# Advice Required



## migrantwing (5 Aug 2019)

A neighbours friend turned up today and he called me over. His friend has a Halfords Carrera E Bike. He had a puncture and needed an inner tube etc, so I helped. He asked me if I knew anything about E bikes, I said 'no'. He wants to change the bike from a 300 watt to a 500 watt. I understand that this would entail changing the back wheel and possibly the battery. What do I need to know to be able to do this for him? I don't mind doing it as it's a bit of a project and I enjoy bike maintenance, but if I will be way out of my depth, I'll pass.

TIA


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## CXRAndy (5 Aug 2019)

A bigger motor will require the controller capable of delivering more Amps to get more power or higher voltage. A bigger battery in Amperage will give longer range.

It depends whether his controller and motor will tolerate higher voltage or more current or both. See if any forums 'endless sphere' have done this upgrade.


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## Cycleops (6 Aug 2019)

Looks like he'll also have a bike that no longer conforms to e-bike regulations if he goes ahead. Might be worth pointing that out.


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## cyberknight (6 Aug 2019)

mods would invalidate the warranty too


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## fossyant (6 Aug 2019)

Not cheap is the answer.


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## I like Skol (6 Aug 2019)

My advice is fix the puncture and walk away. If he wants a more powerful bike then perhaps suggest he gets a licence and some insurance and buys a motorbike!


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## steveindenmark (6 Aug 2019)

I like Skol said:


> My advice is fix the puncture and walk away. If he wants a more powerful bike then perhaps suggest he gets a licence and some insurance and buys a motorbike!


I agree with that. 

There is doing a favour and doing a favour.

I would point him in the direction of Google and a bike shop.


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## Racing roadkill (6 Aug 2019)

If he wants it to go quicker, tell him to look on line, there’s a software mod that tricks the limiter into thinking the wheels are smaller than they are, hey presto, your e-bike is now shifting at motorbike speeds, without having to up the motor size.


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## Pale Rider (6 Aug 2019)

The Suntour motor on the Carrera is difficult to de-restrict.

Replacing the motor might not do what he wants because quoted watt numbers are only a guide.

The Carrera motor is quite perky for what it is, so he could buy a '500w' motor which is no faster.

Then there's the possibility the new motor won't shake hands nicely with the existing electronics.

If he must have a faster bike, buying a cheap hybrid and converting it would be a better option.

Leaving aside watt ratings, anything that assists above 15.5mph would be illegal.

You may not want your hands on that.

Building the bike is no offence, but if you did it for yourself you would have control - and responsibility - over how it was used.


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## gbb (10 Aug 2019)

An example of folk updating their motors etc. I just opened FB and saw an advert for a 1500w motor, 48v, 15.5 ahr system. He's built ot well from the looks of it and explains.
Done 100 miles, no problems. Nearly reaches 37 mph. Battery is like new and has only been charged 7 or 8 times.

Sounds great until you do the simple maths....its doing 15 miles maximum to each battery charge.


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## CXRAndy (10 Aug 2019)

He is sacrificing range for outright speed I think there are better ways of utilizing an ebike motor setup 


gbb said:


> An example of folk updating their motors etc. I just opened FB and saw an advert for a 1500w motor, 48v, 15.5 ahr system. He's built ot well from the looks of it and explains.
> Done 100 miles, no problems. Nearly reaches 37 mph. Battery is like new and has only been charged 7 or 8 times.
> 
> Sounds great until you do the simple maths....its doing 15 miles maximum to each battery charge.


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## migrantwing (25 Aug 2019)

Thanks for the input and info guys. I haven't seen the guy since, so hopefully he's gone off the idea.


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