Bosch performance line cx - feels like it’s holding me back.

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
Recently got a ghost asx essential, had the firmaware update.
now I expected some difference in riding technique/style, however something I’ve noticed a couple of times and noted speeds today. So on ‘flats’ if Im pinning it I noticed that if I hit 17mph or above it almost felt like the motor was trying to slow me down. Pedal strokes suddenly felt very heavy, whilst in emtb mode.
make sense?
 

Jackware

Member
Subscriber
Oct 30, 2018
1,855
2,009
Lancashire
You know the bikes restricted by law to around 15.5mph?
All you're experiencing is the sudden loss of assistance.
You can either get used to it and keep your speed just under the limit or derestrict it but then it's illegal to use on public highways and may invalidate your warranty.
 
Last edited:

Jackware

Member
Subscriber
Oct 30, 2018
1,855
2,009
Lancashire
Perfectly clear, do you think the assistance cutting out feels different to before you had the firmware update?
Others who know the Bosch system better than I do might know if the way the assistance stops has changed, ie either just stopping or ramping down.
 

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
Again not sure didn’t ride it enough prior to the update.
I’m expecting to feel that drop of assistance, but this just feels different. I’ve got more ‘in the tank’ on the flats and was just thinking surely I must be able to go over 17mph.
 

lightning

Well-known member
Apr 5, 2021
715
409
UK
Mine cuts out fairly abruptly when hammering it to the cutoff speed in maximum assist mode, it's better in the lower modes
 

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
Back out again today and it’s so weird. Trying to maintain a speed of 18-19 mph on a flat is nigh on impossible. It genuinely feels like the motor has engaged but is severely slowing the pedal stroke. today I likened it to riding uphill on a normal bike in the smallest ring and just grinding away.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,066
4,585
Weymouth
How much you feel the motor cut off depends on a few factors. You will notice it least on a smooth surface like tarmac than even on a gravel road and if off road you will notice it less if you are in a lower gear with a higher cadence. Obviously tyre compound, tyre pressure, suspension settings, trail conditions, gradient, and even wind resistance also make a difference. After all in a mode like EMTB you are likely to lose 50% of the crank watts as soon as the motor cuts off.
 

rod9301

Member
Oct 10, 2020
143
70
US
Yeah, because it gives you more assistance then trail, so when it cuts out you feel it more.

Either get your legs stronger or deal with it.

I have the same motor on my haibike nduro and it doesn't bother me.
 

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
Yeah, because it gives you more assistance then trail, so when it cuts out you feel it more.

Either get your legs stronger or deal with it.

I have the same motor on my haibike nduro and it doesn't bother me.

Tbf it’s not like I’m riding slow, it’s just a strange feeling. I think there’s the element of changing gear and upping cadence as well.
Again it’s a new way of riding, interestingly rode a normal bike today and felt even more draggy actually thought there was something wrong with that bike!
 

lightning

Well-known member
Apr 5, 2021
715
409
UK
The U.K. 15.5mph cutoff is pretty crap if you are a regular MTB rider.

When l got my Ebike l was continuously bouncing it off the limiter, the USA limit of 20mph is much better.
 

2WheelsNot4

E*POWAH Master
Oct 17, 2021
889
682
Scotland
You know the bikes restricted by law to around 15.5mph?
All you're experiencing is the sudden loss of assistance.
You can either get used to it and keep your speed just under the limit or de-restrict it but then it's illegal to use on public highways and may invalidate your warranty.
No its more than that. Im experiencing the same sensation. Its a bit like you get hit with sudden drag.
Propelling a 52lb bike is one thing. but when youre already doing 15..5mph, even on a slightly downward incline and you try to pedal above, you get the feeling of drag. Its almost when you get to about 17mph that its holding you back. The feeling is tangible.
And Im used to previously riding a 40lb+ old steel commuter.


Its restricted by law to ASSIST you up to 15.5mph, which at that point the motor should just cut out, and you would be from them on in 'normal' bike mode. Even using the gears 3 or 4 up, it has this odd feeling like theres some sort of friction at work.
 

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
No its more than that. Im experiencing the same sensation. Its a bit like you get hit with sudden drag.
Propelling a 52lb bike is one thing. but when youre already doing 15..5mph, even on a slightly downward incline and you try to pedal above, you get the feeling of drag. Its almost when you get to about 17mph that its holding you back. The feeling is tangible.
And Im used to previously riding a 40lb+ old steel commuter.


Its restricted by law to ASSIST you up to 15.5mph, which at that point the motor should just cut out, and you would be from them on in 'normal' bike mode. Even using the gears 3 or 4 up, it has this odd feeling like theres some sort of friction at work.
Not just me then! Phew.
 

lightning

Well-known member
Apr 5, 2021
715
409
UK
Mine has "resistance" when you exceed the motor assist speed, it feels like the brakes are binding.
But they aren't, and there's only a slight drag from the motor.

lt's because you are used to the assistance and then it's suddenly not there, if you ride an ebike then get straight back on a regular bike it initially feels the same.
 

