Hi another Kiwi, I started with the standard 38 tooth chain ring. I found that on cassettes with an 11 tooth top gear they could quickly start to slip/jump or play up. I went to a 40 tooth chain ring with a 12-14-16-18-21-24-28-32-36 cassette and found this gearing was very good for my particular commute that combines some slow off road climbing sections with a blast home on the road.

 

However although the 12 tooth top gear lasted longer than the 11 tooth one it still started playing up sooner than I would like. I also noticed that both the steepest hills that I climb off road were possible to climb in the 32 tooth bottom gear.

 

So I then put on the current 42 tooth chain ring with the 12-14-16-18-21-24-28-32-36 cassette. The aim here was to do the hardest work on the road in the 14 tooth gear 8, and hope that this would last a lot longer than either the previous 11 tooth or 12 tooth top gears, but still allow me to maintain a speed in the 18 to 22 mph range in eco. The speed I can maintain in this gear is just what I wanted ie 18 to 22 mph in eco. I only put this chain ring and cassette together on the 28th of June and have so far traveled 234 miles and will have to find out as the miles increase how much longer it will last than the 11/12 tooth top gears.

 

I was not sure if the 12 tooth top gear combined with the 42 tooth chain ring would be a usable gear but have been pleasantly surprised that it allows me to pedal at up to 25 mph in eco where the gradient is ever so slightly down hill or there is a tail wind. I am reluctant to push too hard in the 12 tooth top gear as from previous experience I know it can start to jump/play up. As soon as I start to need to put more effort in I change down to the 14 tooth gear 8 at the lower 18 to 22 mph speed range in eco.

 

That 36 mph top speed that I see is on steep downhill sections of the road with the assist switched off. I have not noticed what my cadence is but will check next time and let you know.

Edited July 16, 20169 yr by georgehenry

Hi anotherkiwi, I set the display to rpm, and found that around 85 rpm in my 14 tooth gear 8 with the 42 tooth chain ring equates to just over 20 mph. My comfortable cruising pedal range seems to be from 80 to 90 rpm and if the rpm start to fall much below 80rpm I want to change down a gear. The exception to this is when climbing hills where I seem to dig in at just below 80 rpm.

 

This 80 to 90 range in my top 12 tooth top gear with the 42 tooth chain ring is in the range from 22mpg to 26mph and the 30 mph figure that I get on steeper down hills basically free wheeling with the motor off is around 106/107 rpm.

 

You should probably allow a good 10% + or - for error. I hope this is useful. It reconfirms that my gear 8 is just where I want to be cruising in eco trying to maintain or slightly exceed 20 mph at around 85 rpm.

Edited July 20, 20169 yr by georgehenry

I re-set my display before heading home and although very tired as it was the last of four early starts on the trot I tried to keep a good pace and at the end of the journey noted that my average speed was just over 21 mph for the 10 mile journey completed entirely in eco and using 28% of the battery giving a theoretical range of just over 35miles.

 

At one point I overtook a guy on a racing bike without really thinking much about it but he must have taken um bridge at being overtaken by a large guy on a mountain bike with panniers and worked his socks off to catch me up.

 

It coincided with a very slight downhill where I have previously found light racing bikes to have an advantage but with my new gearing I got in to top gear and pushed my speed up to 24 ish mph completely unaware of the drama behind me.

 

I really was not aware of him chasing me at all but credit where credit is due he caught me up after about half a mile and just got past before immediately turning left to get away from me (and probably throw up!) as I started to re overtake.

 

If we had carried on the same way it would have been a good dual as the road was mostly level with some slight up and down hill bits although I might have been tempted to up the assist level to be cruel!

its funny as hell teasing them road bike lot i get past then knacker em out then when they think can get past me i up it to turbo and fly away at 28mph.

New rack pictures for Fuzzy.

 

Miles now 4556

 

Miles on the Shimano Alivio HG400 MTB12-36t:12-14-16-18-21-24-28-32-36 cassette/42 tooth chain ring now 580 with no slipping problems. With this new gearing I may have cracked the premature cassette replacement I had been suffering but I would like it to last around 1500 miles ideally.

