Hitchcocks Forum

Hello everyone - hope you are enjoying the summer.

I would like to replace my standard silencer to achieve a deeper tone and wondered if anyone had bought one of our hosts replacements? If so, what was the effect and was it a straight forward job - ie: any other adjustment required?

Also, would I be right in thinking that a replacement would lose the catalytic convertor?

Thanks, Rich

That's something I'd be interested in knowing. I'm concerned that the silencers listed for the EFi range may be too noisy. If anyone has actually tried one I'd love to hear your thoughts.

Don't know about "deeper tones", but when I put a shorty silencer on by iron barrel I had cows stampeding and old soldiers diving into ditches thinking they were under attack again, the noise was horrendous. This might not notice so much in town but echoing around the previously quiet hills in North Devon it was not too popular. Just something to be aware of.

Delightful account, 'ALE'! Thanks for the info.

I fitted Mr H's silencer (91080) to my 2012 EFI about 18 months ago. It is a straightforward replacement with adjustment at the rear end to make it fit in a straight line, unlike most of the Indian torpedoes! It is quite noisy with a 'blap blap' sound but I quietened this down by buying a longer baffle and cutting it down to size (6" as opposed to Mr H's 4"), then wiring some silencer packing to the outside. Sounds very nice and there is a noticeable difference in performance; no need to make any adjustments. I've done about 2,000 miles with it and the sound does improve once the carbon deposits start to build up. Yes, you do lose the catalytic converter so if you change the silencer, hang on to the old one as they cost an arm and a leg to replace.

About ten years ago I had a silencer custom made for my iron-barrel Bullet by Peco (now part of Venom Motorsport?).

In my experience, absorption silencers are the best combination of nice sound and straight-through performance. The big disadvantage is that they get progressively louder as the wadding gets blown out. Some have doors on the side so you can repack them.

Anyway, this company made me a straight through silencer out of stainless steel for a ridiculously cheap price - about £65 I think (this was ten years ago, though). All I had to do was specify the inlet pipe diameter, the diameter and length of the silencer box, and then the tail pipe dimensions. They then made it and sent it to me. I asked them to use a layer of metal wadding around the inner tube, as it is less prone to being blown out. Around the metal wadding was the usual (glass fibre?) wadding. It was ugly, mind: the silencer had a rolled seam at each end, so it didn't look as nice as anything our hosts sell. They also included a wrap-around bracket which I used to fix it to the usual mounting point below the rear footrest. In terms of noise and performance it was a knock-out. I always used absorption silencers whenever I could on my previous bikes. My Commando had them and sounded superb. A limited life due to expulsion of the wadding is their main shortcoming.

MickB... the replacement 'cat' silencers DO cost an arm and a leg, and your second arm and leg... plus your spine!

Does anyone know - do they do an emissions test at the MoT? I ask because if they start doing so, we'll probably all have to stick to the stock downpipes (assuming the cat is in the downpipe).

Motorcycle exgaysts are tested for loydness (an opinion), soundness (hokes and leaks) and markings (not for road use etc). Tgats tge case fir my 2008 EFI anyway. I dont think it would be fair to retrospectively introduce tests. The bikes have to pass Euro IV emissions gor import to the EU - but that is only once at import I believe.

Sorry about the fat finger typing!!!