On the face of it, not a particularly exciting topic – bars tend to be a bit forgotten as riders focus on the obvious items like frame, wheels and groupset. But bar choice can make a real difference to performance so it’s worth paying attention to them. Logically they have the potential for significance as they’re one of the first parts of the bike to hit the wind.
Obviously there is a significant difference in shape and setup between road and TT bars, but the principles by which they are (should be) selected are the same.
Triathlete Magazine helpfully conducted some windtunnel testing in early 2013 that is useful for this discussion. Specifically – the difference between aerobars on road drop bars vs aerobars with bullhorns and finally against semi-integrated bars.
It’s clear that there is a significant reduction in aero drag from fitting bullhorns, which should be no great surprise given the reduction in frontal area of the bars. There is further benefit in switching to a semi-integrated bar (the 3T Aura) vs the modular setup thanks to smoothing out the clamping area.
And I have, of course, reinterpreted the graph into figures that may mean a little more.
Note that the figures are for full bike – the bars themselves do not suck up ~50w at 40kph.
2.7w at 40kph corresponds to 1s per 3km. So removing road bars gets you 1s per km and going to the flasher aerobars offers the marginal gain of a third of a second per km.
One of the penalties of increasing integration is reduced adjustability – so I should note that I end up changing the extensions and elbow pads on nearly every set of 3T Auras I work on, but apart from that they’re fairly good value.
Objective aerobar data is actually fairly scanty, but other sources have given very similar figures to those above. The best aerobars can give an advantage of up to 5w at 40kph compared to the trusty Vision Trimax with Bullhorns listed above, although at up to 6x the cost.
As a basic guideline choose aerobars that look small from the front – less frontal area is a strong indicator of performance. Then look for minimal clutter in the clamping area and nice cable routing (= as hidden as possible).
I’ve not found any comparative testing for these. Just manufacturer claims so I shan’t dwell on the topic for too long. Zipp claim a 6.4w advantage at 30mph for their SL-70 which translates to a little over 3W at 40kph. As mentioned last week this advantage is discounted when in a pack but comes to the fore when facing the wind on your own.
As it happens I don’t use the fastest available aerobars or road bars as neither suit my position. Handlebars are first and foremost a Fitting component – I’ve seen plenty of very nice aerobars that were a waste of money as they didn’t provide proper support to the rider and this increased body drag. Likewise road bars need to have the correct reach and drop to work with your position and aid hand comfort. So your priority must be to identify the bars that achieve your position, then try to identify the fastest option from among those.
I had intended to write more but the Speedtheory junior staff member (my 8mth old daughter) has had her own ideas today, so this will have to do. Suffice to say that I frequently encourage riders to purchase a lower level bike in order to fit upgraded bars (and wheels and bearings etc) into the budget as there are real benefits to be had here. But fit/comfort can never be ignored.