 

I had the throttle on my 2011 Oxygen Emate city replaced by Richard at The Electric Bike shop in York Way London who in conversation said that they had found the Yamaha motor was hard on cassettes and this might be a detrimental difference between the Bosch and Yamaha drive systems.

 

On my unassisted mountain bike used exclusively off road in my sandy Surrey area I would expect to have to replace the chain/cassette and chain ring after about a year/year and a half of hard leisure use.

 

The battery is still holding up well and on my ride to work yesterday I used 25% on a mostly cross country route of about 11/12 miles and 29% on my road ride home of 10 miles, all in eco or off dependent on gradient. The top assisted speed on the road was 24mph and on the steepest hills I dropped down to 10mph and 12/13mph on other longer but less steep ones. With the motor off on a sharp steep downhill I hit around 35mph. I cover the 10 mile road trip in under half an hour.

 

I broke my rear rack with the punishment I put it through off road and have had fitted a stronger one. Once again although the fitting bolts looked OK they started to work loose after only a couple of trips and I have replaced them with better ones. Unfortunately when the rack broke it also took out a spoke in the rear wheel that I had replaced and re trued by the e-bike shop in Farnham. They also fitted the new rack. This is the shop I bought my bike from and the backup and mechanical assistance I receive from them has been excellent and very reassuring for someone who is not interested in mending the bike themselves.

I'm not surprised the rack broke.

 

I have the same one on my pushbike.

 

It was cheap enough, and is fine for occasional light leisure use.

 

But the difference between that rack and the Tubus on my Rose is night day,

 

The Tubus is steel, and the joint where the legs converge is properly filleted and welded.

 

It will probably outlast me - hopefully you now have something similar.

 

There might be something in the shop mechanic's remark about the Yamaha motor being harder on cassettes.

 

Power delivery on the Yamaha is less smooth than on the Bosch motor, although transmission wear aside, I could live with it.

When I was looking to buy a purpose built bike for my home to work commute that could cope with the cross country stuff I wanted to do the sDuro seemed the best value (£1750) quality hard tail bike I could find at the time and so far so good.

 

I actually preferred the torque and instant power delivery of the Yamaha in comparison with the Bosch when I test rode them against each other in 2015 but was unaware of the tendency for destruction of the highest gear 11 tooth cog that my regular 10 mile hilly road trip would inflict.

 

However my crude solution of just upping the gearing so that you are in a gear with more teeth more of the time when travelling at higher speeds does seem to be working and my bottom 36 tooth cog still allows me to climb everything I need to off road. With the Yamaha I also could convert it to a dual chain ring at the front for an even wider spread of gears if I wanted to.

I would be worried by the rate of transmission wear that you are experiencing.

I am up to 812 miles on this cassette now with no problems and over half the miles are off road with 100kg+ of me on board and two fully loaded panniers so I do give my transmission a fair bit of punishment.

Transmission wear looks high to me, and I could say, truthfully, that I'm still on the original transmission of my derailleur Bosch bike after several thousand miles.

 

But rather like the dreaded battery range question, there are so many variables it's difficult to make a reasoned comment.

I agree Rob that there are a lot of variables and maybe the combination of the weight my bike carries, the off road conditions it encounters on the way to work with no way to properly clean it for the journey home on the road, the Yamaha motor being anecdotally harder on the transmission than the Bosch, that my motor assists at all the speeds I ride at and that I could get into top gear on the original lower gearing and stay in that gear powering up a number of long hills on the way home without needing to change into a lower gear could certainly get an 11 tooth top gear playing up quite quickly.

 

My 23 ish mile round trip also adds miles to the bike quite quickly and the cassettes that played up may have had a higher mileage on them than I thought.

 

Anyway now I am measuring how far this higher geared set up will go before the cassette wears out and it will be interesting to see how far it gets.

I believe that many e-bike manufactures are using components from bicycles that are just not up to the job. On my Giant and Cannondale mountain bikes I have covered thousands of miles without chain or gear problems. Luckily my Scott e-bike with a Bosch drive seems very gentle on the transmission. I find that the motor performs much better and the stresses are lower when I use a lower gear that the one I presumed was right. The motor does not feel happy when labouring.

I really like the instant power availability and torque of the Yamaha motor and have had no issues with the majority of the gears available to me, and do not seem to get any premature wear issues with the chain or chain ring.

