Gears

[tomato paste]

I'm looking to buy my first mtb, which will also be electric. I don't have any mtb experience, but have some city and road bike experience, and have ventured off into the local trails enough to recognize the necessity of a suspension system. I live in southern Germany near the black forest, and plan to ride on trails, fire roads, and take tours of the local area on gravel and pavement. Many of the surrounding villages here have trails with long gentle hills that are paved or well maintained gravel. But the connections between trails can be short, rocky, and undeveloped. Its easy to exceed 25km on these gentle slopes using a road bike, so I would like a high high gear... But there are often steep, short climbs, requiring a low low gear... I'm also trying to avoid two chain rings.

I see the Canyon Spectral: On and Commencal Meta Power with 12 speed SRAM Eagle NX, but, as a price sensitive consumer, is the reduced gear range of a less expensive 10-speed good enough for what I'd like to do, considering that we have a motor? My fear is topping out at 25km/h on a gentle 2km long slope and not having a gear high enough to continue accelerating after motor cutoff due to friction. And the same fear works on the opposite end, say I have that high high gear by selecting the appropriate chain ring, will the motor be able to compensate for the loss of a low low gear on very steep climbs? Does it matter at all?

 

[steve_sordy]

I have never owned a gravel bike, but I do know that one of those would be perfect for your needs, all you need then is to find one that is pedal assist.

 

[SquireRides]

Q. "My fear is topping out at 25km/h on a gentle 2km long slope and not having a gear high enough to continue accelerating after motor cutoff due to friction."

The smallest sprocket on NX is 11 teeth. This is also the case for all Shimano 10/11 speed systems, I believe. If you spend more on Shimano or SRAM the smallest you'll get is 10 teeth.

This means there's really very little difference between mid and high end systems, when it comes to cranking out the speed.

Q. "And the same fear works on the opposite end... will the motor be able to compensate for the loss of a low low gear on very steep climbs?"

There is more variation here. 10 speed Deore is common on entry level ebikes and tops off at 42 teeth. 11-speed NX is 42t. 11 speed SLX and XT, you'll usually see 46t, and 12-speed NX is 50t. This means spend a bit more and you will get better climbing ability.

In my experience of both 11-speed NX and XT, for all but the steepest climbs, 42t should be enough, but i personally love to have a 46t (or bigger) as a last resort gear, even on my eMTB.

If your ideal bike comes with 11 speed NX, get it. By all accounts, you could add a 11-46t cassette (Suntour do one) and it will work. But I do not think any of the 10 speed systems out there will shift on to such a large sprocket.

 

[tomato paste]

Q. "My fear is topping out at 25km/h on a gentle 2km long slope and not having a gear high enough to continue accelerating after motor cutoff due to friction."

The smallest sprocket on NX is 11 teeth. This is also the case for all Shimano 10/11 speed systems, I believe. If you spend more on Shimano or SRAM the smallest you'll get is 10 teeth.

This means there's really very little difference between mid and high end systems, when it comes to cranking out the speed.

Q. "And the same fear works on the opposite end... will the motor be able to compensate for the loss of a low low gear on very steep climbs?"

There is more variation here. 10 speed Deore is common on entry level ebikes and tops off at 42 teeth. 11-speed NX is 42t. 11 speed SLX and XT, you'll usually see 46t, and 12-speed NX is 50t. This means spend a bit more and you will get better climbing ability.

In my experience of both 11-speed NX and XT, for all but the steepest climbs, 42t should be enough, but i personally love to have a 46t (or bigger) as a last resort gear, even on my eMTB.

If your ideal bike comes with 11 speed NX, get it. By all accounts, you could add a 11-46t cassette (Suntour do one) and it will work. But I do not think any of the 10 speed systems out there will shift on to such a large sprocket.

Thanks, that answers it very clearly.

 

[stiv674]

My Focus has the Sram EX1 system, it only has 8 gears and it hasn't been an issue for me so far. It's 11-48 teeth.

 

[SquireRides]

My Focus has the Sram EX1 system, it only has 8 gears and it hasn't been an issue for me so far. It's 11-48 teeth.

Agreed. Being on an ebike, the number of gears is not so important because the motor does compensate for the effort you would otherwise feel when you're 'not quite in the right gear'. I shift way way less often on my ebike than my normal bike. Seriously, I almost feel like having 11 gears is an annoyance because I frequently shift between 2.

But the range is still relevant, and 11-48t is a good range.

 

[stiv674]

Agreed. Being on an ebike, the number of gears is not so important because the motor does compensate for the effort you would otherwise feel when you're 'not quite in the right gear'. I shift way way less often on my ebike than my normal bike. Seriously, I almost feel like having 11 gears is an annoyance because I frequently shift between 2.

But the range is still relevant, and 11-48t is a good range.

I was looking at a Haibike before which had the double front sprocket, far too much choice!

I mainly use the middle four cogs...