Cracked Peashooter

Just out for a ride on the 920 this afternoon, & stopped in a convenient wooded area for a pee. As I got back on the bike I noticed the left hand silencer or should that be amplifier!!?? had cracked through the tube which joins it to the exhaust pipe, which was keeping the plot together. Two miles from home it broke further up & had to rely on the rubber bobbins.
These Peashooters were purchased less than 3,000 miles ago to replace the ten year old ones which had also cracked within a few miles of each other. When I fit them I make certain that they bolt up with no stress & they have all been British made.
Does anybody have any tips/suggestions?
Cheers,
Martyn.

Norvil sells EXTRA soft Iso's ,these induce more shake ..have you got the soft ones...? Just a thought.

Never experienced this in 130,000 miles. It's either the quality of the silencers or the way they're mounted. Were the last pair that cracked of the same manufacture as the recent ones? Are the exhaust pipes the correct shape and do you have the correct mounting plates for the exhaust system? Lastly and partly subjective, how much does your bike vibrate?

Should add I've not had the same silencers for 130,000 but never had problems within that mileage.

I put lowball ones on mine and both cracked in the same spot within a few thousand miles of use. Since they were trashed (and cheap) anyway I just welded them up and kept on going.
FWIW

130.000 you are the man to ask about durability :!:

The ISO rubbers & silencer bobbins came from Andover Norton. The pipes from Mick Hemmings when I purchased the first Peashooters. These were the type with the Norton logo engraved/stamped at the end. The bike is very smooth, even smoother than before the rebuild. The only thing that is getting less smooth is the disgraceful state of the roads! The mounting plates are also correct, so it would seem to be a quality issue. Work hardening or embrittlement caused by plating perhaps?
I did had a similar problem with a pair of stainless exhaust pipes on my 750. These broke on the heat effected zone of the welds. Ha ho!

Pretty annoying nerve wracking when exhaust breaks up on the fly. We can list all the possible failure factors but which of em actually apply in each case and how do ya know before hand, so just some or have to throw more money at it till or weld bead before finding some lasting joy there. No matter how soft the off the shelf iso cushions the front one can all stand some bench grinder beveling some rim down. Ahhhh so.

Ahaaaa -so grasshopper. Relieve stress points every opportunity. :roll: