Maybe Big John can help with this coz I found it quite interesting

Ian, as far as I remember he was an ex Rolls guy who made pumps. He also had a thing for Scotts and updated the design and slotted it into a Seeley frame. At one point my dad was seriously thinking about buying a Silk.

Anyway he took some of the IP he'd developed for the road bike and made a trials bike with a monocoque chassis and a dual range gearbox. The jingoistic UK motorcycle press made a big song and dance about him challenging the Spaniards and then he faded away.

I have a test of the Silk road bike somewhere.

*edit* The idea of the s/arm pivoting about the gearbox sprocket has been taken up by BMW who use it on their (now discontinued) enduro bike.

Edited April 17, 201016 yr by TooFastTim

Ian, as far as I remember he was an ex Rolls guy who made pumps. He also had a thing for Scotts and updated the design and slotted it into a Seeley frame. At one point my dad was seriously thinking about buying a Silk.

Anyway he took some of the IP he'd developed for the road bike and made a trials bike with a monocoque chassis and a dual range gearbox. The jingoistic UK motorcycle press made a big song and dance about him challenging the Spaniards and then he faded away.

I have a test of the Silk road bike somewhere.

*edit* The idea of the s/arm pivoting about the gearbox sprocket has been taken up by BMW who use it on their (now discontinued) enduro bike.

Thanks for the insight TFT - really interesting

My Dad helped develop the silk trials bike.

It got changed from a monocoque to a traditional tubular frame.

Even though the swinging arm pivot was same axis as the gearbox shaft giving consistant chain tension I remember a tensioner was still added as it seemed to make the bike smoother on low revs as it kept the tension more consistant.

My brother rode it in an A & B natioanl at Brimham rocks. Must of been about 1981.

The gearbox was the best. 4 gears + high and low ratio giving a total of 8.

Was great for those sections where you thought 'I need second and a half' select 2nd gear & high ratio and bingo!