Nah, never do on most things..Leave it open it,ll run for ages..                                                                                                                                                                             

Restrictor kits are just that, they only restrict the engine, they don't actually change it in anyway.

Roachy's restrictor kit for example is nothing more than a set of washers in the inlets restricting the amount of flow and a physical limiter on the throttle bodies restricting the amount you can turn the throttle.

It doesn't affect the way the engine runs at all and someone owning an unrestricted CBR who never turns the throttle more than roughly a third of its total movement would suffer exactly the same restriction.

So far she's done a little over 17,000 miles on her bike in around 14 months and it still runs perfectly.  Oh and it's capable of a lot more than 80, indeed the time it takes to get up to around 80 is probably not much less than a standard CBR.  After that it needs a good run up to get a lot more, but it is capable of a lot more.  I'm not going to print how fast she's been on it, but there has been times when I've been seriously going some to catch her on a mildly tweaked CB1300!

I'm a fan of the two year restriction.  I'm not sure the level of 33bhp is correct, but I think given how cheap very fast motorbikes are nowadays everyone should be made to endure it.                                                                                                                                                                              

Yeah we came to the conclusion that he is a typical 18 year old that knows everything, but hopefully will listen to people who have had the experience of this rather than mates who just want him to show off without thinking of what could happen to him ... or god forbid someone else.

Interesting post .............. as I have just bought a 600 bandit for my son which will be restricted. A mate's son has a restricted 600 Hornet and my mate has ridden it and reckons its the top end that's down, but will do almost 100mph and accelerates almost as well as before it was restricted and will hold 80mph all day. I expect/hope the bandit to be the same. So very much the same as GeoffB

Also had a mate with a XJR1200 that had been restricted and he didn't know  as he had come from a 400, we did wonder why he was forever changing down when he was in top when he was out with us on the twisties. Took it back to the shop, got it de-restricted and he nearly shat himself !!!

The thing with the bigger cc bikes is that most of them are physically a lot heavy so the performance will be relatively worse

So there seems to be lots of contradiction, I'm riding the bandit up to get it restricted at the end of next week, so will be able to tell you first hand, before and after                                                                                                                                                                              

whats wrong with getting one of the newer 250s which i think are all at about 33bhp, i should imagine that they will really hold their value too if looked after. dont think its gonna be long before the testing system is all changed again, in my opinion every one should work there way up in stages, especially the young and stupid maybe you could be allowed say a 600 or over if you are over 25                                                                                                                                                                             

He already has a 600 bandit Julie ... which he posted about before & was advised at the time about                                                                                                                                                                              

Just PM'd you shell                                                                                                                                                                             

just meant everyone generally Shell, rather than being allowed for example an R1 the day you pass your test                                                                                                                                                                             

The newer 250s are pretty neat little machines.  The problem with getting one is that I suspect someone would be bored after a couple of years anyway and then looking at having to spend money to upgrade.

Also, the risk is that those who choose to upgrade could easily go out and get a FireBusaZZR1 and kill themselves on the first corner.

The reason why I like the restrictor system is people, like yourself, can pass their test, get a 500/600 and restrict it.  Then two years later they derestrict it and wahey, they have a new bike!  And although it will be more powerful, it will be a bike they're very familiar with so far less likely to catch them out.                                                                                                                                                                             

yes I agree but bear in mind that if you want to get a bike of a dealer to get it restricted then its very difficult to get a test ride.                                                                                                                                                                             

JJ have you derestricted the honda today? How does it go now?                                                                                                                                                                              

It goes sort of bruuuum bruuuum?                                                                                                                                                                             

ah well bit of a sore point, the two screws that hold it in place are well and truly stuck and i cant shift them being a feeble girly so its gonna have to wait. have had a good run out today and have been able to get as much speed out of it as i can cope with so think i can put up with it a bit longer!

I agree with the 33bhp restrictor system, BUT I don't agree with the 125 rule.

At 33bhp, its like the old 250 rules and there wasn't anything wrong with those                                                                                                                                                                             

Disappointment then. I'm sure you'll find a big strong man to sort it for you. lol. Mind you sometimes the anticipation is better that the actual.                                                                                                                                                                              

Impact driver - that's what you need Julie.

I used to have one, but my ex "recycled" it along with all my other stuff.                                                                                                                                                                             

mmm think I may be able to find a random bloke on sat. will let you all know how it goes,do remember it being a lot more nippy tho.                                                                                                                                                                             

I can comment on restrictors on the VFR400... Mine is an unrestricted NC21 around 60 hp AJ's is also an NC21 restricted to 33. I have ridden both bikes so think I am well placed to comment..... AJ's is down on acceleration and top speed. Although it will show just over 90 mph on the clock.... more than enough for someone who has only passed his test 15 months ago.... and if he wanted to go faster I would be a very unhappy Bluenose... Acceleration wise it is down but not enough to worry about... I still get surprised sometimes at the rate he passes me and is more than adequate for someone with his experience.... We came home from a motorway run yesterday with no problems... the bike was more than up to it.. On the upside.... he gets more MPG.... but i dont care cuz I earn more than him.... On the whole I am in favour of restrictors because I think they allow new riders to have the Big Bike experience yet keeping the available power at a sensible level.....   I have told him if if he painted it Blue and white instead of red and black it would go a lot lot quicker but like most kids he wont believe a word i tell him...... LMAO                                                                                                                                                                             

dont they work like a gastric band  just stop the amount of fuel being pumped into the engine  making it half throtle so long as the engine gets up to full running temp causing water vapure to sit in cold engines  then i cant see how it could do any damage     duno just thought id throw it in there too                                                                                                                                                                              

It depends where the restrictors are fitted. some are fitted to the exhaust headers. each engines power curve is different. obviously, top speed is dependant on highest rpm achievable which if you look at any dyno readout won't be at the highest part of the power curve. Power will drop off before you get to full achievable RPM. kept in its power band a bike with say 50 BHP will excelerate the same as 33BHP but 50BHP will excelrate for longer untill it reaches the top of its power curve with a higher RPM (probably) and higher top speed. Thats probably as clear as mud now.