The Secret Weapon (by Paul Clipper on Trail Rider Magazine) (31/05/2011)

Hey, do you want to add some excitement to your ride? Do you want to make your bike feel like you just picked up ten horsepower and unlimited traction? And all you have to do to get this is change your rear tire?
                It’s not much of a secret weapon, though. At least two years ago, people started showing up with observed trials tires on the back of their bikes. More than two years ago; I know I saw David Knight ride the Endurocross two years ago with a trials tire. Last year it seemed everybody had to have them at the Endurocross, and then after that race the promoters decided that they were going to outlaw trials tires for the event because it was too much of an advantage. I saw and heard, but I didn’t pay much attention.  Charlie started using a trials tire and raved about it. I figured I’d try one when the opportunity presented itself, but in the mean time I wasn’t going to lose any sleep over it.
                Then Drew Smith of Works Enduro Rider sent me a Vee Rubber VRM 308R trials tire to try out. It sat in the garage for a while, but then I had shredded both the tires on my bike at the Quarry Run, and was looking around for new rubber to mount. I figured I’d put a new Dunlop 745 on the front-the 745 is the replacement for the awesome but no longer produced 739 and the trials tire on the rear. I friend of mine came into the garage after I was done, looked the bike over, and said “That bike isn’t right. What’s up with that tire on the back?”
                He doesn’t ride much anymore, and maybe assumed what I had put on there was the equivalent of the Trials Universal tire that plagued the wheels of all the new “ dual purpose” bike of the ‘70s. But he was right, it sure looks odd to have a relatively skinny, relatively smooth-tread tire on the back of a 450 four stroke. I wasn’t even sure if the tire wasn’t too skinny, it was after all a 4.00 x 18. But I figured I’m going to ride the Ammonoosuc turkey run on it, and we’ll see what happens.
                The Ammo was pretty much typical New England riding, the stuff we all love. We had plenty of dry weather leading up to the event, and then we had the last shreds of hurricane Hannah or some such storm the day before the ride. When we got there it was all wet, roots, ruts and mud, and plenty of slippery rocks. We started on the asphalt, and that’s one place where this particular trials tire doesn’t work too well. Even with 12 pounds of pressure it’s pretty squirmy on a paved road. Oddly though, the tire is DOT approved, so it’s perfect for a dual sport mount, just as long as your riding doesn’t include a long, high-speed commute.
                Once on the trail though, the new, odd-looking rubber shined like your grandfather’s old brass pocket watch. Wet rocks and roots? No problem. You know how we talk about knobby tires “digging down” and getting traction? The trials tire doesn’t dig-down, it just sticks like suction cups. For the first time in my life, on this Sunday, I rode a whole NETRA turkey run without ever once spinning my rear tire on a root. All this tire did was hook up, all day long. It thrusts the bike forward like the back end of the bike has claws instead of knobs. In all the mud and slippery conditions, I have to say l’ve never felt anything like it.
                It was funny though, the back tire got so much traction it was plainly over-driving the front tire into things. I may have never slipped the back tire all day but it was simple to gas it and skid the front tire, especially if it was on anything really slippery, like a greased flat rick. This is a prime situation to put you on your side, so it’s something I had to be ready for. One thing’s for sure, the Dunlop 745 does not grip wet rocks like the 739 did. Dunlop doesn’t make the 739 anymore, and I’m not the only NETRA rider who’s going to miss it.
                The only place the trials tire didn’t work so great on was topsoil-mud and wet turf. The really sticky, loamy mud would fishtail the bike unless there was rock right under the surface to grab hold of. Most knobbies don’t work well here, either. Also, I hit the brakes coming down a small hill on a grassed-over powerline two-track, and the back tire slid so well that I swear the bike sped up. Probably a new knobby would work better here, a used one would have worked almost as bad as the trials tire.
