Thruxton How To Remove Baffles From Eu (not Us) V&hs?

Thinking that the C-clip with welded spot applies to both US and EU spec V&H slip ons, I decided to remove the baffles from the latter fitted to my Thruxton R, safe in the knowledge that if this modification turned out to be too loud, I could simply refit the baffle and clip to each can.

It turns out I was wrong as I can't even remove them in the first place; instead of the C-clip with spot weld that I expected to find, I have a restrictive contraption welded in place in at least three places that I can see - and perhaps more that I can't.

See this photo shot from inside the exhaust pipe looking towards the tail pipe.



Can any forum member who has done this mod to a 1200 Thruxton with EU V&Hs please share their experience of doing it and subjectively, how loud the end result is?

 

Thank you, Andy.

That's mega-helpful, especially with the photos to visualise your explanation - even if once done, there's no going back! I've already taken the intake snorkel off so will try the V&H mod before deciding whether to de-cat.

 

One further question that came to mind on the ride home from work (on my owned-from-new 1998 Honda Hornet, shhhh). As beautiful-looking, massively capable and 600 sportsbike-quick as the Hornet is, the exhaust note is bland even with the equivalent mod having been done 19 years ago to what we are now discussing for my Thruxton R. This is especially-so on the overrun where it just makes less noise. No soul.

If I make the above modification to the Thruxton's V&H cans, will I lose the lovely popping and burbling on the overrun? It might seem trivial (and it is in the scheme of things) but I do rather like it.

Thanks, Andy or anyone else with such experience.

 

Cool, thanks! My train of thought was that because the Thruxton pops more with the V&Hs - which have more baffling than the standard cans - opening them up would remove this characteristic.

Cheers!
CR

 

BTW Andy - Nice paddock stand! Which one is it, please? I currently use a Oxford Premium Paddock stand but need to modify it because the leverage isn't enough for my wife to lift the bike whilst I hold it vertical; she prefers not to do the holding and I prefer not to routinely try and do the lift by myself even though I can.

Your paddock stand looks perfect as the amount it lifts the bike is much less than the Oxford stand, and with what seems like a similar length lever, the mechanical advantage will consequently be greater with yours.

(I've just noticed your stand is on a lift, so hope they are not part of one item!)

 

Thanks, Andy

Close-up the welding seems to leave something to be desired - at least on the image in the ebay advert - so I will go ahead and get a price for having my Oxford stands cut down and compare with the ebay option.

Cheers!

 

A tip for anyone else doing this baffle mod.

From the exit end, the inside diameter of my V&Hs is 41mm so I took a gash piece of 50mmx20mm softwood and made a plug with my 42mm hole saw. I then sanded the plug evenly down to a fraction under 41mm in order that it could slide inside the V&Hs without getting stuck.

5 minutes' work well spent as the plug then dropped perfectly inside each V&H where the 5mm pilot hole from the hole saw stopped my 5mm metal drill from skating around. The result was two nicely central 5mm holes that I then drilled out to 10mm. I'll listen to what the result sounds like before I go any bigger; if necessary I can go up to 32mm with my step drill bit.

Whilst the mod can be done with the cans in situ, I removed mine in order to have better control of the angle I drilled at as well as let the swarf drop out; not necessary, but to my mind preferred for a tidy job.

Stand by for another post over the next day or so.

 

Today's update.

With the catalyst still in place, the 10mm hole in each V&H baffle has made the square root of bugger all difference to perceived sound and noise level at idle, full chat or anything in between. As indicated from posts I have read it certainly seems that the cat is the most effective baffle in the system!

As the next stage though, my step drill is currently at a local metalworking shop being welded on to a 20cm metal rod to allow it to reach to the baffle. I feel a pair of 32mm holes coming on - the largest that this drill will make in the 41mm baffle.

 

Thanks for the link, Taipan. Although I won't be doing it, still interesting to see.

A local welding shop made my step drill extension today, so this evening I drilled the baffles out to their maximum diameter; they are in fact a long perforated tube, originally with end closest to the exhaust outlet closed, so when this is drilled out the baffle becomes a pipe that is open at both ends.

I ended up putting the cans back on the bike for the drilling because as the step drill reached an ever larger diameter, so the torque became too much to safely hold. The cans therefore need to come back off for me to clean the swarf out - and whilst I'm at it I will polish the cut ends of the baffle tube, but see the embedded image to understand what I described above.


The sound at tickover is a little deeper and louder, so a road test is in order tomorrow before I decide to decat.

One other thing I did was put the intake snorkel back on having ridden for a few days without it. Yes, it made the bike sound like an angry demon being poked with a stick but it had no class and nothing added to the symphony. Just a boom for the sake of noise.

 

Thanks for the reminder to post back after riding the bike with the non-removable EU spec V&H baffles drilled out; as with your US spec V&Hs and to use your words; the sound is perfect, nice and deep with a bit of a growl at the top end. The amount of popping on the overrun is perfect too, so at least for the moment I'll not bother with the fiddly de-cat and x-pipe.