Least noisey trialer

[Wingboy]

Originally Posted by Bob_M

I'll be in the market as soon as i sell my Ducati. ??

WHHHHHAAAATTTTT?

Sorta like selling one's soul to the devil .

It's ok,i have another track only Duc that is staying put.
The one in the middle is for sale.

[lamotovita]

Originally Posted by tenorjazz

Hope you don't mind if I open this Least Noisey Trialer question up just a little....

I'm riding an old vintage Bultaco, and it isn't very quit at all. I have been trying to come up with a way to make it as quiet as possible. Anybody else interested in making their vintage trails bike quieter?

I first took a stock exhaust and added an internal spark arrester which cut the DB's by about 5 then I modified the end of the pipe with a custom do-jiggy that cut it another 5-10 db. A lot better, but still not where I want to be. I had another muffler laying around so I cut it open and stuffed it with this ceramic fiber material that I use on the outside of my pottery kiln, it didn't work. I have an idea to build a custom muffler with all kinds of baffles in it and see if that will work.

One of the more interesting things is I found to help out were a couple of iPad DB meter apps. I just run the bike next to my iPad and can see how I'm doing.

The next thing you need to do is cut all the fins off the cylinder and head, then build a water jacket around those parts. you can mount a radiator on the fork tubes. That will make a big difference. You could probably coat the primary case with automotive bed liner or something similar for further sound reduction.
By the way why don't you post a photo of your bike in the Vintage Trial thread on this forum. We like to see the old iron.
http://www.advrider.com/forums/showthread.php?t=731048

[DerViking]

A snorkel that points the pipe down a bit can help with perceived volume, but may not fool a DB meter.

I have always thought my Gasser was as quiet as anything. If you work at it, you can be super stealth on the 300, as you can do most intermediate moves just barely off idle.

The Beta Rev3 ive spent time on is comparable in sound level, not bad at all.

My xr650r is deafening wide open, and I have to wear ear plugs when out touring. But on trail, at low throttle, is really isn't that loud, though it seems much louder to me than my old KTM 250EXC. Awhile back I was on a ride, met up with 2 ktm smokers, joined up and rode a trail around a set of hills. My dad was trialsing with the dogs on the hill (big hill, maybe 750') to him the XR was no worse than the KTMs, and none of them were very loud, which I found interesting.

That said, some of the really barky 4 strokes are just obnoxious no matter how you ride them.

[ADW]

Originally Posted by tenorjazz

Hope you don't mind if I open this Least Noisey Trialer question up just a little....

I'm riding an old vintage Bultaco, and it isn't very quit at all. I have been trying to come up with a way to make it as quiet as possible. Anybody else interested in making their vintage trails bike quieter?

I first took a stock exhaust and added an internal spark arrester which cut the DB's by about 5 then I modified the end of the pipe with a custom do-jiggy that cut it another 5-10 db. A lot better, but still not where I want to be. I had another muffler laying around so I cut it open and stuffed it with this ceramic fiber material that I use on the outside of my pottery kiln, it didn't work. I have an idea to build a custom muffler with all kinds of baffles in it and see if that will work.

One of the more interesting things is I found to help out were a couple of iPad DB meter apps. I just run the bike next to my iPad and can see how I'm doing.

Try one of these: http://www.thedbsnorkel.com/
I've not used one personally but they're premade, ready to go. Might give you that next step you're looking for.