Tire, Tire Pressure, Gooving, etc.

[trachy357]

So, at my schools I get alot of questions about tires. Everything from what brand to run to grooving patterns. I hope all the following information gets you a little closer at the track.

First off, I think rubber is one of the most important factors to going fast, ONCE YOU HAVE EVERYTHING ELSE FIGURED OUT. Look at MotoGP. Any level of motorcycle racing is the same. If you want the fastest times you have to have the best tire. I personally run Dunlops and think they are currently the best for our application. However, for the normal guy, your wasting your money if your practicing on the best rubber in town. Until you become a good intermediate I do not think it is neccesary to run Dunlops or Michelins for that matter. But as I said before if you want your fastest lap times...the best rubber always prevails. I suggest for JOE AVERAGE to buy some maxxis or metzlers...then go out and get some practice. When it is time to become an AMA National Pro....buy the best. Yes, I said buy! Even the pros pay for tires!

The next thing is tire pressure. For everyone this is difference! What works for me may not work for Jeff Ward or vice versa. A lot of things come into play. Riders weight, riding style, altitude, bike, brand of tires, suspension settings, track temp., track surface, amount of dirt, type of dirt...I think you get my point. I use tire warmers and like to do my tire pressure when they are hot. Depending on all of the above conditions my tire pressure hot ranges from 22-28. Most of the time I like to run about 25 or 26 both front and rear HOT. This translates to about 22-24 COLD. A good way to figure out what you like is to test....You need a tire pyrometer. This is a devise that measures the temperture of the tire. With use of a lap timer and some laps at the track you can find a good base pretty quickly. Go out on the pavement only and run several laps about 15 minutes. Come back in and decide at what point during that session did the bike feel best. Let the tires cool down completely and go back out. Let say at lap 8 it feels the best...Come in on lap 8 and get the tire temp using the tire pyrometer and get the pressure. You can then use this as your base. I like adjustable tire warmers...I run my tire warmers between 110 and 130 degrees on the front and 135-155 on the back....I then set my PSI. Really it is just about testing and finding what works best for you and then adjusting from there.

Grooving....I almost never groove. I think a simple grooving can help at least with your mindset. ALthough at the AMA Nationals I rarely see any of the top guys grooving. At Pikes Peak last year I tried everything from a rain to a slick including different grooving patterns and even a DOT. I was amazed in how little the times actually changed. I was sure the rain tire would be faster in the dirt, but it was basically the same. In fact I ended up running a grooved slick. For those that are unfamilar with Pike Peak...It is a 12 mile hillclimb..really the unltimate supermoto race with a half asphalt and half gravel road. It can be incredibly slippery and you would certainy bet you would see the difference between a rain and a slick. My point being is I really don't think grooving helps you all that much.

Another trend I see at the National is called sipping. You use a Razor blade to make small teasrs into the tire. This enable the tire to get hotter. You see this on cold days and / or at track that have very little grip. At Parking lot races you see this alot.

I hope this helps and please other chime in on what you do...

[M Dubya]

Great stuff Gary! :clap: Truly appreciated. :thumbup:

[Moto Meccanica]

"Another trend I see at the National is called sipping."

Most of the fans I see are chugging or pounding at the races, I see more sipping at golf tourneys.:eek:


I never groove tires either, waste of time IMO.

[BSC450]

Thank you Gary! Great info!

[clarkie]

I suggest for JOE AVERAGE to buy some maxxis or metzlers...then go out and get some practice

wow, I guess I will always just be Joe Average :hmmm:

[Bran761G/77]

i groove my tires every race. front and rear. i notice it in acceleration and braking in the dirt. just MO .

[trachy357]

See if the gooving actually helps your lap times. Also see how it affects your lap time over the course of 20 laps. I bet you would be surprised.

