Hi! Clip-on aero bars have been discussed a lot. But I couldn’t find any information on this specific point, so please share your thoughts if you have any:
When you’re at first getting into triathlon, a common suggestion is that you should start out with a road bike, and add a set of clip-on aero bars, and get a bike fit, in order to get more aero, and save some watts/seconds. According to Specialized’s “Win tunnel”, you will save 1.40 mins over a 40 k course. Bikeradar claims you will save 30 watts or so.
But I assume this is if you can keep the aero position for the entire bike leg, right?! Whenever you change position, you will lose some of that saving. And the key point is: When your arms are in the clip-ons, you can’t change gears. So if you’re riding a rolling or hilly course, you’ll either be in a non-optimal gear a lot of the time, or you will have to change your arm position constantly to be able to change gears, creating extra drag every time.
Now, how much of the savings are left, if you compare those real world drawbacks to riding in the drops, where you can brake and change gears without changing your position? I would guess less than 50%, on most courses I have seen. What is your take?
I put clip Profile Design aero bars and fast forward carbon seat post, my bike was fit prior to the change, I then had it fit again with the changes, I am pretty comfortable on it in aero. I do not have a problem changing gears, I can reach over with either hand and stay in aero and change gears. I did a fairly hilly Olympic last weekend and found I could climb very well moving to the hoods, makes me wonder if it is a better solution for hilly courses.
~30 watts when you’re in aero vs on the hoods of the road bar. Pretty much the same from base bar to aero bar on a tri/tt bike.
I think the Redshift Seat Post is perfect for this application. Combine it with a low-stack aero bar, and I bet those 30 watts will go up a bit. We’ve only tested with higher stack aero bars like a standard Profile, but Redshift allows most people to go lower than that.
Beats me on watt or exact time savings. But, before I got a Tri bike I used clip-ons with my road bike but stopped once that was in my stable. The immediate next few rides without the clip-ons with my road bike I was 1-1.5mph slower avg pace for my normal training ride routes (between 18-30 miles) consistently.
I remember first time I use clip-ons I increased my avg speed almost 2mph on the very next ride on a steel framed downtube shifter bike. The following year is when I upgraded to a slightly new carbon bike with STI (was a bit faster due to more gears and being able to shift in the middle of hills instead of grinding through it regretting the wrong gear choice).
I don’t really have an answer beyond: it depends.
So many factors can mess with a wind-tunnel claim, like you say. Bottom line is that if you have a good position which you can use for as much of the ride as possible then you’re probably optimising things.
I’ve done 70.3 races on TT bikes, aero roadies with clip-ons and just plain road bikes with nothing. Fastest time was the road bike by some margin - but it was a different course and I was probably in better shape so it’s hard to see the actual difference. I spent the whole time in the drops. Check out what pro cyclists choose on TT stages in grand tours. They were almost all on roadies without clip-ons last week at the Giro D’Italia - but it was a short, uphill TT and at the end of two weeks of racing so perhaps it’s not a meaningful comparison but I still think they’d choose the best setup on the day.
I gained 1-1.5 mph from hoods to clip-ons and keep an arm on the pads when I shift gears. I don’t have any info on riding in the drops because I get grumpy pretty quick in that position. Which courses are you riding to need to be out of aero more than 50% of the time?
IRL the losses are small. If you shift 1X/min (on average) and it takes you 1sec. to reach over and hit the lever, that’s 1min. spent shifting per hour. If you were 10% slower for that 1min., that means you lost 6sec. That even ignores the fact that many of the times you shift you’d be off the aero bars anyway (cornering, steep climbs, twisty descents).
The far bigger issue is the non-aero drop bar sitting out in the wind, costing you >45sec. vs. an aero basebar.
No, I think you’re way off with the 50% loss of savings due to gear changes.
It will of course depend on how you move to change gear, how quickly you do it and how often you’re likely to change for a given course, but unless you really go overboard with all 3 of these the impact will be pretty small.
When I did this I could easily change gear in a second or two without moving to far from my aero position. One arm would stay where it was, I’d roll back the other shoulder a little to reach for the hood, change gear and be back in full aero in no time. Even mid movement I doubt I was losing much if anything over a drop bar position and the proportion of time spent reaching for gears, even if frequent, was still small. I made a significant improvement going to clip-ons and the gears were never as big a deal as I thought they’d be. Bar end shifters are better but clip-ons with STI shifters work well enough and don’t cost you much time.
I have a TT bike and an aero road bike - no clip ons.
Obviously the TT bike is quicker (increased speed for given power) and it’s my weapon of choice.
But I’m doing a couple of foreign events so I’m going to build a road bike with clip ons - forward seat post / new saddle, clip on bars and Zipp 606 combo. I’m having a bike fit with the “new” set up and am hoping to get a result somewhere between the 2 “old” bikes. Will be interesting to get some data and see if I’m right ! Having looked at my fit data I can get pretty close on the road bike.
(The reason I’m not using the TT bike is it’s got integrated brakes which are a PITA to set up after it’s been stripped to fit in my bikebox, and they’re both hilly events where personally I feel the “road” bike will be better for me (ie less of a disadvantage))
If you shift quickly and not 20 times per minute, the aero losses from a few quick shifts over the course of an hour are very low. Nearly trivial if you spend the rest of your time in your aerobars hammering.
Otherwise, the addition of low profile clip on aerobars and the better body position that they allow will give you quite significant aero improvements, even if you change nothing else about your bike. My experience in the real world is that it can be in the 2, 2.5, or 3 minute range per 40k (assuming it takes you about an hour to do a 40k). Nothing to laugh at and hugely better than just riding in the drops.
If you shift quickly and not 20 times per minute, the aero losses from a few quick shifts over the course of an hour are very low. Nearly trivial if you spend the rest of your time in your aerobars hammering.
Otherwise, the addition of low profile clip on aerobars and the better body position that they allow will give you quite significant aero improvements, even if you change nothing else about your bike. My experience in the real world is that it can be in the 2, 2.5, or 3 minute range per 40k (assuming it takes you about an hour to do a 40k). Nothing to laugh at and hugely better than just riding in the drops.
+1
My experience with aerobars on road bike is about 60-90s improvement over 15 miles on my usual time-trial route, which is hilly and twisty, plenty of gear changes and moving in/out of aero. Aerobars are the single biggest improvement you can make to a road bike, doesn’t make sense to race without them.