Anyone have guidance on when to select which of these tires? I have done events successfully on the non-tubeless 40c version. I have though, experienced a few ill-timed flats on the 40c.
I am interested in the 36c Tubeless specific to fight off flats (and perhaps be faster in certain gravel conditions). But, I am leary of the extra weight for climby-er courses.
Regardless of the weight in grams listed on various websites, I am finding the 40c non-tubeless are coming in 80-90 grams LIGHTER per tire than the 36c Tubeless.
Thoughts?
BTW - anyone heading from Colorado to Rebecca's Private Idaho (Sun Valley ID) this coming weekend? I am looking to find a ride for my bike! I am going to fly, but would love to send my bike with someone driving if they have room, and willing to pay.
Update - I did some more measurements of the Tubeless 36c vs. the original (non-tubeless specific) 40c and in some cases, the weight difference is as much as 120 grams (lighter for the 40c).
Also note - When I say above that I have done events on the 40c non-tubeless and experienced some flats, I should say that I also have had a lot of completely clean runs in long gravel races, WITHOUT any flats on this setup. I would say several clean runs, and one or two events where I had cuts in the 40c from bottoming out (pinch flat) super hard, on the front wheel, when I came across unexpected drops and rocky terrain on a course I wasn't super familiar with and was somewhat flying blind.
Thoughts? Anyone ridden a bunch on both and can weigh in?
I've run the MSO 40c (120tpi) as my front tire for about a year and a half. I set it up tubeless with Stans sealant on Velocity A23 rims and it has held pressure admirably since day one. The same couldn't have been said for the USH 35C that I've been running as my rear. In fact, I was so concerned about the USH that I converted to a tube in the rear at 8pm the night before last year's DK200. But I digress..
I have not had a single issue with the 40C non-tubeless tire - no flats at last year's DK200 or at RPI (~40PSI), nor during other more local to me races and thousands of training miles.
In an effort to run tubeless in the rear as well as the front, I was eager to get my hands on the new 36C tubeless tire as my X-Fire chainstays will not allow me to run a 40C rear. I hadn't suffered a single flat on the USH with a tube, but was determined to get a tubeless rear setup once I heard about the new 36C tubeless version. I switched over earlier this summer, and have been happy with the ability to run a slightly lower pressure in the rear. I was running ~60psi on the tubed 35C USH, now down to ~45-50PSI tubeless 36C MSO. The ride is much more pleasant, and my climbing grip is much improved due to the tread pattern and the lower pressure.
I'm somewhat tempted to test the tires at lower pressures, maybe down to 30-40PSI, but at the same time I haven't wanted to mess with what has worked for me...
My track record is this. After a handful of gravel events messing around with different set-ups including Specialized Trigger and some others, I landed on the 40c MSO as a great choice.
I had an awesome run at RPI, free of flats, with the 40c mounted tubeless using Orange Seal, mated to a Specialized Roval MTB wheelset (slightly narrower 1 generation older Roval Carbon circa 2011/2012).
Again, used the 40c MSO for DK200 and much training leading up to it. Mounted tubeless again with Orange Seal, this time to Specialized Roval CLX40 Disc wheelset (much narrower aero road/cross clincher wheelset). Difficult to set up tubeless initially, although later determined this may have been due to choice of tubeless valve stem and not seating in rim correctly. But got it over time.
No problems in training. No problems for first 75 miles of DK200. Then flatted front tire likely bottoming out and pinching / tearing on a rocky descent. Would not seal with sealant despite much coaxing and spinning and gassing with CO2. Had to go to tube, and ultimately became real pain as continued flatting over and over with tubes. Later discovered bit of damage to the rim. I should say, rear tire with same exact setup (40c MSO tubeless to Roval CLX40) held up with no problems for entire 200 miles and looked fresh as a daisy when all was said and done.
Trying to decide on setup for RPI this weekend. Want to go with aero rims instead of MTB rovals. Little gun-shy after DK200 experience. Right now have 36c Tubeless MSOs mounted up with Orange Seal and they are holding air beautifully and feel very sturdy and secure. But... I can't get over 100 - 120g weight gain per tire, with the 36c being the heavier. And as you noted, the 40c just floats over the gravel so beautifully.... like a hovercraft. Hard to imagine feeling as plush and fast (and safe) on the 36c.
Rambling a bit here, but really appreciate your advice and let me know what you think of all the above.
I have nothing bad to say about the tubeless 36c MSO. I know it is a little heavier than the "old" 40c, but I've become less weightweenie about my gravel bike lately. The ride quality is good, and if the heavier tire means that it may be just as (or even more) durable than the old 40c MSO or the 35c USH, then I'm all good.
I will probably resist the temptation to run lower pressures. I raced the combination of MSO 40c front (40psi)/36c(50psi) rear at the local Eager Beaver 100 a few weeks ago and the high speed technical descents on the race course were littered with folks with flat tires. Once again, I had no issues. I wonder at what point and how much running a lower pressure for a more supple ride will increase the risk of a torn/punctured tire...
Again, great info. Thanks for the thoughts and guidance.
I mostly agree with your thoughts on avoiding flats. I came out of my first DK200 experience, basically saying that the #1 priority above all else, should be avoiding flats when regards to tire and wheel selection. More than weight, more than aero, etc. So with that in mind for RPI, I may well stick to that philosophy. The 36c are on the bike now, mounted, holding air, and feeling pretty bomb-proof.
I am coming at gravel mostly as a mountain biker. So I think when I roll on true gravel (not a smooth dirt road with no rocks, but actual loose gravel) that wider tire just feels super-rippin'. Its hard to feel same float and general confidence in pushing the tire's limit, on the narrower stance.
But some of that may just be mental and getting used to the different feel.
I rode the 40c version at Lost & Found in '15 and the 36 tubeless in a 3-day event in Texas this spring and found that the ability to run 35-40psi over 3 days and 240 miles made up for the weight and lack of volume. The MSO 40 is a great tire, but I feel I got more out of the 36 by being able to run lower pressure and still whack the occasional rock. It felt like I actually got more usable volume out of the smaller tire.
