Stem lengths for a TCR - bike fit advice

Discuss light weight issues concerning road bikes & parts.
Hexsense
Posts: 928
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

Mr.Gib wrote:
Fri May 17, 2019 3:57 pm
I do find it strange that people who are concerned about the aerodynamics of their position often set their bars so low that they can barely use the drops. You should be able to ride on the drops indefinitely in reasonable comfort. That's what the drops are for. And when it comes to aero, don't forget that your elbows also bend.
Elia Viviani disagree with you, and i agree with him.
https://youtu.be/k8Vrv9bfk7Y?t=190

If drop is sustainable all day long, would that make hood position useless?
If you set your drop so high that you can be in drop all day long then what do you do when you want to get extra aero or extra stable handling of low center of gravity?

Why not setting the hood to where you can sustain all day long, and drop low enough that it give you lowest center of gravity, and most aero when you need it.
Elbow bend on hood for surge (aero, with less stability).
Straight down arm in drop for tight control (like descend). Sustainable-ish, but may not for the whole ride.
Elbow bend in drop for actual sprint.
Otherwise, stay on hood. It's default sustainable position.
Last edited by Hexsense on Fri May 17, 2019 9:07 pm, edited 1 time in total.

by Weenie


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Calnago
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by Calnago

^Yup, that’s what I’d agree with. The drops should certainly be useable for sure, but all day indefinitely, not really, at least for most. If you can sustain that position all day, good for you. You don’t need the hood position at all then. Just stay on those comfy drops all day long.
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devonbiker
Posts: 70
Joined: Wed May 30, 2018 1:26 pm

by devonbiker

jih wrote:
Fri May 17, 2019 3:50 pm
Back to the OP: 100mm and 110mm stems aren’t drastically different, and stems aren’t difficult to swap. Just try both and see which you prefer? You may find there’s not much difference on the road.

I generally run 110mm, but sometimes swap to a 100mm and a few spacers for very long rides. I’m good on either.
What height are you and what size frame do you ride? I'm trying to find a sweet spot for both long rides and training rides, and find swapping stems a bit of a faff - it takes me ages to get the stem straight and centred on the bar, and my OCD doesn't help, so once I'm happy it's going to stay there :lol:

devonbiker
Posts: 70
Joined: Wed May 30, 2018 1:26 pm

by devonbiker

Mr.Gib wrote:
Fri May 17, 2019 3:57 pm
To the OP, re stem length, don't sweat it. I rode various Giant TCR Advanced SL's for a few years (I am 183 cm - size ML) and I experimented quite a bit with different stem lengths. When you take your first ride on a shorter stem you notice the steering is a bit more reactive to bike movement, more so out of the saddle, but your body compensates for the change in about 5 minutes and it becomes a non-issue.

Get your saddle located appropriately and then choose the stem length that results in a position that works for you based on your priorities and what feels good for your body. Doing super long rides? You'll want it higher and shorter. Racing crits? Longer and lower. Bad back? Go back to the Defy. I do find it strange that people who are concerned about the aerodynamics of their position often set their bars so low that they can barely use the drops. You should be able to ride on the drops indefinitely in reasonable comfort. That's what the drops are for. And when it comes to aero, don't forget that your elbows also bend.
How many mm of spacers did you run under your TCRs? I have gone down to 17mm but to be honest on the drops I feel like my chin is almost touching the front wheel and it would probbaly give me neck ache from looking up if I was to use this position for more than 5 mins. But for riding on the hoods (which is my preferred position) it feels great. TBH the only advantage I see of being on the hoods if you already have a slammed stem is the greater braking control as you have more leverage and power by using the ends of the levers with your index and middle fingers.

I will also need to cut my carbon steerer at some point as the stack height is massive.

Mr.Gib
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by Mr.Gib

Hexsense wrote:
Fri May 17, 2019 7:17 pm
Mr.Gib wrote:
Fri May 17, 2019 3:57 pm
I do find it strange that people who are concerned about the aerodynamics of their position often set their bars so low that they can barely use the drops. You should be able to ride on the drops indefinitely in reasonable comfort. That's what the drops are for. And when it comes to aero, don't forget that your elbows also bend.
Elia Viviani disagree with you, and i agree with him.
https://youtu.be/k8Vrv9bfk7Y?t=190

If drop is sustainable all day long, would that make hood position useless?
If you set your drop so high that you can be in drop all day long then what do you do when you want to get extra aero or extra stable handling of low center of gravity?

