First impressions: BMC Alpenchallenge AMP Cross LTD

ephemere

Member
Region
USA
City
Bay Area, CA
Two days ago I received my first e-bike, the BMC Alpenchallenge AMP Cross LTD. This is a lightweight carbon-frame mid-drive fitness hybrid, I believe similar in concept to the Specialized Turbo Vado SL (mid-drive) and the Cannondale Quick Neo SL (hub-drive).

I am not a bike mechanic, but I hope to service this bike myself. It arrived with the front hydraulic disc brake way out of adjustment (not rideable). After some time on YouTube, I used the folded business card trick, but I still had to eyeball it for fine-tuning. I ordered this tool which seems to be a pro version of the folded business card. I need a torque wrench and a work stand. Due to the D-shaped seat post, I'm getting a dropout-style stand rather than a clamp stand.

I was hoping this bike would seem like a "normal" bike when the motor is off, and it does. Overall I prefer my Salsa for an acoustic ride, but the BMC is in the same ballpark and is a different experience with the flat bar. I've done two 30 km test rides. The first had 700m of incline, and I used the motor intermittently. The second had 250m of mild inclines, and I did not use the motor at all. I am not an avid cyclist by any means. I thought I would use the motor to flatten hills, but now I think I will use the motor whenever I want a break regardless of grade, and I will allow myself to attack grades unassisted. The motor is an insurance policy protecting me from digging myself into a hole far from home. For this reason, I think the restriction to USA Level 1 (32 kph) will be more than adequate for me, and I don't expect to pursue derestriction.

Somehow, pedaling out of the saddle doesn't feel nearly as good on this bike as on my Salsa, which is a bummer on climbs. I'm pretty sure this is because of the flat bar, and maybe something like a Jones Loop (see below) would help. Or maybe I just need to get used to it.

One advantage of the BMC's light weight (15 kg) is that I've already had to dismount and ease the bike through a rocky passage on a trail. Also, stopped at city intersections, rotating the bike while straddling.

The Shimano E8000 motor seems powerful, although I have nothing to compare it to. I have not even engaged level 3 ("boost"). I do like how the motor power is proportional to pedal torque up to the mode's max-torque parameter. It feels responsive and natural. Maybe all mid-drive systems do this.

Mid-motor bikes put stress on the drivetrain, so I should keep an eye on the chain wear. I already have a digital caliper I can use for that. I don't know how much of this wear is from harsh gear changes and how much is from high torque on the chain while in gear. For the former, wouldn't the right approach be to ease off the pedal torque (and hence the motor) during a gear shift? I can see where this might trip people up because if the motor is (say) doubling your torque, you need to ease your legs to half the force that you're used to. Given the otherwise excellent integration between the motor and the Di2 shifting, I am surprised that there is no logic to cut the motor during a shift.

I expected the motor to be loud, but it is louder than I expected. On the plus side, it provides audible feedback about how much pedal torque I'm applying at any instant, which helps implement the strategy of easing off the torque to shift gears.

The Shimano UI overall is great, with good integration between the motor control and the Di2 shifting. The little display is unobtrusive but very clear and informative. But I don't care for the shift buttons. Di2 is excellent, but on my Salsa the gear shifters are literally at my fingertips. Here, I have to largely release my right-hand grip to make a shift. Repeated incidental contact with the side of the shifter has rubbed the base of my thumb raw. So far I have not figured out how to optimize this. Maybe just get better at it.

The flat bar is a bit aggressively positioned as I anticipated when I studied the bike's geometry before purchase. Overall, ergonomics are okay for me, not great. But I'm not an avid cyclist and I'm not sure how or even if it could be better. I do miss the multiple hand positions of a drop bar. I am considering experimenting with different grips and/or putting a Jones Loop bar on this bike.

The proprietary seat post and stem are cool and functional designs, but they preclude third-party replacements such as shock posts or stems with different geometry. Although the battery is not hidden inside the frame, the overall design of this bike is super-clean and appealing. BMC apparently put the battery on the seat tube for better weight distribution, which makes sense to me now that I've ridden it. I'm surprised this isn't more common.

The saddle is nice and served me well on two 30 km rides in street clothes.

I don't know what are the best tires for the kind of riding I'll be doing. I'll figure that out over time and stick with the stock 700x40c tires for now.

After two days of riding, I think this bike will meet my needs very well.
 

Deacon Blues

Well-Known Member
Congratulations on your purchase. 🥳
When I purchased my Cannondale Topstone Neo Lefty 3 in September I usually rode up to 40% of my rides with the power off. Now, I keep the power on 'Eco' for almost all of the ride and ride faster to get the same workout (my other bike is a light, carbon road bike).

