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wheelnut46

Front tire questions

10 posts in this topic

I need a new DOT front tire for my "L". Typical Eastern stuff; ride to work and back, woods, some mud, sand pits, whatever I can find etc. etc. There are 2 sizes available for the D606 that I'm probably going to get. 80/100-21 and 90/90-21.

I'm leaning toward the 90/90-21 because I think it's wider than the 80/100-21 and will work better for my needs. Is this correct?

I want to use the ultra heavy duty tubes that only seem to be available in the 80/100-21 size. Some (Michelin) are labeled as being for both tire sizes. Is this correct?

Please forgive the simplicity of these questions. I'm learning the ropes and I do not want to order the wrong parts.

Thanks

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Yes that's true.

All of the ultra heavy duty tubes only seem to be available in the 80/100-21 size. Is this ok to use in the 90/90-21 size or do I need to find a different tire or a different kind of tube?

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according to the dunlop website the d606 is only available in 90/90-21 for the front

Thats what the site says.....and thats all ive seen on sites like dennis kirk and Rocky mountain. Is the first number the width or something? Example: 80/100 means 80mm wide and 100 tall?

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Typically the first number is the width. The second number is the aspect ratio and the third number is, of course the wheel size.

So the first number is 80 (millimeters) and the aspect ratio is 100 (% of the width).

To find the theoretical tire height:

Take the width (80 mm / 25.4 = 3.15) x 100% (aspect ratio) = 3.15 x 2 = 6.3 inches + 21 inch wheel size = 27.3 inches tall

90/90-21

(90mm/25.4 = 3.54) x 90% (aspect ratio) = 3.19 x 2 = 6.38 +21 = 27.38 inches tall.

Theoretically-

The 90/90-21 is pretty much the same height as the 80/100-21 but is slightly wider.

All manufacturers do things slightly different so the numbers are never exactly right on.

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You are fine with that tube. Most of the front tire are just about the same overall size. The differences are minor.

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If you're going to ride typical eastern terrain don't go with the 606. You'll go no where and your frontend will wash alot. I'd suggest a more aggressive tire like the Pirellli MT-83 scorpion pro.

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If you're going to ride typical eastern terrain don't go with the 606. You'll go no where and your frontend will wash alot. I'd suggest a more aggressive tire like the Pirellli MT-83 scorpion pro.

Is this tire any good on the street? I cant find any reviews on it except it's off road capabilities. But if it's skiddish on the road then thats NFG.

You are right though. I need a more agressive front tire that bites. My stock POS was going all over the place in the mud.

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If you want a decent knobby pattern on the street the Pirelli MT-18HD is quite good. I just had one and it gripped good. It's still a knobby and you will give a tad bit of streetability up but I'd say it's a good 55% dirt, 45% street tire.

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