I've just fitted some short "silencers" made primarily for British bikes.They came with 3 reducers,they didn't grip the exhaust pipe,looked ugly too,then I found some reducers,on ebay, stainless 100mm long 35mm inside dia stepped up to 41.27 mm outside dia.The silencer fitted perfect the exhaust pipe side I had to slot with my dremel.The overall fit in my opinion is good,the sound awesome.They come in different sizes tooThe pair for £18. free P&P.I'll post a couple of pics if anyone is interested