Restriction Query

JohnnyCrash

Heres one for ye.Have a Fazer 400 which is rated 55hp.(New)Technically,I should have it restricted.Heres the query.The bike is a 97 with 53k miles on,so surely it wouldnt be putting out anywhere near the 55 horses now?So,if I was able to get the power rated,and it was low enough so as not to have it restricted,would this stand up?? Cheers in advance!!

KamiKazi

So could get it dyno'd, but I highly it's lost the 22BHP you need for it to be learner legal.

JohnnyCrash

KamiKazi wrote: »

So could get it dyno'd, but I highly it's lost the 22BHP you need for it to be learner legal.

But it could have lost enough whereas it would be learner legal under the power/weight ratio????

Del2005

The power is done on the manufactures stated power and the manufactures weight. Most bikes don't match the manufactures power output at the rear wheel, where the dyno measures, or their claimed weights. Then there's also the issue that no 2 dynos will give the same results.

If you where in a crash and the bike can't be started the insurance company could very easily come after you for any money paid out.

The only real way you could do this is to get a letter from the RSA and the insurance company saying that you are legal. The chances of that happening are slim.

JohnnyCrash

Del2005 wrote: »

The power is done on the manufactures stated power and the manufactures weight. Most bikes don't match the manufactures power output at the rear wheel, where the dyno measures, or their claimed weights. Then there's also the issue that no 2 dynos will give the same results.

If you where in a crash and the bike can't be started the insurance company could very easily come after you for any money paid out.

The only real way you could do this is to get a letter from the RSA and the insurance company saying that you are legal. The chances of that happening are slim.

I understand that the power is the manufacturers stated,and that this might vary,but only by a small ammount im sure. But my point is,is that the manufacturers power rating is for a bike brand spanking new off the assembly line,not for a bike thats been around the block a few times.All I was wondering was,if I got the bike dyno'd and the power was down(in my case it would have to be down to 44hp),would this be adequate,or is it calculated from the "NEW" power rating??

Wossack

couple of random thoughts on the subject..

fwiw
for cars they use manufacturers co2 emissions to calculate your tax bracket - irrespective of the condition or age of the car


the inaccuracies of dynos would be the major downfall imo. you could get it run on all the dynos in the country and they'd all give different results..

and finally, for an additional spanner in the works
there's also the issue that the letter of the law doesnt state where the power is to be measured - alot of bike manu's give power output at the crank (ie before it gets to the road via gearbox / chain). And since dynos tend to read from the tyres, they'll generally always read lower then manu specs. How this helps/hinders I dunno, but think its relevant

cantdecide

JohnnyCrash wrote: »

I understand that the power is the manufacturers stated,and that this might vary,but only by a small ammount im sure. But my point is,is that the manufacturers power rating is for a bike brand spanking new off the assembly line,not for a bike thats been around the block a few times.All I was wondering was,if I got the bike dyno'd and the power was down(in my case it would have to be down to 44hp),would this be adequate,or is it calculated from the "NEW" power rating??

My understanding (which is very rudimentary) is that the ifs, ands & buts aren't spelt out in detail so technically....

But...

Ask yourself if you'd like to be having this debate on the side of the road with a Guard under any circumstances...

JohnnyCrash

cantdecide wrote: »

My understanding (which is very rudimentary) is that the ifs, ands & buts aren't spelt out in detail so technically....

But...

Ask yourself if you'd like to be having this debate on the side of the road with a Guard under any circumstances...

Dont want to sound smartarsed about it,but if it was a valid debate,then i'd have one with whoever.If I had a cert to say my bike was rated at 32kw and the weight was 197kg,that would put it at 0.16kw/kg,which is the legal requirement,no?:D

EGOSHEA

JohnnyCrash wrote: »

Dont want to sound smartarsed about it,but if it was a valid debate,then i'd have one with whoever.If I had a cert to say my bike was rated at 32kw and the weight was 197kg,that would put it at 0.16kw/kg,which is the legal requirement,no?:D

Not if the values accepted for this calculation are the ones based on the official spec rather than what the bike's doing after a few years. If the latter was the case (as you're suggesting), a powerful, older bike with a heavy load strapped to it would meet the regulations. But they don't seem to assess it on a case-by-case, 'specifics-of-that-bike' basis.

EvilMonkey

They would use the manufactures specification as they are the only reliable figures to go on, a dyno run could easily be fixed to give you any number you want.

Alkers

Do they measure the power again after restriction or what's the story? Could you not just restrict a bike by something like 1% and get a cert. saying it has been restricted. How can it be tested if Dynos are so unreliable?
Another question, I've a Hornet 250, puts out 36bhp iirc, it's 96 so it's probably gone below the 33bhp limit by now. Even if going by the original manufacturers specs. how would one go about restricting a bike in real terms to bellow 33bhp if it's already putting out less than that figure?

Del2005

You get a cert signed by the garage that fitted the pre approved restricter kit to show the bike is restricted, most kits are easy enough to check if fitted. You would more them likely get away without restricting a 36bhp bike, but if it's in the 40s you will need to get it restricter fitted no matter how old it is.

KamiKazi

Del2005 wrote: »

You get a cert signed by the garage that fitted the pre approved restricter kit to show the bike is restricted

There's no such thing

JohnnyCrash

Del2005 wrote: »

You get a cert signed by the garage that fitted the pre approved restricter kit to show the bike is restricted, most kits are easy enough to check if fitted. You would more them likely get away without restricting a 36bhp bike, but if it's in the 40s you will need to get it restricter fitted no matter how old it is.

A Dragstar 650 is 40hp but it falls under the power/weight ratio!!! even though its 7hp over the 33hp learner limit:D
Also, a mate of mine did his test on a Pan 1100 not too long back and passed.The bike wasnt restricted either!!