Dear Mojo, why have you changed the D2, so it only lasts 50 laps, you says it lasts 100 laps. That's 50 less than the yellow label variety, however 150 laps on those tyres and you can still see the dimple and they are still good for practice. The photos here are of white label D2's that have done 100 laps round Whilton Mill Kart track. Who wants to play spot the dimple! A race day is 60 laps here, so that means you have to buy new slicks for practice day. It's insane, and you wonder why karting numbers are down??? Is there any comment from JAG ROTAX ?
This was a bit of rant that I wrote a while back when Mojo, reduced the amount of rubber they put in the D2 tyre. It meant that the tyre had less weight and less mass to heat up, so got hotter quicker and sticker so was a bit faster. That was all great, but with less rubber on the tyre there was no laps in the tyres and the performance fall off was terrible. Once you were passed 60 laps you were loosing 2 tenths every 20 laps. This makes testing any setup pretty much impossible. It also meant that the old way of only buying new tyres for race day was over. The tyres didn't last a race day and the following practice day prior to race day. I used to watch the top teams put on 2 brand new sets of Mojo's on a Saturday practice anyway, so they could keep the tyre out of the setup equation. Not having money to burn (well at that rate anyway!!) that was not an option. My answer was to run testing on second hand komets which last longer with a performance which stays pretty much the same for several 100 laps. At the end of a race week just hover up some of the old Komets being thrown out by the big race teams and practice tyres are done. You have to know the different between these and Mojos and getting the pressures right then becomes an issue. It's all compromises.
I should probably add a picture of good Mojo. Basically they should have 2 dimples visible, but not on this picture, which show how much tread depth is left. As you can see from the photo after one race day at Whilton Mill these have ZERO tread left.
Tyres change all the time and you have to keep trying things to ensure you are getting the best out of them. Most of the time the tyre manufactures deny they have made any changes, but Mojo did actually change the specs on their site stating that the old tyres were good for 200 laps and these tyres were good for 150. So they did admit to the change, I think the amount of change was as can be seen was more like less than 100. Which doubled the cost of a kart weekend.