Every week I ride my 20 mile Time Trial Route on the nearby Keystone Trail in Omaha. It's basically flat, except for the downs and ups as the trail passes under intersecting streets. Every week I try to best the previous week's time. This is usually an all-out effort. Obviously the wind is always a factor as the trail runs mostly north/south and this time of year we have mostly south winds. Yesterday there was very little to no wind!
I ride a Trek 1200C which isn't the fastest, but then again fast is a very relative thing and becomes even more relative the older one gets. For me it's all about effort.
Anyway...last evening I went out to the 10 mile mark in 30:16. Made the turn...where I lose a bit of time...and hit it hard on the return leg. I kept an eye on the spedometer and the HRM...the cadence plug broke and I need to get it replaced...and maintained a very good effort. The return leg was also 30:16...for a 1:00:32 total time...which was a minute+ faster than the previous PR. Avg HR was 154 with a max of 166. I'm 54 and I figure my MHR to be around 172-175.
Being a runner for almost 30 years I continue to be amazed at the lack of aches and pains I feel after such a hard effort on the bike for an extended time period. Had I run all out for an hour and covered 8 miles I'd been feeling the effort for a good day or more. Gotta love the cross training benefits of the bike!!!
That's a terrific effort over 20 miles! We do a 10 mile TT at Lowes Motor Speedway in Charlotte/Concord, NC but as you can well imagine it is about as flat as it can be. The biggest variable as you pointed out is the wind. Even though you're riding a "neutral course" wind wise my times vary and reflect the amount of wind we have. My best time over 10 miles is just over 24 minutes but if I knew I was going twice as far I'm sure it would be a good bit higher.
BTW the course record is around 19 mins.......the fellow who holds the record comes around me in a blur.........