Anybody fitted one?
Not looking for “performance gain”, its just because the cat can hanger bolt has sheared AGAIN - once at 2500 miles, now at 11500. What a poor design!
I guess that now we definitely know for sure that high-tensile bolts are still weak in shear!
Getting a bit tired of this, so thinking of dumping the cat and getting a remap to suit once the warranty is up.
The MIVV system looks good, but I’m guessing there will be quite a few out there to choose from.
Just a thought. Not all bolts are made equal. Have a look at Unbrako bolts. Forged heads, radiused, rolled threads and heat treated.
I’ve been wondering about the de-cat pipes that I see on sale, primarily how you’d get through an MOT, as I presume the test will check emissions don’t exceed the Guzzi original design spec to comply with the ‘construction and use’ regulations?
I’m dreading to see how the V100 exhaust box survives a winter as it doesn’t look that robust compared to the stainless steel ones I’m used to, which is what got me to thinking about options.
I think the cat box IS stainless, it just discolours when it gets hot. The main issue is the weight hanging off that stupid bolt which is only anchored at one end, coupled with the vibration.
There is no emissions test in the MOT for motorcycles and I’ve got a feeling that for reg 61 Construction and Use Regulations, motorcycles are classed as “exempt vehicles”, though not sure on that one.
Cheers Speedy. I’m no engineer so it may be my terminology but the manifold box under the bike definitely doesn’t look ‘stainless’ to me compared to the shiny confections I had on previous bikes, it’s manky already after a few summer months, hence the doubt about winter. Just to check we mean the same thing it’s labelled number 1 on the attached diagram
As for Reg61, I’m not sure either as the Gov website on motorbike MOTs says the test will check that the exhaust is ‘secure, complete and not too noisy’ Motorcycle parts checked at an MOT - GOV.UK.
Your guess is at least as good as mine regarding whether the absence of a Cat would mean the exhaust system was ‘incomplete’. One way to find out, but it could be expensive!
On digging further into the Government’s MOT inspection manual for bikes, there’s no mention of completeness or emissions, just noise and secure attachment: MOT inspection manual: motorcycles - 8. Exhaust noise - Guidance - GOV.UK.
I think I just answered my own question!!
Hi again. Yes the cat box is “stainless” it just discolours easily. It doesn’t actually corrode as such. There was a very similar material on my last FJR 1300.
As far as “completeness” goes, it just means that if the system was designed with headers, collector and mufflers, they should all be there. Only no-no is if the system is marked “off road use or race use only”.
There again, peeps have been known to put stickers over these, as the tester is not allowed to remove them…
Bit like the cops in Amsterdam ( Jules & Vincent conversation in Pulp Fiction…) 
the test is to make sure it does not have emissions above a stated level, not to test it is the same as it came out of the factory.
euro5+ has not changed the emissions levels from euro 5 but specifies the vehicle must be desgined to meet euro 5 for a longer period (higher milage).
I’ve put a euro 3 bike through mot with the cat removed a few times and it still passes every time.
I think remap/v boost being fitted is something to consider before MoT time.
I have kept my original exhuast for my euro 5 V85TT but will hopefully pass MoT without refitting it.
Euro 3 bike I refitted the cat because the replacement pipe had got too tatty anyway but its an easy swap.
I’m seriously considering fitting a decat system as the cat fitted is so ugly and for something supposed to be stainless looks really cruddy. Corrosion resistant maybe but surely not 316.
it does get a bit tatty looking in winter, but so do the mistral header pipes if you ride all winter like i do 
the big benefit is the engine runs so much better and doesnt feel like it’s being held back.
riding modes actually do something after decat, with it on they are barely noticable apart from the traction control being more aggressive in rain mode. throttle response in sport mode is noticably sharper now.
Should be an old post somewhere about of mine. Covers the Chinese v Mistral de-cat, pro’s and cons as well as the current situation regarding mot rules and modifications to the exhaust system. We compared the system side by side with the standard set up.
