i have plans to do several Time Trial Races This Year. I have a TT bike and was averaging a pace of about 21.5 mph (I’m 62). In hopes of increasing my speed, I bought a Zipp Super 9 rear disc wheel. I’ve gone on 3 rides and am actually slower 20.5 mph (about my average on my road bike).
Does this make any sense? In reading about the wheel, zipp says, regardless of how slow or fast you are, there should be improvement. Ive been riding a TT bike for the last 3 years (about a third of my training). Also riding a road bike. Do i just need to be patient about getting use to it? Any advice would be appreciated.
Adding to some of the questions above…
What is your TT bike?What wheel were you using before? What tires & tubes were you using on the old wheel and on the new wheel?Same tire pressure or different?Any other changes to your bike?Per above, any chance the rim or tire is rubbing on the brake or frame?
I ride around the same speed. I have an IA16. I got a lot faster when I went from 90mm rear to a disc. (I made some other changes at the same time, but I am pretty sure the disc helped.)
You ride with power? Otherwise we can’t help much.
If you do, ride a known little segment a few times and bring both wheels. Park your car even if you must. Do it as close to same power as possible.
One mph is mammoth change in the world of TT. Either you’re experiencing a localized phenomenon related to wind or something OR something horribly wrong with the bike.
But one mph change in local wind is imperceptible to a human.
Yeah, without power, wind and pressure data from all the rides there is no way to solve this problem. Switching to a rear zipp disc that is in good condition with identical tires and pressures did not make you go slower. Something else did.
Also, your position on the bike, clothing and helmet are all identical?
Crosswinds absolutely could make the difference. You say you “can” measure power. Did you on these rides? Was average power, normalized power and VI the same among all the rides?
Wow I’ve never heard of this. Disc always gives you an advantage. I couldn’t go over 18.9mph with my road bike so got a tri bike with disc from the get go. I averaged 23mph on the exact same course. I think you should go back to 404. It seems like disc is not for everyone and you are one of them.
I did have PM On the last ride, it was about 15w less than on the toad bike. Perceived effort felt same. Maybe just a bad day?? I’m Going to keep testing. Will head out on another ride today.