Halford's Carrera Tugging?

[doclatham]

Hi All

I mentioned this point in another thread, but it was buried among a lot of other words, so I thought I'd give it it's own thread to see if any of the experts can help out.

So I now have the Halfords Carrera e-bike and have ridden about 90 miles so far this week. Everything seems great except for an annoying "tugging" sensation at a certain speed. I get the same effect on both mine and my wife's bike so I ruled out it being a fault.

As I haven't ridden any other ebikes I don't know if this is normal, or at least normal for this type of ebike.

The symptoms.
NB: The bike only displays in KM

When I get close to the motor cut-off speed (about 25 km/h) rather than the assistance gradually get less, it actually feels like a brake has been applied. I can only describe it as a "tugging" sensation as if the motor is actually applying a braking effect.

However, if I change down a few gears, increase my cadence and get my speed up to about 30 km/h the sensation goes away again.

One test I need to do is to get p to the speed where the problem occurs and then actually try switching to "No Assist" or even switching the system off and see if that has an affect.

Overall it hasn't ruined the experience, but it is frustrating - is it simply the assistance switching on and off in a jerky fashion and so me feeling and then not feeling the full weight of the bike? I think not, as the effort I have to exert when the bike is "tugging" seems less than the effort I need once I get out of the trouble zone and up to say 30 km/h - the bike is easier to pedal at 30 than it is at 25?

Might just be my imagination, but I thought someone on the forum might have an explanation

David

 

[flecc]

The abrupt cutoff on some designs is an uncomfortable experience and many avoid riding at that speed for exactly that reason. Depending on the circumstance it's best to ride at either just below the cutoff speed under power, or above it unpowered, exactly as you've found.

The nicest designs in this respect are those that phase down the power assist slightly as they approach the cutoff speed, since that avoids the snatch effect of an abrupt cutoff. This is just one of the many reasons why we advise a trial ride before buying.
.

 

[LeighPing]

15.5 mph is just too slow and easily achievable, even my 4 year old grandson can hit that speed on his tiny little kiddy bike.

My 250w kit bike does the same thing as yours at 21 mph. Yet I rarely need to go up to that speed. I merrily tootle along at 16 to 18, which is a realistic 'adult' cycling speed.

Yes, the Carrera's are a good buy. As far as ebikes / pedelecs go. But 15.5 mph needs a 'goodbye'.. and you can do that for around the same price with a brand new ebike motorised kit on a brand new road or mountain bike.

 

[mountainsport]

15.5 mph is just too slow and easily achievable, even my 4 year old grandson can hit that speed on his tiny little kiddy bike.

My 250w kit bike does the same thing as yours at 21 mph. Yet I rarely need to go up to that speed. I merrily tootle along at 16 to 18, which is a realistic 'adult' cycling speed.

Yes, the Carrera's are a good buy. As far as ebikes / pedelecs go. But 15.5 mph needs a 'goodbye'.. and you can do that for around the same price with a brand new ebike motorised kit on a brand new road or mountain bike.

View attachment 14763

I like your reasoning.

MS.

 

[mountainsport]

The abrupt cutoff on some designs is an uncomfortable experience and many avoid riding at that speed for exactly that reason. Depending on the circumstance it's best to ride at either just below the cutoff speed under power, or above it unpowered, exactly as you've found.

The nicest designs in this respect are those that phase down the power assist slightly as they approach the cutoff speed, since that avoids the snatch effect of an abrupt cutoff. This is just one of the many reasons why we advise a trial ride before buying.
.

You are totally correct about physically trying before buying but you must also bare in mind that during that over whelming process of buying im sure that over 90% of people will not feel that annoying tugging feeling until they have had the bike in their possession over a short period of time.

Therefore, I think it is all down to the redevelopment of the programing or to the software.

MS.

 

[doclatham]

Thanks for the feedback - at least I know it appears to be a feature rather than a fault. I'll just push on to 30 kph and use the motor on the hilly bits. At least on the way to work. On the way home I'll probably go for the keep the speed lower option!

 

[doclatham]

You are totally correct about physically trying before buying but you must also bare in mind that during that over whelming process of buying im sure that over 90% of people will not feel that annoying tugging feeling until they have had the bike in their possession over a short period of time.

Therefore, I think it is all down to the redevelopment of the programing or to the software.

MS.

Very true - I had the bike for a 2 hour test ride, but as we kept to an official bike route around our town our speed probably never got high enough. It was only when I hit the open road that I noticed it.

Anyway - it's not the end of the world - just wanted to be sure it wasn't an actual fault

Thanks

 

[mountainsport]

Very true - I had the bike for a 2 hour test ride, but as we kept to an official bike route around our town our speed probably never got high enough. It was only when I hit the open road that I noticed it.

Anyway - it's not the end of the world - just wanted to be sure it wasn't an actual fault

Thanks

No problem, here is the joke, but how long will or can you tolerate this for? Please don't get me on the wrong side but riding an ebike is a beautiful experience and it would be so satisfying to know that everything is at maximum operating correctly.

Please note and excuse me for being a bit of a perfectionist

MS.

 

[Alan Quay]

Very true - I had the bike for a 2 hour test ride, but as we kept to an official bike route around our town our speed probably never got high enough. It was only when I hit the open road that I noticed it.

Anyway - it's not the end of the world - just wanted to be sure it wasn't an actual fault

Thanks

The problem goes away if you can de-restrict it. It wouldn't surprise me to find a standard Chinese controller in the bottom of that battery.

Sent from my HTC One_M8 using Tapatalk

 

[doclatham]

Good point. All I would actually need is it increasing from 15.5 to 17.5mph. I am sure there are many who would disagree on that point, but I'm already travelling at that speed under my own steam. Not sure I want to void my warranty just yet though

Sent from my SM-G900F using Tapatalk

 

[D8ve]

The big issue is post accident.
Will the police prosecute you for uninsured, motorcycle.
Will insurance cover you for your injuries.
Will insurance cover damages others claim from you and your motor vehicle.
That's the possible big ** available if you get hit by a car?
I average 17 mph now even with traffic lights and cars. It would be nice to have some extra speed but its legally a bike.

 

[LeighPing]

It would be nice to have some extra speed but its legally a bike.

And so are these two..

 

[IR772]

I have a Haibike MTB, no dongle fitted, and between about 15.5 and 17 MPH the assistance drops away in a measured way.

It shows me how much help the engine and battery is giving (thank you very much) and teaches me to cruise at about 15-16 MPH, the comfort zone.

Its the lovely difference between a bike and an ebike.

 

[KeithMac]

My Gtech softens the assist at 15mph and doesn't surge.

I believe the call it hysteresis, if you're bouncing around the cut off point the controller needs some lag or hysteresis programmed in to stop the surging.