Some of you may have read my post at back in April about a custom cut I was experimenting with to create a front specific version of the Schwalbe Hans Dampf. While I was happy with the results of that cut, I decided to try it again but with a more aggressive cut to reduce rolling resistance even more. The result came out even better than I had hoped. Rolling efficiency is much better while the resulting loss of braking traction is almost imperceptible. Meanwhile, cornering traction is exactly the same as a stock tire because the cornering knobs aren’t modified.
In the first version I made my ramp cuts just in front of the sipe on the center knobs. In version two I started the cut just behind the trailing edge of the sipe and cut almost down to the casing on the leading edge of the knob. This really decreased the slope of the ramp on the knob to reduce rolling resistance. I then went a step further and cut 1-2mm off of the top of the remaining flat section of the center knobs.
For the wide spaced center knobs I did a deeper diagonal cut to decrease the slope of the ramp on them as well. The new version cut starts at about 45% of the diagonal width of the knob, whereas the old version started at roughly 30%. On the inner transition knobs I went just a tiny bit deeper on that cut so that these knobs match all the other smaller knobs to ensure a smooth roll.
Of course doing a cut this complex is time consuming. I put in about 45 minutes from start to finish. I can hear the haters now, “Dude you could have been riding 45 minutes longer! Why bro? Why?” To that I respond, ‘You gotta recover some time. Using that time you normally waste in front of the TV to make your tires a bit quicker, is time well spent in my opinion.’ Besides, if you are doing any enduro racing, having a faster rolling tire that gives up almost nothing in the braking department can only help you move up a few spots in the finish results.