Tri bike vs road with good aero position

Aug 14, 17 16:58

Post #1 of 17 (7732 views)

I know this has been discussed at ad nauseam but I'm thinking of building a do everything bike and getting the stable of bikes smaller.

So let's but take a flat ironman course with light wind.

Same rider

1 round tube road bike with 78 degree seat angle and aero bars

Vs

A non super bike like cannondale slice

Same wheels, same power output

How many minutes faster will the slice be?

Yellowfin Endurance Coaching and Bike Fits
USAT Level 1, USAC Level 3

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 14, 17 17:13

Post #2 of 17 (7716 views)

My experience of going from a 20 year old aluminium road bike to a Trek Speed Concept was that not much time was saved over a half ironman - probably around a minute or so (repeated the same course a year later on power numbers within a few watts on a similar weather day). However, I had a pretty aggressive position on my road bike and could stay in it for a half ironman, but over the last 40 mins I was desperate to get off my bike. On the Trek I was comfortable in an aggressive aero position for 5 hours. I am sure other people will have different opinions and experience, but mine was that the time savings over a half weren't huge, the comfort savings on the other hand were massive.

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 14, 17 18:50

Post #3 of 17 (7635 views)

Same wheels, cockpit, and fit coordinates? Just off the top of my head I'd say 3-4 minutes.

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 15, 17 0:10

Post #4 of 17 (7550 views)

actually I am in a period trying to understand the same
I have been riding my tri bike, fitted, aggressive, zipp 808, Cervelo P3 for about 6 years in many races
Last year I crashed and this season I can't use it to give more time the shoulder to recover.
My FTP is at the "normal level" of any other season (just to say).
I went for my 4th Ironman Switzerland, previously done always with P3. and I did it on Cervelo S3 with mini aerobars and again Zipp 808
I was really curious to see the aero penalty...instead no penalty!!! same power, same lap times!

One thing I have to add: I can deal with the S3 much better the cornering, descent etc. than P3. My guess is that I lost 2-3minutes in total for aero and gain the same 2-3mins on tech handling.

Overall, my idea is that if you are well fitted on road with aerobars and you don't use any downtube bottles (only behind the saddle) as in the tt bike, i think you can minimize the loss very well.
in hilly courses probably you ll see the same times. on super flat like Florida and Arizona, you ll see more difference.

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 15, 17 6:15

Post #5 of 17 (7413 views)

According to best bike split the time difference would be 16 minutes over an ironman course (maryland)

Yellowfin Endurance Coaching and Bike Fits
USAT Level 1, USAC Level 3

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 15, 17 7:32

Post #6 of 17 (7363 views)

I'm going to neglect your actual question ;)

I'd just like to point out that even if a road bike with steep seat angle and clip-ons were just as fast and just as comfy as a tri-bike, it still doesn't make this single bike an equivalent replacement for two bikes. The reason being that you have to convert back and forth between rides. I know there is a system available to make saddle position changes and clip-on attachment/removal easier - maybe it's good enough to make this work, I'm not sure. But any conventional set-up requires too much messing about between rides if you want to alternate between road bike and tri bike rides. You can perhaps make the saddle switch acceptable using two different saddles mounted on separate seatposts with a height indicator or collar so that it's easy to switch and get the saddle height and tilt the same every time, but switching clip-ons regularly would be a pain IMO and you'd end up just riding the bike in whatever format you'd left it after the last ride.

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 16, 17 21:13

Post #7 of 17 (7195 views)

I have a bunch of bikes. But one bike I have, that I love, is this very bike. Still have a tri bike, still have a roadie, but I have my experimental bike - can be switched between road and tri setups Anyway, with electronic shifting and careful purchases you can create this bike fairly easily - PM me if you want to know how I did mine.
I'm not sure I believe 16 minutes. I mean, I believe 16 minutes in a wind tunnel or software application. But, on the road, I doubt it. Speed on the bike is about hard work, a good position, and some know how - bike handling skills might be a thing of the past (I grew up racing BMX and mountain bikes).
How many times are you in a fixed aero position for miles on end with no turns, changes in terrain, or wind conditions? I guess what I'm saying is wind tunnel results are awesome but you still have to ride your bike. And, you have to ride it in the real world. A road bike with aerobars under a fit athlete is still a mean machine regardless of what the software spits out. But build it and race it and see if you like it. Why? Well, the only loss is in not trying.

