Can someone describe the "modern" road bike fit?

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cheapvega
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by cheapvega

From what I understand it seems to mimick a TT fit- zero offset seatpost + seat forward, short cranks, narrow bars, long reach, high stack. Would that fit philosophy warrant sizing up on a frame? The only issue I see with going up a size is if the seatpost angle is a little lazy. I keep hearing about this new fit philosophy but I can't find anything concrete around it. Goal seems to be to get you long w/o going low.

I just went from 42 to 38 bars and the fit feels cramped. I have a 90mm stem and I think I will try a 120. But I just ordered a new frame with very similar geometry to my old one and I feel like I made a mistake :oops: But I am a very generic 175cm (maybe with slightly long arms) and 54cm frames seem to fit me well.

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Mr.Gib
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by Mr.Gib

I don't think frame size should change (some even go smaller because they are seeking a lower front end). And the so called modern fit depends on what you are doing. If racing or riding hard, the pressure on the pedals counteracts some of the weight on the hands, so it works well. For more endurance oriented riding, a less extreme forward shift might be better. But perhaps most importantly, fit is still rider dependant. Lots of elite level riders still using more "traditional" amounts of saddle setback (Pidcock?). I've taken the approach to only move as far forward as my hands can tolerate.
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.

TobinHatesYou
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by TobinHatesYou

Mr.Gib wrote:
Fri Jun 14, 2024 4:47 pm
I don't think frame size should change (some even go smaller because they are seeking a lower front end). And the so called modern fit depends on what you are doing. If racing or riding hard, the pressure on the pedals counteracts some of the weight on the hands, so it works well. For more endurance oriented riding, a less extreme forward shift might be better. But perhaps most importantly, fit is still rider dependant. Lots of elite level riders still using more "traditional" amounts of saddle setback (Pidcock?). I've taken the approach to only move as far forward as my hands can tolerate.

Going up a size on conventional frame geometry would be a stop-gap. Even a 58cm bike doesn’t have enough extra frame reach for a rider who would normally ride a 54cm. My ideal race bike would have the stack height of a 51/52cm frame and the reach of a 62cm frame.

There’s basically no extra weight on the hands in practice. The load is on upper arms / triceps, which will take a bit of conditioning for most. Start doing planks. Frankly I find more upright fits more taxing as my arms become more horizontal and less supportive.

apr46
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by apr46

I think the "modern" bike fit is still evolving and hasnt really settled. If you look at the changes to Pogacars position from the v3rs to the new v4rs with the steeper STA, then narrower enve bars and now the zero offset post, I think we are still very much in the phase of iterating and testing tradeoffs between aero, comfort etc.

If i were to guess, I think we will settle on less effective saddle to bar drop; but a good amount of that will come from saddles that are lower in addition to being further forward. The positions will be longer, the bars narrower than 380mm and the stems a lot longer than 120mm. It sounds like you currently arent sizing down and are planning to run a pretty average bar and stem combo so I would guess that the new bike is probably the right size to try a more forward saddle position.

With my limited experience on really narrow bars with a 130mm stem vs. sort of narrow bars with a 100mm stem, i would agree that the more forward stretched out position actually puts less strain on my back and arms, despite it being lower.

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Mr.Gib
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by Mr.Gib

TobinHatesYou wrote:
Fri Jun 14, 2024 5:26 pm
Going up a size on conventional frame geometry would be a stop-gap. Even a 58cm bike doesn’t have enough extra frame reach for a rider who would normally ride a 54cm. My ideal race bike would have the stack height of a 51/52cm frame and the reach of a 62cm frame.
But you're hardly representative of the average, and in particular not representative of someone who is using a 90mm stem. I ride with plenty of guys with pretty deep experience, some with past lives as professionals, and I can't think of any on stems longer then 120mm other than the 130mm on my Parlee which has a shortish reach. While some of these guys could handle shifting forward somewhat, I doubt any would be happier beyond a centimeter or two. A longer stem and or longer reach bar will almost always be the solution for the vast majority. Nothing wrong with rocking a 140. And like you point out, a bigger frame often doesn't get you the reach desired anyway, and introduces a range of other problems.
TobinHatesYou wrote:
Fri Jun 14, 2024 5:26 pm
There’s basically no extra weight on the hands in practice. The load is on upper arms / triceps, which will take a bit of conditioning for most. Start doing planks. Frankly I find more upright fits more taxing as my arms become more horizontal and less supportive.
I disagree. The more you rotate the whole body forward "around the clock", the more weight the hands will have to bear. Using the tops and the bends for additional support can transfer a good portion of the load to wrist and forearms, but most riders won't or can't hold that position all day. Upper arms doing a little extra work is a non-issue IMO (just a bit of HTFU needed). But too much pressure on the hands can result in nerve issues. Big guys in particular need to be careful.

One benefit of this so called "modern fit" that might be overlooked is the reduction of pressure on sitbones. My ass has never been happier, and I've only moved about 2cm forward from a professional bike fit done about 5 years ago. Also lots more time in an aero posture (made possible but the new forward position) which helps distribute saddle pressure.
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.

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LouisN
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by LouisN

Don't Forget: shorter cranks, thus less leg flexion, more open hip angle.
This can mean higher saddle position, or depending where you're at, opens to larger frame size.

