Gearing and motor

[Karen HB]

OK. Following loads of good advice on this forum and from some MTB bods I know, my other half bought me the Cube Access WLS Pro 500 as a joint birthday/Christmas prezzie. Lucky girl me!
However I have a couple of niggles/questions.
1. Is the motor supposed to be engaged all the time when I pedal? I know this might sound like a daft question but on my first trip out the motor seemed to cut in and out when I was on the flat. It worked all the time up an incline (probably because I'm pushing harder), but I was under the impression that the motor was supposed to assist whenever the bike was pedalled. If not I don't have a real problem with this, but it does feel a bit clunky whenever the cuts in and out. Do I just need to get used to it?
2. This one is the biggest problem I have. The gearing is very low. This is great for steep or rugged off-road stuff, but on the road it's terrible. The fastest I can get the bike to is 16 km/h and my legs are going around on the pedals like a mad clockwork toy!! There are 10 gears but I haven't got lower than the top 3 (going up hill). Most of the time I have to ride on roads to get to anywhere off-road here and with this gearing my travel speed is very slow. One of the reasons for getting the bike was so I could join my husband on rides, but he'd just leave me behind! I had hoped the e-MTB would enable me to keep up with him (most of the time).
The question is can I get the gearing changed? Its the front cog that's tiny. I had anticipated that the gearing would be somewhere in the mid range for an MTB not the bottom. Am I just stuck with this?

I know I should have probably ridden one of these before we bought, but the nearest dealer to us is 100 mile round trip. You live and learn, but I will be very disappointed if I can't change anything as it will limit what I can do.

Any suggestions or is it a case of tough doodah!

 

[LeighPing]

On most bikes (mine is hacked to 20 mph) the cut off point for the motor is 15.5 mph. When you touch that speed the motor cuts back. On, off, on, off, in, out, shake it all about, ad infinitum. It's not particularly fast and it can take some getting used to.

I can't advise you on the other points, as I have no knowledge of your particular bike. Is there a manual? Do you have it? Good luck.

 

[EddiePJ]

edit... Crossed with the reply by LP.

In respect of the bikes speed and the feeling of it cutting in and out, the motor is set to only assist to the UK legal cut off speed of 15.5mph http://www.pedelecs.co.uk/electric-bike-guides/uk-electric-bike-law/
By changing this which someone is bound to suggest, it will then make your bike illegal to use anywhere other than on private land that has no public access or right of way. Discussion for that subject can be placed/found here. http://www.pedelecs.co.uk/forum/forums/speed-pedelecs-s-pedelecs-non-eapcs-overseas.43/

It would appear that your bike comes fitted with a 15t front sprocket as standard, which is the same size as I use and find perfect for off road use.
Clearly road work is a different matter, and the front sprocket can be swapped out for a larger one.
A quick guide for you. http://www.connexchain.com/en/product/connex-e-bike-ritzel-fuer-bosch.html
and one link to an online shop. http://www.bike-discount.de/en/shop/e-bike-sprocket-18334 There are plenty of UK outlets selling front sprockets, but Connex are in my opinion the best available.

For every one pedal stroke, the sprocket turns 2.5 times, and the 15 t sprocket is the equivalent of a 37.5T conventional sprocket. For off road use, I wouldn't personally recommend going much greater, but try an 18t and see how you get on.

You can also buy a dual front sprocket conversion kit, and if memory serves me correctly, Gubbins from this very forum had one for sale a while back. Here is a link to Gubbin's profile page, you could message him from there. http://www.pedelecs.co.uk/forum/members/gubbins.11443/

 

[Emo Rider]

Selecting the right gear and pedaling at at least a 80 to 90 rmp cadence will minmize the "driving onto a field of mud effect" when hitting the 15.5mph cutout. If your tyres are under inflated this will make the drag worse. The only thing that is happening at this point is that you are now driving an unassited bicycle. And, yes, this part of getting use to your new machine. Welcome to the club

 

[Karen HB]

OK guys, Thanks so far, but I think you've misunderstood slightly with the first point. I am well aware that the motor is designed to cut out at 15.5 mph. However, I can't even get that fast (I think becasue of the low gearing). The fastest I get is 16 kmph (not mph), which is very slow, unless I'm going down hill and then I can obviously free wheel. I'm not a speed junkie, but 16 kmph is very slow on the road (although perfectly fine off-road).
The motor seems to cut in and out all the time (not just as 'faster' speeds) except when I'm climbing. The manual does refer to the motor giving less support when applying less pedal power, but this feels like it's disengaging and then re-engaging all the time, giving a clunky feel to the pedals and an uneven surge in speed. It maybe I just need to get used to it.

I'll have a look at front sprockets (although does this consitute to modifying the bike?). My non-electric mtb has 3 front cogs and I find I use the larger two on road and the smaller one off-road. I just need something that gives me a bit more speed (without the manic leg rotation) for on the on-road parts of my trips. Usually I have 3 to 4 miles before I reach an off-road section.

 

[soundwave]

https://www.badassebikes.com/en/badass-box/bosch/typ3-4-bosch/a-114/

that will remove the speed limit and easy to remove. it will half the speed on the display tho.

hold down the i and power button and you can change it from kph to mph and set the time ect.

you will need a spanner and a crank puller to change the front sprocket and will not effect anything warranty wise.

the cut off speed should be 25kph and you should be able to get to that speed with what you have now so could be a motor fault and will need the dealer to plug it in to there software and see if there is a problem with it first.

i also bought the kit from gubbins.

