Road Bike, Cycling Forums banner

1 - 13 of 13 Posts

·
Coupdevill
Joined
·
34 Posts
Discussion Starter · #1 ·
I am hoping to get a screaming deal on a 53cm 481 SL but first want to get some sizing advice.

My numbers for traditional geometry (mm):

Seat tube:535
Top tube:545
Seat tube angle:72.8
Head angle: 72.5
Head tube:149
Set back:158
Stem length:110

I'm using the following componets:

DA10
Ritchey Pro Logic WCS bar & stem
Fiz'ik Arione
Look Ergo seatpost

Look 481 SL Geometry:

http://www.lookcycle.com/v2/anglais...e/2004/geom.php

Seat tube:?
Top tube:548
Seat tube angle:72.5
Head angle: 72
Head tube:149
Set back:159
Stem length:?

Thanks!

Coup










http://www.lookcycle.com/v2/anglais/catalogue/2004/geom.php
 

·
Registered
Joined
·
10,160 Posts
seems obvious...

With only a few millimeters difference in any dimension, the frame should fit fine.

Why the question about seat tube? LOOK's geometry chart clearly shows it as a center to center measurement. They also list the standover height.

Based on your listed dimensions under traditional geometry, your setback of 158mm indicates that the 535mm "seat tube" is a c-c frame size, just like LOOK uses, since 158/535 equals the cosine of the 72.8 degree STA.

The only significant difference might be the head tube length. If your traditional frame has a conventional headset, then the head tube with the headset installed, will be 10-15mm taller than the LOOK, since the LOOK has an integrated headset that only adds 15mm to the length. This could cause a problem, depending on how much spacer and the stem angle being used on the traditional frame.
 

·
Registered
Joined
·
10,160 Posts
same stem...

The stem length shouldn't change, but read the revision to my post about the head tube length.
 

·
Coupdevill
Joined
·
34 Posts
Discussion Starter · #4 ·
C-40 said:
With only a few millimeters difference in any dimension, the frame should fit fine.

Why the question about seat tube? LOOK's geometry chart clearly shows it as a center to center measurement. They also list the standover height.

Based on your listed dimensions under traditional geometry, your setback of 158mm indicates that the 535mm "seat tube" is a c-c frame size, just like LOOK uses, since 158/535 equals the cosine of the 72.8 degree STA.
I added the Seat tube height just because I had it. Where do you think I will end up on a stem 110 or 100?

Thanks for the quick reply.

coup
 

·
Coupdevill
Joined
·
34 Posts
Discussion Starter · #5 ·
C-40 said:
The stem length shouldn't change, but read the revision to my post about the head tube length.
I'm trying to keep my set up as close to this as possible:

Saddle height:739
Saddle set back:368
Length saddle/bar:826
Max saddle/bar height:70
Bar height:170

I'm thinking I should only have to add 10-15mm of spacers to hit nirvana, or am I missing something?

coup
 

·
Registered
Joined
·
10,160 Posts
head tube length....

My geoemtry chart says the 53cm has a143mm head tube. Add 15 mm to that and you get 158mm, with the headset. Compare your setup to this dimension.

Another thing I have overlooked is the BB drop. The LOOK has a pretty standard 70mm, if you frame has more drop then you may have a greater height problem. While adding 10-15mm may not sound like much, the max. is 30mm. Personally, if I needed 30mm of spacer, I'd go to a higher rise stem.

On last thing to compare is fork length, although it's pretty rare to have a big difference these days. LOOK use a pretty average 367mm length. 374mm is about as long as I'v seen for a carbon fork.
 

·
Coupdevill
Joined
·
34 Posts
Discussion Starter · #7 ·
C-40 said:
My geoemtry chart says the 53cm has a143mm head tube. Add 15 mm to that and you get 158mm, with the headset. Compare your setup to this dimension.

Another thing I have overlooked is the BB drop. The LOOK has a pretty standard 70mm, if you frame has more drop then you may have a greater height problem. While adding 10-15mm may not sound like much, the max. is 30mm. Personally, if I needed 30mm of spacer, I'd go to a higher rise stem.

On last thing to compare is fork length, although it's pretty rare to have a big difference these days. LOOK use a pretty average 367mm length. 374mm is about as long as I'v seen for a carbon fork.
Sorry I didn't mention that I am coming off a Giant TCR size medium:

TT 555
Stem 90
20mm spacers.

So you can see where I am at.
 

·
Registered
Joined
·
10,160 Posts
that's different...

Sean Vill said:
Sorry I didn't mention that I am coming off a Giant TCR size medium:

TT 555
Stem 90
20mm spacers.

