Saw a couple yesterday at the vic brittain. Quiet (and remarkably similar in sound) as a market traders generator on tick-over, healthy bark when the throttle opened up... didn't seem offensive tho

I changed my mind a bit since I heard the first one, there was one at or club trials the other day so I had a bit of moan at him, he told me he had removed all the restrictors from the exhaust. Then I saw him again a week later with the restrictor back in, well some of them anyway, sounded so much better

So all you 4RT owners out there put your restrictors back in and save our land you know you want to.

Cheers

Chris

the 4 strokes at sheffield indoor was were very loud in comparison. if the noise travels further than a 2 stroke you can guarantee someone will complain with twice the volume bikers are in the minority and we all no what happens when it comes to a vote!

The problem is from a rule book / and legal point of view you have say this is the line in the sand - i.e. 92 db

Now if we conclude that some bikes (be they not maintained two strokes, old British bikes or new four strokes) are too loud then the rule should be changed

In Denmark if i understand it correctly they've moved to a ride by test

The RPM's that are in the chart in the handbook are universally acknowledged to be out of date and thus too low

Maybe it is possible to write four strokes tested this and that way and two strokes another way but it would have to be done in such a way that the industry didn't get upset

Maybe a trials person will do what Derek Elwell did all those years ago and make a quieter pipe for bikes and sell it (and hence DEP pipes)

re residents complaints - you have to show the council that your conducting noise tests, enforcing that and take readings from around the area - every centre *should* have a noise meter operator (or more) - get on to your centre or even Rugby if you are having problems

rabie

The problem is from a rule book / and legal point of view you have say this is the line in the sand - i.e. 92 db

Now if we conclude that some bikes (be they not maintained two strokes, old British bikes or new four strokes) are too loud then the rule should be changed

In Denmark if i understand it correctly they've moved to a ride by test

The RPM's that are in the chart in the handbook are universally acknowledged to be out of date and thus too low

Maybe it is possible to write four strokes tested this and that way and two strokes another way but it would have to be done in such a way that the industry didn't get upset

Maybe a trials person will do what Derek Elwell did all those years ago and make a quieter pipe for bikes and sell it (and hence DEP pipes)

re residents complaints - you have to show the council that your conducting noise tests, enforcing that and take readings from around the area - every centre *should* have a noise meter operator (or more) - get on to your centre or even Rugby if you are having problems

rabie 

agree rabie, and well done with the sidcup 60 - great trial.

if there are any manufacturers reading these and other comments regarding noise on modern 4-strokes then as a middle of the road clubman rider the top end power of a modern 4-stroke is not needed, bottom to mid-ranged power is what most riders need and noise only comes with under performing baffling.

the problem with noise is not really a power output issue, but more weight of the components to curb the noise. if an in-line four 1000cc jap bike producing 160+ bhp can sound less offensive when passing you by at road side using less than half its power, then why do modern 4-strokes trials bike have to be any louder than any road going 250cc bike? - its more a matter of the weight of the silencer (baffling) and not power output that is governing the noise db level. if montesa added 1 kilo to the bike to have it baffled better then surely this is not to much to ask.

torque and mid-range is needed, Sherco are claiming to be producing a lighter 4-stroke bike then montesa, montesa I would have thought would have the means and technology to improve the baffling and maintain the bikes current weight surely

agree rabie, and well done with the sidcup 60 - great trial

Cheers

As for the manufactures, well its up to us (clubs, rides, ACU, etc) to put pressure on them (manufactures, importers, industry) to produce a bikes that are quiet enough that we can ride with out upsetting anyone

rabie

It says a lot when 50% of the people who voted on this poll say it IS too loud, and these are people who LIKE motorcycles!!!!!

2 4RT riders said yesterday that they thought their own bikes were too loud, and that was the worst thing about owning one.

It's not just a blanket 4 stroke thing though, i see a few of the little 125 Scorpa's being worked very hard at trials and they are nowhere near as loud as the Mont even when being mercilessly thrashed.

Come on Montesa/Honda, sort it out.

Edited January 24, 200521 yr by t-shock 250

Hmmm...

Just a thought, probably wrong but wouldnt it be something to do with the scorpa 125 being air cooled? and having no radiator... things like that?

Richard

That would have nothing to do with it. The culprit is the exhaust, as the bike appears to get louder depending on how many restrictors are removed from the exhaust.

Not only the exhaust, but the compression ratio also effects volume. The Scorpa is probably not as highly tuned as the 4RT so the ignition stroke would be softer, therefor, not as loud.

doug's bike has HRC internals and the CC has been increased - anyone know the exact CC size?