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Unofficial Fall 2019 EPIC Ride POSTPONED TO SUNDAY

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12 minutes ago, TimTheAzn said:

Unless I'm misunderstanding your statement, grip level absolutely changes depending on the size of the contact patch. More rubber to the road you get more grip. That's one of the main reasons for trail braking.

Grip is the friction between the tire and the road. The friction is based on pounds per inch. More area equals less pounds per inch but the overall pounds per inch is a constant. Math and physics are very clear in this.

Trail braking is to preload the front tire. You have to load the tire before you work the tire. You are putting more weight on the front before you turn hard.

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11 minutes ago, 2talltim said:

No trail braking has to do with weight transfer. More weight = more friction 

Ok. You are partially correct but it does much more.

Sure weight transfers forward when you get on the brakes but trust me when I tell you that when you trail brake you are doing a couple things.

1. Putting forks into their working range.

2. Enlarges the contact patch of the front tire on the pavement because the weight is transferred forward. There is friction between tire and the road whenever the tire is touching the ground, even when straight up and down. The size of the contact patch determines the maximum level of grip that can be used, whether it is for brake pressure or lean angle. Think of it like this, you only have 100 points of grip in any tire. You must manage that level and if you go over 100 points of grip you slide and or crash.

3. Provides direction because speed = radius. 

Edited by TimTheAzn

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3 minutes ago, TimTheAzn said:

2. Enlarges the contact patch of the front tire on the pavement because the weight is transferred forward

Yes, but both half's of that statement are needed. MORE weight on a larger contact patch will of course increase grip. Which is what you just described.

What we are saying is the same weight on two different contact patches is the same grip.

This is unfortunate, it appears we are both correct. Just different circumstances.

Edited by Tonik

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And I will add to the above. If you could load the front trail braking and magically NOT increase the patch size you would have the same grip if you did load it and increased the patch size.

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5 hours ago, Howabusa said:

Iron pony will only sell and mount the stock size tire.

Do they have every rim memorized?. pull it and cart it in.

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No. They ask for what bike the wheel is from and they look up what tire size is stock. I am sure it has something to do with liability.

Edited by Howabusa

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So you tell them a bike model that the tire is actually for.

🖕 IP

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The reason for running a taller+wider tire is the profile is generally better at full lean and will give a little more lean angle. Tip-in would also be quicker than with a more flattened out tire. You'd get more contact patch out of a taller tire giving you more grip at lean but that's only because you run out of contact patch sooner on a flatter tire when you exceed the tire edge - Lean angle is a bit more limited on a thinner tire but that's fine as you can compensate by getting off the bike more. 

 

You don't want to exceed the tire edge. :p 

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8 minutes ago, what said:

The reason for running a taller+wider tire is the profile is generally better at full lean and will give a little more lean angle. Tip-in would also be quicker than with a more flattened out tire. You'd get more contact patch out of a taller tire giving you more grip at lean but that's only because you run out of contact patch sooner on a flatter tire when you exceed the tire edge - Lean angle is a bit more limited on a thinner tire but that's fine as you can compensate by getting off the bike more. 

 

You don't want to exceed the tire edge. :p 

Yup. I can use every cm of 55 when I run them, a 50 tire it is impossible to run to the edge. Usually have 1/4" chicken nuggets left on them after draggin parts. 

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8 minutes ago, 2talltim said:

Yup. I can use every cm of 55 when I run them, a 50 tire it is impossible to run to the edge. Usually have 1/4" chicken nuggets left on them after draggin parts. 

A taller tire should make you drag hard parts before you run out of lean angle, typically. 

 

Example - I went from a wider/taller tire on the Grom to a thinner tall tire. I ran out of lean angle on the wider/tall tire beforeI ran out of grip. On the newer thinner tire I run out of grip before I run out of lean angle. Obviously I'd rather run out of lean angle first however the wider tires cause a really bad geometry tearing issue that is not solvable and kills my front tire after 1 race weekend. The difference in maximum lean angle is not much but it's there. Now that I know where that maximum angle is, I can get off the bike more right before that point to lessen the impact on corner speed. 

Edited by what

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4 minutes ago, what said:

A taller tire should make you drag hard parts before you run out of lean angle, typically. 

All I know is I never have any chicken strips left on the taller 55. And can never get rid of them on the stock 50. Draging hard parts with both. 

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14 minutes ago, TimTheAzn said:

Taller tire typically is harder to get to the edge. 50 vs 55 vs 60.

Then my bike defies the laws of physics... :dunno:

I have several examples on the shelf at home. 

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And all poor @Iggy wanted was a new tire.

  • Haha 2

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16 minutes ago, Tonik said:

And all poor @Iggy wanted was a new tire.

Q3+ and done. Sticky with decent lifespan. 

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😉

2 hours ago, 2talltim said:

All I know is I never have any chicken strips left on the taller 55. And can never get rid of them on the stock 50. Draging hard parts with both. 

1. Add Preloaded.

2. Try pushing your fat ass away from the dinner table a little earlier😅

  • Haha 1

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2 hours ago, 2talltim said:

Then my bike defies the laws of physics... :dunno:

I have several examples on the shelf at home. 

Ok, this is a real puzzle. We need to solve it. Put a shorter tire on and figure out a way to keep the bike upright. Chock the front perhaps. It would be helpful if you add your amount of weight to the seat if possible.

Lay a 4x8 beside the bike and lift up the edge furthest from the bike until it hits a hard part. Then measure the distance from the edge of the 4x8 to the ground.

Put a taller tire on and repeat. Then post results. TiA.

Edited by Tonik

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5 minutes ago, Tonik said:

Ok, this is a real puzzle. We need to solve it. Put a shorter tire on and figure out a way to keep the bike upright. Chock the front perhaps. It would be helpful if you add your amount of weight to the seat if possible.

Lay a 4x8 beside the bike and lift up the edge furthest from the bike until it hits a hard part. Then measure the distance from the edge of the 4x8 to the ground.

Put a taller tire on and repeat. Then post results. TiA.

I will do that. Sometime next year :lol:when I change tires again. Have 50 on there right now, and a 55 on the rack i'm going to next. 

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2 hours ago, Tonik said:

Ok, this is a real puzzle. We need to solve it. Put a shorter tire on and figure out a way to keep the bike upright. Chock the front perhaps. It would be helpful if you add your amount of weight to the seat if possible.

Lay a 4x8 beside the bike and lift up the edge furthest from the bike until it hits a hard part. Then measure the distance from the edge of the 4x8 to the ground.

Put a taller tire on and repeat. Then post results. TiA.

I tried this and the board turned/rolled over????

What air pressure should I be running for this exercise.

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1 minute ago, B-Mac said:

 

What air pressure should I be running for this exercise.

Anything other than what the tire/bike manufacturer recommends. Might want to start a thread on that. We will figure it out as we are way smarter than they are.

  • Haha 1

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My bike came with a 180/55/17, but my cousin has a set of race take-offs from his 1985 Caprice Classic. Should I use DynaBeads or just slap some hamsteak in there and hope for the best?

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The way I test my air pressure is I ride into a large body of water and see if the tires make the bike float upside down or if I just keep riding along on the bottom. If the bike doesn't float then I need to increase my air pressure. I will say though neutral buoyancy is about where you want it set for track though as you don't want too much air in there reducing the contact patch. 

Edited by what
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I just had a genius idea.

As has been undeniably demonstrated, more weight not more contact patch increases grip. The answer here is to load our saddle bags with sand.

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9 hours ago, Tonik said:

And all poor @Iggy wanted was a new tire.

Nah lol I'm having too much fun watching the debate. Also there's bunch of useful information. ;)

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