Login required to started new threads

Login required to post replies

Prev Next
Base bar vs Aero bar on TT bike build?
Quote | Reply
As I continue to design my new bike, am thinking about where our sport is going. I really would like to some some DL races, but really do not want have to buy 2 bikes.
(Stanford has a DL sprint Triathlon on Saturday, and no aero bars are allowed).

So thinking about some thoughts from DarkSpeedWorks as shown below.

"How about a tri bike with road drop bars (and clip-ons, if desired)?

Both "road" and "tri" bikes have their own advantages. A road bike has the brakes and shifters in easy reach, the drop bars have lots of hand position options, the bike will be welcome at group rides, it's far faster (and safer) for technical descending and cornering, it's more versatile for utility riding like navigating traffic, trips to the store, commuting, etc. But a tri bike can be faster in TT efforts and the frame is more aero (important qualities for a tri race bike), a tri bike allows you to get in a better body position for generating good power while maintaining a low and aero position, it is often more comfortable for riding on aerobars (if fit correctly), etc.

But the way to get much of the best of both worlds (and save you money from buying extra bikes) is a tri bike, but one fitted with road drop bars and (well-designed, well-fitted) clip-on aerobars. In many ways, it is the true multisport bike because it makes for an aero tri bike that is equally fast on super fast descents as it is on pancake-flat time trial courses.

It also give you options as you enter different events, progress in skill and experience, or change in your tastes: (1) keep the drop bars and clip-ons on the bike and use it that way for your training and/or multisport racing. Or, (2) keep the drop bars on the bike, take the clip-ons off, and use it for road riding if your triathlon passion morphs more to a bike riding/bke racing passion (nearly all tri frames, with a few small position tweaks, can--and do--function perfectly well as 'road bike' frames). Or, (3) switch out the drop bars and clip-ons for full aerobars if you want fully maximize your aero advantage on flat courses.

For a bunch of reasons, a well-designed tri bike typically does a way better job as a road bike, than does a road bike set up as a tri bike. If it helps, for a visual, here are a few photos of tri bikes set up with drop bars (on one of our fb albums):
http://goo.gl/MhJS4o

You might be a good candidate for the tri bike with drop bar solution. When set up right, it rides flawlessly, it's super versatile, and it's fast. And it has worked great for us."


Since I am looking at a Cervelo P3 Di2, one of his pictures is a P3 with drop bars and road controls.


Giving more thought to a setup with drop bars. Since I would like to consider doing a DL Triathlon, and Stanford has one on Saturday, I really do not want two bikes.

I really think I am going to get Di2. Everyone just loves it. I have had mechanical cables snap also. I little more risk but it does seem to make your solution even one step better.

With Drop bars and clip on aero bars, one can have the Di2 switches at the end of the TT bars. Then if you need to take off for a DL race, you just unplug the switches and no
cables to deal with. Also, if one uses road Di2 shifter/brake on the drops, one can shift easily if one hands are cold and cannot push the buttons easily or have gloves on.

Since I really only do Oly tri distance, and most have many hills as you know having lived here, I am up a lot of the time anyways either climbing or flying down windy hills.

So, how much of a negative would this be with not as much an aero base bar?

I also like that the Di2 base bar control has a second input in them so if I wanted to had sprinter Di2 buttons, I already would have the ports.

An example of a bike made this way, and this may be one Tim Deboom rode?







Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

Boom Nutrition code 19F4Y3 $5 off 24 pack box | Bionic Runner | PowerCranks | Velotron | Spruzzamist

Lions don't lose sleep worrying about the sheep
Last edited by: h2ofun: Mar 5, 15 9:48
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [h2ofun] [ In reply to ]
Quote | Reply
If you use di2 you could swap between a TT cockpit and a draft legal cockpit and only have to run two cables, for the brakes.

Based on various wind tunnel and field tests I put the aero penalty of drop bars and STI shifters at about 1 minute per 40k.

You could probably reduce that to 30-40 seconds per 40k by using an aero drop bar. Bontrager makes one with room for clip ons.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jackmott] [ In reply to ]
Quote | Reply
jackmott wrote:
If you use di2 you could swap between a TT cockpit and a draft legal cockpit and only have to run two cables, for the brakes.

Based on various wind tunnel and field tests I put the aero penalty of drop bars and STI shifters at about 1 minute per 40k.

