I personally think there are three important factors for tires:
- 1. Tire Condition
- 2. Tire Selection
- 3. Tire Pressure1. Tire Condition
Make sure you have tires that are in good condition when you go racing. The tire is the only thing in contact with the ground. Good new tires have sharp edges, taller knobs, and will give more grip than worn out tires. More grip means you can corner harder, brake later, and carry more speed through difficult technical sections. Look at the comparison of the two tires below
A new and worn out 2.5" Kenda Nevegal
The problem with the tire on the right is that even though it still has a significant amount of meat left in the knob the sharp edges have been rounded off due to braking and cornering. The sharp edges generate a ton of grip, and with out these edges the tire will never perform as well as it did when it was new. Having new tires on your bike will improve your times at the races.
But I can't afford a new set of tires for every race you say. I've heard that comment a thousand times. This is my trick. Decide to buy one or two sets of race tires. If you're going to buy one set get a tire that is going to perform well in all conditions. Buying 2 sets of tires is better. A set for the dry and a set for the wet. See the tire selection section below for my opinions on what tires to use in a variety of conditions. Put these good tires on your bike on Saturday morning, practice and race on these tires, then pull them off Sunday night and save them for the next race. When your race tires wear out, and are no longer good enough for racing, use them for practice tires. Do all your riding and training on old worn out tires. Yes it's a pain to constantly switch the tires on your bike, but this way you'll always have good tires come race day, and without having to spend a ton of money on new tires all the time.
Another tip. You love those 3C Maxxis Minion tires, but they're $90 each in the store, and you can never find them on a good deal. Try out some slightly cheaper tires. Kenda Tires offer all the performance of the Maxxis or Michelin tires, at a fraction of the price at $65 a tire, and last longer. You can get 3 Kenda tires for the price of 2 Maxxis or Michelin tires, which means more race tires. If you're dead set that the Maxxis or Michelin tire makes you faster on the race course, keep them as a race tire, and do your practice and training on the less expensive Kenda Tires. The money you save by buying the cheaper tires for the off season may mean you have some extra cash for another set of race tires you love for next season.2. Tire Selection
No single tire is ideal for all conditions, this is obvious. What isn't so obvious, is which tire is best suited to the current conditions. For this reason I'm going to split this section into a couple sections based on course conditions:
- A. Hardpack Courses
- B. Loose over Hardpack Courses
- C. Wet Courses
- D. Muddy Courses2A. Hardpack Courses
For a hard packed course you're going to want a tire that rolls well since rolling speed is likely going to help. You want the tire to have a large ramped center knob that will create a large contact area with the ground, with a ramp to reduce rolling resistance. Tall skinny knobs down the center and on the sides are going to squirm because they can't penetrate the surface, will create significant rolling resistance, and won't offer much grip. In short you want a tire with lots of contact area and with short, stable center and side knobs. This combination will give the least rolling resistance, good grip, and the most predictable handling on hardpack conditions. My personal favorite tire for these conditions is the Stick-E Kenda Nevegal, 2.5" for the front and 2.35" for the rear. I like this 2.5" / 2.35" combination because the larger front tire offers better braking and cornering grip, but the rear tire has less rolling resistance. I like the Nevegal because it has great short, ramped knobs down the center that are large and blocky, with the side knobs being similar in design. The tire is predictable, stable and rolls fast. A good choice from the Maxxis line would be the 3C Minion DHF, and a good Michelin tire is the Comp 24.
Kenda Nevegal Maxxis Minion DHF Michelin Comp 242B. Loose over Hardpack Courses
Loose over hardpack is generally any type of loose material on top of a hard packed in surface. This generally takes the form of sand, loam or gravel. These surfaces are tricky because the sections of the course that are soft and loose material is found are the sections where you need the most grip (because that's where everyone is cornering and braking). Where you don't need the grip, the course is generally hard packed. You could use one of the hard pack tires I recommended in 2A, but since they all have short large blocky knobs, they don't penetrate into that soft loose material very well, and don't provide a great amount of traction. The ideal tire is something that has a deep but large and blocky knob that is stable, yet tall enough to generate grip in that loose stuff. There is really only one tire I like for these conditions and it's the Kenda Excavator. Both the 2.5" and the 2.35" Stick-E versions are excellent. Both have the same size knobs, with the only difference being a slightly smaller casing for the 2.35" and the center knobs on the 2.35" are significantly shorter than those on the 2.5". I've run the 2.5" Excavator on the front and the 2.35" Excavator on the rear on courses where having low rolling resistance is important but need both braking and cornering grip into and through some loose corners. Dual 2.35" Excavators would likely be a good choice for even lower rolling resistance if there isn't much heavy braking, and could also be a good setup for mostly hard pack conditions. The difference between the 2.5" and 2.35" Excavator can be seen below:
Kenda Excavator 2.5" Kenda Excavator 2.35". Notice how the knobs are the same size in terms of area, but the knobs on the 2.35" are much shorter2C. Wet Courses
I personally love riding and racing in the wet. I like it because I love how the tire reacts differently to roots, rocks, dirt and mud ... it's much more interesting than when things are dry. For wet conditions a tire needs to be able to penetrate the wet ground and generate grip. A large blocky knob like those found on the Nevegal and Minion won't penetrate the ground well, and are going to slip around on the roots. A good wet tire needs a fairly open tread to allow mud to clear, but enough small knobs to form around objects, penetrate the ground, and provide lots of edges for braking and cornering grip. However for most BC courses a spike tire isn't the ticket because of the large amount of rock or root require a knob that has good support. My default wet weather tire is the 2.4" Stick-E Kenda Telonix tire on the front and rear. The Telonix has a series of ramped, thin, but wide and sharp bars down the center for excellent braking grip, but with reasonable rolling resistance. These sharp bars are separated by a pair of side by side spikes that offer good lateral stability. The side knobs are a series of H-shaped knobs separated by a single spike. These side knobs offer good penetration but also have lots of edges that generate good cornering grip. My pick from Maxxis for wet conditions would be the 2.5" Super Tacky High Roller, and my pick from Michelin would be the 2.5" Comp 16. You can see obvious similarities between these three tires, which is why they all excel in wet conditions.