Last edited by: PennBen: Aug 16, 17 21:14

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 16, 17 22:45

Post #8 of 17 (7153 views)

surfNJmatt wrote:

I know this has been discussed at ad nauseam but I'm thinking of building a do everything bike and getting the stable of bikes smaller.

So let's but take a flat ironman course with light wind.

Same rider

1 round tube road bike with 78 degree seat angle and aero bars

Vs

A non super bike like cannondale slice

Same wheels, same power output

How many minutes faster will the slice be?

As someone mentioned, the best bike split website can help you calculate the actual aero gain/penalty. I just did IM Canada, and I did the calculations and decided to take my tarmac (road bike) over Shiv (tri bike, much heavier) as the expected finish times were very similar, given that IM Canada has a lot of viscous climbing at the end.

Now, I'm thinking what if I had a roubaix-like endurance road bike, which is supposedly more comfortable? Can it help my run afterwards? Food for thought...

Re: Tri bike vs road with good aero position [PennBen] [ In reply to ]

Aug 16, 17 22:57

Post #9 of 17 (7142 views)

PennBen wrote:

I have a bunch of bikes. But one bike I have, that I love, is this very bike. Still have a tri bike, still have a roadie, but I have my experimental bike - can be switched between road and tri setups Anyway, with electronic shifting and careful purchases you can create this bike fairly easily - PM me if you want to know how I did mine.
I'm not sure I believe 16 minutes. I mean, I believe 16 minutes in a wind tunnel or software application. But, on the road, I doubt it. Speed on the bike is about hard work, a good position, and some know how - bike handling skills might be a thing of the past (I grew up racing BMX and mountain bikes).
How many times are you in a fixed aero position for miles on end with no turns, changes in terrain, or wind conditions? I guess what I'm saying is wind tunnel results are awesome but you still have to ride your bike. And, you have to ride it in the real world. A road bike with aerobars under a fit athlete is still a mean machine regardless of what the software spits out. But build it and race it and see if you like it. Why? Well, the only loss is in not trying.

When I lived in San Luis Obispo, I could ride on highway 1 for 100 miles with multiple segments of 15 miles without coming out of aero.

Re: Tri bike vs road with good aero position [Shiv88] [ In reply to ]

Aug 17, 17 0:16

Post #10 of 17 (7102 views)

Shiv88 wrote:

surfNJmatt wrote:

I know this has been discussed at ad nauseam but I'm thinking of building a do everything bike and getting the stable of bikes smaller.

So let's but take a flat ironman course with light wind.

Same rider

1 round tube road bike with 78 degree seat angle and aero bars

Vs

A non super bike like cannondale slice

Same wheels, same power output

How many minutes faster will the slice be?

As someone mentioned, the best bike split website can help you calculate the actual aero gain/penalty. I just did IM Canada, and I did the calculations and decided to take my tarmac (road bike) over Shiv (tri bike, much heavier) as the expected finish times were very similar, given that IM Canada has a lot of viscous climbing at the end.

Now, I'm thinking what if I had a roubaix-like endurance road bike, which is supposedly more comfortable? Can it help my run afterwards? Food for thought...

I happen to have exactly that set-up with a 76degree seat angle and shorty-aerobars on my road bike sporting a fairly aggressive drop (14 cm).
My Slice is 78degree with 18 cm drop (I have long arms).

My Tri-Bike is still 1.5-2 mph faster than my road bike on exactly the same course (with the same kit, wheels and tires).

In a past HIM, I once got smoked by somebody in my age group who was on a road bike.
Pretty depressing.

