"Typical continental quality but at a price . GP 4000 are en excellent tyre in either tubular or clincher. Tight fit need to be stretched, look great on the wheels, light, wear well, smooth reassuring feel. Was using Zipp Tangente , but GP 4000 better in all respects and would highly recommend ."
"Purchased for 3 Peaks challenge Australia. (Long Steepish climbs) Normally don't run 28 teeth. Using SRAM force, works well, virtually noiseless. Shifts smoothly despite large cog . Steel spacers between cogs. Quality look and feel. Long Rear derailleur not required , but would say this the limit. Any more teeth( 30,32) and Apex or Force with longer arm may be required."