You could probably reduce that to 30-40 seconds per 40k by using an aero drop bar. Bontrager makes one with room for clip ons.

Interesting. One reason to change from my existing bike is I am told I could gain 1 or 2 minutes.

Now, most races I do in Northern Calif tend to be pretty hilly, so a lot of time one is not locked into the aero position anyways.
(Like the Donner Tri, or Auburn)

Have a link to the Bontrager you are thinking about? could not seem to find anything that I thought met your idea.

I thought about having 2 seperate front ends, one just TT, and one just road. With Di2, as you say, this become very easy. Just would cost me a few more bucks
to have both setups. But if I really want max speed, maybe this is what I would need to do. I plus for STI shifters as I said was if one is racing in the cold,
like I did at IMLT, and I had on big gloves, pushing those tiny Di2 buttons would seem hard, while shifting with the STI shifter would seem pretty easy.

.

Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

Boom Nutrition code 19F4Y3 $5 off 24 pack box | Bionic Runner | PowerCranks | Velotron | Spruzzamist

Lions don't lose sleep worrying about the sheep
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [h2ofun] [ In reply to ]
Quote | Reply
The issue I see in a set-up like the pic, is with height. When you get the pad height correct, the drops are way too low. get the drops right and the pads are too high. An undermounted aero-bar with the pads right at bar height might get you close enough for both positions. You might also have length issues. Two complete front ends might be your best answer, but then you have to re-cable the bike every time you switch. Two complete bikes? Yes, that's the answer!

---------------------------
''Sweeney - you can both crush your AG *and* cruise in dead last!! đŸ˜‚ '' Murphy's Law
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [Sweeney] [ In reply to ]
Quote | Reply
Sweeney wrote:
The issue I see in a set-up like the pic, is with height. When you get the pad height correct, the drops are way too low. get the drops right and the pads are too high. An undermounted aero-bar with the pads right at bar height might get you close enough for both positions. You might also have length issues. Two complete front ends might be your best answer, but then you have to re-cable the bike every time you switch. Two complete bikes? Yes, that's the answer!

If you use Di2, then you do not have to recable.

Since I do not ride road bikes, having the drops to low is maybe not an issue for me.
And I have no idea what a correct drops are in the right position would mean.

Like anything, if you want to try and do 2 things with one, would not be ideal under certain setups.
Now if they did not have this darn DL stuff coming, ....

.

Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

Boom Nutrition code 19F4Y3 $5 off 24 pack box | Bionic Runner | PowerCranks | Velotron | Spruzzamist

Lions don't lose sleep worrying about the sheep
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [Sweeney] [ In reply to ]
Quote | Reply
I have a setup similar to the pic but with a slightly high/short tri bike as opposed to a road bike. I ride day to day with my stem flipped up, giving me a 6-7cm drop to STI shifters and slightly less to aero pads, drops are fully usable.

For some races I leave it as is. For others, I can flip my stem and be at about 9-10cm to pads. Drops are then less useful but the hoods position is somewhere in between standard hoods and drops.

To the OP, I think going this route is a compromise and certainly not the right idea if you want to search for seconds. Its a great idea if you want one less bike, don't mind 40 seconds lost, and you can get your position right. Going in between two setups is possible but not worth it to me unless you're using di2.
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jackmott] [ In reply to ]
Quote | Reply
jackmott wrote:
If you use di2 you could swap between a TT cockpit and a draft legal cockpit and only have to run two cables, for the brakes.

And I think it was superdave that suggested having two front brakes, one routed and attached the to road set up and one routed and attached to the tri set up. It is easier to remove and install a front brake than re-rout the brake cable each time you swap.
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jackmott] [ In reply to ]
Quote | Reply
jackmott wrote:
If you use di2 you could swap between a TT cockpit and a draft legal cockpit and only have to run two cables, for the brakes.

Based on various wind tunnel and field tests I put the aero penalty of drop bars and STI shifters at about 1 minute per 40k.

You could probably reduce that to 30-40 seconds per 40k by using an aero drop bar. Bontrager makes one with room for clip ons.

Is this the one? http://www.bontrager.com/model/11292

Wonder what aerobars would fit on these?

Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

Boom Nutrition code 19F4Y3 $5 off 24 pack box | Bionic Runner | PowerCranks | Velotron | Spruzzamist

Lions don't lose sleep worrying about the sheep
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [h2ofun] [ In reply to ]
Quote | Reply
There is some wind tunnel data out there that indicates that the aero difference of drop bars may be a lot less than one minute per 40k if you use a good set of aero drop bars (with clip on aerobars of course). And that doesn't even take into account the speed and cornering advantage of drop bars on hilly and technical courses.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Last edited by: DarkSpeedWorks: Mar 5, 15 13:32
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [chaparral] [ In reply to ]
Quote | Reply
chaparral wrote:
jackmott wrote:
If you use di2 you could swap between a TT cockpit and a draft legal cockpit and only have to run two cables, for the brakes.


And I think it was superdave that suggested having two front brakes, one routed and attached the to road set up and one routed and attached to the tri set up. It is easier to remove and install a front brake than re-rout the brake cable each time you swap.

Yup, that's how I suggested to do it if one were building a bike for TT/Tri where front braking performance was of less concern than in road events.

https://www.kickstarter.com/...bike-for-the-new-era
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [DarkSpeedWorks] [ In reply to ]
Quote | Reply
DarkSpeedWorks wrote:
There is some wind tunnel data out there that indicates that the aero difference of drop bars may be a lot less than one minute per 40k if you use a good set of aero drop bars (with clip on aerobars of course). And that doesn't even take into account the speed and cornering advantage of drop bars on hilly and technical courses.

That surprises me, is the data public?

Want: 58cm Cervelo Soloist. PM me if you have one to sell

Vintage Cervelo: A Resource
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [SuperDave] [ In reply to ]
Quote | Reply
SuperDave wrote:
chaparral wrote:
jackmott wrote:
If you use di2 you could swap between a TT cockpit and a draft legal cockpit and only have to run two cables, for the brakes.


And I think it was superdave that suggested having two front brakes, one routed and attached the to road set up and one routed and attached to the tri set up. It is easier to remove and install a front brake than re-rout the brake cable each time you swap.


Yup, that's how I suggested to do it if one were building a bike for TT/Tri where front braking performance was of less concern than in road events.

But you are stuck still dealing with the back brake cable. I totally lost that with Di2 you do not need to worry about the FD and RD, but you are still cabled to the front and rear brakes. :(
.

Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

Boom Nutrition code 19F4Y3 $5 off 24 pack box | Bionic Runner | PowerCranks | Velotron | Spruzzamist

Lions don't lose sleep worrying about the sheep
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jeremyb] [ In reply to ]
Quote | Reply
jeremyb wrote:
DarkSpeedWorks wrote:
There is some wind tunnel data out there that indicates that the aero difference of drop bars may be a lot less than one minute per 40k if you use a good set of aero drop bars (with clip on aerobars of course). And that doesn't even take into account the speed and cornering advantage of drop bars on hilly and technical courses.

That surprises me, is the data public?

Specialized published it then quickly took it down:

http://forum.slowtwitch.com/...rch_string=;#5442187
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jeremyb] [ In reply to ]
Quote | Reply
jeremyb wrote:
That surprises me, is the data public?

You betcha. Vision/FSA did some aero testing on equivalent set ups. Going from drop bar plus clip-ons to equivalent technology aerobar (pursuit base bar) made you gain just 9 sec per 40k at 25mph.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [Nick B] [ In reply to ]
Quote | Reply
Nick B wrote:
jeremyb wrote:
DarkSpeedWorks wrote:
There is some wind tunnel data out there that indicates that the aero difference of drop bars may be a lot less than one minute per 40k if you use a good set of aero drop bars (with clip on aerobars of course). And that doesn't even take into account the speed and cornering advantage of drop bars on hilly and technical courses.


That surprises me, is the data public?


Specialized published it then quickly took it down:
http://forum.slowtwitch.com/...rch_string=;#5442187

Not exactly. Specialized changed a lot more than the bars in this test (I saw the video), the whole bike was different. The methodology was kinda kooky.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [h2ofun] [ In reply to ]
Quote | Reply
h2ofun wrote:
SuperDave wrote:
chaparral wrote:
jackmott wrote:
If you use di2 you could swap between a TT cockpit and a draft legal cockpit and only have to run two cables, for the brakes.


And I think it was superdave that suggested having two front brakes, one routed and attached the to road set up and one routed and attached to the tri set up. It is easier to remove and install a front brake than re-rout the brake cable each time you swap.