Why not setting the hood to where you can sustain all day long, and drop low enough that it give you lowest center of gravity, and most aero when you need it.
Elbow bend on hood for surge (aero, with less stability).
Straight down arm in drop for tight control (like descend). Sustainable-ish, but may not for the whole ride.
Elbow bend in drop for actual sprint.
Otherwise, stay on hood. It's default sustainable position.
Indefinitely is a bad choice of words. How about a situation of strong crosswind for an hour or more in a group ride? Been there many times and the drops is a whole lot safer. Same for long decents in gusty conditions. And Viviani's application is quite different than most recreational cyclist. (Viviani's body is also a bit different than may of his fellow competitors and his experience and preferences may not be applicable to the whole of professional cycling and certainly cycling in general). I am more refering to weekend warriors who are not flexible enough to use the drops in the situations I describe above. Those folks definitely need their bars higher regardless of how "useless" the hoods are. And as to the hoods being useless, again, we all have elbows I assume.

Perhaps my view is biased. I am blessed with palms on the floor flexibility, and I am equally comfortable/uncomfortable with my quads just grazing my torso in the drops or sitting upright in the hoods. So in my case yeah, I can ride on the drops "all day" and yet my body can't go any lower. I find I often use the drops not to change my torso angle but to refresh my arm and hand postion. Another reason to have the drops "easily" accessible.

I think we are saying the same thing: "Why not setting the hood to where you can sustain all day long, and drop low enough that it give you lowest center of gravity, and most aero when you need it." My point is what happens when you need it for an hour, but your body can't get there comfortably?
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

zefs
Posts: 438
Joined: Sat Aug 05, 2017 8:40 pm

by zefs

Hip flexibility plays a role too, not only back flexibility for setting up the handlebar position. Too low and you loose power.

devonbiker
Posts: 70
Joined: Wed May 30, 2018 1:26 pm

by devonbiker

Hexsense wrote:
Fri May 17, 2019 7:17 pm
Mr.Gib wrote:
Fri May 17, 2019 3:57 pm
I do find it strange that people who are concerned about the aerodynamics of their position often set their bars so low that they can barely use the drops. You should be able to ride on the drops indefinitely in reasonable comfort. That's what the drops are for. And when it comes to aero, don't forget that your elbows also bend.
Elia Viviani disagree with you, and i agree with him.
https://youtu.be/k8Vrv9bfk7Y?t=190

If drop is sustainable all day long, would that make hood position useless?
If you set your drop so high that you can be in drop all day long then what do you do when you want to get extra aero or extra stable handling of low center of gravity?

Why not setting the hood to where you can sustain all day long, and drop low enough that it give you lowest center of gravity, and most aero when you need it.
Elbow bend on hood for surge (aero, with less stability).
Straight down arm in drop for tight control (like descend). Sustainable-ish, but may not for the whole ride.
Elbow bend in drop for actual sprint.
Otherwise, stay on hood. It's default sustainable position.
You have more powerful braking on the drops. Due to pulling the ends of the levers instead of the middle part. You get far more leverage with the same amount of force. Probably doesn't matter if you ride discs but makes a difference on rim brakes.

zefs
Posts: 438
Joined: Sat Aug 05, 2017 8:40 pm

by zefs

I think it's the opposite (atleast for me), because when you pull at the end of the levers there is more lever distance to cover = less braking force.
But it depends on the how you setup the hoods on the handlebars (high vs low).

devonbiker
Posts: 70
Joined: Wed May 30, 2018 1:26 pm

by devonbiker

Just to update you all, I fitted the 110mm stem. Initial impressions is that it feels more comfortable for short rides, and feels slightly better when descending. I'm not sure about climbing through - the extra reach combined with a gradient forces your weight backwards which makes it feel like more of a stretch the hoods, and when stood up climbing you are sligthly less upright, which I don't think I like. But it's early days. I've got just 12.5mm of spacer under the stem and the saddle is about 10mm from fully forward on the rail.

Will keep it on for a few weeks and decide whether or not too keep it after a couple of longer rides. To experiment and revert is better than not experimenting at all.

Thanks everyone for the useful advice.

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