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
Mine has "resistance" when you exceed the motor assist speed, it feels like the brakes are binding.
But they aren't, and there's only a slight drag from the motor.

lt's because you are used to the assistance and then it's suddenly not there, if you ride an ebike then get straight back on a regular bike it initially feels the same.
I noticed this yesterday, rode a normal bike and it felt like there was dragging. I guess I was expecting to be able to hit the 15.5 and then be like a bat out of hell with my chubby little legs propelling me to the heady road bike speeds!
 

lightning

Well-known member
Apr 5, 2021
715
409
UK
You can fit a dongle that removes the speed limit, if you want.

l fitted one to my friends 2020 Bosch Gen 4 hardtail and it was fabulous, an easy 26mph and that wasn't even in the highest assist mode.

Obviously illegal though, unless you are on private land. The dongle has to be activated each time you turn on the bike, so anyone trying the bike out would find that it was the standard 15.5mph and nothing out of the ordinary
 

SurreySteve

Member
Jan 9, 2022
30
10
Surrey Hills
Have you tried with it switched off? I'm not suggesting you ride it like that longer term but if you don't have it switched on at all then you'll at least know. Not sure what you could do about it ... I know my onboard speed is 1-2 mph different to my GPS speed so take that into account perhaps. Given the mechanical internals I don't see how they could do that from the software TBH and it's probably more about how the power gets removed vs actual drag.
 

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
You can fit a dongle that removes the speed limit, if you want.

l fitted one to my friends 2020 Bosch Gen 4 hardtail and it was fabulous, an easy 26mph and that wasn't even in the highest assist mode.

Obviously illegal though, unless you are on private land. The dongle has to be activated each time you turn on the bike, so anyone trying the bike out would find that it was the standard 15.5mph and nothing out of the ordinary
Thought about this but my only concern is how it affects the warranty
 

Jamsxr

E*POWAH Master
Mar 30, 2019
518
632
Surrey
Surprised so many people ride with the U.K. speed limit. For me at least, on my local trails, it takes a large part of the Ebike fun factor away.
 

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
Surprised so many people ride with the U.K. speed limit. For me at least, on my local trails, it takes a large part of the Ebike fun factor away.
Hmm have to disagree with you here, for me at least it gives me far more energy to do the downs, purely because it doesn’t sap my energy on the climbs. It’s got me back riding again And enjoying it without a shadow of a doubt (despite what I posted at the top)
 

SurreySteve

Member
Jan 9, 2022
30
10
Surrey Hills
Hmm have to disagree with you here, for me at least it gives me far more energy to do the downs, purely because it doesn’t sap my energy on the climbs. It’s got me back riding again And enjoying it without a shadow of a doubt (despite what I posted at the top)
Depends really ... if you have to keep up with mates on non-eBikes on the downhills its a lot of work spending the whole time with the extra friction. My local trails vast majority of the downs I'm faster on an analogue bike
 

Jamsxr

E*POWAH Master
Mar 30, 2019
518
632
Surrey
Hmm have to disagree with you here, for me at least it gives me far more energy to do the downs, purely because it doesn’t sap my energy on the climbs. It’s got me back riding again And enjoying it without a shadow of a doubt (despite what I posted at the top)

Horses for courses. I’ve been without an Ebike for 18-months, love my analog bike, I enjoy the grind - most of the time.

An Ebike gives me speed and power on the flat mellow trails, less cardio and more time to focus on having fun. No doubt having an easy shuttle is also great.

Thankfully there are plenty of options to de-restrict without invalidating the warranty.
 

ashleydwsmith

Member
Apr 15, 2022
93
48
Guildford uk
Horses for courses. I’ve been without an Ebike for 18-month, love my analog bike, I enjoy the grind - most of the time.

An Ebike for me gives me speed and power on the flat mellow trails, less cardio and more time to focus on having fun. No doubt having an easy shuttle is also great.

Thankfully there are plenty of options to de-restrict without invalidating the warranty.
What are these de-restricitn without invalidating warranty options?
 

Jamsxr

E*POWAH Master
Mar 30, 2019
518
632
Surrey
What are these de-restricitn without invalidating warranty options?

Not sure about Bosh, but on my old e8000 ST Unlocker was pretty discreet and reversible, same goes for Brose.

No 1 criteria for me when it comes to buying an Ebike. Can I de-restrict and still get warranty support.
 

Zaskar20

Active member
Aug 17, 2021
140
133
UK
I originally purchased my eMTB because I had a worsening hip problem that was causing pain, exacerbated by cycling. It was a game changer! since purchasing the bike I have used Tour mode as an absolute minimum. After reading this thread I tried Eco mode. It was a real struggle and felt like I was riding through thick treacle. It seemed much worse than riding my old mtb, and I was riding with assistance!
This was caused by many things, such as weight of bike, thickness of tyres, my (un)fitness etc.
One thing it was not caused by was friction or resistance of the motor, because the ride was assisted.
I would almost guarantee the same issues would be causing what you are describing.
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

513K
Messages
25,121
Members
Join Our Community

Latest articles


Top