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Old 08-24-2012, 03:02 PM   #103
viola-tor OP
Needs to ride!
 
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Joined: Feb 2008
Location: Rockies. Freakin' Rockies.
Oddometer: 2,071
Quote:
Originally Posted by Scott Baja View Post
I dont know if this has been discussed in this thread. My fuel milage was going down. Started out over 35mpg, then slowly going down to about 29mpg. The rear scorp was worn out, so replaced with half used dunlap 908. My mpg increased back to over 35mpg. Also, I had been tacking about 5k at 75mph, now with different tire, about 5k at 80mph. The gearing is 16 45. Dont really know why or what this means, its just the results so far.
Quote:
Originally Posted by DirtJack View Post
Don't know why I hadn't thought of this before. Viola-tor's recent mpg measurements have been made with his 19/17 street wheels mounted and he may be comparing mpg figures obtained with his 21/18 knobby wheels. I don't know if he uses his GPS distance (which is usually a little less than an accurate front wheel odometer) or what the odometer says. At any rate the wheels do have a different outside diameter, but I don't think enough to account for the difference. Needs to be checked out though.

It's true, I do switch back and forth on wheel size, gearing, and tire type often. Previously this has only had a variation of a 3 or 4 MPG difference max over years of riding with various rubber. I'm now experiencing 10-15 MPG off the "usual." SIGNIFICANT! I'm pretty sure something else is going on...

Brakes seem fine, chain seems fine... But keep the ideas coming! It'd be great if it was something silly/easy.
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