Louis :)

cheapvega
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by cheapvega

apr46 wrote:
Fri Jun 14, 2024 7:49 pm
It sounds like you currently arent sizing down and are planning to run a pretty average bar and stem combo so I would guess that the new bike is probably the right size to try a more forward saddle position.
I tried a seat forward and up position for a while and switched to one lower and more backwards. I think it was putting too much weight on my hands. I might keep the same height but push the seat forward as I sit on the front of the saddle in the climbs. I'm heavier (90kg I think) and my hands get numb pretty quick- trying to find a fit to help with that and moving the saddle back/down helped.

TobinHatesYou
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by TobinHatesYou

Most former pros are just about the last people you want to talk to regarding progressive bike anything. If we’re going to talk about modern bike fits we should be talking about the most avant garde examples like Hester’s, van Schip’s, van der Hoorn’s, Hansen’s, etc. van Schip is using a 180mm stem, Hester and Rutsch 170mm stems.

mikehhhhhhh
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by mikehhhhhhh

Interesting thought, you pretty much described my latest and most successful fit.

After the first two unsuccessfully tried to set my saddle as far back as it goes, seat too high and suffering with all sorts of issues the third attempt was radically different.

Seat as far forwards as possible, 160mm cranks, 30mm of spacers and I've never felt better on the bike.

I should be on the size down ideally, but stack would be ridiculous.

I think I'm more comfortable with 20mm spacers - with less hand pressure, but I can hold an elbows down aero position so well with 30, that I'm apprehensive to change for the sake of road TTs.

Something to train over winter perhaps...

apr46
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by apr46

cheapvega wrote:
Fri Jun 14, 2024 9:15 pm
apr46 wrote:
Fri Jun 14, 2024 7:49 pm
It sounds like you currently arent sizing down and are planning to run a pretty average bar and stem combo so I would guess that the new bike is probably the right size to try a more forward saddle position.
I tried a seat forward and up position for a while and switched to one lower and more backwards. I think it was putting too much weight on my hands. I might keep the same height but push the seat forward as I sit on the front of the saddle in the climbs. I'm heavier (90kg I think) and my hands get numb pretty quick- trying to find a fit to help with that and moving the saddle back/down helped.
If you take a step back and ask "why are the new fits a thing?" it comes down to optimization of aero vs. comfort.

In that context simply rotating the rider forward is a half measure if the goal is to reduce the frontal area of the rider. If you move the saddle forward or even forward and down with shorter cranks with knee flexion and hip angle, not max knee extension being the limiter you can acheive a similar range of movement with a lower vertical height. To manage the back angle then you need to increase reach. You could move the hands down, but moving them out in front alows you to bring the shoulders up and in while keeping the hands in front of the torso. Again you have minimized the frontal profile.

If you did all of that, unlike trying to rotate your whole body forward, it shouldnt put more weight on your hands, but your shoulders and upper back would need to get used to it.

Jaisen
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by Jaisen

mikehhhhhhh wrote:
Fri Jun 14, 2024 9:57 pm
Interesting thought, you pretty much described my latest and most successful fit.

After the first two unsuccessfully tried to set my saddle as far back as it goes, seat too high and suffering with all sorts of issues the third attempt was radically different.

Seat as far forwards as possible, 160mm cranks, 30mm of spacers and I've never felt better on the bike.

I should be on the size down ideally, but stack would be ridiculous.

I think I'm more comfortable with 20mm spacers - with less hand pressure, but I can hold an elbows down aero position so well with 30, that I'm apprehensive to change for the sake of road TTs.

Something to train over winter perhaps...
Same, I have a 25mm spacer stack, went down one size frame, slammed the saddle as far forward as it can go, and have a 130mm stem. I also put on shorter cranks. My bike fit is the best I have ever had, but as Mr. Gib warned about for long endurance rides I did feel some pressure on the luna part of my palms, which I don't get when riding hard. Luckily for me since I got a pair of Assos RS Targa gloves my hand pressure is completely gone even on long endurance rides. The tiny pads dissipates the pressure really well. I never wore gloves previously so it is kind of surprising how good they work, and if I crash I have a little protection.

I guess my spacer stack isn't "sexy" since my stem isn't slammed, but I can easily hold elbows down for pretty long stretches at a time. Also at 10cm of saddle to bar drop I feel that is enough anyway to get fairly low. I wonder what the modern fit saddle to bar drops tend to be on average.

DaveS
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by DaveS

The problem with zero setback posts can be too much weight on your hands. I want to be balanced over the saddle, so I use a 25mm setback on my smallest or next to smallest frames, with 11.5 cm saddle to bar drop. The reach difference between frame sizes is rarely even 10mm. Compare reach at the same stack height. Each 10mm of additional stack reduces reach by 3mm.

boots2000
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by boots2000

I think there is something to this new fit philosophy (forward saddle and horizontal forearms). But I also think you need to experiment and see what works for you.
I would be super hesitant to buy a frame specifically for this purpose without verifying what works for you.
It is easier to mockup a bike where the cables/hoses don't go through the headset bearings of stem. Get a zero offset post and different stem(s).
Some don't produce good power forward, some are actually not more aerodynamic, some don't do well with a shorter crank.

Like the kids say "F**k around and find out".

RoadDonk82
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by RoadDonk82

For those who use forward saddle/long stem fit: are you comfortable on descents? I find downhill corners/switchbacks uncomfortable when I am forward on the bike. It's much easier for me with saddle in more traditional position. Thoughts?

toxin
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by toxin

you shouldnt have your weight on the saddle through corners anyway

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