i would suggest purchasing longer fork tubes and not using the fork extensions. i had the 4" screw in extensions on my 650 also and loved it. i bought a set years ago and put them on my 1100. one broke at speed.... it could have been really bad but luckily i was going pretty slow and was able to park the bike, and then change my pants. PCS used to have the longer fork tubes but it looks like they stopped selling them. a quick google search came up with a couple of hits for 41mm extended forks. you could contact the sites and ask it those extended forks would work on the 1100.

zonker

I know several that tried it.....most had the same result as Zonker. Definitely could be a safety issue and not recommended.

Just so you know.......the 1100 and 650 fork tubes are almost identical. What threads into a 650 tube will thread into an 1100 tube. So it can be done.......i just know I'd never do it after seeing all the failures. 

I went with longer tubes from Frank's Forks a number of years ago. Never had an issue.

Thanks Mick,

there don’t seem to be anywhere in the UK to get longer forks so I can import them from the States, I think I will do it that way.

Much appreciated,

Austen