Re: Tri bike vs road with good aero position [PennBen] [ In reply to ]

Aug 17, 17 0:21

Post #11 of 17 (7098 views)

PennBen wrote:

I have a bunch of bikes. But one bike I have, that I love, is this very bike. Still have a tri bike, still have a roadie, but I have my experimental bike - can be switched between road and tri setups Anyway, with electronic shifting and careful purchases you can create this bike fairly easily - PM me if you want to know how I did mine.
I'm not sure I believe 16 minutes. I mean, I believe 16 minutes in a wind tunnel or software application. But, on the road, I doubt it. Speed on the bike is about hard work, a good position, and some know how - bike handling skills might be a thing of the past (I grew up racing BMX and mountain bikes).
How many times are you in a fixed aero position for miles on end with no turns, changes in terrain, or wind conditions? I guess what I'm saying is wind tunnel results are awesome but you still have to ride your bike. And, you have to ride it in the real world. A road bike with aerobars under a fit athlete is still a mean machine regardless of what the software spits out. But build it and race it and see if you like it. Why? Well, the only loss is in not trying.

I don't get your point. It sounds like you're saying aerodynamics only exist in the tunnel or on paper and somehow don't impact the reality of cycling. That is completely incorrect. Tunnel testing, CFD or other analytical methods may not be able to exactly reflect your specific ride conditions, but that does not make them irrelevant.

Besides which, I do spend the vast majority of my time during any race going in a straight line in aero. Corners are almost never a major factor in triathlon. For criterium racing or the like, cornering skill is critical and aerodynamics during cornering may also be relevant for guys in solo breakaways. But in a triathlon, cornering is of minor importance so long as you're somewhat competent.

Re: Tri bike vs road with good aero position [Ai_1] [ In reply to ]

Aug 17, 17 0:58

Post #12 of 17 (7087 views)

Ai_1 wrote:

PennBen wrote:

I have a bunch of bikes. But one bike I have, that I love, is this very bike. Still have a tri bike, still have a roadie, but I have my experimental bike - can be switched between road and tri setups Anyway, with electronic shifting and careful purchases you can create this bike fairly easily - PM me if you want to know how I did mine.
I'm not sure I believe 16 minutes. I mean, I believe 16 minutes in a wind tunnel or software application. But, on the road, I doubt it. Speed on the bike is about hard work, a good position, and some know how - bike handling skills might be a thing of the past (I grew up racing BMX and mountain bikes).
How many times are you in a fixed aero position for miles on end with no turns, changes in terrain, or wind conditions? I guess what I'm saying is wind tunnel results are awesome but you still have to ride your bike. And, you have to ride it in the real world. A road bike with aerobars under a fit athlete is still a mean machine regardless of what the software spits out. But build it and race it and see if you like it. Why? Well, the only loss is in not trying.

I don't get your point. It sounds like you're saying aerodynamics only exist in the tunnel or on paper and somehow don't impact the reality of cycling. That is completely incorrect. Tunnel testing, CFD or other analytical methods may not be able to exactly reflect your specific ride conditions, but that does not make them irrelevant.

Besides which, I do spend the vast majority of my time during any race going in a straight line in aero. Corners are almost never a major factor in triathlon. For criterium racing or the like, cornering skill is critical and aerodynamics during cornering may also be relevant for guys in solo breakaways. But in a triathlon, cornering is of minor importance so long as you're somewhat competent.

Yes, a road bike set up at the exact same angles as a Tri-bike handles like crap and is sometimes outright scary in the aero position....each and every time.
And in 20 years of Triathlons, I have never ridden a course where there wasn't at least one technical section where staying in aero and In Control wasn't providing substantial time gains at the pointy end.

Just ask Slowman and the other builders back then (names escape me right now), why and how they modified the road frame geometry for Tri.

