RM 85 mini dirt bike exhaust

[TheWizard]

I was just wondering if anyone is currently using one of these RM 85 or CR 85 style exhausts on their bike. I used to use a SBP expansion chamber and I felt a noticeable difference in performance, but did not like the way I had to mount it on my bike. The baffle seemed cheaply made because my dad had to re-rivet it twice and the whole set up just created more vibration on my bike. Maybe it was the mounting method, I don't know. At the end, I was just not happy with it. I removed it and went back to my speed demon pipe. It sounds way better and no increase in vibration. Still trying to find the perfect pipe, I was looking into one of these RM 85 or CR 85 exhausts to put on my bike. I have plenty of room, and I do realize it would have to be a custom install. I already have someone that would do it. I just wanted to know if anyone is using one now or has used one in the passed. Do these style of expansion pipes really do work? Is there a substantial power increase in bottom and top end? Will I notice more vibration? Any advice and information would be greatly appreciated. Thanks everyone!

 

[culvercityclassic]

I used a ktm 65 pipe and the bike runs great, I also did port work, piston work and a big carb. It's like night and day, ride it to work everyday too. Great low and top end performance.

Slice-dice-and re weld to fit.

 

[TheWizard]

Was there any additional vibration with that pipe? And your bike is bad ass! Thank you?

 

[TheWizard]

And another thing, you don't burn yourself on the pipe? That's another question I had for those types of pipes. I see everyone that has one does not wrap it. I'm assuming it does not get that hot.

 

[culvercityclassic]

No vibration really from the pipe, more like from the motor. The pipe does get hot, and it will burn you, it has not been an issue with being in the way tho. This pipe tucks in nice, some may not. Just don't ride with shorts on... Laf

 

[TheWizard]

Lol! That's all I wear is shorts, but I'm willing to chance it. Looks like I'm definitely going to get one. I just installed new front suspension forks with disk brakes. With that new fork, I have plenty of room now between the front tire and the front tube of the frame.

 

[Earbiter]

I just recently installed a yz85 pipe on my bike, nowhere near as nice as above, but I still have some work to do on it. I haven't noticed any additional vibration. My install does stick out a bit tho, making peddling... odd to say the least. Power increase was great, lost a little bit of low end but mid range and top end were a huge improvement. I still have some carb tuning yet to do tho.

 

[TheWizard]

I saw a video on YouTube who has a YZ 80 pipe on his bike. He did something to the rear baffle where he gained more low and top end power. Thanks for your information, and your bike and pipe looks really cool. Here is the link to the video, I hope it works. If not, just search for it on YouTube. Yz80 exhaust on motorized bike. It will come up. Thanks!!!
http://youtu.be/1_kAkipr1jM

 

[Rudz]

He just cut it open, removed baffles and packed it to silence it

 

[exokinetic]

I love me some Dirtbike pipes!

Here are a couple Pro Circuit KX80 pipes on race bikes I build:

If you really want to do it right, google:

"Firebreather CR Machine"

You will find a modular exhaust manifold designed for fitting dirtbike pipes (like the one in your image as well) to our China Girl Engine.

It truly is an awesome set of parts, I wouldn't recommend anything else if you plan on putting a dirtbike pipe on your Chinagirl, or building a custom pipe for that matter.

It is soooo simple, double O-Ring slip fit seal, retained with springs, just like basically all OEM Dirtbikes.

Do yourself a favor and check it out!