Power to Weight Ratio on a restricted licence?!?!

[HD]

Okay, so it seems that having a bike that is 33bhp, 0.16kw/kg and is fun does not come as a package in the motocross/enduro/supermoto typed bikes.

So then I think around 33bhp bikes? Wr250, perfect. Wait, thats far too light. DRZ400? Well it turns out that that is too light aswell. Apparently it is 0.2144 bhp per kilo. The DRZ is about 0.25!

So other than getting am sv650 or similar and restricting it, what am I supposed to do?

Or can I play the 'sorry officer thought it had to be 33bhp' card if I get caught? Its not gonna be exactly 33 with a decent exhaust but they allow you 36 I have been told? (false info?)

But the likelyhood that I will get pulled on a wr or a drz is high(er) I would guess.

If I can play the '33bhp card' then I would rather go with the wr250 option.

What are the consequences if it satisfies (just) the 33bhp limit but not the power to weight ratio?

Thanks gents!
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Rusty '02 Vito Camper + CBR600F3

[G]

WR250R/X? A slow-assed bit-revvy trail engine in a too heavy chassis? Whatever floats your boat .

Ok, you're limited to slow bikes, but I certainly wouldn't pay loads of money for the privilege.

Anyway, I doubt it does actually get near 33hp at the rear wheel, so you're probably ok (think I read 26hp on a dyno in the US?)

DRZ is more so, but real world weight with some fuel in isn't too far off either.

I have never heard of that particular bit being enacted to do someone, though I would worry more about getting a 'proper' supermoto or enduro - ie a competition based one.

[Glenben92]

As far as I know, nobody takes any notice of the weight ratio, just the power. and thats only IF you get pulled, IF you get asked, IF they demand to test it and IF they can be arsed. I wouldn't worry mate, 33bph and you're already wearing too many halo's to fit your lid over
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57 Huoniao HN125-8 - , 97 Kawasaki GPZ500S -
99 Yamaha FZS 600 -
Mod 2 Passed - 01/10/2010

[MaybeGuy]

none of the police around here know the law themselves. I was restricted for about a month before getting bored.
i was also pulled a fair few times in that period
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[Capt Castle]

Assuming you've typed the units correctly:

[HD]

[Capt Castle]

[HD]

Haha, its fine.
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Rusty '02 Vito Camper + CBR600F3

[Charlie]

Get a Honda Hornet 250! They're great fun and I might be selling my soon.
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Past: Honda x8rs, Honda City fly, Honda Hornet 250, Honda VFR750, Yamaha xt600e.
Current: Honda CBR929RR & Yamaha XT660Z Tenere

[HD]

Its 12 months away yet

And was more after a enduro/supermoto but who knows...?
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Rusty '02 Vito Camper + CBR600F3

[Rogerborg]

As far as I can tell, the "36bhp" figure comes from this thread at the sv650 forum but it's not clear whether that's the figure used by one police force, all forces, or the CPS.

There's nothing in the statute or case law that I know of that indicates whether it's 25kW at the crankshaft or the rear wheel, but to be safe, assume it's the crankshaft (so you should have significantly less at the rear wheel). Since calculating crankshaft power is voodoo science, that's probably where the 10% margin comes in.

Likewise, "weight" isn't specified. However, it would presumably be the weight of the bike as it was when you were stopped, i.e. wet weight with any luggage.

I think the chances of you falling foul of the power-to-weight test are vanishingly small. However, if you're worried, you could restrict a WR250 slightly. Either rig up a throttle stop or find a washer that fits inside the air intake, then drill out most of it. Get it dyno'd for peace of mind.