Kenda 2.4" Telonix Maxxis High Roller Michelin Comp 162D. Muddy Courses
I have personally never used a mud spike tire before, so I can't offer up any opinions on which of the spike tires out there is the best. Click here to check out an article that Si Paton wrote for Pinkbike on Mud tires though
. For severe mud conditions the wet weather tires I recommended in section 2C are likely going to clog up with mud, and won't have tall enough knobs to generate good levels of grip in deep mud. There are 4 really good mud tires on the market. The Kenda King of Traction, the Maxxis Wet Scream, the Maxxis Swamp Thing and the Michelin Mud 3. There has been a recent trend of cutting down Wet Screams and using them on wet or drying courses instead of using a Telonix or High Roller as well as on muddy courses. I can't say I've ever tried this, but it seems to be working for the World Cup guys, cutting tires is a science, and one I'll hopefully write more about in a later tech article. The Swamp Thing is not as aggressive as the other three tires and fits between the High Roller and the Wet Scream, this is evident when you look at the pictures below. Unfortunately I couldn't find a good picture of the King of Traction as it was only just release in the fall of 2008. As a result I don't have a set yet, nor could I find any pictures online.
Maxxis Wet Scream Maxxis Swamp Thing Michelin Mud 33. Tire Pressure
Tire pressure is very important, and something you should play around with. Every good rider and racer should have a repeatable tire pressure gauge. This is important for being able to achieve repeatable tire pressures. For the record I'm 195 lb, so all tire pressures are for a rider of my weight. If you weigh less you'll likely run lower tire pressures, and if you weight more you'll likely run higher tire pressures.
As a quick diversion I almost always use a regular 0.8 mm wall thickness cross country tube in the front, and a good medium weight 1.2 mm wall thickness free ride tube in the rear. I find this gives a good compromise between flat resistance and weight. For a smooth course I might use cross country tubes front and rear, and for a very aggressive course where I'm running low tire pressures for grip I might use a free ride tube in the front and rear.
For wet conditions you're generally going to want to run lower tire pressures to help the tire conform over everything on the trail, in order to help generate some much needed grip. In wet conditions rolling resistance likely isn't your first concern, so go ahead and lower those tire pressures. Don't change your tire pressures just before the race. Make sure you've worked out the ideal tire pressure long before practice is up in order to ensure you won't flat during the race. I personally use around 25 psig in the front and about 27 psig in the rear for wet courses. If I'm struggling for grip and can get away with the lower pressures I may lower than even further.
For dry conditions I generally use an intermediate tire pressure of 28 psig in the front and 32 psig in the rear. This offers a good compromise between rolling resistance, grip, and stability. In the dry you can corner harder, and you don't want the tire to be rolling around on top of the rim.
For hard pack conditions run high tire pressures. I generally use 32 psig in the front and 35 psig in the rear, sometimes even more at places like The Ranch in Kamloops. There is no need for low tire pressures in hard pack conditions. Running low tire pressures isn't going to give any more grip and you'll only gain stability in the corners and lower the rolling resistance with higher tire pressures. Since edges aren't a help in hard pack conditions anyway having more edges in contact with the ground isn't going to increase the amount of grip, so keep those tires nice and hard.4. The End
That wraps up my first tech article on tires and tire pressures. I'll be posting up another tech article soon. Let me know if there is something in particular you'd like me to write about. If you have any questions, comments, if I've missed something, or you feel I'm just plain wrong, please leave a comment below.http://timmigrant.pinkbike.com
Do you like articles like this or do you have something to say that would help others out in a technical manner? Well then contact me at brule.pinkbike.com and we'll get it out there for everyone to read