Brett Hahn knows his stuff when it comes to tires and tire design. He's the Brand Manager for Continental, here in the US and based in Durango, Colorado. We spoke about the rapid evolution of Plus sized tires from three inches to the increasingly popular 2.6-inch casing size, and also about the effects that wider rims have had upon tire design. To start the conversation, Brett asked me about my thoughts on the 2.6-inch size.
I challenged him that tire makers were either unwilling or unprepared to develop new manufacturing methods that would result in a lightweight laterally stiff plus-sized rim and tire combination, so the 2.6-inch tire seemed to be the perfect balance between using off-the-shelf technology to make the widest possible tire that would be both lightweight and durable.
We can affect tires with dimension or volume. We can affect it with material, and we could concievably affect that in terms with how we lay it up, but that's where we stumble a little bit. This thing ain't broken, but its not serving out current needs.
So, now we have half the psi...
Half the psi, so we've lost a structural component (air pressure). We've lost the inner tube, which was also a structural component - but we're all in that together. We didn't want the inner tube. It did some good things, but it also did a lot of things bad. It pressed the bead into the rim. It was actually a support, even though it was a pneumatic structure, just the same. So, we've come back to material, volume and pressure. We can increase volume and play with air pressure as a structural component, but we don't inherently change the three-two overlap of how a tire is constructed.
How does rim width and the tread profile play into that equation?
If we can actually go to a lower profile and not have to have that "lightbulb" shape anymore. Now, we can actually reduce some weight there, and change how that tire rides, and that does work in that 2.6 volume. It doesn't work in a 2.8 and beyond, and it doesn't really work in the smaller volumes either. Although, we have changed out profiles overall - at Sea Otter, you'll have a slew of things to think about. We revamped the entire range to fix up all the sizing. We had a few that were under size and over size. and on different rim widths, some patterns were not working out. If it says 2.4, it's legitimately a 2.4.
We are also changing that casing shape, recognizing that when we first developed those tires, rim width was 20 millimeters. Now it's a whole new game. We've changed all that collectively throughout the entire range, but we haven't really changed the tire's construction. What we are relying upon, is again, that shape and that volume component. So that's where we are regarding 2.6.
Are these lessons learned from Plus-sized wheels, or an evolution sparked by enduro and all-mountain riders trading up to wider rims and tires?
I don't want to call 2.6 a mistake, but it was an, "Oh, wait a minute minute! Look how well it works on all these regards: with shape, fitment to those wider rims, with the prevailing dimensions that are out there. But, 3,2 died on the vine - it was too much; 3.0 was okay, but that was the infancy of Plus, and we realized that was still too heavy, too vague, and too bouncy. Then it dropped to 2.8 and it started to get way better. It shines for the average Joe who can benefit from that wider footprint and won't get punished for missing a line, and bike packing, even though it's only a sliver of the market, it shines there as well. The last piece was that enduro, that performance rider, who really didn't want that bigger volume and, bingo, 2.6 was the answer.
What did Continental settle upon as the optimal rim width for the foreseeable future?
We went to both sides, We understand that cross country riders are still going to run a narrow rim. The enduro all-mountain guys are going to run that wider, 30 millimeter profile.
Thirty millimeters is not very wide right now, but it was huge when I was first talking about it...
The rims arguably went too wide. Out to a 40? One, you didn't have very many tires that would stay on that profile. And, Maxxis did come around with "Wide Trail" pretty quickly to address that issue, but right about the time they did that, everybody woke up and said, "maybe 40 is a little too much," and we brought it back down to something realistic. So, we're back to 30 and, thankfully, that allows a lot of tires to work just fine.
What do you think an enduro tire should weigh?
Sub nine. If you can get reasonable durability and it works for a broad scope of conditions and for majority of riders, if it's under 900 grams, I think it's okay.