Got my new tires in the other day and finally have the rear changed and it made a very noticeable difference. Gone was the very pronounced wobble with every rotation of my rear wheel. The ride was nice and smooth. One other difference was an increase in rolling resistance. For most cyclists the increase would be minimal, but since I am well above average in the stress on the bike department due to my size, it was definitely noticeable to me.
My normal training route takes me around the same roughly one mile loop several times, so I've gotten to know the route quite well and the amount of effort it takes to ride it. I can usually predict within a few seconds what my lap times will be based upon how it feels that morning. this morning, with the new tire installed I felt significantly slower and my times bear this out.
A week ago, I completed 3 loops of my "one block" segment with times ranging from 4:16 to 4:23. My top speed was 20.6 mph. This morning, on the same segment, in very similar conditions, my times were 4:45 to 4:54 and a top speed of 19.7 mph. I felt the increased work I had to do and my times proved me out.
The increased resistance is likely due to the fact that the new tires have a max. pressure of 75 PSI as opposed to the max of 84 PSI on the old Michelin tire. 9 PSI may not sound like a lot, but it definitely gives a smoother, softer ride. The trade off it it takes more work to get the tire rolling.
Now, it may sound like I'm complaining, but I'm not. I'm just noticing that I won't be setting any KOM's any time soon. I need to work harder, to get faster and lose some of this weight before the KOM's once again fall. :)
Get on your bikes and ride!