Just a thought that occurred to me – why do they have the same gearing as normal MTBs?
There’s eMTB specific saddles, tyres, forks, so why not gearing?
Spesh Levo has 32T chainring and 11-42(ish) – surely you could have a 44T chainring with all that uphill ability from the motor…
Anyone changed their chainring for bigger, or find they’re not using a whole lot of the lower gears?

Given the point that the power stops being applied there would be no advantage in a bigger chainring.

Apart from having higher gearing? So able to pedal faster? (eg. on the road, or downhill)
I guess this thought came to me due to the number of folk who use eMTBs on the road (2 commuters at my place of work do)

If you had a 44t chainring then once the battery had run out you’d struggle to get up even a slight hill in the lowest gear.

Low gears still help for very steep stuff, and as mentioned they cut out a 25kph/15mph, so no point in having too many gears above that.

1(36)x11(11-42 or 46) is probably the perfect gearing for an ebike tbh.

For road commuting, tbh, you’d probably want to delimit it, and the 25k/15mph limit on the road is a pain in arse. About 25mph is a better commuting limit, which will still work with the above gearing.

It’d be interesting to see a survey of the breakdown of how people ride ebikes (what sort of mode/assistance they set them up to give). Mine is a Levo with a 34T I think, I use bottom gear plenty but I have my assistance backed off a fair bit. You do also still have to be able to turn the crank to get the assistance so on the steep stuff where you’re grinding away the lower gear is necessary.

they cut out a 25kph/15mph, so no point in having too many gears above that.

hmm, makes more sense to me, that when you’re going faster you’d want bigger gears. But hey ho. 🙂

Mine is a Levo with a 34T I think, I use bottom gear plenty but I have my assistance backed off a fair bit
Yeah, I’m expecting funkmasterp to tell us about how he rides with the asssist turned off any minute. But I’m think more normal ebikers.. 😉

hmm, makes more sense to me, that when you’re going faster you’d want bigger gears. But hey ho. 🙂

It’s a question of off or on road, off road nah not so much. On road, and if you are riding road regularly, and don’t particularly care about breaking the law, then aye, more gears would be beneficial.

I use my bike for everything, road and offroad, with chunky tyres, which like to sit nicely in the 20-25mph range off road on the flat. (I’m in the unlimited don’t care camp. :lol:)

Downhill you obviously run out of gears at some point, but generally the gear I mention above is prefectly fine.

If i was to stick slicks on I’d want higher gearing for road.

tbh e-road bikes don’t really make all that much sense to me unless they are delimited. even a bifter like me and keep them above the limit.(obviously not in the hills.)

2020 Orbea Wild with the new Bosch motor and Shimano xt 12 speed 32 ring and 10-51 cassette. Not ridden it much due injury but the motor performs best when left in eMTB mode and the low gears, seated are great on steep hills 🙂

and don’t particularly care about breaking the law

aslong as everything is configured correctly you can have bigger gears and still be within the law. Pretty sure DezB is just talking about utilising assist on all hills and getting up to 15 then using higher gears to cruise/downhill at higher speeds under own power.

A legal e bike cuts motor assistance at 15 mph. Above 15mph you have a heavy unpowered bike so you do not need any higher gears than you would on any unpowered bike.

Yep, can’t see it as needed if the bike is being used legally and for it’s intended purpose.

32/11 on a 29er has you going 20mph at a cadence of 80rpm so you are never going to spin out the Emtb you gave as your example under legal powered assist.

If I was to do the same I think I might buy myself a second pair of wheels with road tyres and put a road cassette on it (I appreciate this is no longer as easy as it used to be with Shimano at least as I think they have now changed the spacing between road and mtb). So not higher gears as not needed but a tighter grouping of gears with a higher bottom end.

20-25mph range off road on the flat.

meant on road there btw.

32/11 on a 29er has you going 20mph at a cadence of 80rpm so you are never going to spin out the Emtb you gave as your example under legal powered assist.

I think Dez is talking about the bit where he’s powered up to the top of the hill at 15mph, then wants the full benefit of a 44t to mash on the downhill to get to the same speeds you would on any bike with that chainring size.

I

The way I see it, 32/34t chain ring and 10-50 cassette – the 50t on a normal bike is the bail out gear, it’s barely any faster than a quick walk and only needed for the steepest climbs.

On the same climb on an emtb you’d be doing 2 or 3x the speed, so wouldn’t be in the 50t (or you’d be doing 200 rpm cadence), so yeah, what’s the point in having the 50t?

However, with an emtb you can try climbing stuff that would never be possible on a non assisted bike. Which you need the 50t for… 😁

Ah, ta11pau1 makes the most sense I think – in my mind it was riding stuff you could normally ride (on a normal bike), so you just wouldn’t need those lower gears (like 40/32). But having them, just makes the ebike more capable. Inneresting.
😀

Surely for commuting a Bafang type setup would be better rather than a conventional e bike restricted to 15mph.

15mph is almost a bit slow on some sections of road with faster moving traffic.

Have thought about buying a Bullitt style cargo bike and adapting it to e-motor.

If you are spinning out on 32 – 10 then it would make sense as no way do you need a 32 – 50 when you have a motor to assist you.
However, actually fitting a larger ring on a bike designed for a 1x 32 chainring may not be possible.