[MXCat]

The only places I've found grooving actually helping me is on tracks with loose dirt or sand, like Ocala or Starke. I was very happy that they rear tire had the horizontal grooves in them for the Starke ride. That sugar sand really doesn't like slicks too well.

Of course, most tracks have dirt sections that are more hard packed, since they aren't made of or surrounded by sand.

Just saying.

[Moto Meccanica]

Brandon is also faster with teal gear than red/white gear...

[rowdy]

What characteristics should I look for to tell if I am too low, or conversely too high with my tire pressures?

I do not have a pyrometer, so I will simply be using a tire pressure guage and adjusting from there.

What will my tire do if too high psi? What will my tire do if too low psi?

[Bran761G/77]

Brandon is also faster with teal gear than red/white gear...

acctually mike the burgandy and blue gear produce much more hp than the others...

[rowdy]

STill, if i am getting a kind of squirm or wallow out of my tires, am I too low or too high in tire pressure?

What are the signs and symptoms of either condition???????? HELP please!

[1chicken]

Anyone ever use a groover to sharpen knobbies?? (just nick the leading edge) I thought this might work good for a MX play bike...? Thoughts?

[942dcrider]

STill, if i am getting a kind of squirm or wallow out of my tires, am I too low or too high in tire pressure?

What are the signs and symptoms of either condition???????? HELP please!

From what I have experienced in testing tire pressure...BUT THIS IS JUST MY OPINION...that when tire pressure is too low it will tend to roll and cause a wollowing or even cause chatter. When the tire pressure was too high it would loose grip really easy because the air pressure tends to make the tire balloon more and have less contact patch. With the opposite for low pressure...tire squats and wide contact patch, but bad because it would cause uneven pressure on the patch causing the tire to deform. I have many years in the tire industry and have a pretty good understanding of how air pressure effects tire performance and it has the same concept in bikes. The tough thing is to determine if the wollowing you are getting is due to tires, set-up or riding technique. As I think Gary said previously, the way you ride could be causing the suspension to be performing poorly. As always tetsing is the answer and again write everything down!!!:thumbup:

[huskyfrk]

i have been offered a new set of dunlops but they have been sitting for over 2 years. any thoughts. on a formula car, if it is several months old, it is tossed, i am going to believe that a slick on a bike will age harden over time also. any thought's gary ????? :hmmm::hmmm::rolleyes2:

[veryMoTARDED]

Just so you guys know, you can buy a decent pyrometer from a hobby shop for around 15$ US, Hobby guys use them to tune their nitro two stroke engines. :)

[brian]

Thanks Gary ! I'll say one thing about grooving...it sure lengthens the dirt section on the asphault.....:eek:

[PitBoy]

The way I have always approached my SM is to put the pressure a little on the high side like say, 28 psi. Get the tires warm first and then do 8-10 hard laps. Come in and drop the pressure 1 psi. Head back out and repeat it again. I do this until I drop the pressure enough that the bike starts to get loose. Once this happens I bump the pressure back up to the previous setting (1 psi) and that gives me my hot pressure. Once the tire cools completely now you have a cold pressure. This usually gets me in the ball park and then I adjust from there.

Bear in mind that it might be a little loose in the beginning because of the higher tire pressure. But the objective it to start loose, finish loose and the optimum is somewhere in between. Remember that more pressure stiffens the tire and wont allow it to heat up as much. Less pressure allows more movement in the tire and therefore the tire gets hotter. To hot though and the tire gets greasy from overheating the contact patch.

[RocDog]

Anyone ever use a groover to sharpen knobbies?? (just nick the leading edge) I thought this might work good for a MX play bike...? Thoughts?

I do all the time. I will actually even pick up free used tires from motorcycle shops that have at least a 1/3 of life left in them but the knobs are all rounded out. You can take the grover to the front, back and sides of each knob. Slice off just a sliver from each and you now have a very sharp tire that is almost as good as new when it comes to hooking up.

[RocDog]

So if you have a pyrometer what is the temp you are looking for optimal temp?

