bike sizing reach&stack help

Discuss light weight issues concerning road bikes & parts.
seansis
Posts: 47
Joined: Fri Sep 23, 2016 9:58 am

by seansis

Hello. Sorry for my English.

I choose a new road bike for myself, because it seems to me that now it is very big for me.

Now I have the Simplon Nexio 55 size
ett 555mm,
reach 396mm,
stack 555mm,
stem 105mm (-6 angle),
10mm spacer,
seat tube 530,
head tube 145
But the KOPS method is not followed, my knee is behind the pedal.
And me completely uncomfortable on this bike.
My height is 183cm, weight 67kg, inseam 86cm. I have long arms and legs.

Now I look closely at Pinarello Dogma 65.1 think 2 53 size,
ett 545
reach 386,
stack 542
stem 135mm ( i dont know angle)
5mm spacer
seat tube 545
head tube 139
But I'm afraid that the fall of the saddle-handlebar wheel will be simply huge, because the head tube is very low.
But in theory, the knee should be in the right position on Pinarello. Or I'm wrong?...
I just want to get compact position on road bike.
Should I buy Pinarello Dogma 65.1 53 size?

Any help
Thanks

wingguy
Posts: 3974
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

The Simplon Nexio has a 0.1 degree steeper seattube than the Dogma. Why do you think the Dogma will help bring your knee forwards in a way that the Nexio can't? :noidea:

by Weenie


bobones
Posts: 46
Joined: Mon Aug 12, 2013 11:19 am

by bobones

You should be able to fit the Nexio IMO. I am a similar stature to you and own a 56cm Felt F series that has almost identical geometry your bike that I am comfortable on even with a setback seatpost and 100mm stem. Surely moving the saddle forward on inline post will fix KOPS and perhaps a 90mm stem would make the reach a bit easier? Do you have any photos of you on the bike?

seansis
Posts: 47
Joined: Fri Sep 23, 2016 9:58 am

by seansis

Thank you for responding!

Unfortunately, I do not have new photos on the bike. I quite often change my bike's settings, because I'm still in search of an ideal position.
The reason why I intend to sell my Simplon Nexio is not only the impossibility (as I think) of sitting right position, but also that the saddle slides in the seatpost. Exactly the same problem exists in Cervelo S5:
https://forums.cervelo.com/forums/p/10764/104524.aspx
That's why I can not move the saddle much forward, because this will change the position of the saddle at the pressure of my weight...
Also I do not like short stems, the bike moves quite sharply.

I look at Pinarello to buy because it will be a profitable purchase in terms of price. And I really do not know if a new bicycle will help me solve my problem...

wingguy
Posts: 3974
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

seansis wrote:
Wed Jan 31, 2018 12:35 pm
That's why I can not move the saddle much forward, because this will change the position of the saddle at the pressure of my weight...
So you don't know if you have any problems with the geometry of the Nexio, just that the seatpost head doesn't work? Try thoroughly cleaning the saddle rails and clamping surface and then using something like Ritchey Liquid Torque on the rails, and make sure it's being done up tight enough.
And I really do not know if a new bicycle will help me solve my problem...
But if you don't know which part of the Nexio geometry isn't right for you, no-one here can tell you whether the Dogma will be better. Do you want it longer, shorter, higher, lower...?

seansis
Posts: 47
Joined: Fri Sep 23, 2016 9:58 am

by seansis

wingguy wrote:
Wed Jan 31, 2018 12:44 pm
So you don't know if you have any problems with the geometry of the Nexio, just that the seatpost head doesn't work? Try thoroughly cleaning the saddle rails and clamping surface and then using something like Ritchey Liquid Torque on the rails, and make sure it's being done up tight enough.
I cleaned the clamping surface and the rails from the dust on my Specialized Phenom , also cleared the clamping hole of seatpost pin and put the Finish Line Fiber Grip Carbon inside the seatpost clamping hole. The effect was, but it was short-lived, and still on the next pit I collapsed down with the saddle.
I think the Finish Line Fiber Grip Carbon is identical in composition to the Ritchey Liquid Trading offered by you.
Now I have a Fizik Antares VS with carbon rail and I had to look for a longer bolt so that the mount held this saddle. Also, the problem of the seat post is also that it will not be possible to quickly move the saddle on the road, if it is not convenient to sit, because it is difficult to get the fastening from the seatpost.
And I'm really tired of this problem.

wingguy wrote:
Wed Jan 31, 2018 12:44 pm
But if you don't know which part of the Nexio geometry isn't right for you, no-one here can tell you whether the Dogma will be better. Do you want it longer, shorter, higher, lower...?
I believed that if Pinarello is shorter on reach, then I can be with shorter position, at least with the same stem. Or is it not?
On the seller's picture the saddle at Pinarello is shifted as far forward as possible, and the 135 mm stem means that a rather tall man was sitting on the bicycle.
I want to be just more compactly, shortly, closer to the stem.

wingguy
Posts: 3974
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

seansis wrote:
Wed Jan 31, 2018 1:40 pm
I believed that if Pinarello is shorter on reach, then I can be with shorter position, at least with the same stem. Or is it not?
Ah, ok. That's the first time you've said you wanted the position to be shorter. In which case yes, of course the shorter reach makes it shorter. But then, just being able to move the saddle forward and have it stay there will already make the position shorter. So how much shorter do you want the position to be? We don't know that, do you?