 

The motor pulls strongly and smoothly from the first push on the pedal and how hard you push on the pedals is effectively the throttle on a crank drive bike and the Yamaha motor/system can be very sensitively controlled with your legs that makes negotiating rough tracks, up hill steps and popping over tree trunks really great fun and sometimes amazing what you can get up, over, around etc without stopping.

 

On the road I have found when using eco that I can climb at a higher speed by staying in one gear higher at a lower cadence than I would do on a non assisted bike where I would tend to spin at a higher cadence in a lower gear.

 

At no stage have I felt that the Yamaha motor is struggling what ever I am doing. It has high power and torque from the off and that I love.

 

I may still put on a double front chain ring system as a really wide spread of gears would allow me to push as hard as I like on the road at high speed but still be in say a 14 tooth cog or higher on the rear cassette and still have crawler gears available off road.

 

However the gearing I have now is working really well for me.

.... and how hard you push on the pedals is effectively the throttle on a crank drive bike.

Just to avoid any misunderstanding, you mean, "how hard you push on the pedals is effectively the throttle on a torque sensor bike". The type of motor makes no difference. You can have torque sensors on bikes with hub-motors, chain drive, wheel drive and aero propeller drive. Many bikes with crank-drive motors don't have torque sensors. instead they have cadence sensors and/or throttles.

Hi Daveh, you are of course correct, the torque sensor mechanisms relay how much power is added to your own effort dependent on how hard you are pushing down on the pedal and what level of assistance you are in and the support can be provided by either a crank or hub motor.

 

I have found that the Yamaha system seems to respond instantaneously (0 Cadence system) and this I love particularly off road. The Bosch system I rode back in March 2015 seemed to me a little slower at that time.

Only problem with the zero cadence system is pulling away on steep hills when the surface is loose. (Note to self must buy dropper post)

Only problem with the zero cadence system is pulling away on steep hills when the surface is loose. (Note to self must buy dropper post)

 

Zero cadence would be fine, if the power kicked in from a progressive crawl and increased over say a couple of pedal strokes. In an ideal world all eMTB's would do this, and I have no idea why this isn't a built in design feature.

 

Like you, I'd find zero cadence to be a complete pain and work against setting off from a stand still in an off road situation. That not only including steep loose surface, but slippery conditions as well.

I just like being able to immediately adjust the power to the back wheel with your legs, if it starts to spin you can back off and then gradually on again or off again and each change in pressure has an immediate effect on the power delivery to the back wheel with no delay at all, splendid.

I just like being able to immediately adjust the power to the back wheel with your legs, if it starts to spin you can back off and then gradually on again or off again and each change in pressure has an immediate effect on the power delivery to the back wheel with no delay at all, splendid.

Yes fair enough once you are moving, but if you have to stop where traction is poor then starting again is a nightmare. Many times over the summer I have found myself having to lower the seat to start off, bottom gear even with my 2x chainring set up is just too high to pull away without power where I have been riding. YMMV

I can mirror those words exactly, the only difference being the choice of bike brand and motor.

 

On some occasions both here in the UK and in Switzerland, it has taken several attempts to pull away whilst using assist.

I am heavy (100kg+), carry loaded panniers and this might help to put the power down without the wheel slipping as much.

 

I use the bike to get to work and back rather than leisure and have got to know my various routes really well through repetition.

 

There is a lot sand in Surrey that means the routes stay dryer for longer and I can choose to mostly avoid the worst of the mud in winter rather than seek it out like Eddie.

 

However my own personal experience has been that the system works really well.

I think my Alpine and Eddie's riding may well be on a different level entirely, you wouldn't want panniers where we go! Hence the Your milage may vary.

mine eats 1 bar every five miles

Probably true, although my routes have some great single track sections including loose steep leaf mould bomb hole drop off down hill bits with a downed tree trunk to negotiate as you exit built up with soil on the left to create a ramp that you can clear at just the right speed to negotiate the exposed route intrusions on the track where you land off camber, sand stone washed out drop off shelf's, other downed small tree trunks to lift the front wheel over and then lean forward to allow the rear to follow etc and the panniers and rack do make a racket but it puts a smile on your face at work.