advice needed

[badger180]

hi guys and girls
i brought my disabled son an e bike a few years ago the carrera vengeance and was amazed at how easy it was .
it wizzed up hill without any effort needed from the rider ( just what he required)
i have just brought him the same bike 3 years on and how things have changed he can’t even ride it as his muscles haven’t the power to keep the torque sensor going.
so after some advice on what’s about like the original bike .

 

[Benjahmin]

I'm guessing that what your son needs is a bike with a pas system.
Torque sensing systems (which I think the vengence is) rely on sensing rider effort to give assist. They then multiply this sensed effort by a factor determined by what power setting is selected.
With a pas system the rider merely has to rotate the pedals to get assist, sometimes referred to as ghost pedalling.
Most hub motored bikes are pas, most mid drive bikes are torque sense.
Have a look at all those who advertise on here. Woosh, Juicy, wisper, oxygen, they all have pas bikes, but do ask before you buy.
I would also ask if the particular machine will allow a full acting throttle to be fitted, as it sounds like it might be useful. Not all systems have the facility.

 

[Nealh]

Badger do you still have the original bike ?

As mentioned the original may have been cadence PAS so simple rotation sensing that gives max power by simply ghost pedalling, the later Torque systems multiply the users effort. Any one with muscle, stamina or lung issues will find them hard work.

 

[badger180]

I'm guessing that what your son needs is a bike with a pas system.
Torque sensing systems (which I think the vengence is) rely on sensing rider effort to give assist. They then multiply this sensed effort by a factor determined by what power setting is selected.
With a pas system the rider merely has to rotate the pedals to get assist, sometimes referred to as ghost pedalling.
Most hub motored bikes are pas, most mid drive bikes are torque sense.
Have a look at all those who advertise on here. Woosh, Juicy, wisper, oxygen, they all have pas bikes, but do ask before you buy.
I would also ask if the particular machine will allow a full acting throttle to be fitted, as it sounds like it might be useful. Not all systems have the facility.

many thanks for the reply

Badger do you still have the original bike ?

As mentioned the original may have been cadence PAS so simple rotation sensing that gives max power by simply ghost pedalling, the later Torque systems multiply the users effort. Any one with muscle, stamina or lung issues will find them hard work.

no the bike was stolen but because it was so good we ordered the same again only to find they had changed the tech.

 

[vfr400]

You can get more power more easily if you take a couple of springs out of the chainwheel. Here's what it looks like and an explanation of how the torque sensor works.

Carrera Crossfire/Vulcan Torque sensor

I recently stripped one down so i can describe how it works. To disassemble it, you take the crank/chainwheel off, then remove the 4 screws in the back. There's 4 shim washers in there, so be careful not to lose any. The sensor is held on with three small screws. The sensor is partly...

www.pedelecs.co.uk