 

[Emo Rider]

OK guys, Thanks so far, but I think you've misunderstood slightly with the first point. I am well aware that the motor is designed to cut out at 15.5 mph. However, I can't even get that fast (I think becasue of the low gearing). The fastest I get is 16 kmph (not mph), which is very slow, unless I'm going down hill and then I can obviously free wheel. I'm not a speed junkie, but 16 kmph is very slow on the road (although perfectly fine off-road).
The motor seems to cut in and out all the time (not just as 'faster' speeds) except when I'm climbing. The manual does refer to the motor giving less support when applying less pedal power, but this feels like it's disengaging and then re-engaging all the time, giving a clunky feel to the pedals and an uneven surge in speed. It maybe I just need to get used to it.

I'll have a look at front sprockets (although does this consitute to modifying the bike?). My non-electric mtb has 3 front cogs and I find I use the larger two on road and the smaller one off-road. I just need something that gives me a bit more speed (without the manic leg rotation) for on the on-road parts of my trips. Usually I have 3 to 4 miles before I reach an off-road section.

"Huston, we have a problem!" Apologies for my misinterpretation. Your bike is certainly not working correctly. Aside from taking it back to the dealer, check the position of the magnet, on the wheel, to the sensor mounted on the frame. That is the only easy fix for your performance I can think of. Hope this helps.

Cheers

 

[Karen HB]

Oh no! I can't really take the bike back. My partner bought it on-line (new) but the shop is over 100 miles away. I'm feeling depressed now.
I can check the magnet position, but it looks right.
I don't know what to do.

 

[soundwave]

you need to find a dealer that is local to you that sells bosch bikes as they will have the diagnostic software to see if anything is wrong with it.

if it is not showing any error codes on the screen then its hard to tell what is wrong with it with out the software.

it could just be a faulty sensor.

 

[Karen HB]

OK. I've found a shop specialising in e-Bikes not too far away. They are authorised Bosch dealers and service specialists so even though they don't stock my bike, they should be OK to look at the system. I'll give them a ring tomorrow (they close at 4:30!!) and see what they say.
Thanks for the advice.

 

[LeighPing]

Have you upped the max pedal assist? When I'm in level 1 it will only do 8 mph, and then more mph with each level of assistance going up. All the way to level 6, which lets me do the max speed of 19 mph. Cutting off at 20 mph.

 

[Emo Rider]

OK. I've found a shop specialising in e-Bikes not too far away. They are authorised Bosch dealers and service specialists so even though they don't stock my bike, they should be OK to look at the system. I'll give them a ring tomorrow (they close at 4:30!!) and see what they say.
Thanks for the advice.

If there are no error codes showing do not be disappointed if the shop can not diagnose the problem straight away. The mechanic will probably have to call the cube tech support and walk through the issue together. I had the Bosch training through Raleigh and I have not heard of your experiences or issues. It is what I would be doing.

Cheers

 

[EddiePJ]

Aside from taking it back to the dealer, check the position of the magnet, on the wheel, to the sensor mounted on the frame. That is the only easy fix for your performance I can think of. Hope this helps.

Karen, I realise that you have said that the sensor position is okay, but just for clarification of what Emo Rider has said, here is a diagram.

.

 

[Karen HB]

Yep, that's the position of the sensor.
I haven't tried on the high settings yet and that might be part of the solution. However, I have been thinking about the physics of this as I've had no error message. Now this is a dangerous thing as I haven't done pure Physics since A level! But, the motor was only cutting out when I was on the flat, on a metalised surface. It was fine going up hill. Thinking about this, and the low gearing, it could actually be simply that as the ride was very easy that I was applying uneven pressure to the pedals and the sensor (if it is very sensitive) interpreted some of this to me freewheeling rather than pedaling. Only a theory. Anyway I'm going to give the Bosch dealers a call tomorrow and see what they say.
I might just have to up the front sprocket size. Not sure how the dual thing works?? Is this motor not compatible to using two front sprockets thus increasing the gear range?

 

[soundwave]

the duel kit is 18t and 15t on my bike but you have to change it over buy hand.

and its not very cheap as single ones are 10-20 quid and go up to 25t

with the dongle i reach speeds over 30mph but with 15t you should have no problem getting it to cut off speed.

the extra speed will half the range of the battery tho.

 

[Emo Rider]

the duel kit is 18t and 15t on my bike but you have to change it over buy hand.

and its not very cheap as single ones are 10-20 quid and go up to 25t

with the dongle i reach speeds over 30mph but with 15t you should have no problem getting it to cut off speed.

the extra speed will half the range of the battery tho.

I think, by what the op is saying, they needs to get use to their bike and how it works or get it fixed if there is a problem first. Not everyone is interested in modification of their bikes to operate outside legal and EU regulations. The op stated they used their bike on the road. Hope this helps.

Cheers

 

[Artstu]

Karen can't your other half have a ride before you think about visiting the shop? It sounds like you may have quite a low cadence too, so a front sprocket change will help.

Try all the assist settings too. I never notice any surging at all on mine apart from at the 16 mph cut-out.

 

[soundwave]

i ride my bike on the road and never had a problem with the law i even parked it outside the main plod station.

 

[RobF]

On my Bosch bikes the motor does cut in and out on the flat in lowest eco setting - that may be what the OP is experiencing.

She needs to try tour or sport.

A larger front ring is worth fitting, although I would expect the bike to get to 15mph with the present gearing and not a ridiculously high cadence.

I suppose it's also worth checking the chain is dropping into highest gear - smallest cog - at the back.

 

[Croxden]

Mine will cut out but apart from the sound going I can't feel anything it's so smooth.

That's how it should be, all three of my Bosch bikes were like that. The power tapering off, if that's not happening something is amiss.