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1981 Honda CX500
106 Posts
Discussion Starter · #1 ·
Hi all,

I’ve had this question in my head and cannot seem to find an answer.

Obviously, the original exhaust includes an h-box which is mounted under or to the bottom of the engine. For those who get rid of h-box, most are running various different midpipes to mufflers instead. It is a lot less weight normally when bypassing the h-box.

When bypassing the h-box, I like the idea of supporting the midpipes / mufflers with a second or third mounting point. It seems where the exhaust manifold bolts onto the engine may to be designed to create a seal and to support (emphasis) some weight of the exhaust, I am not sure it’s fully wise to not support the exhaust at a second point somewhere else under the bike or somewhere at the subframe.

My mufflers have
a bracket that line up pretty nicely with preexisting mounting points on the subframe. So I am planning to have a second point of support on the mufflers.

I bring this up because with so many cx500 photos Ive looked at to borrow ideas to mount the muffler up, I don’t see too many that look like the exhaust is supported with anything at all other than being connected to the engine.

Basic question then is it okay to have an exhaust not supported or mounted some place / basically just connected to the engine and that’s it?

Super Moderator
'84 CX650E that is evolving into a GL500
18,946 Posts
What he said^^^^

Mine see more abuse than most (not many of us ride through snow deeper than the footpegs) and I've had them supported by just the header bolts and the muffler brackets for as long as I've had these bikes and it hasn't caused any problems. My current setup has 2 straps supporting each muffler but this set of Harley mufflers are longer & heavier than the ones I've had before and have 2 places for brackets and it was easy to find a place to attach a 2nd strap to the E frame.

BTW: I originally removed the H box on my GL500 back in 2000 because it was in the way of where I wanted to attach the subframe needed to provide a lower front mount for the sidecar plus I didn't think it would survive more than a winter or two and I expected I would replace it with plain exhaust pipe anyway. That was before Murray got involved with producing parts for these bikes so I cobbled together mid pipes from off the shelf car exhaust pipe parts.
When I replaced that bike with Eccles (CX650E based winter machine I'm still using) I used the same subframe and had the same thoughts about the life expectancy of the H box on salted roads so I did the same thing on it.

Those off the shelf exhaust pipe pieces never lasted more than 2 or 2 winters because they would rust out where I held them together with sheet metal screws. The pre-bent pipes I bought from Murray are much better. I installed them in '16 with new aftermarket headers and almost new Harley mufflers; The headers have shed all of their chrome and are badly rust pitted and one of the mufflers spit out a baffle a couple of weeks ago so I'm planning to replace everything but the mid pipes this year.
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