Switching the 350w BPM motor on my Big Bear for a 500w one

[Deleted member 4366]

If it's stamped 250w, you're home and dry. You can set the power to whatever you want as long as you set the speed to 25 km/h. There's a 10% tolerance on the speed, so 27.5 km/h is allowed, but you can't set to 27.5 km/h because your LCD might not be accurate.

 

[John_S]

I've been setting the power cut out speed to 27 km/h on the Kingmeter of my Big Bear. I've assumed that to do so is okay because of the 10% tolerance. Is it actually illegal to set the speed to 27 km/h?

 

[John_S]

Anyone able to answer what I asked above?
Is it actually illegal to set the speed on the LCD to 27 km/h?

 

[Andy Bluenoes]

Anyone able to answer what I asked above?
Is it actually illegal to set the speed on the LCD to 27 km/h?

I don't know the legal answer, but my argument would be you aren't breaking the law if the speedo goes up to 200 on your car....its only when you go over the limit that you are.

 

[D8ve]

A manufactured bike has a 10% tolerance your setting it at +9% if it is actually +11% on test your illegal. Your gamble, I suspect a fairly low risk one though.

 

[Deleted member 4366]

Anyone able to answer what I asked above?
Is it actually illegal to set the speed on the LCD to 27 km/h?

You can set the LCD at whatever speed you like. there's no law against it; however, your bike will be illegal if it goes faster than a true 27.5 km/h with the power still on.

The chance of the speed on your LCD being accurate is pretty slim. That's why they give you a 10% tolerance. If they measure your assisted speed at 27.6km/h, you won't be able to say, "sorry, I didn't realise my LCD was reading slow", when you have it set to 27 km/h.

In reality, I've never heard of anybody's bike ever having been checked for speed.

 

[John_S]

Thanks for your replies. I understand now.

I think it might be better to play it safe and have the setting lower than 27 km/h. I find the 25 km/h setting to be a little too low however, and the power cuts out more frequently than I'd like it to. Maybe setting it at 26 km/h would be a good compromise.

With the LCD set at a 26 km/h cutout, it would need to be incorrect on the low side by 1.6 km/h or greater in order for the actual cutout speed to be an illegal speed. I have no idea how likely it would be to be incorrect by that much though. Would any of you guys know how likely it would be to be out by that much?

 

[Deleted member 4366]

Think about tyre sizes. If you have the original big tyres, it'll ptobably read slow.

If you set the speed to 25km/h and twisted the wheel magnet through 90 deg, it would go 24 mph and it would be very quick and easy to twist it back to get 15 mph. Of course it could get knocked crooked in a crash!