Tire Wear's Relation To Set-up?

[volcom415]

I was wondering about what tire wear can tell a person in general about set-up/ riding style?

I have noticed that when I first started riding (in the canyons) I used to wear out my fronts a lost more than I would my rears. I also would have no chicken strips on the front and maybe a 0.5-1cm on the rear. I wasnt trail braking into turns and I had a 98 F3(bone stock suspension and set-up) that was very soft on the front end. I have since been on a 01 GSXR 6 and have noticed that I never run out of room on my front tire, but I can wear out the rear to the end. I sometimes trail brake into turns but generally try and scrub off speed way before that. My bikes set up was given to me with the front dropped 9mm and the rear raised 14mm(not sure if thats good or bad, just rode it the way it is and have never had a problem). Front and rear suspension has been revalved, not sure about the spring rates. Sorry but I was trying to give as much background info as I could. I have used supercorsas on both sets, so I dont think that it is a change in tire profile issue, although I have been running Bridgestones BT-002s currently.

 

As far as body position, I try and not drag knee unless it just happens. I dont ever really have a problem with excessive lean angle, never drag hard parts and try to hang off a decent amount concentrating mostly on getting my upper body off the tank.

 

One thing that I noticed is that I never really get my upper body low over my tank and sit kind of upright, possibly due to old habits from the F3's riding position.

 

Im wondering if I should be concerned with the wear and if it indicates that I am doing something wrong or if my bike might be set up incorrectly?

 

Any comments or suggestions would be greatly appreciated. I hope Im not asking a really stupid question and realize that I should just shut it and ride the thing situation....

 

 

sean

[volcom415]

anyone?

 

any thoughts?

[Thor]

Tire wear on the road has always been a big concern for me because I put on big miles on a Saturday ride and go through tires more quickly than I think I should. My observations are purely anecdotal, but may be of some help. I only get the edge of my front tire scrubbed on the track. Period. I would never ride that fast on the road, and it is not an uncommon occurance. As far as your front tire wearing more than your rear - this is a style issue. The fastes person I ride with (read: highest risk taker) goes into turns wide and hot and holds the wide line throughout the turn. His attitiude is that if you don't have the control to keep your bike in one tire track throughout the turn, you do not have proper control of your bike. What ends up happening is he is scrubbing some speed off, even on a little throttle, throughout his turn with the front tire. He goes through two or three front's for every rear. Also, if I am close behind him I will gain on him quickly throughout the turn, because I have my speed set and quick steer and am back on the gas fast, while he is still maintaining his entry speed well past the apex. If you turn slowly and are slow to get back on the gas, you will wear your front tire more because it is carrying most of the load. The only time I have worn a front faster than a rear was intentionally working on trail braking. The front feathered down the the wear bars in about 800 miles. I believe trailbraking is an important tool to have on the road, but best practiced on a track. What you want to look at is, "how much time do I spend off the gas or genlty accelerating in a turn." When do you get back on the gas? I would suggest that you slow your entry speed down and practice accellerating out of the turn. In slow, out fast. You will be smoother, more in control, and, believe it or not, faster. This will also give you more opportunities to react to the many uncontrollable factors that present themselves on the road.

 

Ride smart, ride safe.

[volcom415]

Thor,

 

 

Thanks for your reply, but I think that you may have misunderstood my post, although I completely agree with you on what you said. My question is that I was trying to understand how geometry relates to tire wear. I do trail brake sometimes and usually try to go in slow and out faster, however my geometry is set up as follows. -9mm in the front and +14mm in the rear. I also am wondering if my front isnt wearing out to the end if my compression setting may contribute to this. I dont care about running off my chicken strips, but just wanted to know the relationships between the two if any. Thanks again

[Thor]

Again, it is somewhat anecdotal, but the racers (my team members) that I ride with on the street never wear their front tires to the edge. I've never ridden an F3, but I have friends who ride them due to their relaxed geometry and they don't wear them to the edge either. There are a number of factors that come into play regarding how the tires track, but i don't think they are important for your question. First off, I would need to know what 14mm at the rear does in regards to raising the rear. 9mm on my ZX9R raises the rear 1 inch. It is different with each bike based on the swingarm length and geometry. I go by feel after I play with the science, and the questions I ask myself are: Is it stable on high speed sweepers? Does it fall into first gear turns? Does the rear spin up, or does the front push when I don't want it to? Is there some speed or turn that makes the bike feel unsettled? And in your case, can you feel the front tire "grind" in turns? When I am on the track I let the front tire talk to me and I can sense a "grinding" feeling trailing into downhill chicanes. That tells me how fast I am going and when to let off the brakes. You can always ride around geometry on the street, so your personal style and what feels right is what matters. Without riding your bike, I would try bring the front back up in 3mm increments and see what you think of that. It seems, but I could be totally wrong, that your setup is too aggressive for street riding and to take advantage of it you would spend most of your time in the higher RPMs and use sliding as part of your technique in entering turns, and hold mellow as you stand it up and roll it on. Everybody had a sense of what is comfortable for them. You won't know what you like until you start changing things around. Just remember: Don't change more than one thing at a a time, makes notes of the changes and what you thought, and ride the same track of road for each of your tests. It may seem boring, but once you know how every aspect of your suspension works you can start combining settings and get it dialed to exaclty what you want. Most people just ride their bikes as they came from the shop and are missing out on all the adjustments that are possible to make the bike fit their weight and style. Once you take the time (and it takes TIME) you will be much more knowledgable about your bike and it will be the least expensive performance add on you can get for your bike.

 

I hope that was a better answer. Suspension and carburators = the black arts.

[fastfreddie]

by lowering the front and raising the rear you've added to the load on the front tire. that alone will increase its wear/decrease its life...if you like the way the bike handles then it may just be a fact of life.

if the tire wear is abnormal, like tearing, etc. you have a suspension issue...that includes proper tire compound and pressure.

[RoadRunner]

Reaching the edge of front before you reach the edge of the rear, or visa versa is a tyre brand and profile thing, mixed with the bike.

 

Change brand of tyres and you'll get a different result

 

Having said that, why bother thinking about it? It really makes no difference when your riding.

Feel for what's going on