I’ve attempted searching both the forum and the Google but no luck so here is my morning ponderance:
Over the spring/summer I’ve been working on making my road bike position more aggressive. I started with a full stack of spacers and every couple weeks (when comfort/riding felt 100%) worked my way down. I’ve reached the bottom of the spacers and now am looking at the stem. It’s a 6 degree stem flipped to -6 deg. I assume next step is put a steeper flipped stem on the bike as I still feel like I could go lower and be comfortable/produce same power. Using brightspoke.com’s calculator I see that putting a flipped 17 degree stem on would give me an additional ~2 cm of drop.
This has made me wonder, is there a rough rule of thumb for CDA vs stack reduction? Is 2 cm of additional drop worth the hassle of swapping out stems?
Secondly, am I correct in assuming that I might want to consider reducing stem length (~10mm) with that additional drop to preserve reach?
I suppose I knew better but was hoping for some equivalent of the 2’ per mile per pound rule of thumb for weight loss in running.
As I’ve removed the spacers to date I suppose my reach has increased each time and it hasn’t been noticeable or problematic yet. Just wondering if there is a point at which handling is affected by increased reach but I haven’t noticed it yet.
Over on aeroweenie.com you can find this Cervelo data on front end height vs drag for a few different riders:
That is on TT bikes not road bikes but there is a general trend.
Something to think about with road bikes is often lowering the bars merely causes you to lower your hands. Lowering your hands makes you less aero because more arm area is exposed to the wind.
When in the drops with your torso as horizontal as you are likely to actually tolerate when riding, your foreams should be level with the ground.
A lot of pros get this wrong imho…modern pros anyway, a few decades ago the trend was better.
So when riding fast, in the drops, look at your forearms. Are they level? If not, consider raising the bars back up.
Something to think about with road bikes is often lowering the bars merely causes you to lower your hands. Lowering your hands makes you less aero because more arm area is exposed to the wind.
When in the drops with your torso as horizontal as you are likely to actually tolerate when riding, your foreams should be level with the ground.
A lot of pros get this wrong imho…modern pros anyway, a few decades ago the trend was better.
So when riding fast, in the drops, look at your forearms. Are they level? If not, consider raising the bars back up.
Jack - this is interesting and I hadn’t considered it. Just blindly going lower is of less value if it’s with little arm bend then… the ‘best’ position on the road bike then is drops with forearms parallel to the top tube and as flat a back as you can manage based on flex/power/comfort?
Yes, in my opinion (and the opinions of others like Gerard Vroomen)
there are other considerations, for instance maybe you just hate the drops and prefer to ride with forearms flat on the hoods, or maybe you want to optimize for invisible aerobar position rather than drops.
But when you are taking hard pulls on the road bike, think about how you want to position yourself when you do that, get the back flat as you can comfortably/powerful and then minimize the frontal area of your arms.
Something to think about with road bikes is often lowering the bars merely causes you to lower your hands. Lowering your hands makes you less aero because more arm area is exposed to the wind.
When in the drops with your torso as horizontal as you are likely to actually tolerate when riding, your foreams should be level with the ground.
A lot of pros get this wrong imho…modern pros anyway, a few decades ago the trend was better.
So when riding fast, in the drops, look at your forearms. Are they level? If not, consider raising the bars back up.
Jack - this is interesting and I hadn’t considered it. Just blindly going lower is of less value if it’s with little arm bend then… the ‘best’ position on the road bike then is drops with forearms parallel to the top tube and as flat a back as you can manage based on flex/power/comfort?
… Just wondering if there is a point at which handling is affected by increased reach but I haven’t noticed it yet.
It’s typically comfort and not handling that suffers with increased reach. Longer stems on a road bike actually tend to dampen the steering response making things feel more stable in response to steering inputs so longer stems and with it longer reach usually has a stabilizing effect. But if you’re stretching too far forward your back may suffer and you may feel way too stretched out when you ride or have to lock your arms straight to reach the brake hoods or drops, that won’t help comfort or handling.
I believe Kirk Albers had some numbers of aero drag as a function of torso angle claiming CdA dropped at a certain rate for every degree of decreased torso angle which is closely related to dropping your pads by removing spacers or going to drop angle stems. But again that was for riders using aero bars not road drops.
Just make sure you can actually ride for sustained periods in your drops and on your brake hoods as you drop your road bike front end lower. No sense in having a deeply slammed stem if the position isn’t useful when you need it. I see racers off the back, chasing hard and riding tall on the brake hoods all the time, when I’ve talked to lower category team mates about this they often say the drops are spooky or uncomfortable so they always ride up top. Not really a lot of sense riding on a road bike with dropped handlebars if you can’t use the drops at times when they’d help.
BTW, one trick is to use the modern generation of compact shallow drop handlebars. They can help you get a low brake hoods position without having a ridiculously low position when you’re down in the drops. Stems like the Ritchie Curve or 3T Ergonova are examples of compact drop bars.
As I’ve removed the spacers to date I suppose my reach has increased each time and it hasn’t been noticeable or problematic yet. Just wondering if there is a point at which handling is affected by increased reach but I haven’t noticed it yet.
Nothing strange will happen… just depends on what is most comfortable to you. A lot of pros favor a long reach. One advantage is that the standing position on climbs feels more natural. I have a 140mm -17 stem on my road bike.
When in the drops with your torso as horizontal as you are likely to actually tolerate when riding, your foreams should be level with the ground.
When I’m hammering on the flat I have two good low positions. One is grabbing the tops of the hoods (Campy) with horizontal forearms, and the other is in the drops with arms more straight. It may not be as aero, but it is tiring to have my arms bent that much for an extended period. If I had a very slack saddle position, this might be easier.
There is another aero advantage to having low bars and more reach in that the shoulders are more naturally pulled in and it’s easier to turtle
