Spin or use higher power setting

[LesTocknell]

I have a Scott E-sub Evo with Bosch Performance Line and 8 speed Alfine hub gear. I tend to ride on Eco setting but I find the gear ratios a bit high to maintain a high cadence on steep hills. Am I right in thinking that a larger rear cog by enabling me to maintain a higher cadence would give more mileage than just upping the power setting to tour or higher? I know I would lose top end ratio but to be honest the top gear is very high and I'm still able to pedal down quite fast hills so wouldn't really miss this. I live in Herefordshire, my regular riding is the Wye Valley and I also tour with and without camping gear.

 

[kangooroo]

I can't comment on your technical query but it's good to see another Ross-on-Wye-based e-biker who cycles around the hills of rural Herefordshire and the Wye Valley.

I have possibly the least technical bike here but it's still carried me up Yat Rock which must be one of the greatest local challenges, and one which one of my earlier cars failed on!

 

[tommie]

<-- i have the Alfine 8 with an 18T cog on this one,

possibly you could go to a 20T or 22T

you`ll probably be slower and spin faster but it shouldn`t be as hard on the motor and battery.

 

[LesTocknell]

Yes. Hello Kangooroo. I haven't tried that yet but it should be possible. I ride up the shorter pitch between Hole-in-the-Wall and Brampton Abbotts regularly and in Eco I am breathing hard at the top but not gasping as on the unpowered bike! Keep in touch.

 

[LesTocknell]

Yes, tommie. My dealer suggested going up a tooth at a time.

 

[anotherkiwi]

https://www.sheldonbrown.com/nexus-mech.html#sprockets

They aren't very expensive so maybe you could buy a couple of different sizes to see which one you like the most.

 

[kangooroo]

Yes. Hello Kangooroo. I haven't tried that yet but it should be possible. I ride up the shorter pitch between Hole-in-the-Wall and Brampton Abbotts regularly and in Eco I am breathing hard at the top but not gasping as on the unpowered bike! Keep in touch.

This is one of my regular runs extended to include Hoarwithy and Llanwarne. It's my next route I plan to write up. Also recommend Goodrich-Skenfrith-Grosmont-Raglan Castles - potentially all of them on a circular route if your battery has the capacity. (As for unpowered bikes - I wouldn't stand a chance and am limited to an easy ride along the Mon-Brec canal.) I'll keep a lookout for you on rides - we should each be easy to spot because there seem to be so few e-bikes around here.

 

[LesTocknell]

Related to this, does anyone know if the bars that indicate power usage alongside the power settings on the Bosch Intuvia screen are equivalent in each setting ie is the power being used in eco the same as the power being used in tour if the bar display is the same height? (Difficult to explain - I'm trying to work out if it really matters in terms of power usage if I use a higher power setting going up a steep hill)

 

[LesTocknell]

I suppose that what I'm trying to find out is: is it better to lower the gearing on my bike or just use higher power for short bursts on steep sections to minimise battery use?

 

[anotherkiwi]

Lower gearing wins every time.

 

[EddiePJ]

What size front sprocket are you using on the bike?

 

[LesTocknell]

I believe it is 18 tooth which was fitted as standard.

 

[georgehenry]

With hub gears at the back the only and easiest solution is to reduce your gearing by changing the front drive cog.

In relation to Tommie's comment above I thought reducing the number of teeth on the front cog/ chain ring would normally reduce your overall gearing and increasing the size of the front cog ie more teeth would increase the overall gearing, unless I am mistaken or Bosch drives are different.

Your dealer is right. One cog at a time, ride a route you know to see if that reduction is enough and continue until you are happy.

I did the same with my sDuro hard seven Yamaha, but in my case I wanted to increase the speed I could travel at on the road in my highest gear and still have a low enough gear to be able to climb the steepest single track hills on my off road route to work.

Having a derailleur set up I could change both my cassette and front chain ring. I ended up with a 42 tooth chain ring, 4 teeth bigger than standard (38) and a 12/36 rear cassette.

The 12 tooth top gear is a bit more resistant to wear than an 11 tooth top gear and the larger front chain ring allows me to maintain 20 mph to 25 mph on the road in eco dependent on gradient in the 12 tooth top gear, and the 36 bottom bottom gear still allows me a low enough gear to climb in eco the steepest off road tracks I use going to work.

I think e mountain bikes can be fantastic all rounder work horses. I use mine to enjoy a proper mountain bike nearly all off road route to work of up to 18 miles carrying panniers on a rack at the back and then a 10 mile road trip home. So a wide spread of gears is what works for me.

I think that ebikes lend themselves to overall wider gearing than a non assisted bike and slightly bigger gaps between gears.

If you are feeling flush you could change to a rohloff 14 speed hub that achieves what I am struggling to explain above.

 

[anotherkiwi]

With hub gears at the back the only and easiest solution is to reduce your gearing by changing the front drive cog.

Nope. You can buy sprockets for nexus and alfine hubs from 13 to 24. Shimano recommends a minimum ratio of 1.6:1 so you have to think about that in choosing your front cog.

 

[Danidl]

Related to this, does anyone know if the bars that indicate power usage alongside the power settings on the Bosch Intuvia screen are equivalent in each setting ie is the power being used in eco the same as the power being used in tour if the bar display is the same height? (Difficult to explain - I'm trying to work out if it really matters in terms of power usage if I use a higher power setting going up a steep hill)

I believe that the height of the bar column is measuring the instantaneous power from the battery. If one is in eco or touring the movement of the bars is sluggish, while in turbo it's pretty skittish. I would read that as the controller giving a higher gain to the torque measurement got from the pedals.

 

[georgehenry]

Nope. You can buy sprockets for nexus and alfine hubs from 13 to 24. Shimano recommends a minimum ratio of 1.6:1 so you have to think about that in choosing your front cog.

Ah, I stand corrected.Thank for putting me right. Is it easier to change the front or the rear or not much in it.

 

[tommie]

Is it easier to change the front or the rear or not much in it.

I know it can be a fight to change that cog on the Alfine 8, it`s a steel snapring that you have to get out and in again, there`s a youtube video on it somewhere

 

[EddiePJ]

I believe it is 18 tooth which was fitted as standard.

Perhaps try changing the front sprocket before doing anything else.

The current 18t front sprocket is the equivalent of a 45t conventional size chainring.

A 16t would give you an equivalent of 40t and a 15t would be an equivalent to 37t

I also prefer to spin than to grind my way up hills, and switch between 15t and 16t. In truth, I can't really say that for my UK off road riding use, that I have ever really noticed any significant gain or loss between the two. An 18t front sprocket would definitely be a no go for me though.

 

[LesTocknell]

Thanks Eddie. That's really useful. I was able to put the equivalent conventional chainring size in Sheldon Brown's calculator and it gives a low of 32.4 inches and a high of 99.3 which seems about right for the effort needed to climb in Eco and the amount I can still pedal when going downhill.

 

[Trevormonty]

Based on some rough tests on my hilly commute, using lower gear and climbing in eco will half power used compared to turbo.