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ridin' bikes for years
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I talked to an indy shop today about ordering a Metzeler 140 for my 2004 Road King. He said I should get the 130 size because the 140 would have a bigger circumference than the OEM Harley tire and would make my speedo very inaccurate.

Has speedo error been a noticable problem for those of you who have switched from OEM to Metzeler tires? I would prefer the larger footprint of the 140 tire.
 

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Pimp Daddy
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billgran said:
I talked to an indy shop today about ordering a Metzeler 140 for my 2004 Road King. He said I should get the 130 size because the 140 would have a bigger circumference than the OEM Harley tire and would make my speedo very inaccurate.

Has speedo error been a noticable problem for those of you who have switched from OEM to Metzeler tires? I would prefer the larger footprint of the 140 tire.
I would run from that shop!!! The 140's circumference is the same as the 130. The 140 is the measurement in width not height. What a jacka#$ that told you that. I've ran Metzeler's for years and Avon's also and never had a VERY inaccurate speedo, maybe a mile or two per hour but nothing I'd worry about.
 

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The diameter of the 130/90 is 646mm.
The diameter of the 140/90 is 665mm.
The 140/90 is 2.94% bigger. If your speedometer was dead on with the 130, you'd be going 72 mph with the 140 when your speedometer indicated 70 mph.
 

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They aren't quite the same but it won't effect your speedo
Sidewall Radius Diameter Circumference Revolutions Speedometer Odometer
130/90-16 4.6" 12.6" 25.2" 79.2" 800/mi 60MPH 10000mi
140/90-16 5.0" 13.0" 25.9" 81.4" 778/mi 60MPH 10000mi

The calculator is here : http://www.powerdog.com/tiresize.cgi
 

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sr1032 said:
I would run from that shop!!! The 140's circumference is the same as the 130. The 140 is the measurement in width not height. What a jacka#$ that told you that. I've ran Metzeler's for years and Avon's also and never had a VERY inaccurate speedo, maybe a mile or two per hour but nothing I'd worry about.
3 % difference is important to some, maybe not to others. Wouldn't run from these indy shop as they are right with their statement.
 

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nidan said:
They aren't quite the same but it won't effect your speedo
Sidewall Radius Diameter Circumference Revolutions Speedometer Odometer
130/90-16 4.6" 12.6" 25.2" 79.2" 800/mi 60MPH 10000mi
140/90-16 5.0" 13.0" 25.9" 81.4" 778/mi 60MPH 10000mi

The calculator is here : http://www.powerdog.com/tiresize.cgi
You have to put in both sizes at the same time to get the speedometer/odometer difference.
130/90-16 4.6" 12.6" 25.2" 79.2" 800/mi 60MPH 10000mi N/A
140/90-16 5.0" 13.0" 25.9" 81.4" 778/mi 58MPH 9727mi 2.8%
 

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I know the O.E. tire size is a 140 and the speedometer i thought pick up the signal from the transmission. Thats where the sensor is anyway. just order it and install it, you will be very happy....
 

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ViennaHog said:
3 % difference is important to some, maybe not to others. Wouldn't run from these indy shop as they are right with their statement.
His statement was that the indy shop said that it would make his speed VERY inaccurate. By no ones standards is a 2 to 3 MPH difference VERY. They should have said it may cause a couple MPH difference or done what everyone else here has done and pulled the specs.
 

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sr1032 said:
His statement was that the indy shop said that it would make his speed VERY inaccurate. By no ones standards is a 2 to 3 MPH difference VERY. They should have said it may cause a couple MPH difference or done what everyone else here has done and pulled the specs.
you right, I skipped over the VERY statement, 2% -3% isn't in that category. I'll read a little more carefully next time before I respond :spank:
 

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Murphdog , yep .. actually it's 2.75% , and the caclulator is not specific to tire brands which vary somewhat in size.
 

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Even with the pickup in the transmission, the speedo will be off. Increased tire dia makes you go down the road faster w/ the tranny turning the same RPMs.
To truly figure your error, go to:
http://www.metzelermoto.com/media/me_880_product_bulletin.pdf

Find the "Rolling circum. (mm)" for the tire you want.

Go to the site for the tire you have, and find the same info (I've never seen a manufacturer's tire site without this information) and figure the difference.
 

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MegaGlide said:
Even with the pickup in the transmission, the speedo will be off. Increased tire dia makes you go down the road faster w/ the tranny turning the same RPMs.
To truly figure your error, go to:
http://www.metzelermoto.com/media/me_880_product_bulletin.pdf

Find the "Rolling circum. (mm)" for the tire you want.

Go to the site for the tire you have, and find the same info (I've never seen a manufacturer's tire site without this information) and figure the difference.
To make matters a little more complicate, you need to consider that the 'rolling circumference ' is not constant as it increases with rotation speed through increasing centrifugal forces. Now you have something to play with..
 

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Yeah, but the difference in centrifugal forces the from tire to tire in sizes that close will be minute in that computation, and the measurement I indicated is the closest I could get to the "rotations per mile" I always used in figuring correction for speedometer error in 4x4s when changing tire sizes... :D
Now, we gotta figure in the mean ambient temp where you normally ride, and...:roflback:
 

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MegaGlide said:
Yeah, but the difference in centrifugal forces the from tire to tire in sizes that close will be minute in that computation, and the measurement I indicated is the closest I could get to the "rotations per mile" I always used in figuring correction for speedometer error in 4x4s when changing tire sizes... :D
Now, we gotta figure in the mean ambient temp where you normally ride, and...:roflback:
Mega, there's more than that. The more you push the bike, the hotter the tire gets...........
Come to think about it the whole equation is only valid for a new tire
 

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Along with rolling speed changes, isn't there also the issue of tire wear. Through the life of the tire the diameter could change up to 1/2". This is true of OEM and the Met. So won't the OEM tire also cause "very" inaccurate speedo readings itself as it becomes smaller due to wear????
 

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Um, I thought you were just yankin' my chain, but heat would be fairly constant from tire to tire as well, if we're bein' serious, wouldn't it?
 

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MegaGlide said:
Um, I thought you were just yankin' my chain, but heat would be fairly constant from tire to tire as well, if we're bein' serious, wouldn't it?
Just trying to get you off track. I miserably failed...........
 
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