration and average speed of bosch gen 4 compared to stromer when you put the same effort? Which assist levels do you use and how is the battery consumption?


Once again enjoy your new bike.
 
Hope you are enjoying your bike.

I think you have had the bike for around a couple of weeks now. Do you mind sharing your experience a bit?


How is the acceleration and average speed of bosch gen 4 compared to stromer when you put the same effort? Which assist levels do you use and how is the battery consumption?


Once again enjoy your new bike.


Turns out that my bike had an odd problem, the belt had somehow shifted so that it was only tracking on half of the rear sprocket. 44250

Obviously, that was not good so I brought it back to Propel where they replaced the belt and aligned the wheel.
I picked up the bike today and rode it around town for some errands & fun.

The acceleration of the bosch gen 4 is definitely below that of a Stromer ST2 or ST5. The ST2 can accelerate pretty quickly because it has smaller wheels; the ST5 was a wee bit more sluggish but the ST5 had at least 2 miles per hour more of top speed than the ST2.

With the ST2, I could easily accelerate to 25 mph and reach 28 mph with a bit of effort.
Although the ST2's top speed is at least 2mph below that of the ST5,
the acceleration was a wee bit better because of the smaller wheels.

With the ST5, I could easily reach 28 mph without breaking a sweat and hardly a change in breathing.
The cold-start acceleration was a bit more sluggish than the ST2;
however, the DI2 shifting made the whole affair very pleasant.

With the R&M and the E-14, cold-start acceleration is definitely much slower than the Stromers.
Chris suggested starting in a lower gear -- sure but one has to upshift very quickly to reach higher speeds.
Clearly, there's more skill required to accelerate fast w/ an R&M and the E-14 but I doubt that one could
match the raw acceleration power of the Stromer's rear hub motor with the bosch gen4 mid-drive.

With an ST2/ST5 & stopped at a red light, I could easily reach the other side of the intersection before most gas-powered cars on other lanes would catch up to me (hybrids and electrics have much higher torque/acceleration). With the R&M, I've yet to reach that level of acceleration: I start ahead of everyone else but by the middle of the intersection, other cars have caught up with me. That's a wee bit too slow because I feel that cars behind me get impatient. That's not a good thing.

On the other hand, it's hard to imagine how much of an impact the E-14's linear gear range has compared
to the uneven gear range in a conventional cassette. The chain & cassette of my Stromer ST2 were very worn off
(the chain used to get stuck between gears) and Propel replaced those as well. Now, my ST2 shifts very smooth
again, like new. Yet, despite that, I hadn't noticed the uneven ratio between the top gears -- 8/9; 9/10; 10/11.
I had to ride my ST2 for a week while my R&M was fixed and that I uneven ratio frankly bothered me.
I don't recall whether there was a similar uneven ratio in my ST5.

For me, the main advantage of the R&M and E-14 is improved cardio-vascular exercise as David Berry commented before. To get the most of the Bosch gen 4 motor, one has to maintain a high cadence and to do that, one has to upshift & downshift frequently according to current speed, grade & wind resistance.

Regarding power consumption: Interestingly, ST2, ST5 and Supercharger 2 have really large batteries: 814, 983, 1000 respectively but they use power very differently. The ST2 is perhaps closest to the Supercharger 2 in that most of the power goes to the motor. The ST5's Supernova M99 Pro drains the battery a lot. The M99 Mini on the Supercharger 2 is considerably brighter than the ST2 but doesn't drain the battery as much as the M99 Pro did on the ST5. With the ST2/ST5, leaving the bike in lock mode was a big drain on the battery. A few times I had the unpleasant surprise that Omni had drained my battery completely.

Even though my daily commute is short (~ 2 miles one way), there are a lot of stop & go with bursts of intense acceleration in between. Although the Stromer's rear-hub motors are regenerative, that feature doesn't do much in urban commuting in my area because the "hills" are too short and regen before stopping at a light or traffic sign amounts to noise compared to the drain that the next cold-start will do. To avoid draining the battery below 50 %, I had to recharge about every 3 days with the ST2 & a bit more often with ST5. I haven't had a full week's worth of commute yet with my R&M.

Regarding power levels: When I ride w/ my wife for leisure, Eco or Tour is enough. When I commute, I ride always on Turbo. Although I haven't had much experience with the R&M yet, it seems to me that the level of assistance between Eco, Tour, Sport & Turbo is more even than w/ the ST2/ST5 where the difference between level 1 & 2 feels much greater than between 2 and 3. With the ST5, the "S" level after 3 quicked the bike into a whole new level of assistance where it felt like riding a racing horse.

- Nicolas.
 
Super happy to have picked my tricked-out Supercharger 2 today from Propel after they replaced the belt that had been misaligned somehow. Since Chris is a fan of Hexlox, I had all the critical bolts on my bike secured: front/rear axles, seatpost, handlebar, headlight. Now, I don't need to worry about locking the rear wheel!

This belt alignment problem confirmed that it's important to consider the local availability of an experienced LBS even for a bike that should last a year before regular maintenance (brake pads, Rohloff oil change).

Although there is already a horn on the Supercharger2, they managed to install a Loud Horn just underneath the headlight.
However, it is a bit crouded on the handlebar. Chris said he'll look at an accessory bar to improve the ergonomics.

- Nicolas.
 

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Johnny

Well-Known Member
...
To avoid draining the battery below 50 %, I had to recharge about every 3 days with the ST2 & a bit more often with ST5...


Thank you for the detailed response Nicholas, your experience was a good read.

One thing though why do you want to avoid draining below %50? If it is for increasing the battery life then the established opinion is not letting the battery get below %20-25 in use, and not charging above %85.
 
Thank you for the detailed response Nicholas, your experience was a good read.

One thing though why do you want to avoid draining below %50? If it is for increasing the battery life then the established opinion is not letting the battery get below %20-25 in use, and not charging above %85.


I understand the %20-%25 threshold; %50 is just my personal level below which I get range anxiety.

Today, my wife and I went through several errands around town at a leisure pace -- about 5 miles. The R&M charge was 98% before we left, 91% when we got back. I was riding on Tour except a stretch of busy streets in Turbo. We've done similar errands before with our ST2s; the charge would be much lower than that. Her ST2 started at 75% and ended at 60%.
 

Johnny

Well-Known Member
I understand the %20-%25 threshold; %50 is just my personal level below which I get range anxiety.

Today, my wife and I went through several errands around town at a leisure pace -- about 5 miles. The R&M charge was 98% before we left, 91% when we got back. I was riding on Tour except a stretch of busy streets in Turbo. We've done similar errands before with our ST2s; the charge would be much lower than that. Her ST2 started at 75% and ended at 60%.
I see.

I think for very short trips the percentage reading may not be very accurate and interpolating that data may be a little misleading. In my case my Bosch battery drains "slower" when the battery is close to full until around 80 then it drains somewhat faster (while pushing at a similar pace, support level).

Does your ST2 have the 814wh battery ? If it is also used for a couple of years that capacity may have also been degraded a little.

I think both of your bikes are great bikes and with 1000wh you will hopefully never have the range anxiety.