Triathlon - Speed Gains with Tri/TT Bike?

I'm interested in what speed gains people have experienced when going from a road bike to a dedicated triathlon/time-trial bike?

It really depends on what you mean by "speed gain"... do you mean just for the bike leg or the race overall? One of the biggest benefits that I've found going from a road bike to a tri bike is that my run is faster. I would say probably 10-15sec. per mile faster run pace.

I've never really done any TT's on my road bike, so I can't tell if there's a difference. My guess would be probably at least 2-3mph, just because I can get more aero with the tri bike and the coarses are very flat around here... (if it was more hilly, then I doubt I'd see much of a difference).

It really depends on what you mean by "speed gain"... do you mean just for the bike leg or the race overall?

I'm interested in just the gains experienced on the bicycle.

In the short time I've had my TT bike, I have seen a big time difference. For example, I have been riding a 17.5 mile route consistently for the past 3 years on my road bike. My PR on my road bike has been 54:17, at 18.9 mph avg just this year. On my TT bike, after only 100 miles, I rode the same route in 52:16 at 20 mph avg. So 2 minutes better is huge, IMO (especially in a Super or Sprint event). And I'm still getting used to the TT bike as far as handling, position, etc.

It all depends on what you're doing, race wise. I'm just starting to race duath and triathlons, so the TT bike makes sense. But, I still love my road bike too!

One study published in the German Tour magazine Jan 2007

They put Uwe Peschel on a normal bike:

Needed Watts for Speed = 45 km/h :

Stevens San Remo bike with normal handlebar 465 Watts needed to go 45 km/h
Same bike Hands down the drops: 406 watts needed
Same bikeEaston Aeroforce bar: 369 Watts
Same bike Triathlon position (5.5 cm lower bar, saddle forwards): 360 Watts
Same bike Triathlon position (5.5 cm lower bar, saddle forwards) and
carbon Tri spoke wheels front and rear: 345 Watt

Cervelo + Tri spoke front 328 Watts
Cervelo + Tri spoke front + disk rear wheel : 320
Cervelo + Tri spoke front + disk rear wheel +Giro helmet: 317
Cervelo + Tri spoke front + disk rear wheel +Giro helmet + speed suit: 307
Cervelo + Tri spoke front + disk rear wheel +Giro helmet + speed suit +
saddle 3 cm further back: 293 Watts

From 465 to 293 watts... That's a lotta savings.

Thanks for the replies! I've already committed to the purchase of a triathlon bike. I knew that the tri/TT bike would improve speeds, I just wanted an idea of how much to expect. It sounds like I won't regret purchasing! BTW- I'm going from a Specialized Roubaix triple with Profile Jammer GT's to a Quintana Roo Kilo.

Just a piece of advice...make sure you are properly fitted and measured in the bike

One study published in the German Tour magazine Jan 2007

They put Uwe Peschel on a normal bike:

Needed Watts for Speed = 45 km/h :

Stevens San Remo bike with normal handlebar 465 Watts needed to go 45 km/h
Same bike Hands down the drops: 406 watts needed
Same bikeEaston Aeroforce bar: 369 Watts
Same bike Triathlon position (5.5 cm lower bar, saddle forwards): 360 Watts
Same bike Triathlon position (5.5 cm lower bar, saddle forwards) and
carbon Tri spoke wheels front and rear: 345 Watt

Cervelo + Tri spoke front 328 Watts
Cervelo + Tri spoke front + disk rear wheel : 320
Cervelo + Tri spoke front + disk rear wheel +Giro helmet: 317
Cervelo + Tri spoke front + disk rear wheel +Giro helmet + speed suit: 307
Cervelo + Tri spoke front + disk rear wheel +Giro helmet + speed suit +
saddle 3 cm further back: 293 Watts

From 465 to 293 watts... That's a lotta savings.


Well, not so much. You're actually going from 345 watts (for a normal road bike with some position alterations and TT wheels) to 328 (for a TT bike with comparable wheels before adding other fancy stuff) - so less than 5%.

Well, not so much. You're actually going from 345 watts (for a normal road bike with some position alterations and TT wheels) to 328 (for a TT bike with comparable wheels before adding other fancy stuff) - so less than 5%.

You made a mistake. The OP has a "Specialized Roubaix triple with Profile Jammer GT's". That's a regular road bike with short reach clip on aero bars. He said nothing to indicate he has other than regular, boxed, rim. The only aero benefit he has is the short clip on bars, no adjustment in position, and no aero wheels.

You made a mistake. The OP has a "Specialized Roubaix triple with Profile Jammer GT's". That's a regular road bike with short reach clip on aero bars. He said nothing to indicate he has other than regular, boxed, rim. The only aero benefit he has is the short clip on bars, no adjustment in position, and no aero wheels.

