Cone filters

[Mozza]

Hello just a quick enquiry about the legality of the cone filters attached directly to the carbs I keep seeing on cafe racers. Are they road legal? I run open air filters on my xt660x and they aren't technically road legal but are hidden under bodywork so I would have thought it would be the same for the cones. Plus if I do fit them is there any extra considerations I need to make regarding the carbs seeing as though they mount directly to them.

[K2-K6]

Don't think they come into a legal framework for the road, more likely to be observed by insurers as modified and subject to their own policy disclosure practices to make sure you are covered legally.

I'd guess that in the grand scheme of things then if original kit was not used a suitably safe alternatve would be reasonable in the view of many.

[Bryanj]

The only "legal" part of the induction system is that the roar may increase the driveby noise to above the legal limit---but as there wasn't one in the 70's that don't matter

[SteveD CB500K0]

You get up too early Bryan...

I would have said: "Modern bikes make more induction noise than exhaust noise (at least with standard cans) which is why they have such huge airboxes. For MOT purposes (theoretically) any modification that allows more noise than standard is a fail."

But as Bryan says - those rules are not retrospective.

[florence]

That's why I love old bikes, you can use whatever filters and exhaust pipes you like as long as you don't go mad.  I've got aftermarket filters and a laser pipe and the MOT man doesn't even mention it. 

In addition to this you only need one working brake light switch and no side light or indicators are required.  I have even MOT'd a bike with a homemade exhaust pipe.  All in all this makes them very cheap to run and maintain.

[matthewmosse]

It's why most of my bikes are pre 85 models, bypass a whole lot of the rules, I di ironically run with most of the things that you can get away without though. It just means if something stops working then I can pull it off to get an mot  rather than fix a niggling electrical problem, a worthwhile concern if you only have a bike licence and don't particuarly like getting cold in the shed. I ride the wheels off the bikes in winter (minimal maintenence) and spend summer fixing them. Ironic factor with this, my 1974 honda has suffered less from a decade of all year riding in terms of rust than my 125 rebel that I'm using as a stopgap til I get some shedtime. That's needed welding in both of the last 2 winters. I geuss that quality must have been better.

[Mozza]

ok then im sold i think i will get some. does anyone know where i might be able to buy them?? the bike i bought didnt come with an airbox or filters at all (or mirrors, indicators, most of the wiring......the list goes on) so i would probably be saving money and time just fitting the cones.

[florence]

I can sell you a standard airbox if you want one, that would be cheaper I would have thought.  Make me a sensible offer.

If you use a standard airbox you won't have to play around with different jets in your carburettors.

I've also got a mirror, indicators etc, let me know.

[Mozza]

if they are all standard parts im going to have to pass i'm afraid as im turning it into a cafe racer. so bar end mirrors, led indicators etc is what im going for which was also one of the main reason for the cone filters as it would beef up the noise and give me a bit of a boost (however small it may be) in power.

[florence]

Good idea, I prefer non standard which is why I have a standard airbox spare and not on the bike.  I bought it in a job lot of spares and wouldn't dream of fitting it. 

However, I am sure it will be very useful to someone.

[SteveD CB500K0]

K&Ns were our choice back in the 70's

You will need to re-jet the carbs though.

[Mozza]

Think I'm gonna have to give k&n a call they don't seem to have them on the website at least not for my bike, although I think I'm thinking a bit far ahead yet I have only just stripped the bike down ready for sandblasting. I'm just seeing what my options are.

[florence]

I use SB filters on mine and I must say they are marvellous.

[Mozza]

Which ones do you use? First time I have ever heard of that company. If you don't use the standard airbox how are they mounted?

[matthewmosse]

Custom fastners in Newtown sell S&B filters plus a few other goodies for the 500/4 like shock absorbers. Be aware that to fit S&B filters you'll need to kinda squash them sideways to clear the frame. I fitted a set for a while but decided the re jetting was too much of a chore so went back to standard kit (still got them in a box somewhere along with a custom battery and elecctrics boxes that were to go on a 550 chop I gave up on). I mainly got them as I was testing a few unknown engines in the bike and was right royaly fed up with fighting the standard airbox into place. Another place I think is closer to you that may well be worth a visit is JW motorcycles near Borth. He builds racing speck frames for classics including the 500/4 as well as stocking a good range of parts. Also knows his onions when it comes to older (and probably new) bikes.