PLEASE NOTE THAT WITH THE INTRODUCTION OF THE EUROPEAN 3RD DRIVING LICENCE DIRECTIVE LAWS AS OF JANUARY 2013 THE LAWS BEHIND RESTRICTION CHANGED COMPLETELY AND THIS INFORMATION IS NO LONGER RELEVANT. READ MORE ON THE MAG (MOTORCYCLE ACTION GROUP) WEBSITE.
As some of my article could still be of potential (historic) interest, i've left it here for my visitors to read:
You can read the law on 25kW / 33.5BHP motorcycle restriction yourself, in 'The Motor Vehicles (Driving Licences) Regulations' (1999), where Interpretations/section 3, gives 2 definitions of a 'large motor bicycle' (for both with, and without a sidecar). Without a sidecar, the words used are as follows: "in the case of a motor bicycle without a side-car, a bicycle the engine of which has a maximum net power output exceeding 25 kilowatts or which has a power to weight ratio exceeding 0.16 kilowatts per kilogram". This law is available for the public to read at this URL: legislation.gov.uk
I don't see why people should be ripped off when it comes to restricting, so i thought i'd air my views on the matter.
NB: THIS IS PURELY MY OPINION - PROVIDED "AS-IS" - AND BY READING IT, AND CONTINUING TO READ ON YOU ARE AGREEING THAT I CAN AND WILL NOT BE HELD RESPONSIBLE FOR ANY INACCURACIES OR BAD THINGS THAT MAY OCCUR AS A RESULT. THIS IS NOT TO BE USED AS A GUIDE AND I SUGGEST YOU GO AND DO YOUR OWN RESEARCH ON THE MATTER, AND DRAW YOUR OWN CONCLUSIONS AS I HAVE DONE.
Just to clarify this is based fully on my own logic and a little research and i do not want anyone to take this as gospel. I am not an expert (or even trained in law).
I used to agree with what appeared to be a majority view on motorcycle restriction.
But i spent many hours reading on the net, and here's what i did to my vehicle:
Restricted my CB500 with a "Honda" restriction kit (which for my bike is basically 2 x #125 jets and a couple of engine air intake thingumies with a cut-out piece of metal through them to reduce airflow) that i purchased over the phone from Essex Honda (01245 354844), for...
£28 + £5 postage. Inclusive of VAT.
Note: I have been told by a member on a forum i frequent that Essex Honda no longer do these kits, but feel free to check as i haven't bothered - i've already got mine! Edit: I've also seen threads with people claiming otherwise. Before you all ring up bugging Essex Honda though, read on for a better way of getting hold of the kits.
Here is information from my receipt for my CB500 restrictors as bought from Essex Honda in 2008:
Stock code / Description / Price (Ex VAT)
16221MY5710 / INSULATOR, CARB LH / £8.33
16211MY5710 / INSULATOR, CARB RH / £8.33
99101GHB1250 / JET, #125 / £5.63 (Note: 2 were required, total: £11.26)
Total £33.00 (Incl VAT).
New addition: The above parts are available from David Silver Spares (thanks for confirmation of that from Spetom, on Bike Chat Forums) and thus more than likely also available via your local Honda dealer - order using the "stock code" (i.e. part number). Don't ask for a "CB500 restrictor kit" as i'd wager the staff are unlikely to know what you mean. Or worse, ask you when you'd like the bike booked in
A further new addition: restrictorkits.tripod.com - do restrictors for a good few bikes. There is of course, a few well-known auction sites you can look at too.
Please do note that i am not recommending any of the above places to buy - i'm not even able to say if they are genuine shops (i'm merely providing them as other people have sent the information to me), you'll have to make your own careful decision on where you wish to get ahold of restrictors - just bear in mind the potential ramifications if your bike is not restricted properly, and that i will take no responsibility for any issues with these 3rd parties.
Remember that you need two copies of the jet (99101GHB1250), one for each carb.
Note: Some people don't bother with the jets, and its possible that another restrictor kit may not even include jets.