Had a levo for 18 months. Mine is 36 up front, was spinning out on descents a lot, could go up to 38t. Now has 1×10 drivetrain with a Saint mech, 11-34 cassette. That’s enough for anything I’m climbing regularly, just TURBO up the climbs 😉

Exactly, Rich 😊

My Bosch Ebike has a 14t front ring, no idea about whats on the back but it seems to have the same cadence as the others in my group. I asumne its all about the internal gearing of the motor.

My Bosch Ebike has a 14t front ring, no idea about whats on the back but it seems to have the same cadence as the others in my group. I asumne its all about the internal gearing of the motor.

As I’ve recently found out, the old Bosch motors don’t drive the chainring directly, for each turn of the cranks the chainring turns 2.5 times. So you have a 35t chainring upfront.

Bosch chainring spins at 2.5 times the crank speed, so 14t is the equivalent of a 35 tooth ring.
I’m of the opinion that there’s not a lot of point in having gears that propel you to 25mph, anyone who could pedal one to that speed on the flat would be quicker on a normal bike.
Ideal gearing imo, would be a comfy spin that could be maintained, on the 25kph limiter,
And low enough gears to get up hills.
I guess it may not be a well known fact, but if you ask a motor to pull from lower revs it uses more current, they are more efficient when revved higher.
Edit: beaten by tallpaul 👍👍

I’m of the opinion that there’s not a lot of point in having gears that propel you to 25mph, anyone who could pedal one to that speed on the flat would be quicker on a normal bike.
Ideal gearing imo, would be a comfy spin that could be maintained, on the 25kph limiter,
And low enough gears to get up hills.

I think you have missed the point. It is about when you start going downhill, not using the motor. I used an MTB with a 32 / 10 earlier this year and could have done with a higher gear at times.
And if you are not riding uphill as 3 mph then you don’t need the 32 / 50 on the other end.

Basically a different range of gears biased towards a higher set of ratios may be what is need for some people.

I could do with a double chainset for how I use my Levo – a 30 or 32 for MTBing with lower or zero assistance and a 42 for full turbo commuting, to spread the wear on the cassette. But that isn’t possible so I’m hoping better lube increases drivetrain life…

Yep, am not using 36×11 on the flat, not with bloody DH tyres on! It’s all about intended use. Mine is 99% local and there aren’t any bits I’d need a granny gear for. Might regret the gearing on a Welsh trip, but I’ll be back home before my calves can say OW. Motivation is also related to durability. Having destroyed a couple of rear mechs, am hoping the shorter cage Saint on there might last a bit longer and that 10 speed is more durable.

In your situation Guru, definite case for N+1…

yeah, it does seem like I’ve missed the point tbh 😂😂

Nothing spreads wear on a drivetrain like another bike… 😉

I have been told by ebike riders and shop mechanics that the battery lasts a lot longer if you spin the gears more – crunching higher gears leads to quick battery usage and higher temps in the motor.

Yeah, I’m expecting funkmasterp to tell us about..

Oops, apologies funkmaster, obviously meant chiefgrooveguru

Are E Bikes more prone to chain snap ?

When I last rode one I was often really worried it might happen and I would have had no way to fix it if it did.

Also less wear on the motor if all the little gears/bearings are spinning at higher RPM and lower torque. I think my parents powerflys have something daft like 26 (29er) and 28t (650b) chainrings matched to 11-34 cassettes. It basically means top gear is a nice cadence at 15.5mph.

Surely for commuting a Bafang type setup would be better rather than a conventional e bike restricted to 15mph.

Within the law the e-bike would let you climb any hill at 15mph without sweating. Once on the flat the weight should make little/no difference to your speed once you’ve accelerated. A de-restricted bike could go faster, but then you’re talking about keeping up with mopeds not keeping up with cyclits. Obviously in parts of Europe you have other classifications for faster e-bikes which maybe we should bring over if only to mpp up those that insist their de-restricted e-bike is a grey area or legal (i.e. being prosecuted for riding a derestricted e-bike as if you’d been riding a track motorbike on the road without a licence would arguably be draconian and probably wouldn’t happen, being prosecuted for the wrong class of e-bike on a shared path might stand a chance).

I suspect that the chainstay is what restricts the size of the chainring.

It amazes me the gearing on modern bikes. The geometry and suspension kinetics are such that bikes climb extremely well but there is a drive towards ever increasing cassette range matched to ever decreasing chainring sizes.

grannyjone

Member
Are E Bikes more prone to chain snap ?

NO

Its no more stress than a tandem and we don’t snap chains on that

Remember that post i put up about the 50mph e-bike vid?

Plod went around to see him.

I’ve snapped 3 chains on a couple of ebikes. Two on my own Powerfly with the chain being under 250 miles old both times and once on a Whyte e150 demo bike with under 400 miles on it.

why do they have the same gearing as normal MTBs

My mates 7 Grand ebike has 1×8 gearing, Not many ‘normal’ bikes have that.

Having demoed a few, the ones I tried worked best when at a certain cadence, never measured it but mibbe 90rpm?. So correct gearing seems needed.