Then your question about whether the extra drop will be ok.... well, will it? You haven't told us how much drop you have on the Nexio, what your saddle height is, or what kind of discomfort you are experiencing on the bike. So how the heck can we know if it will be ok for you?

seansis
Posts: 47
Joined: Fri Sep 23, 2016 9:58 am

by seansis

wingguy wrote:
Wed Jan 31, 2018 2:42 pm
Ah, ok. That's the first time you've said you wanted the position to be shorter. In which case yes, of course the shorter reach makes it shorter. But then, just being able to move the saddle forward and have it stay there will already make the position shorter. So how much shorter do you want the position to be? We don't know that, do you?

Then your question about whether the extra drop will be ok.... well, will it? You haven't told us how much drop you have on the Nexio, what your saddle height is, or what kind of discomfort you are experiencing on the bike. So how the heck can we know if it will be ok for you?
I apologize. I forgot to write this.
My current drop of the saddle-handlebar is 11.5 cm.
Saddle height - 77cm (BB centre -> top of saddle).


The problem is that with intensive cycling I automatically move forward, and I sit not on the sciatic bones, but on the soft tissues of the inguinal region. It causes numbness, pain.
I think the saddle shift all the way forward would partially solve my problem, but on my bike it's impossible. That's why I thought about the shorter frame. Pinarello was just on sale, so I thought about it.

DJT21
Posts: 186
Joined: Sun Mar 27, 2011 7:35 pm

by DJT21

Go and get a bike fit. The reason you feel uncomfortable is because your saddle is too high.

77cm seat height with an 86cm inseam? I'd guess at least 2cm too high.

You will never get a bike to fit properly if the saddle is too high. You can potentially do yourself an injury aswell.

Work out your correct saddle height then go from there. I'd expect everything else to change once you've worked it out.

seansis
Posts: 47
Joined: Fri Sep 23, 2016 9:58 am

by seansis

DJT21 wrote:
Thu Feb 01, 2018 12:11 am
Go and get a bike fit. The reason you feel uncomfortable is because your saddle is too high.

77cm seat height with an 86cm inseam? I'd guess at least 2cm too high.

You will never get a bike to fit properly if the saddle is too high. You can potentially do yourself an injury aswell.

Work out your correct saddle height then go from there. I'd expect everything else to change once you've worked it out.
I do not think that I'm sitting too high. I could err in the measurement of my inseam. So often I say the meaning 86-87. I think 87 is more accurate.
There is also a formula for determining the saddle height - inseam * 0.883. In my case, it turns out: 87 * 0.883 = 76.8. This is my 77cm saddle height.

I would gladly pay for the bike fit, but we do not have professional trainers and engineers on this issue.

In particular, does it mean that with ETT 545, the saddle will be closer to the stem than with ETT 555 if the saddle height is the same?

coriordan
Posts: 161
Joined: Thu Nov 16, 2017 3:30 pm

by coriordan

Bike seems small to me but the issues tie up with a bike too big. For reference, I am 180cm and would ride a 56/7 in traditional geometries.

You must have very short femur bone if you're not able to get KOPS measurement with your knee in the right place on a 55cm frame, the saddle must be so high! I would imagine you need a much longer stem (130mm?)

bobones
Posts: 46
Joined: Mon Aug 12, 2013 11:19 am

by bobones

seansis wrote:
Wed Jan 31, 2018 12:35 pm
Unfortunately, I do not have new photos on the bike. I quite often change my bike's settings, because I'm still in search of an ideal position.
Surely you can take a new side on photo of you sitting on the bike and post it here? If not, I suspect you're just looking to justify getting a new bike! :-)

User avatar
dj97223
Posts: 665
Joined: Sun Nov 06, 2005 7:27 pm

by dj97223

Not That There's anything Wrong with That! :lol:
“If you save your breath I feel a man like you can manage it. And if you don't manage it, you'll die. Only slowly, very slowly, old friend.”

seansis
Posts: 47
Joined: Fri Sep 23, 2016 9:58 am

by seansis

coriordan wrote:
Thu Feb 01, 2018 12:58 pm
Bike seems small to me but the issues tie up with a bike too big. For reference, I am 180cm and would ride a 56/7 in traditional geometries.

You must have very short femur bone if you're not able to get KOPS measurement with your knee in the right place on a 55cm frame, the saddle must be so high! I would imagine you need a much longer stem (130mm?)
130mm ... Then I just do not get to the switches, alas.
I have an old photograph of my position on the bike. You can laugh or say I'm stupid, but this frame really big to me relying on intuition. Most of my comrades are chasing small frames (52-54) with a height of 175-180 cm.

Image

by Weenie


DJT21
Posts: 186
Joined: Sun Mar 27, 2011 7:35 pm

by DJT21

Is that a picture of you taken during your pedal stroke? If so, your saddle is too high; your left leg is over extended.

Just lower your saddle, you've got nothing to lose.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post