The Bontrager 38mm CX0 has been around for a long time. I have used them for the past 4-5 years and it is hard to beat as fast tire that can handle a little tech. It has held up to some nasty singletrack sections in races where I have bottomed the tire on the rim hard.
I have used them on several rims. The main ones being a Stan's Crest and, currently, Industry9 CX alloy rims. I use yellow Stan's tape. I probably run mine higher than most. I just completed the Gravel Grovel in Hoosier National Forest on these and was running 38psi front and 45 psi rear in horrible condtions. Probably a little high, but I do ride some singletrack on it and am not always gentle.
I did suffer a puncture early in the race as went into a very rocky creek bed at around 20mph. I stopped and the sealant sealed the puncture and I hit it with CO2 and went 50 more miles with no issue. I should have run across the creek bed as it was a source punctures for several others.
Thanks for the reply Fett. I used the 38mm CX0 (tubless) years ago on Stans 355 rims with absolutely no burping. They work outstanding for cross here in CA. Since I have moved on from that bike/wheelset, I have been reluctant to use the CX0 for fear of burping (being that the Stans rim is slightly over sized for those non_tubeless MTB setups). I currently have HED Belgium +, LightBike carbon (with internal rim hook) and NOX Compost (with internal rim hook). I might give them a try in the new year once cross stops. They really are a great tire. Too bad Bontrager doesn't make them tubeless ready
fastonflats wrote:Has anyone tried out the Maxxis Refuse in the 700x40c size? They seem to set-up tubeless well and roll fast on the pavement. Sidewall cuts have not been an issue and the casing feels pretty supple. The lack of tread means that they are best suited for straight line gravel and pavement riding when you want to have a bit more volume under you. I'd be interested in hearing other people's feedback on them.
fastonflats, I am running this tire now front and rear. It is very impressive! As to traction, I assumed like you that it would be a straight line tire and suck at traction. But have been really surprised to find that it has exceeded my expectations in every way. Traction is very good, much better than it looks, and in fact I am able to take fast downhill curves faster than my fellow riders with more knobby tires. I expected a lot of drift in general. There is none. I am slightly more cautious in the curves, but not because of any detectable loss of traction. Climbing out of the saddle on steep hills, I feel no more wheel slip than with more knobby tires I've owned. And these tires are super tough. The tread area is very thick as the file tread is molded into a solid extra layer of rubber that is added to the regular tire thickness, which makes it extremely puncture resistant. And the casing is also very thick and pretty stiff. Mine are mounted to stans grail wheels and the thick casing helps the bead to pop into place better than any tire I've tried, mtb or otherwise. The tires become more supple as they're ridden. You'd think the stiffness would result in high rolling resistance, but they roll pretty fast. I'd ride through a bed of broken glass with these things. Tread wear is also better than expected.
I run Compass extra light Bon Jons. I have many thousands of miles on them. Like well over 8K on ENVE AR Disk rims—with at least 1,500 miles before they wear thin or have strands on the sidewalls begin to fray. Once in a while a new one has to be babied to get it to hold air, but once it holds--it it stays that way. I’ve had two flats, both from hitting a sharp rock that cut the tread, and both sealed up once I added some more sealant back home.
Michigan gravel roads are mostly dirt with little sharp gravel. I also run them at a lower pressure than most--27psi front, 30-31 rear. I weigh around 165lbs.
I would not do a criterium at these pressures (the sidewalls deflect and squirm in corners if at speed)… but for straight-line racing and corners on gravel (always taken much slower than asphalt) these tires are gold. Then, when I do a road ride with the racing club, I pump them to 40psi front, 45 rear, and hang with most guys, most of the time. I’m a couple weeks short of 60.
I use 650b x 47 GKSK on gravel, and on road sections on primarily gravel rides. They’re surprisingly smooth on road (wouldn’t say fast lol) and they’re prefect for the gravel in my area.
There are rides when I use this bike only on paved roads. Like in winter when the roads have bits of snow or ice and my road bike with slicks isn’t enough. Also on multi-day credit card tours (the bike is beefier and has braze-one for bikepacking gear). I leave on the GKSK but I’m wondering if it’s with it to swap tires (GK 38 for example). Thoughts?
When I’ve examined them they have very thick sidewalls. They are not supple, and so at low pressures they will be much slower than an extra light Compass.
I ordered some Maxxis Velocita ARs for my Revolt. Haven't had a chance to mount them yet but I tossed them on the scale. 370 and 375g, so pretty much right on the button for weight. They're not paper thin like Compasses and feel a bit more pliable than Gravelking slicks.