The single easiest place to get a restrictor kit fitted is (indirectly) via F.I. International (Note: There's little to no point contacting the company directly as they only sell to trade customers, and the kits are expensive too!) - usually this is what happens when you go through a garage and ask them to obtain and fit you a restrictor kit for your bike (i.e. they'll call F.I., order the expensive kit, then fit it to your bike and give you a single bill of a couple of hundred quid).
I am also under the impression that Suzuki are able to get their hands on restrictors cheaply, because they used to give you them for free if you bought a brand new 33BHP bike from them. I have also heard Honda doing something very similar - and as i was able to purchase restrictors so cheaply from Honda (and now David Silver, by the looks of it), this would as good as confirm the fact in my eyes.
If anyone does have any further ideas on where restrictor kits can be purchased, please let me know and i'll update the site to share this knowledge around.
Now, if i didn't happen to be quite so new to biking and bike mechanics at the time, i would have fitted those restrictors myself. But i'm afraid, ability-wise, i wasn't able to, so i paid my old mechanic (nice guy over in the Midlands, works for £24/hour to boot!) for a couple of hours extra labour, to have them fitted for me, along with a few other bits and bobs i wanted doing - before i rode across the country back to where i now live.
I'm a very wary and cautious kind of guy, and i personally felt 100% safe with this, riding for over 18 months on the restrictors before i was legally able to take them out.
NB: THIS IS PURELY MY OPINION - PROVIDED "AS-IS" - AND BY READING IT THUS FAR, AND CONTINUING TO READ ON YOU ARE AGREEING THAT I CAN AND WILL NOT BE HELD RESPONSIBLE FOR ANY INACCURACIES OR BAD THINGS THAT MAY OCCUR AS A RESULT. THIS IS NOT TO BE USED AS A GUIDE AND I SUGGEST YOU GO AND DO YOUR OWN RESEARCH ON THE MATTER, AND DRAW YOUR OWN CONCLUSIONS AS I HAVE DONE.
To explain (NB: I'm not an expert, or even "in the know", i have simply done some research and applied some logical reasoning):
1) Apparently the law on restrictions states that the bike ridden (for the 33BHP restriction we all know and love), must be 33BHP (technically it states 25kW, which is about 33.5BHP, but let's not quibble over such matters). Irritatingly, it doesn't actually state where it must be measured from (apparently it could be the crank shaft or the back wheel, and no one is very sure although i suspect the used metric to be back wheel if it was to be somehow tested - although many knowledgeable people seem to suggest the intended figure of measurement would be the crank, which isn't possible to measure under normal testing conditions, and certainly not accurately with a standard dyno!), so therefore i personally would stay away from any homebrew efforts at restricting my bike, in case the "wrong" bit is measured - assuming you even have the equipment to measure accurately! (As an aside different bikes need to be restricted in different ways too, otherwise the bike may not run right - the fuel/air mix could be easily messed up, potentially resulting in you blowing it up/seizing/etc - some bikes are quite complicated to restrict! e.g. GSX-R600's use a modified ECU which is well outside the scope of your normal DIYer - this is yet another reason to let someone else do the research, and buy their finished product). The generally-accepted consensus (and my opinion too, having once read the law in question) is that the law does not say how the bike must be restricted, or even whether this must be proven or documented (Please see links to the law itself at the top of this article).
2) As we all know, it is assumed that the individual is totally innocent until proved guilty of a crime (apparently anyway.. Of course this fundamental human right seems to be in the process of erosion by those in power at all times, but i believe the discussion of that point that would warrant a whole website to itself, so i won't digress further). Anyway, from what i've been told, the crime regarding riding without restriction would be "riding otherwise than in accordance with [your] license" (as your driving license only permits you to ride a motorcycle of up to 25kW / 33.5BHP) and also as a consequence "riding without valid insurance" as your insurance company will retrospectively not cover you for riding if you don't hold a valid license). So we clearly have 2 elements here:
Element A) Riding without valid license.
