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Premium Member
1974 T120 5 speed.
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106 Posts
Discussion Starter · #1 ·
My project needs tires. I have read every tire thread in the last few years and I am more confused. Old tires on it now are;
Rear 4.00H18 K87
Front 3.25 x 19 Continental Blitz

I want to use K81s but sizing is different from when these tires were new. I had a vendor tell me the equivalent sizes are now

Rear 4.25/85 H18
Front 4.10 H19

This doesn't seem correct. I can't find real word dimensions for any of the dunlops offered.

I did find 3.60 x 19 , in OZ

Research just gets me deeper in confusion.
 

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Super Moderator
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8,837 Posts
Hi Brian,

I can't find real word dimensions for any of the dunlops offered.
Research just gets me deeper in confusion.
If, by "real word dimensions", you mean overall dimensions (diameter and width) - http://www.dunlopmotorcycletires.com/tire-line/k81/ and scroll down.

I had a vendor tell me the equivalent sizes are now
I did find 3.60 x 19 , in OZ
Mmmm ... depends, especially the front - 4.10 x 19 overall diameter is very similar to 3.25 x 19 but the overall width is greater, which some riders find gives vague steering on a relatively light bike like a Triumph twin.

3.60 x 19 TT100 are also available in GB. 'Back in the day', Dunlop recommended 3.60x19 front, 4.10x19 rear on Triumph twins. The 3.60 has a similar overall width to the 3.25 x 19 but a smaller overall diameter, which leads to 'daylight showing' between the top of the tyre and the lower edge of the fender, when the bike is viewed from the side.

Just as a matter of interest, why not 3.25x19 and 4.00x18 Avon Roadriders?

Hth.

Regards,
 

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Premium Member
1974 T120 5 speed.
Joined
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106 Posts
Discussion Starter · #3 ·
Thanks Stuart, I do like the asymetrical center tread pattern on the Roadriders. Lot of grooved concrete between me and decent canyons. It seems the width of the AM26 3.25x19 is 3.9", only a tenth under the 4" listed dimension for the K81 4.10x19. I kind of ruled out the Avon due to reports of center cracking reported a few years back. I will reconsider.
 

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Super Moderator
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8,837 Posts
Hi Brian,

width of the AM26 3.25x19 is 3.9", only a tenth under the 4" listed dimension for the K81 4.10x19.
Bear in mind that's on a WM3-equivalent rim; certainly originally, your bike had a WM2.

If you want a narrower-overall front, I believe 'fraid you have to look at a Dunlop K70. :(

Hth.

Regards,
 
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