Eric F 

I've been running IRC Boken Doublecross 38mm tires for a bit (https://www.bikeforums.net/cyclocros...oss-tires.html), and I like them a lot for the riding in my local area. They're tough, predictable, and provide good grip in my conditions. As I've spent time with them, they don't seem to roll as efficiently on pavement as I felt initially. 2 weeks away from BWR-CA, I'm having second thoughts about them as my tires for the event. My previous Pirelli H/M 40mm combination was really good all-around, but those tires on my rims end up with almost no room between the chain stays (they measure over 42mm, installed), and I wasn't comfortable with that.

Comparing the smooth surface rolling resistance of the IRCs and Pirellis, it looks like the Pirellis are approx. 10w more efficient. Of course, there are a lot of factors to tire efficiency, especially when things aren't smooth, but 10w was enough to catch my attention, and confirms what I was feeling on the road. For everyday riding, 10w is pretty meaningless. For a 5+ hour event, with a large portion on the road, those watts are going to be helpful nudge towards the finish line where I'm anxious about whether or not I will be able to finish.

There's a ton of tire options out there, and everyone has their opinion on what's "best". Koyote's mention of WTB Vulpines certainly caught my attention, and I almost pulled the trigger on those. I also looked at some of the other IRC offerings that would roll better than the BDCs. My brain kept going back to the Pirellis, however. The fast-rolling H on the rear, combined with the dirt grip of the M on the front, was a combination that worked for me....so I ordered a set in 35mm width. On my rims, they will probably measure out at 37mm+. Being a bit lighter than the IRCs isn't going to hurt anything, either.

The new Pirellis were delivered today, and will get their first run on Saturday.

Koyote

Eric, I'm always hesitant to change anything out so close to a big event. (Ha! Says the guy who just came in from the garage, where he was mounting a new saddle -- less than 48 hrs before a race. ) BUT: you don't want to head into an event with tires that are not inspiring confidence. Seems like you probably made the right decision.

FYI, the 40mm Vulpines continue to impress me. I do notice Orange Seal on my rear triangle sometimes after riding, but they seem to seal up nicely -- I've not yet had to stop and pump air into a tire. I've also now bought a pair of the same tires in the 120tpi "SG2" variant, which comes with a puncture protection liner. They weight only about 45g more per tire (as per my kitchen scale), but are apparently even smoother-riding. They'll go on the bike when the non-SG2 Vulpines are worn out.

Eric F 

I have 2 weeks. If the 35mm Pirelli experiment doesn't play out, I can go back to the IRCs. I think I have a good idea what to expect from the Pirellis. Dialing in the pressure is going to be important.

I may still try 36mm Vulpines, but not until after BWR.

dwmckee

What Kyote said. Plus for quickly dialing in tire pressure I suggest trying the Silca tire pressure guide. I find that it is always within a PSI or two of what I want. And use a separate high quality digital gauge because most pump gauges are not very accurate.

t2p

Conti Terra Speeds are relatively light and roll really well on hard surfaces including pavement

Eric F 

Noted. Maybe something for me to try in the future.

Eric F 

Pirelli H and M 35mm tires installed. This is the first set of tubeless tires that I have been able to get on rims without the use of at least one lever. The rear tire pumped up easily with just my floor pump. The front needed some help from a Airshot canister. The valve cores that had been on these wheels were gunked up and not flowing air very well. I scavenged replacement cores from some used tubes and got everything working properly. Even without sealant, they are holding air pretty well. I'll add sealant this evening, and take them out for a ride tomorrow afternoon.

Eric F 

Test ride today…It may be confirmation bias, but the 35mm Pirelli H/M combo feels fast. The perception was that they are quicker to get up to speed and roll easier than the IRCs they replaced. I expected the slightly narrower width to feel a little more sketchy, but they weren’t at all. I pushed them a bit on the moderate singletrack sections that I frequently ride on my gravel bike, and they were great. Being narrower, and running a little more pressure (42psi), the ride was a little harsher, but it wasn’t dramatic. Dropping about 100g of rotational weight is a bonus, too.

For my needs at BWR in 2 weeks, these tires will be my pick.

Eric F 

Follow up...The Pirellis were 100% the right call for BWR. On fast paved downhills (coasting), they proved their rolling efficiency by easily keeping pace with my buddy on 32mm Gravelking slicks. In the dirt, the front tire traction was excellent when I needed it to be, and the rear grip was notably better than folks on slicks. Being that our route had us off pavement more than half of our riding time, they were great. For me, this combo is a winner.

t2p

good to hear the Pirelli’s worked well

yikes - friend was on 32mm GK slicks ... not a fan of GK slicks - especially in 32mm
size

Eric F 

He did well on them, but he’s also a very skilled rider in the dirt. His skills saved his @$$ a couple of times.

phrantic09

I would give the Speedero or Thundero a shot when you have a chance. The Thundero is pretty quick, especially on dirt

Eric F 

There are a ton tire options that interest me, including the Tufos. Also on my list is the Challenge Getaway, which BBR tests at about the same as the Tufos for rolling resistance.

For the immediate future, I'm going to stick with the 35mm Pirellis. I'm really happy with the combination of different treads on front and rear, and I don't have any events I'm currently targeting where I might want to further optimize performance. For now, I'm, just going to ride my bike.

phrantic09

I’m excited for the P-Zero Race TL coming out in 35 and 40mm sizes. Those things will be great summer tires for the dirt around here.

SoSmellyAir

Bike Closet has the Terra Speeds in 700x40c on sale.

$35 for black sidewalls: Continental Terra Speed 700 ProTection TR + Black Chili – Bike Closet
$40 for cream sidewalls: Continental Terra Speed 700 x 40 Cream Sidewall Fold ProTection TR + Black Chili – Bike Closet

$10 shipping regardless of how many (or few) you buy. So I bought 3 black ones plus some clothing.

Time to setup my existing Maxxis Ramblers tubeless, just for practice.

tempocyclist

What what now? Imma be straight on those in the 35's for sure!