SPEED road bike vs tri

tri bikes tend to be little faster due to the aero position.  once you have aero bars and proper fit, speed should be the same. 

road bike vs mountain bike is night and day, i have ridden on a mtb and did a number of my triathlons 1st year on a nice heavy duty XC full suspension.  probably ave 17-18 mph, on the same course and my tri bike i ave 22-23 mph.  for 10 mile sprint. 

I can't yet figure out how people average over 20 mph on their bikes.  I look forward to my first tri, just so I can witness how fast some folks travel up the hills.  I've been improving by either a lower heart rate or a little faster mph but I'm still quite a way off from 20 mph.

This morning on the TDF they had the Cervelo guys talking about their P4 bike. I "think" they indicated that over a 60 minute ride the bike would improve the time by 40 seconds. I also "think" this was over last year's TT bike, but I was not really listening too closely, so I may have the facts a bit off. For the top athletes that would be a big deal. Of course Trek may do as well.

to avg 20,, you need to be riding 23+ is my motto,,, to take in account slowing for turns, hills etc...

that's what I tell myself so I don't look at my speed, see 20mph and think to myself I'm doing ok

thanks for your responses...
   the first responce was very good... so from a 17-18 ave on a mountain to a 22-23. 5mph difference. thanks!  any thoughts about a road bike average with and without aerobars?

I have them on my road bike for comfort and so that I'm used to that position for tri racing since I prefer to ride my road bike most of the time. They put me about 4 inches lower than if I were on the drops with extended arms. They are perfectly comfortable.

Today, I'm switching to my tri bike for training the next couple weeks so I can adjust for my next race and I'm not very excited about it. My normal training route is ~60 miles with ~5,000 feet of climbing. The road bike rides it so much better.

22-23 mph ave is quite slow sorry to say.  for me at least having seen elites race, who ave 25 mph. 

i have seen matty reed (pro triathlete) who rode on the same course as me.  and ave 28 mph while i managed 21.5 over 25 miles / 40km.  he still managed to run a 10 k in 33 min after that.

Edited by trix 2009-07-23 12:56 PM

remember also...i consider myself a decent biker and its definitely my str.  i have been mtb for a while.  it took a few rides to get adjusted to TT bike, and road cycling in general.  but imo it was a quick transition. 

so what would the difference between road bike with aerobars verses tri bike?

I'm still in the first month of my tri bike, but my road bike with aerobars was set up with a great fit. Right off the bat, the tri bike was more comfortable, some being the fit and some being the carbon fram instead of aluminum. The new geometry and gearing have required some adjustment. I did get sore in some new places at first, perhaps to some new angles, and the new gears are a bit different as well. My rides were a bit more efficient immediately, 1 - 1.5 mph at the same heart rate, but I expect that the improved position, lighter weight, and aerodynamic properties of the new bike will be even better once I get better acclimated to it.

I just looked at the results of the last race I was in. The top 10 finisher had avg. speeds of 23- 24 mph. I'd like to be that slow.

Edited by lextek 2009-07-23 6:59 PM

you can't compare course times from different courses of course.  Yes I'm a dork. 

For me I think it's been about 0.5 mph for a Trek Madone vs. Trek TTX with the same wheels. But I'm still adjusting to the steeper angle and I'm hoping to improve upon that in the next couple weeks which will be the first stretch that I've really trained some decent mileage on the TTX.

thanks for your reply-  this gives me some good insight when im ready to move up (areobars or tri bike)

On my mountain bike in olympic races I was averaging between 19-20.
On my tri bike in the same races, courses, conditions and fitness level I was averaging 21-22.

MTB vs road bike speed depends alot on specific MTB.  With my F/S MTB & knobbies (tires) I max out at around 17mph for an hour ride on road, but with 1.5" slicks on my hard tail MTB & can ride 20mph.  At speed another limiting factor is spinning out MTB gearing (typically 44/11 vs road 50-53/11-12).  I cannot hold above 105-110 cadence for an hour.

Very interesting test done here with road & TT bikes.
http://www.cyclingnews.com/features/how-aero-is-aero

Used pro cyclist & SRM power meter under identical conditions to measure power differences at speed in actual outdoor track conditions (not wind-tunnel).  Basically found that pro cyclist riding 40kph on std road bike & helmet in drops (i.e. very good baseline aero position) could do 44kph with full TT bike & TT helmet at same power output.  Roughly half that speed advantage could be had by just adding properly fit clip-on aerobars (more aero rider position), and roughly 2/3rds of that could be had by aerobars plus TT helmet. 

Personal experience adding clip-on aerobars and 0-offset post ("Pseudo TT positioning") to my decent road bike (07 carbon Tarmac) consistently bumped my near-LT cruise on flat straight course by about 1-1.25mph to my (admittedly mediocre) TT speed (21+mph in drop to 22.5-23mph in clip-on aerobars).
And on long open rides the more relaxing arm positioning made me more comfortable too.