Whisper 905se speed limit

briancv37

Just Joined
Mar 6, 2025
4
0
Hey, I've just purchased a whisper and wondered if there is a way to make it quicker? I've seen various answers from yesterday to no
When you hit 15 on peddle assist it then seems restricted by the motor, on twist throttle it will do maybe 17at best on full charge.
I did see something about disconnecting wires is that a thing?
 

AndyBike

Esteemed Pedelecer
Nov 8, 2020
1,516
641
15.5mph is the legal limit.
As these are assist, thats the maximum you are allowed to get assisted, and after that its only your leg strength that will increase your speed(or a hill, or a tailwind)

If you want to go faster than that with assistance, the bike then is obviously illegal and you risk losing the bike(you lose it permanently) or god forbid you're in an accident, then the law and court will utterly hammer you, and depending if there are others involved, you lose the bike, but do gain a rather stylish prison uniform or at the very least a big fine.

If you think 15/16mph just isnt cutting it for you, then the best option is a moped(which you only need a provisional licence for) and money wise a 2nd hand moped isn't that far off the cost of many new, basic Ebikes
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
7,649
3,551
Telford
Hey, I've just purchased a whisper and wondered if there is a way to make it quicker? I've seen various answers from yesterday to no
When you hit 15 on peddle assist it then seems restricted by the motor, on twist throttle it will do maybe 17at best on full charge.
I did see something about disconnecting wires is that a thing?
Wisper have sold many different bikes since they started twenty years ago. How can we help you if you don't tell us which one you have?
 

briancv37

Just Joined
Mar 6, 2025
4
0
So aside from the law,

Is there a way to do what I asked? 95% of my journey is off-road and flat. Paddle assist feels like peddling a bowl of custard once you hit 15pmh.

I saw something about disconnecting a wire, possibly blue others said grey does anyone know anything about that?

I'm not expecting to get much, but a slight increase would be good.
 

StuartsProjects

Esteemed Pedelecer
May 9, 2021
1,825
1,030
So aside from the law,

Is there a way to do what I asked? 95% of my journey is off-road and flat. Paddle assist feels like peddling a bowl of custard once you hit 15pmh.

I saw something about disconnecting a wire, possibly blue others said grey does anyone know anything about that?

I'm not expecting to get much, but a slight increase would be good.
So 5% of the time the bike will be used on the road ?
In which case exceeding the limit is breaking the law.

Even if you are 'off road' for it to be legal to exceed the speed limit you need the permission of the land owner, do you have that permission ?

Can be difficult for forum members to give you advice in such circumstances since part of the rules we all agree to follow are;

"Pedelecs operates a one account per person policy. You agree to not use the Service to submit or link to any Content which is defamatory, abusive, hateful, threatening, spam or spam-like, likely to offend, contains adult or objectionable content, contains personal information of others, risks copyright infringement, encourages unlawful activity, or otherwise violates any laws."
 
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sjpt

Esteemed Pedelecer
Jun 8, 2018
3,936
2,810
Winchester
The 95% offroad part would also be illegal if you derestricted, unless it was on private land with no public access. (eg no bridleways, canal paths, bike paths)
 

thelarkbox

Esteemed Pedelecer
Aug 23, 2023
1,402
438
oxon
There are a number of solutions that could apply, it all depends on which control system motor and perhaps even battery are involved. If for example your modded bike attempts to draw more amps from your battery than it can provide at best the bms will shut the battery down for 5 mins or so, we dont want to talk about worst cases - see the news for possible instances..

In some cases fooling spoofing or even replacing the speed sensor input to fool the system to thinking your moving slower, could be as easy as selecting a larger wheel size in the system config.. - this will have the knock on of providing an incorrect speed reading too..

If complications exist/arise its often easier to gut the control system and replace it, However the net gains will be upto 4-5 extra mph perhaps a bit more, and after say 17 mph any acceleration will peter off until max mph is slowly crept up to. And if run at length at top rpm and excess power supplied the motor may well overheat cooking hall sensors or worse the coils/magnets..

Perhaps just take the time on the bike to clear your mind and chill for a bit without any urgent distractions.. and enjoy the extra 3-7 minutes on the bike the restricted system provides.
You might find dropping max speed to 14 mph useful even..