Tri bike vs. Road bike speed gain

2mph is not guaranteed with the purchase of a tri bike. If you are well-fit and well-positioned on your road bike it could be considerably less.

Here's another thought though: train more. I bet most of those who finished in front of you did.

So were you part of a relay team?  Are you comparing your results with others who only did the bike and run?  Getting "tagged" in T1 and heading out on fresh legs, lungs, and heart, is not going to correlate to someone who just swam 1.2 miles.

No. He said he did both bike and run. His RR says that it was 70.3 Poconos, where the swim was canceled.

Back on topic: if the OP already has clip-on aerobars, then a 2 mph gain from a dedicated tri bike would be optimistic. It's the body position that makes the greatest difference, and the bike makes a smaller contribution. Dollar for dollar, an aero helmet is generally considered to be the best investment in speed.

Have you read "How Aero is Aero"

It basically shows that you get about half the benefit of going to a tri bike by adding aero bars to a road bike.

I am no expert, but from what I have read, if you already have a road bike (especially a carbon frame road bike) gaining 2 mph off the switch would be unlikely.

It's tough to buy instant speed by switching to a different bike. In our sport, the 97%ile is still the engine.

That said, the key things here are:

1. Optimal bike fit and position.

2. Acclimating to a new bike.

Top professional triathletes and bike racers can acclimate to a new bike quickly becasue they do so many miles, have great bike handling skills and it is part of their jb to be adaptive to new bike designs based on sponsor requirements, etc. Even then mistakes are made at the pro level. Top French professional cyclist and all-around nice guy Laurent Jalabert switch time trial bike brands prior to one season and it ended in calamity. He went backwards on his new team bike used in the time trails and his team mechanics botched wheel changes in time trials since they weren't fully trained on fast wheel changes with rear-facing horizontal dropouts.

The lesson: Most of the time new equipment will slow you down at first, until you become acclimated to it.

For amateurs that acclimation takes months. Months. And that is assuming the set-up and position is optimal from day 1. It usually isn't.

Look at how many posts you read on forums with titles like, "I bought a time trial bike [sic] and I went slower!" or "My triathlon bike isn't as comfortable as my road bike!"

When you dig a little deeper into those threads we learn the person has owned the bike for a month.

There is almost no such thing as "free" speed from equipment. You have to learn how to use it, have it optimized for you and then get acclimated to and comfortable on it. You have to meet it at least half way. That takes time. A few months minimum for a recreational level athlete like you and I.

Well, having run Pocono the same day the OP was there, this is a really tough call and it depends on how the question is viewed.  That course was very technical for a tri course.  If this is about gaining 2 mph average there, then not likely.  You simply have to know the bike and how to ride it.  Reports of the course vary widely because people's background varies tremendously.  Those of us with mountain biking backgrounds thought it was awesome.  Those without it (or less of it) tended to think it was pretty hard, some would say dangerous.  i could see many people actually losing some time by using a tri bike simply because they're not quite as capable for all the maneuvering and the people don't know how to do it that well.  I know I'm faster with it because I'm very familiar with the bike and I'm confident in my handling skills and ability to negotiate the course.  I'm not sure it'd be a full 2 mph difference on this course between road and tri bike for me though. 

Many of the other posts address the differences in general, and is what should be looked at for long term.  And that is it depends on how well you're set up on the current bike and how much better the tri bike improves things.  It's very possible, but not guaranteed to get that difference.  Aero advantages will make a rather noticeable difference on most every (if not all) road course tris you'll ever do after that one.

(I hope this makes sense because it's late but I can't sleep)

Interesting.

I just bought a tri bike after dozens and dozens of triathlons spanning 3 decades off and on. 

Here are my thoughts, based ONLY on my experience.  I have only recently found these boards. I just never spent much time on a computer....I have 5 kids, it took alot of time to get them to the point where I had some time of my own. The info on these boards is an eye opener.

When I was young, in the mid to late 80's, I won my age group in most races I entered. I won outright a number of times. I came from a college track background.  NOBODY had a tri bike, they had not been invented.  Some folks started showing up with clip on bars, but hardly anyone really understood them.

I went a few years doing other endurance/athletic endeavors and came back to triathlon 3 seasons ago.  I figured I was 50 and was about to smoke some age group races.  HOLY COW!!!  I could not believe the change I saw.  I could not compete.  I worked hard, I know how to do this stuff.  This year I began to place in my age group again, and won my age group in 2 sprints. I'm still not there in oly and above.  My ride was a Specialized Tarmac (carbon) that I bought after the first year back when I rode a Specialized Allez (aluminum). I bought some really good wheels last year (Cosmic Carbone SR). I got faster.  I started riding with a group.  I could keep up fine, and beat most of them.  Some of them did triathlon. Some of them showed up to the same HIM I did this year.  I got creamed. They had tri bikes, I did not.  I KNOW I beat these guys day in and out on our road bikes. To hell with it, I bought a tri bike. 

