MikeD1

Currently riding a 28 yr/old Centurion Dave Scott Ironman bike with Tange #1 steel frame. Approx 23 lbs, stock wheels with Michelin Krylium clinchers. Bike is a bit oversized for me at 58cm, I should probably be on a 55-56cm. The reach is way too long and with clip on aero bars I am way too stretched out. Considering purchasing a Carbon frame bike like Wilier GTS, Fuji Gran Fondo, Scott Solace etc. Partly for correct fit and more comfort, but also could better justify the purchase if indeed it helps me be significantly faster. So, with a CF bike that weighs 5-8lbs less etc how much faster can I expect to be? Many of the courses I ride are moderately hilly: 800-1400 ft. climbing in the 16-17 mile distance with grades up to 10-13%. So far doing Sprint Tris and training rides up to approx.. 40 miles. May do some Oly distance races in the future as well as Metric Centuries. FWIW, I just turned 60, I know that the engine is the most important factor and work hard on that, just wondering if dropping $2K+ will yield significant speed increase. Thanks for any input!
FWIW, 1st Sprint bike leg was 17 miles with about 800 ft of climbing and I averaged 18.5mph. Based on additional training I think I'm probably at about 19 or a little faster now on that same route.

StanSeven

You'll find some improvement with lighter weight on climbs that steep. You'll also feel better with the smaller frame - there's not much worse that trying to get up a steep hill on too large a bike. But the largest factor is mental - you'll push harder because you want to justify the expense and get maximum enjoyment.

rpenmanparker 

I agree with everything @StanSeven said, but would qualify his answer by adding that it is almost impossible to get a consensus on this forum regarding your question about bike weight. But nothing is worse than a bike that doesn't fit, and over more than 20 years the efficiency of bicycles has improved dramatically for one reason or another. So you can hardly go wrong with a new one. It is possible to get good weight to price value, so if you are interested in that, work the internet hard for specifications. IOW do your homework.

bruce19

What they said. A bike that fits will be more comfortable and more responsive and that alone is going to make you ride better.

merlinextraligh

Bicycle Speed (Velocity) And Power Calculator

My bet is you're looking at 1-2 minutes over a course with 1400 feet of climbing.

If you want a precise answer, you can brake the course down by segments (each climb by length and grade; each descent by length and grade, and length of each flat portion) enter them into the calculator for each bike weight, then total.

But I think you'll be surprised that it's a smaller difference than you might guess.

nuke_diver

Recently (6 months ago) purchased my first new bike since 82. The new bike probably won't be faster on the flat or slightly rolling terrain. The bike will almost certainly be faster for longer uphill rides (I got mine because I live where there are a fair bit of hills and there were some slopes that were very very hard on the old bike and not really a problem on the new...partly due to weight the rest gearing). The new bike is much more responsive (accelerating faster, handling quicker) than the old. So if you are looking only for speed you are not likely to get it I think...maybe a bit. You may find less fatigue if you go out harder though so you might be able to hold the same top speed longer.

evrythngsgngrn

MikeD1

Really appreciate all the input. Great link on the calculator and the video was excellent. A good friend who I used to race Cat 3 with years ago ran a shop for years and knows a lot about fit. He just stopped by this morning for another reason, took one look at me on the bike and said "yep, definitely too big, too much reach for sure" He volunteered to bring over some of his fit gear next week and measure me on the bike and trainer. I will definitely take him up on the offer. He also suggested that using aero clip ons with this much reach is probably losing me as much power as the aero is helping . . . and pretty tough on the back. I felt this was the case but wasn't really sure if I just needed more time on the bars as well as more stretching etc. But at this point on going to forget the bars . . . at 5'11" and about 155lbs I am much lighter than most of the last 40 years, but pretty sure I was racing at about 145lbs. I think I have at least another 5 or 6 lbs I can drop just by cutting down on beer (darn!!