TT bike or road bike for a hilly 70.3? The hills take less off it than you’d think3 October 2026On the flattest 70.3 in the library a TT bike saves our rider 16:25. On the hilliest it still saves 15:30, or 11:28 if they sit up on every steep descent. What a hilly course really changes.
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Are clip-on aerobars worth it? What they’re worth on your road bike3 October 2026 · reading it nowOn a road bike, clip-ons save our rider about 7 minutes on the flattest 70.3 in the library and about 6 minutes on the hilliest. Used only where it’s safe, still about 5 minutes. Why the hills don’t make them pointless.
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What gearing do you need for a hilly 70.3? Start from the steepest half-kilometre3 October 2026San Salvador’s steepest half-kilometre averages 9.9%. At the watts our rider climbs at, that takes a 34 × 34 on a compact. How to work it out for your course.
Why was I slower? How to read a comparison of two rides3 October 2026Wind, position, fitness or the road? How the compare splits a gap into reasons, what “can’t tell” means, and why descents are timed rather than explained, on a real 19:22 gap.
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Blog · 3 October 2026 · 2 min read

Are clip-on aerobars worth it? What they’re worth on your road bike

Clip-ons are the cheapest speed in triathlon. A pair costs less than a race entry. Are they worth it on your course, or only on a flat one?

How much do clip-on aerobars save?

The site puts clip-on aerobars at 0.28 m² of drag area, against 0.325 in the drops and 0.35 on the hoods. We put them on one rider, 75 kg on a 9 kg road bike holding 200 W normalised, used everywhere except climbs steeper than 3%, on three IRONMAN 70.3 courses from the library.

They save about 7 minutes on Eagleman, the flattest of the 123 IRONMAN 70.3 courses in the library, about 7 minutes on Goa, which rolls, and about 6 minutes on San Salvador, the hilliest, with 1,341 m of climbing.

That’s a bit under half of what a whole TT bike is worth on the same courses. For the price of a pair of bars, that’s a lot of time.

Only where it’s safe

Not everyone wants to be on the bars at full speed down a mountain. Used only between −3% and +3%, sitting up on the steep descents and never faster than 55 km/h, they’re still worth about 7 minutes on Eagleman and about 5 minutes on San Salvador.

So the advice to leave clip-ons off for a hilly course doesn’t hold up. On the hilliest 70.3 we have they’re worth less than on the flat, but they’re still worth minutes.

Your position decides it

What they’re worth to you depends on how low you actually get on them. 0.28 is a typical figure. A rider perched on clip-ons with a high front end gets much less. In the predictor you can type your own drag area for each position and watch the time follow. And check the rules: most triathlons allow them, most group rides don’t.

What the predictor said, with and without clip-ons

What clip-ons save on a road bike, course by course

Eagleman, flat7:19 faster

Goa, rolling7:10 faster

San Salvador, mountain6:08 faster

San Salvador, used only where it’s safe4:37 faster

A model, not a measurement. What it can show depends on the numbers above (what you typed, and what your files recorded) and on assumptions this page states; anything it cannot stand behind says so rather than drawing a tidier line.

Clip-on aerobars on a road bike, three courses

	Eagleman · flat, 91 km, 3 m up	Goa · rolling, 92 km, 334 m up	San Salvador · mountain, 90 km, 1,341 m up
Road bike, no clip-ons	2:44:38	2:55:10	3:19:11
Clip-ons, except on climbs above 3%	2:37:19 · 7:19 faster, ± 0:19	2:48:00 · 7:10 faster, ± 0:19	3:13:03 · 6:08 faster, ± 0:19
No clip-ons, kept under 55 km/h	2:44:38	2:55:15	3:19:23
Clip-ons from −3% to +3% only, the same top speed	2:37:19 · 7:19 faster, ± 0:19	2:48:23 · 6:52 faster, ± 0:18	3:14:46 · 4:37 faster, ± 0:15

Drag areas from the predictor’s list: 0.35 m² on the hoods, 0.325 m² in the drops, 0.28 m² on clip-ons. For a 75 kg rider on a 9 kg bike holding 200 W normalised, harder up the climbs and easier down them, in still air and with no stops: the predictor, asked on 3 October 2026. The give or take on a saving is what a drag area taken off a list rather than measured could put it out by.

Try clip-ons on San Salvador