I'm in the very early stages of getting used to my bike, a Trek 7.5 SC.  I'm faster.  I don't know how much faster I'll end up being, but the position suits me well.  And THAT, I think, is most important.  In what I have seen over the last few years, it's kind of like swimming with a wetsuit. Some people gain very little, some gain a bit, some make huge gains with the added bouyancy and new position in the water.  I gained very little with a wetsuit. 

From the riding/training I've done so far on the new ride I bet I gain AT LEAST 2 mph on the new bike. MAYBE you can make an argument that I wasn't set up as well as I could have been on my road bike, I'm not sure yet.  What I do know is that I have a running background....a BIG running background.  Opening up my hips in the tri position has been huge for me.  I have an idea that, like the wetsuit, some people make bigger gains then others.  Some, because of their physical makeup, make really big gains. I think when it's all said and done a  2 mph gain will be on the very light end for me. Once I get truly dialed in and run the race wheels I bet I'm close to 3.0 better. I'm stunned at how well the position suits me.

I'm my own experiment right now.  The best part of this sport is tweaking your work and your equipment.  It's very unique to each person.   Pretty cool. No wonder we all enjoy it so much.

My first 2 years of racing triathlons I was riding a roadie with clip ons. This winter I bought a tri bike. I have only been riding the tri bike since January. I went through the comfort issues but it was not that bad for me. The biggest problem I had was being able to hang on in a cross wind.

I am about 1.5-2 mph faster on the tri bike on my training rides. I do not own race wheels or an aero helmet. I can not compare race results because the 2 races I did this summer changed the bike course from last year. My run in the races I did this season was a lot better coming off the tri bike.

My personal feeling is that my road bike is not right for me somehow (fit is off, not the right size maybe) so the tri bike always feels better to me. I'm not sure.

I train at 16.5 mph on my tri bike.

I train at 15.0 on my road bike.

I have raced between 18 and 23 mph on my tri bike.

I have never raced on my road bike.

There!  That was completely inconclusive and useless.  Sorry.

However, there are a lot of people who have done multiple 40k Time Trials with road bike, tri bike, with disc, with 808's with aero helmet, etc.  All with power meters.

Thanks for the replies!  I was thinking that Pocono with rainy conditions was something of an equalizer between a road and a tri bike, I was thinking in more general terms, and was really surprised with where I finished.  I seem to underestimate my rankings.

I was also surprised at the comments some folks had on the "hills", and how "technical" the course was.  I thought more people would have had mountain biking experience of some kind.  I guess not. 

I'm not expecting to jump on a new bike and pickup 2 mph, planning on training on it, getting a good fit (I suspect my current bike is a bit big) and we'll go from there.

Wow, that's an eye-opener. I'm very new to biking - just started riding in July.  I didn't want to invest a lot of money in a bike so I bought a used entry level road bike that looked about the right size for me for $400.

I was pretty pleased with my race results in September, but it sounds like putting on some clip on aerobars and getting the bike fitted will help quite a bit.

I have read several strict studies over the years and if everything is equal between the road bike and tri bike concerning wheels, components ,etc. the difference in time over 40K is around 2.5 minutes. Not sure what that is in mph.

Just my 2 cents...  If your road bike is already a carbon frame with high quality components, you won't see much of a speed gain.  If I remember correctly, tdf riders are usually on road bikes for most of the stages.  Some things to consider:

1. Terrain.  You'll find that some people swear by road bikes for hills and tt bikes for flats.  And others who say it really isn't that important.  But what is most significant about terrain is that you'll find people who can really rock the hills, and those who can fly on the flats-but very few who have talent for both. 

2. Rolling resistance (tires).

3. Aero helmet-as others have mentioned, this may very well be your best investment.

4. Professional fit if you haven't already.  If you haven't, you may not be using the max power your legs can provide.

Most importantly, if you make any change, give your body time to adjust.  My speed dropped when I got my fit, and again when I got my tt bike.  It wasn't the best experience either time, but the bike leg in my last tri reinforced that I had made the right decisions.  Both times my speed dropped, I did recover, but it took a few weeks.  (My experience was different-my road bike weighs a ton compliments of the aluminum lead alloy they used that year, low end components, and is much less aero.)

By the way-I really want to congratulate you on your finish.  15th in your ag in a HIM is a great finish.  Congrats.

I'm 53 and I've been riding for 4 years.  I bought a tri bike in July.  Comparing from 2008 to when I got my tri bike to after I got the tri bike:

Before total rides:  402

Rides over 19 mph:  58

Rides over 20 mph:  8

Since July 8, 2011:  52

Rides over 19 mph:  30

Rides over 20 mph:;  9

Rides over 21:  1

Unfortunately, I had a calf injury that prevented me from running in August and have not yet done any races with the tri bike.  I ride with a couple guys at lunch and I'm faster on my tri bike riding solo that on my road bike and only pulling 1/3 of the time on my road bike.

Shane-Thanks for keeping my post clear.  I'm not a tdf guru, so I'm not familiar with all the rules.

As far as the components-I was only trying to make a point about a good bike vs one with gearing issues.

The type of bike you're riding is not th only variable in the equation.