So you can see where I am at.
Guess I missed the point about the traditional geometry, you should have asked for a comparison of these two. You'll need a 10mm longer stem on the LOOK. You should be OK on the spacers, if anything the LOOK might be taller with the 15mm top section on the headset.
 

·
Registered
Joined
·
354 Posts
HI CoupdeVill,

Assuming your Giant is a 73.5 STA, your 55.5 TT on that would comparitavely feel about 1.9cm longer than the Look (assuming 1.2cm of length gained for every 1 degree increase in STA). Do you feel streched out on the Giant? I used to ride a 54cm KG281, am your height at 5 foot 9 (I do not know what your inseam is though-mine is long at 85.5cm) and remember being a little stretched out on the TCR Medium with a 110mm stem. My current bike, the Look 585 in 53cm (54.5 TT, 73.5 STA) would be 1cm shorter across the TT, and it fits me perfectly with a 115mm stem. Along the lines of what C40 said, it seems that a 53cm will be a great fit with a 110mm stem.

Aloso, are you sure that the head tube length measurement is accurate on the Look? For my 585 it says 151mm, but measured length is 159mm. For comparison's sake, I am running 10mm of spacers on my 585, with a 115mm, 84deg stem, about pedals about 1cm behind ball-of-foot, with about 12cm saddle to bar drop. I run Campy, and the hoods are shorter than Shimano's: I always seem to feel a little more streched out with a bike that is set up with STI, so I often ride with a shorter stem to get the same position on the hoods.

BTW, I loved those new Contact 11's. I was on the ski twice and it may have been my favorite ski of the show-at least in the top 3. It actually felt pretty similar to the Rossi Multix, just a little livelier though.
 

·
Coupdevill
Joined
·
34 Posts
Discussion Starter · #10 ·
dawgcatching said:
HI CoupdeVill,

Assuming your Giant is a 73.5 STA, your 55.5 TT on that would comparitavely feel about 1.9cm longer than the Look (assuming 1.2cm of length gained for every 1 degree increase in STA). Do you feel streched out on the Giant? I used to ride a 54cm KG281, am your height at 5 foot 9 (I do not know what your inseam is though-mine is long at 85.5cm) and remember being a little stretched out on the TCR Medium with a 110mm stem. My current bike, the Look 585 in 53cm (54.5 TT, 73.5 STA) would be 1cm shorter across the TT, and it fits me perfectly with a 115mm stem. Along the lines of what C40 said, it seems that a 53cm will be a great fit with a 110mm stem.

Aloso, are you sure that the head tube length measurement is accurate on the Look? For my 585 it says 151mm, but measured length is 159mm. For comparison's sake, I am running 10mm of spacers on my 585, with a 115mm, 84deg stem, about pedals about 1cm behind ball-of-foot, with about 12cm saddle to bar drop. I run Campy, and the hoods are shorter than Shimano's: I always seem to feel a little more streched out with a bike that is set up with STI, so I often ride with a shorter stem to get the same position on the hoods.

BTW, I loved those new Contact 11's. I was on the ski twice and it may have been my favorite ski of the show-at least in the top 3. It actually felt pretty similar to the Rossi Multix, just a little livelier though.
Very stretched out on the Giant with a 90mm stem!

Not sure about the head tube length, as I have not yet recieved the bike.I'm thinking the 110 shoud be close to perfect, possibly a 100.

Thanks, Contact 11 was a hit.

coup
 

·
Registered
Joined
·
10,160 Posts
151mm head tube??

The charts that I have show no 151mm head tube for a 585, only 148 for a 53cm (M) and and 156mm for a 55cm (L).

I've got a 461 and a 381 in the 51cm size both have the same 120mm HT, just as advertised.
 

·
Registered
Joined
·
354 Posts
My 159mm measurement came in with the carbon cone above the top bearing. Maybe they don't measure it when they take the HT measurement? I was happy with that, as I have such long legs that I end up with a ton of saddle-to-bar drop otherwise with a frame that fits me. 1cm of spacers looks much better on a race bike than 2cm.

C-40 said:
The charts that I have show no 151mm head tube for a 585, only 148 for a 53cm (M) and and 156mm for a 55cm (L).

I've got a 461 and a 381 in the 51cm size both have the same 120mm HT, just as advertised.
 

·
Registered
Joined
·
10,160 Posts
headset not included...

The headset is not included in the HT length measurement. The extended top on my headsets are about 15mm tall.

I assume you have the 148mm head tube for a size M?
 
1 - 13 of 13 Posts
Top