In the past I've used exhaust tubing.
The bushes are usually split, and don't take
Much to fit.

PVC pipe long enough to cover your for tubes and piece of soft timber and a hammer to tap the PVC and drive in ya seals

you actually need 2 pieces of PVC the outer piece close to the outer edge of the seal and the inner as protection........plenty of helpful vids on U Tube showing the whole process any plumbing outlet will carry all the sizes depending on your bike or some times you may be lucky at Bunnings