The comfort of narrow handlebars.

A light bike doesn't replace good fitness.

Moderator: Moderator Team

Post Reply
kulivontot
Posts: 1163
Joined: Sun May 16, 2010 7:28 pm

by kulivontot

nathanong87,
I'm not doubting that, just the magnitude of the difference. Everybody shit on disc brakes until they tested them and it was only like 8 seconds in an extreme crosswind. Same for internal cables, integrated brakes and bar/stem combos. Actually gains may be statistically insignificant. They could also be huge, that's why I'd like to see some data.

ch00bzs
Posts: 77
Joined: Sat Jun 14, 2014 4:49 pm

by ch00bzs

just switched from 40 to 38
off saddle with hands on hood, feels a bit unstable
but when sprinting on the drop, i feel no problem

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



Marin
Posts: 4035
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

Broke my 42s in a crash, got some 40s. 1st ride this evening. They feel good on the rollers already.

nathanong87
Resident master of GIF
Posts: 3405
Joined: Mon Jul 18, 2011 2:44 am
Contact:

by nathanong87

kulivontot wrote:nathanong87,
I'm not doubting that, just the magnitude of the difference. Everybody shit on disc brakes until they tested them and it was only like 8 seconds in an extreme crosswind. Same for internal cables, integrated brakes and bar/stem combos. Actually gains may be statistically insignificant. They could also be huge, that's why I'd like to see some data.


i see , u are talking about two different things. The perceived added leverage with a wide bar , then you are asking the question is narrower 'aero-er'.

kulivontot
Posts: 1163
Joined: Sun May 16, 2010 7:28 pm

by kulivontot

Leverage is not based on perception, it's basic physics. I asked about leverage because it is a legitimate factor for mountain bikers. If somebody wants to crunch the numbers to prove it's a negligible factor for road, I'd be interested as well.

User avatar
Tapeworm
Posts: 2585
Joined: Thu May 03, 2007 10:39 am

by Tapeworm

"Leverage" is not required for sprinting. Resistance to propulsive forces are.
"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

kulivontot
Posts: 1163
Joined: Sun May 16, 2010 7:28 pm

by kulivontot

go on

User avatar
Tapeworm
Posts: 2585
Joined: Thu May 03, 2007 10:39 am

by Tapeworm

Ok, my physics nomenclature might be a bit off but here goes....

The bike's drive train only works in a single plane. Any forces applied which are not in this plane are inefficient.

Rocking the bike adds nothing to the propulsive forces. Hence you want to *resist* the rocking of the bike as much a possible to ensure downwards force being applied by the leg is not at a tangent. The handlebars need only be long enough for you to pull on to resist those forces.

Track sprinters who put out (comparatively) *massive* amounts of torque can manage this with 36cm handlebars.

I think the rest of us mere mortals will be fine.
"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

Marin
Posts: 4035
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

Ok, went from 42s to 40s on my "fast" bike and did the 1st ride today. I really like how they feel, I definitely notice that the bars are narrower. It felt faster on the flats, but then this is usually highly subjective.

This year, I started climbing in the drops a lot (Pantani style), and here's where I found that I would have preferred my wider bars. Definitely more strain on the arms. However, it's probably a matter of getting used to it, plus I set a new PR on a steep climb (10secs faster on 10min @ 8%), and 2 PRs on rolling segments, so the narrower bars are definitly not slowing me down.

kulivontot
Posts: 1163
Joined: Sun May 16, 2010 7:28 pm

by kulivontot

The way I understand it is something like this:
Downward force on the pedal propels the bike forward through the drive train, the higher the downward force the faster the sprint. Pulling up on the handlebars allows one to use their upper body strength to further push down harder on the pedals. Imagine standing on a scale next a bar that's attached to the floor. You'll weigh more on the scale if you pull upwards on the bar. Your handlebars act as a lever which allows the forces enacted on the bike frame to be larger than the force applied by your upper body. Longer lever means larger mechanical advantage which means less strain on your arms for the same force on the bike frame. Try sprinting from the tops with your hands next to the stem and you'll see what I'm saying.
I would gather that track sprinters are more concerned with aero than the average road cyclist and are also much beefier all around than the average road cyclist. The question of "does 2cm of leverage matter?" is not something I have an answer for, just pointing out what I perceive as a potential tradeoff to think about. I would think that this potentially would have a more noticeable impact than the aero advantage, which is why I thought it would be neat to have actual data. But if narrower is more comfortable then that probably trumps everything else!

User avatar
Kayrehn
Posts: 1776
Joined: Thu Mar 24, 2011 6:06 pm

by Kayrehn

When I'm at my limit I like to tuck myself into a ball of pain hence it's 40cm for me definitely. I entertained the thought of trying 38cm but getting another Zipp sl 70 for an experiment is rather expensive...

Sent from my SM-G900F using Tapatalk

11.4
Posts: 1095
Joined: Tue May 23, 2006 4:33 am

by 11.4

We keep hearing about leverage here, but all we're really doing with wider bars is tilting the bike to one side and pushing harder with pedals on the other. The bike is going to keep its line anyway (or at least you want it to), so being tilted over buys you nothing. It's just a compensation for bars that are too wide to begin with. It also means you can only brace your pedal stroke with one side of your torso and shoulders because the other side is slack. Make sense? If you stay aligned over the centerline of the bike (using narrower bars), you don't waste energy flipping the bike back and forth, you use both arms jointly to offset the much greater force you are applying into a pedal stroke, and you are simply applying an opposing force to your pedaling force in something that's closer to the same plane. Again, why would you pick up a weight at arm's length rather than vertically right next to your body?

KWalker
Posts: 5722
Joined: Mon Dec 28, 2009 8:30 pm
Location: Bay Area

by KWalker

^Bingo

And why we see thrashing in road sprints a lot IMO is from fatigue and technique breakdown. If you ever get to watch track sessions even the best short distance riders won't thrash nearly as much as your average roadie.
Don't take me too seriously. The only person that doesn't hate Froome.
Gramz
Failed Custom Bike

felipedana
Posts: 129
Joined: Mon Aug 20, 2007 11:20 pm
Location: Rio de Janeiro, BRAZIL
Contact:

by felipedana

yes.. that's correct..
I've noticed that quite a lot watching some sprint finishes.. most track guys don't throw the bike sideways as much as roadies

User avatar
Rick
Posts: 2034
Joined: Sat Aug 29, 2009 4:30 pm

by Rick

11.4 wrote:We keep hearing about leverage here, but all we're really doing with wider bars is tilting the bike to one side and pushing harder with pedals on the other....


When you stomp down on the pedals, a longer bar should make it easier for the bike to be held closer to upright.

Imagine a ridiculously long bar: you could mash the pedals very hard, yet still keep the bars level (and the bike vertical) with very small forces at the end of the bar.
Imagine a ridiculously short bar: at some point you simply couldn't prevent the bike from tilting over in response to the torque on the pedals, or at least it would require a lot of strength. .

I have no idea where the optimum is, but longer bars would definitely make it easier to keep the bike upright just from the physics involved.

Again, why would you pick up a weight at arm's length rather than vertically right next to your body?

Because it is not about how much weight you can lift, it is about applying the correct force to keep the bike vertical. This is assumimg we all have "enough" strength to keep it vertical and in the the common ranges of bar widths. So they are at shoulder width ± a few inches.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



Post Reply