[specialized117]

So what exactly do you do in sipping? Never tried, maybe give it a try and see how it does

[RocDog]

So what exactly do you do in sipping? Never tried, maybe give it a try and see how it does

I have never done it on a road tires but have done it a bunch on rock crawler tires. I use a groover and turn the blade upside down and use the 2 sharp ends to sipe. Or you could just use a sharp blade. Just be careful not to slice too deep. I may give it a shot also. Just sipe the very middle of the tire. That way when you are on dirt which is when you are trying to keep the bike upright using more of the middle of the tire, you will be using the siping. I think I woud make a slice every half inch around the tire. maybe an inch to a inch and a half long. The tire will seperate at the sipe on acceleration and the sharp edge of the tire will grab a little. Same with braking also.That is the theroy at least.

[specialized117]

I have never done it on a road tires but have done it a bunch on rock crawler tires. I use a groover and turn the blade upside down and use the 2 sharp ends to sipe. Or you could just use a sharp blade. Just be careful not to slice too deep. I may give it a shot also. Just sipe the very middle of the tire. That way when you are on dirt which is when you are trying to keep the bike upright using more of the middle of the tire, you will be using the siping. I think I woud make a slice every half inch around the tire. maybe an inch to a inch and a half long. The tire will seperate at the sipe on acceleration and the sharp edge of the tire will grab a little. Same with braking also.That is the theroy at least.

Ok cool thanks for the explantion, I might try it on some old tires first so I don't go to deap and screw up new tires.:laughingr

[Ludachris]

The next thing is tire pressure. For everyone this is difference! What works for me may not work for Jeff Ward or vice versa. A lot of things come into play. Riders weight, riding style, altitude, bike, brand of tires, suspension settings, track temp., track surface, amount of dirt, type of dirt...I think you get my point. I use tire warmers and like to do my tire pressure when they are hot. Depending on all of the above conditions my tire pressure hot ranges from 22-28. Most of the time I like to run about 25 or 26 both front and rear HOT. This translates to about 22-24 COLD.

First of all great write up!
I mostly road race (big tracks, no dirt) my supermoto, but the resident Dunlop tire guy suggested that I run my tires at 33 front/30 rear hot. It always seemed high to me, I am about 260 with all my gear on.
I do understand that there are various factors and preferences involved in this subject, but would like to hear opinions.
Thanks!

[AussieDevo]

RR tracks definitely need higher pressures, how much higher you will need to have a play.

[M Dubya]

I ran Pirelli Super Corsas on a full size road cousre (Grattan) a few years back and I had to run 30/30 to keep the tires from getting torn up. They stuck like glue too. 30/30 is pretty close to what I would have run on a full size sportbike. Faster tracks and higher corner speeds generate more heat.

[Ludachris]

That makes a lot of sense.

[FreeRider001]

I run 32 in both the front and back. I think it has alot to do with each ridder. Im really light so it doesn't take as much pressure because the tires don't flex as much under my waight. (155lbs after a dump lol) My dad is 230lbs and runs 36 front and 34 rear....I think you should just try them at dif pressures and see what hooks up the best with the least amount and movement. LOL my road bike tires ( bicycle) are kept at 58lbs were most keep there's at 60-64.

[kingwarrior]

the way i understand that putting cuts into the tire was just to help the rubber move around the same as what your doing with the siping you talk about , not putting groves for more traction ????

[pjdmd]

many brands mentioned. one thing not mentioned for newbies is to get supermoto specific tires. They are formulated to warm up in a lighter weight bike. I've been using the Continentals and love them, have had 2 pair and plan on getting a third.

[ftwconcepts]

I got on a set of continental SM DOT tires and they are not much better than knobbies on the asphalt and not much better than slicks in the dirt. I love my dunlops and at my skill level am happy with metzler as well but comparing non-DOT race slicks with DOT SM tires is not very fair.