Last edited by: windschatten: Aug 17, 17 1:02

Re: Tri bike vs road with good aero position [windschatten] [ In reply to ]

Aug 17, 17 1:21

Post #13 of 17 (7074 views)

windschatten wrote:

Ai_1 wrote:

PennBen wrote:

I have a bunch of bikes. But one bike I have, that I love, is this very bike. Still have a tri bike, still have a roadie, but I have my experimental bike - can be switched between road and tri setups Anyway, with electronic shifting and careful purchases you can create this bike fairly easily - PM me if you want to know how I did mine.
I'm not sure I believe 16 minutes. I mean, I believe 16 minutes in a wind tunnel or software application. But, on the road, I doubt it. Speed on the bike is about hard work, a good position, and some know how - bike handling skills might be a thing of the past (I grew up racing BMX and mountain bikes).
How many times are you in a fixed aero position for miles on end with no turns, changes in terrain, or wind conditions? I guess what I'm saying is wind tunnel results are awesome but you still have to ride your bike. And, you have to ride it in the real world. A road bike with aerobars under a fit athlete is still a mean machine regardless of what the software spits out. But build it and race it and see if you like it. Why? Well, the only loss is in not trying.

I don't get your point. It sounds like you're saying aerodynamics only exist in the tunnel or on paper and somehow don't impact the reality of cycling. That is completely incorrect. Tunnel testing, CFD or other analytical methods may not be able to exactly reflect your specific ride conditions, but that does not make them irrelevant.

Besides which, I do spend the vast majority of my time during any race going in a straight line in aero. Corners are almost never a major factor in triathlon. For criterium racing or the like, cornering skill is critical and aerodynamics during cornering may also be relevant for guys in solo breakaways. But in a triathlon, cornering is of minor importance so long as you're somewhat competent.

Yes, a road bike set up at the exact same angles as a Tri-bike handles like crap and is sometimes outright scary in the aero position....each and every time.
And in 20 years of Triathlons, I have never ridden a course where there wasn't at least one technical section where staying in aero and In Control wasn't providing substantial time gains at the pointy end.

Just ask Slowman and the other builders back then (names escape me right now), why and how they modified the road frame geometry for Tri.

That's not the point I took from his post. Perhaps I misinterpreted his argument. Nevertheless, I disagree with his assertion, as I read it, that analysis is inconsistent with reality.

I also think 16mins sounds a little on the high side but the actual difference will likely vary widely depending on the specifics of terrain, bike fit, impact on power, etc...

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 17, 17 6:02

Post #14 of 17 (6977 views)

Try as you might, I just don't think you can make a road bike into a competitive tri bike. The combined handling and comfort of a tri bike over 112 miles just cannot, in my opinion be duplicated on a modified road bike. Tri bikes are engineered to be good at triathlon racing and road bikes are not.

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 17, 17 6:19

Post #15 of 17 (6965 views)

Another thing to consider is how you run off a road bike vs a triathlon bike position in a race situation.

Dan Kennison

facebook: @triPremierBike
http://www.PremierBike.com
http://www.PositionOneSports.com

Re: Tri bike vs road with good aero position [dkennison] [ In reply to ]

Aug 17, 17 7:12

Post #16 of 17 (6939 views)

dkennison wrote:

Another thing to consider is how you run off a road bike vs a triathlon bike position in a race situation.

That's the point I was (and maybe the OP, too) trying to make. More comfortable bike = better run split?

We all know "the bike for show, the run for dough." If I am doing 112 mile time trial, I'd take my tri bike every time, but I took my road bike to IM Canada 2017 thinking that climbing is easier with road bike & it would reflect on my run split positively, in theory. My tri bike is almost 10 pounds heavier than my road bike.

Now, I'm thinking what if I bring a Roubaix (endurance bike, supposedly more "comfortable") to IM Canada 2018, and can it help my run? Will it be a wash? Just thinking aloud here.

Re: Tri bike vs road with good aero position [surfNJmatt] [ In reply to ]

Aug 17, 17 18:14

Post #17 of 17 (6829 views)

I completely agree that aerodynamics and geometry matter. I guess my point can be summed up by saying - assuming you can achieve your correct position - a fit athlete will be fast on a tri bike and/or a road bike w/ aerobars. And, the OP should try it and see if he likes it.

Our Partners

transition-DOT-area-AT-slowtwitch-DOT-com

Advertise with us

©1999-2024 Slowtwitch, Inc., and Slowtwitch.com
Reproduction of material from any Slowtwitch.com page
without written permission is strictly prohibited.