I was in accident on my St1 so ended up buying the ST1-x as a replacement out of the insurance money. I must say, I was a little underwhelmed by everyone always comparing the ST1-x with the ST2... I realise those 2 bikes are "similar", but price points, they are world's apart, and I would imagine a lot of people entertaining purchasing an ST1x are coming from an ST1 not an ST2! I personally find it very hard to justify buying a bike like the ST2 that costs $3,000 more and the ST1-x is already twice as expensive as the first e-bike I bought 5 years ago.... So, I'd prefer more reviews comparing the St1 to the ST1-x!
On that front, I use my bike for commuting and I was probably most concerned about the ST1x having Aluminum forks - particularly as they ST1 had originally been sold to me as a bike that absorbs the road bumps more because of the carbon-fiber forks! So, I personally do not understand why Stromer regressed on the forks for the ST1-x. My commute is typically urban and feels half way to off road owing to the utilities workers utter inability to rip up a road to check the gas/water/sewer/cable etc and then reseal it perfectly flat and inline with the original road. Add in a few winters and freezing temps and you've got one pot-holed bumpy ride on bitumen!That said, at the end of the day, I didn't notice much difference. I guess on either bike, the bumps are absorbed for the most part with the Big Ben tires, and the harder those are pumped up, the more bumpy the front end ride is.
With respect to the back wheel and bounce... I originally had a fully sprung Brooks saddle which absorbed most of the road shock. My Stromer dealer talked me into getting a thudbuster seatpost and all I can say is... no difference. Unless you are heavily invested in racing cycle seats, I'd recommend getting a decent seat with springs as its cheaper than the seatposts, and much more portable across different bikes! But, no doubt as everyone with Stomer notes, something is needed on the back end because that is one harsh ride without springs there somehow. Seatposts do transport across from ST1 to ST1-x.
As to the ride of the ST1-x vs the ST1 - now in that regard, they are UTTERLY different beasts! The ST1 rides like the older models... Its slow to start, picks up speed like crazy by the third crank of the peddles and just zips along! I had no problems going up hills, adding more power to never break speed on the uphills bits of my ride (unless it started to get steep...). The St1-x... Seems to be MUCH more dependent on your cadence (which I suck at). If you are peddling strongly, the ST1-x is punchy! No other word for it - you feel that power helping you along! But woe betide you if you slow down your cadence - then it suddenly seems to lurch and slows down (particularly when going up hills). I am gathering from the forums (mainly having to read the ST2 forums as the ST1 forums are useless for understanding the mechanics of this bike), it is to do with the torque sensor and settings. I have just noticed on the app I can adjust the torque/speed/agility of the bike to a variety of setting (e.g. urban, snow, tour) and am hoping that by tinkering with these, I can stop the bike lurching on the hills as my cadence wanes. I just haven't done a ride yet with the my phone with me... You can adjust on the screen in the cross bar as well, but the fine tuning is easier from the app.
[Update - I have added comments later in this thread revising the ride - once customised it is better!]
The ST1-x also only has 3 levels of power. I am finding in Level 1, it is actually much more like riding an ordinary bike. Whereas in the ST1, the eco mode felt like you were getting a decent workout with a bit of boost, Level 1 on the ST1-x seems to literally just cancel out the weight of the bike so you feel like you are on an ordinary cycle ride. You are still going faster... but it takes more effort to sustain speed (yes, you actually use more than the 3 smallest rear cogs!). Level 2 (which seems to be where most people end up) feels more like half way between eco and city mode on the ST1. Level 3 is like a turbo boost - ZOOM! But, I have got to get the torque thing sorted out because at the moment, I am lurching up hills when in Level 3... It might be a miscalibrated torque sensor or it might be I just haven't got the torque in the right mode for my type of erratic cadence - but I look forward to getting that sorted out because Level 2 and 3 are very nice when its not lurching! Overall, I suspect I might end up getting a bit more of a workout on the ST1-x, but its nice to know that I have the power when I need it!
The St1-x does have some nice additional features - the regen is MUCH better when going downhill! I go down a couple of steep hills and on the ST1, the regen would cut out once I got past 40km/hr which led to me riding the brakes hard. In addition, you had to keep tapping it into regen, and then when at the bottom of the hill, tap it back to a boost mode. On the ST1-x, when you apply the brakes, the regen automatically cuts out and goes back to whatever level you were in - nice!!! And the highest level of regen is slowing me down a lot on even very steep hills. The ST1-x also has a boost mode. I haven't got that sorted out yet - its lurching like when I am in Level 3... when it works, its fine, but its erratic application right now is not impressing me. Again, I am hoping this just a torque sensor issue. However, I wouldn't say the boost was a lot... Maybe half way betweeen whatever modes you are in. Maybe its the cadence/torque thing again...
The light is good - I was told the front light made me look like a motor bike coming head on in the day, but wasn't quite so visible from the side. The panier rack is as pathetic as it was on the ST1. Anti-theft all looks interesting... I do know the bike rolls when you have it lock mode... I read somewhere that it rolls for about 60ft before the back wheel seizes up. Would be nice if it seized up earlier - 60ft is enough to get my bike from a bike rack to a car... That said, as long as there is a GSM signal, it is nice to know I can lock and arm the anti-theft from my phone - and see where the bike is! Nice add-ons...
Those are my first impressions!