Studying your photos have given me some ideas how to attach my Xootr crossrack to my Birdy's head tube.

Just some questions on the rear suspension rubber bush: You mention it's more progressive. Now I know what that means but I fail to see how it is much different? Seems to me one rides with the bush under a certain compression and therefore a certain spring force; road movement would result in deviations around that operating point just as with a normal bush. The only difference I see is with a depression in the road which would cause the bush to more gently decompress and with longer movement... a sinusoidal movement would result in a lop-sided sinusoidal response... but the catch is the catch - it stops response beyond a certain point and so lops off the lop-sided sinusoid resulting in a little jar as the catch catches? (Sorry for all the double-talk.)

I suppose I may have to try something...