Yup, that's how I suggested to do it if one were building a bike for TT/Tri where front braking performance was of less concern than in road events.


But you are stuck still dealing with the back brake cable. I totally lost that with Di2 you do not need to worry about the FD and RD, but you are still cabled to the front and rear brakes. :(
.

If it is that tough, there are cable coupling solutions.


https://www.kickstarter.com/...bike-for-the-new-era
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [DarkSpeedWorks] [ In reply to ]
Quote | Reply
http://www.tririg.com/galleries.php?id=2014_08_TriRig_Alpha_Wind_Tunnel_White_Paper&num=71






That shows that clipons are 90 seconds slower than the Tri rig Alpha

Want: 58cm Cervelo Soloist. PM me if you have one to sell

Vintage Cervelo: A Resource
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jeremyb] [ In reply to ]
Quote | Reply
DarkspeedWorks is still hanging his hate on the vision study with totally unknown protocol and unclear data presentation, despite various other sources of data contradicting his interpretation of it.

Because he really likes drop bars.




jeremyb wrote:
http://www.tririg.com/galleries.php?id=2014_08_TriRig_Alpha_Wind_Tunnel_White_Paper&num=71






That shows that clipons are 90 seconds slower than the Tri rig Alpha



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jackmott] [ In reply to ]
Quote | Reply
jackmott wrote:
DarkspeedWorks is still hanging his hate on the vision study with totally unknown protocol and unclear data presentation, despite various other sources of data contradicting his interpretation of it.

Because he really likes drop bars.


But seems a fair point if you can ride faster in the hills with drops, wind tunnel stuff does not matter?

I hear all the time if lots of hills, ride a road bike. If flat, TT bike. Is this not what the Pro's do?

.

Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

Boom Nutrition code 19F4Y3 $5 off 24 pack box | Bionic Runner | PowerCranks | Velotron | Spruzzamist

Lions don't lose sleep worrying about the sheep
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [h2ofun] [ In reply to ]
Quote | Reply
Road bikes are lighter, and road bikes are sometimes better handling on technical descents.

So if a course has lots of up hills and technical downhills you will sometimes see professional time trialists use a road bike, depending how comfortable they are descending on their tt bikes. You also see teams like garmin using the S5 road frame with full on TT cockpit a lot of times in these situations.

For triathlon purposes there are approximately 0 courses where a road bike is clearly faster. At savageman it may be about a tie.

I have measured myself on an S5 vs P3 on a technical loop, using strava's comparison feature. I can see from that that I do lose fractions of a second in tight corners on the TT bike. But it makes those seconds back in just a few meters of straight road following them. TT bike faster overall by a lot.

This is a long winded way of saying, TT bike with TT cockpit is pretty much always faster if you set your position up well and practice riding it. I don't understand why drop bars offer any handling benefit either.






h2ofun wrote:
But seems a fair point if you can ride faster in the hills with drops, wind tunnel stuff does not matter?

I hear all the time if lots of hills, ride a road bike. If flat, TT bike. Is this not what the Pro's do?

.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jeremyb] [ In reply to ]
Quote | Reply
jeremyb wrote:
That shows that clipons are 90 seconds slower than the Tri rig Alpha

That is not the research I was referring to. The tririg paper is interesting, but there are some very big problems with their methodology. The main thing is that they did an 'apples to oranges' comparison.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [DarkSpeedWorks] [ In reply to ]
Quote | Reply
Can you link the research you are discussing?

What is the benefit of a drop bar over a base bar? You can get a wide base bar with good hand positions. What differences do you see?
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jeremyb] [ In reply to ]
Quote | Reply
90 seconds from the best bar to a 44cm wide round road bar. Both an aero profile, and 40cm width would give back some of that time to the road bar with clips. Not to mention, using a shallower drop to further reduce FA.
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [Runless] [ In reply to ]
Quote | Reply
No way that those changes would equate to 81 seconds though.

Want: 58cm Cervelo Soloist. PM me if you have one to sell

Vintage Cervelo: A Resource
Quote Reply
Re: Base bar vs Aero bar on TT bike build? [jeremyb] [ In reply to ]
Quote | Reply
Didn't say so. Just that the tririg comparison makes the drop bar look worse than it could.

Hell, even running a flat top like the zipp ergo 70 or FSA compact pro wing would even things out a little.

It's a shame spec hasn't reposted their win tunnel comparison.
Quote Reply

Prev Next