Unbelievable watt savings

[kgreene10]

Today’s article in Cycling Weekly has wind tunnel data to indicate that narrow handlebars can save an insane number of watts —

https://www.cyclingweekly.com/produc...-my-handlebars

At 35kph, a 30cm bar saved 17.6w over a 36cm bar (already very narrow) in quite an upright position. Lather gains are to be had for even narrower bars and higher speeds. Then amp this up further given than most of us are on bars wider than the baseline 36cm.

It just seems impossible. If you read the piece (or watch the video), what’s wrong with the test that could render the finding incorrect?

[HenryA]

Originally Posted by kgreene10

Today’s article in Cycling Weekly has wind tunnel data to indicate that narrow handlebars can save an insane number of watts —

https://www.cyclingweekly.com/produc...-my-handlebars

At 35kph, a 30cm bar saved 17.6w over a 36cm bar (already very narrow) in quite an upright position. Lather gains are to be had for even narrower bars and higher speeds. Then amp this up further given than most of us are on bars wider than the baseline 36cm.

It just seems impossible. If you read the piece (or watch the video), what’s wrong with the test that could render the finding incorrect?

I don't doubt the results, but, I think the problem comes when the rider can't breathe efficiently.

[Carbonita]

Back when I did tunnel tests and cfd, albeit on thankfully inanimate bodies (wings, nozzles, planes, tanks), repeatability was important. Multiple data points at the same position to assess measurement error. Having a human test subject makes that difficult due to changes in position, cadence, clothing fit, etc. Tour mag uses a test dummy (just the spinning legs IIRC). The results seem qualitatively reasonable, but add some gusty yaw conditions and those aero bars are gonna feel mighty too narrow.

[kgreene10]

Originally Posted by HenryA

I don't doubt the results, but, I think the problem comes when the rider can't breathe efficiently.

The test rider reported feeling more comfortable with the 30cm bars than the 36cm ones, amazingly. But I hear you. I bet a world tour tech has calculated the optimal watt-to-milliliter of O2 trade-off.

[EB]

Clearly the answer is to dispense with the handlebars and just hold onto the stem.

[Philster]

I've found moving to 40cm bars results in a noticeable increase in speed, but I struggle with believing these watt savings when you add them up.

If you have the right socks, bar, chain wax, etc., the bike would be basically pedaling itself.

[robertbb]

Originally Posted by EB

Clearly the answer is to dispense with the handlebars and just hold onto the stem.

aaaand spat my coffee all over my keyboard.

[Louis]

Originally Posted by EB

Clearly the answer is to dispense with the handlebars and just hold onto the stem.

Who needs a stem?

[prototoast]

I think pretty obviously narrow handlebars significantly reduce wind resistance. I don't even think it's that big a deal for breathing, I routinely hold the tops of my bars near the center while climbing. The issue is cornering and high speed control. That's where lighter bars can really help, and so I think it's more a question of comfort and control than doubting the actual wind resistance data.

[dddd]

Round-jaw model, perfect.

Gripping your bars adjacent to the stem is reportedly quite aero for as long as it's comfortable enough.

[Mark McM]

Just like the old saying goes, "narrow is aero."

I don't find the results of the test hard to believe. Some years ago I used to regularly do our club's weekly time trial, and found that riding a clip-on aerobar (vs. riding in the drops) would increase my average speed over the 10 mile course by over 1 mph. The main difference in riding position with the aero bars was that my arms were narrower.

And as mentioned above, I often descend in a tight crouch with my hands on the bar tops right against the stem, and knees against the top tube. In this position I often pass other riders on descents who are in the drops and putting power on the pedals while I am just coasting.

As the others said, riding with such a narrow position doesn't give as much control on the bike, and can lead to safety and handling issues, so those 24cm super narrow bars aren't for all situations. But I've adapted pretty well to doing criteriums with a bar that is 35cm wide at the hoods.

[kgreene10]

Mark McM are the 35mm bars you mentioned Enve ARs? I can’t seem to find narrow carbon aero road bars available for purchase in the U.S. The WX-R bars mentioned in the article aren’t available outside the UK.

[Xrslug]

I’m intrigued by how these would feel on the bike, 32.5 cm at the hoods, 37.5 cm at the drops, UCI legal, and seem thoughtfully designed (they ship to US):
https://www.aero-coach.co.uk/store/A...ars-p509540543

[glepore]

AR's aren't close. Really comfy but like 38 x42
Other bars from boutique manufacturers get down to 34 or less but are $$.

[Mark McM]

Originally Posted by kgreene10

Mark McM are the 35mm bars you mentioned Enve ARs? I can’t seem to find narrow carbon aero road bars available for purchase in the U.S. The WX-R bars mentioned in the article aren’t available outside the UK.

My handlebars are Enve SES Aerobars, purchased a few years ago. They appear to be the same or similar to the Enve In-Route Handlebar. I bought the smallest size, which was 40mm at the drops and 35mm at the hoods, and were the narrowest (at the hoods) aero drop bars I could find at the time. The Enve In-Route appears to have a similar size available (40mm at the drops, 35mm at the hoods).