I have been using the Conti Ultra 2000 tyres on our tandem, very successfully for quite a while. These tyres have now been discontinued and replaced with the Ultra 3000. It seems like the tyre has a silicon tread. Otherwise they look exactly like the Ultra 2000ís. It seems like these tyres very prone to cutting by road debris. Where punctures were rare on the 2000ís we now get them regularly. I must also add that we are in the middle of our rain season and there is a lot of glass and other debris washed onto the road shoulders. Has anybody else had the same problem with these tyres. Another odd thing is that Conti has suddenly dropped the price of these tyres... very odd.
Keep those wheels spinning !!!!!