                Another observation: Laying the bike over and gassing it on a hard-packed dirt road. You know how you can spin a knobby and hang the back end of the bike out, flattrack style? It can’t be done on a trials tire. Well, it can’t be done unless you really gas it stupid-hard and unweight the back end. You’re more likely, again, to push the front wheel in the turn rather than slide the back end. I really am impressed. The tire was so much fun to ride on I found myself doing all sorts of stupid, fun things on the bike that I don’t usually do. I can think of rides or situations where I’d be just as comfortable using a typical rear knobby, and I’m sure I will in the future. But for right now this tire is staying on the bike until it’s worn out. The Vee Rubber VRM 308R is one of the lower priced trials tires, and WER has them in stock. The one we have is a tubeless style, though of course I use it with a tube because I don’t have tubeless rims. It costs about 90 or 100 dollars, depending on the daily price of oil or whatever else. You’ll hear Michelin is the best trials tire, and it should be at about $180 a pop, but they’re also so soft and flexible I’m not sure that they may be the best trails tire for strict trials riding. If you can afford one, try it out. Dunlop also makes a good trials tire, for about $120 each. There are others available, from all the various tire companies, but be aware that the really cheap Cheng Shin trials tire is actually the modern version of the Trails Universal dual purpose tires of years gone by, and may not perform as well as you might expect.
                Speaking of tires, this past summer has been a tire changing frenzy. Near as I can tell, I’ve changed twelve tire in the past three weeks, which was quite a change from last year. I already wrote about it, but I think last year I only changed one tire, and it was a flat. This  year, as you recall, I rode the old tires on the old bike at the new Hampshire classic, and hated them. So I got the bike back in the garage, cleaned it off and let it sit until right before the next ride a month later then I put two new tires on it, my last 739s, figuring I’d use the bike in the quarry run. Well, as luck would have it, my new bike came in early, and rather than use the stock tires on the new bike, I swapped those two tires with the new 739s on the old bike. Then, I sold the old bike to a friend, who insisted I take. The “stock” tires off that I had just put on (Pirelli ISDE/DOT legal tires) and instead put on “something decent.”
                Well, I did want to sell the bike, and the customer is always right, so I put a set of Dunlop 745s on the old bike and delivered it. So what is that, so far, six tire changes on two bikes?
                 Before I continue, let me insert a plug for my new favorite tire irons, the motion pro T-6 Combo Lever. They have a box wrench on the end the same size as your axle, and the 12/13 Combo is specifically designed for putting a tire ON, while the bigger ones are made to take a tire OFF. Get one of each. They’re aluminum so they’re real light to carry and they don’t scratch the rims as easily (painted KTM rims). I’ve wrestled some massive tires with these tools and they do a perfect job.
                Then I rode the Quarry Run on the new bike and toasted both tires completely, so  changed both of them. In doing so I got the trials tire on the rear  rim before I realized it was directional, and of course I had it on backwards, I wouldn’t normally reveal that I’m capable of such mistakes, but I’ll tell you this one time, just as long as you promise not to tell anyone else. In my defense, the trials tire only had the directional arrow on one side, and I looked on the other side for it. So I had to pry the trials tire off-on easy feat with a tubeless tire-turn it around and put it back on. Three more tire changes.
                In the mean time, my girlfriend and I went out for a ride on the 950. Before we went out I put  a new Pirelli Scorpion dual sport tire on the back, and odd as it might seem I must have pinched the tube because it had a slow leak that I didn’t know about. We stopped for ice cream about 40 miles from the house, and got back on a bike with a flat rear tire.  I of course packed on tools and no tube, and it was of course Labor Day Sunday. We lucky to get back by airing it up to about 55 pound at every gas station on the way to the house. Fixed that once I got a new tube, so that’s two more tire changes.
                Then I have this street bike here (a classic 1974 Honda CB750K4 with 2300 original miles on it) and it’s been rolling around on 35 year-old tries. So I finally got a new set of tires for it, and replaced the front tire first. Went back into the garage after lunch, and the front rim was on the concrete. Damn! I was certain I hadn’t pinched the tube, but there it was, flat. So I pulled the wheel, took the tube out and checked it for holes. Didn’t find any, so I dribbled soapy water in the valve stem and there was the leak. A bad Schrader valve. Might have taken 30 seconds to fix if I would have checked it on the bike, but no, mister Efficiency has to take the tube out to find out the valve is bad. I fix that, mount the tire and then spend 45 minutes trying to get the wheel back on the bike because something in the ancient disc break system is out of whack. I mount the new rear tire with a new Schrader valve. That’s three more tire changes.
                Oh, and I have new tire I want to try on the 950. I think I’m going to get a tire changing machine.

credit by: Trail Rider Magazine