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Bosch gen4 volspeed, speedbox question

RsGaz

Active member
Subscriber
Nov 6, 2020
109
56
N. Lincolnshire
So to those that have fitted a speedbox or volspeed to their gen 4 Bosch with 625 battery, how has it affected the battery range? Does the extra power reduce range by a large amount?
 

RickDale

Member
Aug 24, 2023
5
1
Queeny, Bradford
Don't bother with the speedbox, bosch smart system detects is after 100ish miles and you are left in limp mode. While it was attached the range did not decrease too much but I suppose it depends on the type of ride.
 

RsGaz

Active member
Subscriber
Nov 6, 2020
109
56
N. Lincolnshire
Don't bother with the speedbox, bosch smart system detects is after 100ish miles and you are left in limp mode. While it was attached the range did not decrease too much but I suppose it depends on the type of ride.
Thanks for that, I’m on a purion not the smart system.
 

Planemo

E*POWAH Elite
Mar 12, 2021
605
706
Essex UK
Does the extra power reduce range by a large amount?
There isn't any extra power, only extra speed.

But yes, go above the regular 15.5mph limit and you will be using more energy. How much depends on how long you spend above 15.5mph, how much effort you are putting in, the gradient, terrain etc etc.

Tbh and without being rude it's a bit of an unanswerable question. But FWIW, going twice the speed (31mph) will use 4x the amount of energy as air resistance is roughly proportional to the cube of speed.
 

jonmat

Member
Feb 22, 2020
101
72
Sheffield
It does reduce battery range for obvious reasons. Volspeed 4, rarely go above 20 mph on the flat, not much difference if used sensibly.
 

kevins1966

New Member
Oct 2, 2023
3
1
Scotland
So to those that have fitted a speedbox or volspeed to their gen 4 Bosch with 625 battery, how has it affected the battery range? Does the extra power reduce range by a large amount?
Doesn't really effect my range as it depends which level of assist your using.my 625 battery on mtb Road rides can still get me 65 miles range and I'm 19 stone. My road bike ep8 motor with 500 battery only gets around 30 miles.
 

Burner

Member
Sep 18, 2022
59
20
Manchester
Hi Mike got volspeed4, on mine , I fitted it as soon as I got the bike , so I don’t know about mileage difference but I get about 50 miles off a charge . I cruise at about 19-20 , so it keeps the assist going instead of cutting off at a pathetic 16!!,
 

E-MAD MALC

Active member
Subscriber
Nov 16, 2021
405
239
EAST SUSSEX
Don't bother with the speedbox, bosch smart system detects is after 100ish miles and you are left in limp mode. While it was attached the range did not decrease too much but I suppose it depends on the type of ride.
Did you use this speedbox version
For the latest generation of the motors with Bosch Smart System, we have developed SpeedBox 1.1 for Bosch and SpeedBox 1.2 for Bosch, which is also compatible with the rear wheel valve magnet
 

E-MAD MALC

Active member
Subscriber
Nov 16, 2021
405
239
EAST SUSSEX
I believe they were getting complaints about the original speedbox for the gen 4 being used with the smart system
Thats why the brought out the new version to get over the problem
 

kaiosid

Member
Jun 20, 2019
2
2
germany
We do use the speedfun furious and no problems with the Bosch smart system so far. Of course, if you ride at high speed the range will be lower, as energy consumption grows in square with speed. But that´s just general physics, nothing to worry about ;)
 

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