To prove this crime, the bike would need to be proved to be producing over 25kW (and logic dictates that the only way you can "prove beyond all reasonable doubt" (as required to be convicted under criminal law) a bike is producing over 25kW is to test it, and to back this up, i have heard of the police putting bikes on a dyno to check 25kW restriction). So therefore if during that test the bike does not produce over 25kW, no crime has been committed - so the logical answer is that it does not matter how you restrict your bike, providing it is under 33.5BHP/25kW if tested, otherwise you surely cannot be proved beyond all reasonable doubt to have committed this crime (although that won't necessarily mean the matter won't be tested in court, but i would certainly expect a verdict of "innocent" at the conclusion of court proceedings (NB: I have not the slightest of experience in law - this is just what the average person (me) understands as the way in which the law (is supposed to) work!)
Element B) Riding without valid insurance.
This is more tricky, because of how slimy the sales and insurance industry can be (i should know, i have plenty of experience in sales environments!). Obviously if it can be proved you are riding without a valid license your insurance company has their excuse to withdraw cover in the event of an accident or claim. However, some insurance companies also have their own (very naughty in my opinion) get-out-of-paying clauses! To summarise what i learned from the insurance companies i spoke to: Many places are happy to provide an insurance policy and take your money - but then in the event of an accident, they "could" (will), ask for proof of restriction. Of course if you can't produce this, they've got all the excuse they need! (whether or not the onus is on them to prove you guilty or you to prove yourself innocent is another matter, as it's contract/civil law in play here)
However, it's not all bad news. Other insurance companies i spoke to said that if i sent them a dyno printout of the restricted bike after taking out the policy, with a signed message from the garage that tested it, stating that the bike in question is a genuine under 25kW/33.5BHP bike, then they would be happy to provide cover, and need no further proof in the event of an accident (NB: They still have the right to test your post-accident bike if they desire to). The good news is that it costs in the region of £30 to have a dyno done professionally (or so i believe).
Other companies said very similar, except they did not demand that the garage sign the dyno.
And the company i went with this year (Carole Nash if anyone's interested - let me know if any other companies have a similar stance) claimed to work on the spirit of "utmost good faith". Basically they said i need not provide ANY proof of restriction. However they said that if i had an accident, they would test the bike (as they have right to). Of course, this is not a problem for me, as i am (well, was) a genuine 25kW/33.5BHP CB500 restrictee.
Basically, it seems to be down to the T&C's of the company you deal with, and of course it could get sticky because some sales bods can and do lie! (personally i suggest recording the conversation if you are concerned of this because there is a lovely law i've heard of - but not checked into - called estople, that apparently means they are bound by their word, so if a salesman representing the company says you're definately covered if you can provide a dyno, then you are, and you can take them to court/the FSA regarding that if they try to U-turn).
3) Why would Honda produce an official restictor kit if it was illegal to use it (there was not even a disclaimer anywhere on the kit i purchased - i just received the bits and a sales receipt through the post). Surely that would've open them up to lawsuits from Joe Public without a disclaimer? Unless of course, restriction certificates are bull (logical conclusion, no?).
So essentially, as i have the insurance company on board, and a valid restriction that i have LEFT IN, i feel i have nothing to fear in court (assuming it even got that far, as my engine air intake plastics have the characters "2 5 k W" engraved into them, which can be seen without having to remove any bodywork - i believe this would satisy most coppers). So happy 33.5BHP riding to me, with a total cost of £33 (parts) and a couple of hours labour!
EDIT: WEST YORKSHIRE POLICE CONFIRM THAT CERTIFICATES ARE NOT NEEDED:
I would like to draw everyone's attention to this thread on Bike Chat Forums, in which a member called "sickpup" claims to have emailed West Yorkshire police, asking what proof of restriction is required, to which the police replied with:
If someone has an alternative view to this they can debate with me, i'm happy to hear about it. I would also like to openly invite comments and corrections, please get in contact. I believe this is something that should be discussed in detail.
This guide (currently v4) was originally produced and published on http://blackmotorcycle.webs.com/
NB: If you want to reproduce this guide elsewhere, feel free - but it must be included in it's complete form (i.e. including every paragraph, all the disclaimers and this message).
Please note this page is intentionally mistitled, as the law is actually a 25kW restriction, which is around 33.5BHP - but for the sake of simplicity everyone calls it 33BHP.