Tires: IRC M5B
Posted: 06:13 pm May 06 2005
I've finally found a tire I can LOVE for the rear wheel and it's the soft terrain, M5B. I've tried many hard terrain rear tires with limited success. Almost all work great for the first 50 miles or so, then I might as well be lubing them up with grease since the traction I've gotten couldn't be any worse.
As background, I ride the Sierra Nevadas on the west slope in El Dorado County. The area is mainly new formed mountains of rock with thin soil cover. With that in mind, I've always bought hard terrain tires. After all, what could be harder than granite?
The hard terrain tire has three predominate features to it; The knobs are shorter than soft terrain tires, the rubber compound is soft so it can grip hard surfaces with an almost sticky like fashion, and the knobs are fairly close together to allow a larger ground contact patch with hard surfaces.
My main problem has been with the rubber compound being soft on a hard terrain tire. I round off a knobby just doing a few throttle chops up and down my paved street while jetting my carb. That's not wheel spin folks, that's just the tire gripping the asphalt. Hard braking, without lockup, is even worse for the tire wearing. I'm not made of money so I can't afford to stick a new tire on every single ride.
This winter here has been especially wet, so I thought I would give a soft terrain tire a try. The soft terrain tire is set up with a hard rubber compound so the knobs biteing into the soil, won't bend out of the way, are spaced far apart so mud doesn't clog them up, and the knobs are long to allow deep penitration into the soft soil.
I picked the M5B at the recommendation of the local bike shop. I get them from rockymountainmc.com for less than $45 each on the 120x80x18 size.
Let me just say this tire is the best tire I've found for any of the conditions I currently ride. I suspect it would not be a good tire on concrete like surfaces, but that's not my riding conditions. The only problem I've found to date is that it is possible to tear a knob off the tire if you excessively spin the wheel on a sharp object like a rock or edge. The tire is directional, but you really have to study the knob pattern to realize this. I plan on running one backwards after things dry out around here during the summer just to see if a fresh sharp edge is better than the directionability of the knob pattern.
This tire crawls up moss covered river rock, deep loam, sharp edged slate, smooth stones, gravel roads, etc. Far superior in all those conditions after 150 miles on it than a brand new hard terrain tire, any make or model I've tried. Of course it shines in mud. Several deep rutted mud filled trails were thrown into the mix of the last enduro I rode, usually I TRY to ride between the ruts but the rear tire slips and into the crevace it goes. Not with this tire. Where ever I pointed the bike, the tire would track faithfully behind without trying to find the lowest rut on the trail. When I did want to break traction in places like a switch back or a drift through a corner on a fireroad, the tire was fully under my control. No sudden slips or grabs, I could control the rear tire perfectly with either the throttle or the brakes.
I like the tire so much, I odered 2 more just to have on hand. Like I said, under $45 each is a complete bargain compared to more than twice that for the same tire at the local shop. (I'll support a shop and it's owner, just not what must be highway robbery with a $75 price for a tire I can get for $44 and some change.)
This tire comes is several sizes; 110, 120, 130 and 140. The KDX can easily work the 120. The 140 is a monster tire best left for the open class 500 twostrokes.
In conclusion, I feel this tire is great for just about any and all conditions except concrete like trails. The hard rubber compound lasts a good long time and as long as you don't go nuts spinning it on a stuck lip, the knobs will stay on the tire and not tear off. I look forward to trying it out in CC's neck of woods up in Oregon in a couple of weeks. When I do, I'll report how they performed there.
As background, I ride the Sierra Nevadas on the west slope in El Dorado County. The area is mainly new formed mountains of rock with thin soil cover. With that in mind, I've always bought hard terrain tires. After all, what could be harder than granite?
The hard terrain tire has three predominate features to it; The knobs are shorter than soft terrain tires, the rubber compound is soft so it can grip hard surfaces with an almost sticky like fashion, and the knobs are fairly close together to allow a larger ground contact patch with hard surfaces.
My main problem has been with the rubber compound being soft on a hard terrain tire. I round off a knobby just doing a few throttle chops up and down my paved street while jetting my carb. That's not wheel spin folks, that's just the tire gripping the asphalt. Hard braking, without lockup, is even worse for the tire wearing. I'm not made of money so I can't afford to stick a new tire on every single ride.
This winter here has been especially wet, so I thought I would give a soft terrain tire a try. The soft terrain tire is set up with a hard rubber compound so the knobs biteing into the soil, won't bend out of the way, are spaced far apart so mud doesn't clog them up, and the knobs are long to allow deep penitration into the soft soil.
I picked the M5B at the recommendation of the local bike shop. I get them from rockymountainmc.com for less than $45 each on the 120x80x18 size.
Let me just say this tire is the best tire I've found for any of the conditions I currently ride. I suspect it would not be a good tire on concrete like surfaces, but that's not my riding conditions. The only problem I've found to date is that it is possible to tear a knob off the tire if you excessively spin the wheel on a sharp object like a rock or edge. The tire is directional, but you really have to study the knob pattern to realize this. I plan on running one backwards after things dry out around here during the summer just to see if a fresh sharp edge is better than the directionability of the knob pattern.
This tire crawls up moss covered river rock, deep loam, sharp edged slate, smooth stones, gravel roads, etc. Far superior in all those conditions after 150 miles on it than a brand new hard terrain tire, any make or model I've tried. Of course it shines in mud. Several deep rutted mud filled trails were thrown into the mix of the last enduro I rode, usually I TRY to ride between the ruts but the rear tire slips and into the crevace it goes. Not with this tire. Where ever I pointed the bike, the tire would track faithfully behind without trying to find the lowest rut on the trail. When I did want to break traction in places like a switch back or a drift through a corner on a fireroad, the tire was fully under my control. No sudden slips or grabs, I could control the rear tire perfectly with either the throttle or the brakes.
I like the tire so much, I odered 2 more just to have on hand. Like I said, under $45 each is a complete bargain compared to more than twice that for the same tire at the local shop. (I'll support a shop and it's owner, just not what must be highway robbery with a $75 price for a tire I can get for $44 and some change.)
This tire comes is several sizes; 110, 120, 130 and 140. The KDX can easily work the 120. The 140 is a monster tire best left for the open class 500 twostrokes.
In conclusion, I feel this tire is great for just about any and all conditions except concrete like trails. The hard rubber compound lasts a good long time and as long as you don't go nuts spinning it on a stuck lip, the knobs will stay on the tire and not tear off. I look forward to trying it out in CC's neck of woods up in Oregon in a couple of weeks. When I do, I'll report how they performed there.