Why would you want to pedal out of the saddle while climbing hills on an ebike? I often pedal out of the saddle on my road bike, but never with my ebike. Instead, I go up one or two power levels and blast up the hill. That's the best part about owning an ebike.

I plan on converting my drop bar to a flat bar. There's something about my Cannondale that causes my thumb and next two fingers to go numb on both hands during long ride. This also occurs on the road bike, but not nearly as much. I like the look of the Jones Loop bar, but I've read that some riders find the angle of the bar to be hard on their wrists. After more research I ended up ordering a Denham handlebar from the UK.
Here's a link: https://www.cyclesense.co.uk/m61b0s745p26689/KOGA-Satori-Denham-Handlebar-31-8mm

Here's a link to an article about how the bar was designed: https://www.cyclingabout.com/koga-denham-bars/
 

ephemere

Member
Region
USA
City
Bay Area, CA
That Cannondale looks like a beautiful bike.

Many thanks for the reference to the Denham handlebar. I like that the video shows it being used with Ergon grips, while the Jones is designed for their own longer grips. One possible advantage of Jones is that it is available in a 2" rise version, which might be a better match for BMC's stem design that can't take more spacers. I look forward to hearing how you like the Denham handlebar on your Cannondale.

As for pedaling out of the saddle without assistance, my theory in getting this bike was to use the motor deliberately and sparingly to build conditioning and eventually use my Salsa more. I live in a pretty hilly location, and although I'm in good shape I think that's one reason I never got into cycling. Maybe I could accomplish the same goal leaving it in Eco mode and just pushing harder, as you suggest. However, this Shimano motor is loud. I'm both noise-sensitive and self-conscious about calling attention to myself. Frankly, it's a relief to turn the motor off. It's pretty funny how the torque-sensing provides audible feedback about my irregular power delivery throughout a pedal cycle as the motor instantaneously matches my own torque. I suppose that will encourage me to develop a smooth power delivery (although I'm not using clips). I would suggest to anyone considering a Shimano motor to try it first and make sure you're okay with the sound.

EDIT:

I just tried a short loop with climb, with the bike set to Eco for the duration. I think you are right that I can achieve the same conditioning results by leaving the assist on and going faster. I'll try that on my next significant ride. Also, I probably exaggerated about the motor noise. It really isn't that bad.
 
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Deacon Blues

Well-Known Member
I have mountain bike knobby tires on my Cannondale and they're as noisy as motor (which is quiet in eco mode). When I arrived home the other day my neighour commented that she could hear my motor as I came down the road (she rides a Specialized Vado). I thought that was strange, since the road was a slight downhill and I had turned the motor was turned off. What she was hearing was my noisy tires (which I'm replacing with tires with a less aggressive, and hopefully quieter, tread).
 

bob armani

Well-Known Member
Congrats on your new bike purchase. Your in depth review is very informative. I like the design of the Jones Bars. They look like they will serve the purpose you are looking for. Good luck with all of your other mods. I can relate to going faster on a hill in Eco, but at the same time getting a great workout. I also pondered that issue and found my comfort zone. Ride safe!
 

McCorby

Well-Known Member
However, this Shimano motor is loud. I'm both noise-sensitive and self-conscious about calling attention to myself. Frankly, it's a relief to turn the motor off. It's pretty funny how the torque-sensing provides audible feedback about my irregular power delivery throughout a pedal cycle as the motor instantaneously matches my own torque. I suppose that will encourage me to develop a smooth power delivery (although I'm not using clips). I would suggest to anyone considering a Shimano motor to try it first and make sure you're okay with the sound.
Interesting. My Felt Sport-E 50 has the E8000. While it’s louder than my girlfriend’s Trek Verve+ with the Bosch Active Line, it’s in no way obtrusive. The increased noise is a small price to pay for the significant more power that it delivers IMHO. Also, some frame designs can transmit more noise than others, so maybe that could be your issue.

Why are you worried about drawing attention to yourself btw? Are you riding where ebikes aren’t allowed?
 

ephemere

Member
Region
USA
City
Bay Area, CA
Interesting. My Felt Sport-E 50 has the E8000. While it’s louder than my girlfriend’s Trek Verve+ with the Bosch Active Line, it’s in no way obtrusive. The increased noise is a small price to pay for the significant more power that it delivers IMHO. Also, some frame designs can transmit more noise than others, so maybe that could be your issue.
Today for the first time I left the motor on for an entire ride, and to be honest I now think it's not as loud as I originally perceived.

Why are you worried about drawing attention to yourself btw? Are you riding where ebikes aren’t allowed?
Fair question. It's just my personality; I prefer to be stealthier. I would not ride where e-bikes are not allowed, at least if I knew they were not allowed. Are there places where bikes are allowed but class-1 e-bikes are disallowed?