I don't think I did. My post was pointing out that the big wattage savings suggested by Dalai's post, from moving from a road bike to a TT bike, weren't realistic. The OP could put aero wheels on his road bike, he could adjust the position by fitting a longer stem, moving his saddle forward and getting the bars as low as possible by removing spacers (if any) and flipping the stem to a more horizontal position if he hasn't already done so. Once he's done all that, the wattage savings (according to those German tests) made by moving to a TT bike without the disk wheel, speedsuit etc would be about 5%. Not insignificant, but nowhere near what Dalai's post suggested.

I don't think I did. My post was pointing out that the big wattage savings suggested by Dalai's post, from moving from a road bike to a TT bike, weren't realistic.

Sorry if my post wasn't entirely clear about the savings between the road and TT bike. My comment "From 465 to 293 watts... That's a lotta savings." was just from the previous topic I cut and pasted and not indicative of the gains based only by swapping out the road frame for TT...

If you can get the same ideal position on both frames the difference would be minimal. What it does show is alot of small changes can in the end result in some major improvements! :thumb:

Dang - makes me want to use my mountain bike frame, strap on aerobars, a disc wheel, and slicks, and go road race on it! LOL

I took possession of the new (to me) bike today. When I get fitted and more comfortable, I'll post what gains I might see. Thanks for all of the replies! The replies were helpful with no confusion here.

Pics?

Is it realistic to compare the improvement in the percentage of wattage improvement to speed improvement? In other words if you are averaging 25mph and the areo helmet improved things in wattage about 1%. Could you expect your average speed of 25mph improving to 25.25mph?

Now I know a lot of it is going to depend on what speed you are going. The faster the more improvement. This was done at about 28mph, I think.

I am going to get fitted for my P2C next week. I am curious what improvements it makes in my average speed for my regular loop.

I also have purchased a aero helmet and speed suit but have not used them. I plan on buying a solid, back disk wheel next week. More because I am curious what effect these things have on average speed. They were really not purchased for competition as I am not a very good cyclist.

I average about 23.5mph for my loop presently. I want to see if with these toys I can get to 24.5 mph.

I have found it hard to compare my AVS on my road bike compared to my P2C because apparently there were always some serious fitting issues that I did not realize. I did get a basic fitting for my P2C and I think that accounts for a decent chunk of the improvement I have seen. But it also has introduced a calf cramping issue that I believe is also related to fit.

As I am also new to cycling some improvement is going to be related to me getting stronger and in better shape and loosing 25 pounds over the last year is also going to account for some improvement :)

I just love riding for an hour in the evening as fast as I possibly can. Staring at my computer trying to get the average speed to just be a little higher.

The much quoted John Cobb showed a 2 minute gain for well trained athletes over 40K by using aero bars versus road drops. The advantage would actually be more for slower riders.

Aside from this, there was a recent study (can't find it now) that showed a definite advantage on the run by using a bike with a steep geometry (78-80 degree seat tube) of tri bikes versus the slack geometry of road bikes (73 degrees).

How you position affects your run is more important than how much faster your bike split is. You are not just doing a TT, and 60-120 seconds gained on the bike can be easily lost on the run if your bike position hurts your run.

With around 125 miles on the TT bike so far, I would say that it has been worth an extra 1 mph. This is in comparison to my road bike with shorty aero bars ( Jammer GT ). The wheelsets are probably comparable (Shimano 560's on the road bike & Xero Lite's on the TT bike (low spoke count Velocity Deep V's)).

I have not yet had a pro fitting on the TT bike. A racer buddy did tweak the position for me, but we set it up more on the side of comfort for the time being, since I was having some issues remaining in the aerobars for very long with the bar low. I'll lower the bars as I become more accustomed to riding aero, and I will get a real fitting before next spring.

I think that I should be able to wring more speed out of the old TT bike by bringing my back closer to horizontal. Add in an aero helmet and a good wheelset and who knows? Maybe I'll bring my speed up to a respectable level yet!?

Position is the primary key and being able to stay in that position. No point having an agressive position which you can stay in and ride sitting up on the bull horns... It is always a comprimise between aero and comfort!

i always seem to ride faster on my tri bike... apparently the aero position is faster...fit/position has a hude effect on your times.. but as for asking a specific speed difference.. you'll ride differently from day to day... you'll also get stronger.. as time goes on... i really don't think you can answer this question with one answer...
i have noticed that on my road bike when i go from the hoods to sitting up i usually lose about .9-.7 mph...

Just a piece of advice...make sure you are properly fitted and measured in the bike

+1

And by someone who knows how to fit a TT position.

Also, you'll be encouraged to train harder to justify all that money spent on the bike. ;)

I trained really really hard for my first TT ridden on my TT bike - all my friends knew I had the new ride, and many knew what I'd paid for it, so I didn't want to look like a loser just throwing around piles of cash. While it wasn't my PB time for long (it was a slow course in windy conditions anyhow), it was my best placing (in relation to field size) because it was the first TT of the season - in February - and I'd been going so hard compared to everyone. My team had the best aggregate time, and I had the top time on my team - - I can see the team cup from where I'm sitting - the only thing I've ever won in cycling.

And I honestly felt great relief that I was able to justify the purchase.