# Question for the fit experts-585 Ultra



## unknownrash (Dec 25, 2005)

Hey guys,

I am LOOKing at a 585 Ultra want to make sure that getting a 55cm frame is ideal for me. I like to ride pretty aggressively and put in about 25-30 miles a day during the weekdays. Anyways here are my numbers from the Wrenchscience fit page. Thanks.


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## bedazzle410 (Sep 26, 2005)

I am sure the people with more knowledge on this topic will respond. but it seems to me that the 55 look is to large of a frame for you. I am 5' 11' and have a 34" pants inseam and ride a large 585 which has a 56 cm top tube with 42 cc bars with a 110 stem. I am now getting a large 595. I am a little concerned about the seat height in that I ride with my seat 82.5 cm from the center of the crank to top of seat.


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## oneslowmofo (Feb 29, 2004)

I too think that the Large (56) would be the wrong size. I'm around 5'11 and ride a medium with a 54.5 top tube and a 130 or 120 stem (depending on the time of year). It fits really well. You should also consider the head tube length. 

One other thought is on the recommended seat height (from Wrenchscience). With my height I'm running a saddle height of 74.5cm. Given that, I think it reinforces that a large is too big.


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## unknownrash (Dec 25, 2005)

oneslowmofo said:


> I too think that the Large (56) would be the wrong size. I'm around 5'11 and ride a medium with a 54.5 top tube and a 130 or 120 stem (depending on the time of year). It fits really well. You should also consider the head tube length.
> 
> One other thought is on the recommended seat height (from Wrenchscience). With my height I'm running a saddle height of 74.5cm. Given that, I think it reinforces that a large is too big.


So how much seatpost do you have showing? The dealer I was talking to said that if I were on a medium that I would have too much seatpost showing.


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## C-40 (Feb 4, 2004)

*wrong size...*

Have you never owned a bike before? If you have, is the saddle height 73cm, as suggested? Any error in taking your inseam measurement will throw everything off. Whatever you place in the crotch to measure inseam must exert saddle-like pressure, otherwise you could measure up to 2cm too small. I'd never rely on any of the online fit calculators myself. 

www.coloradocyclist.com/bikefit

FWIW, I've got about the same inseam and ride with a 73cm saddle height. To produce an aggressive 9-10cm drop from the saddle to the bars, I ride a 51cm 585 with only 5cm of spacer under the stem (145mm total HT length, with headset and spacers), with a common 110mm x 84 degree stem.

You're 7cm taller, so you would need a longer stem. The largest frame you'd want to consider would be a 53cm.

Your dealer doesn't know much if he thinks you'll have too much post showing with a 53cm frame. Even with my smaller 51cm, I only use a small amount of the extra length provided by my 350mm seatpost. The amount of post showing is irrelevant anyway. What's important is the proper head tube length, to avoid a goofy looking stem and spacer setup.


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## oneslowmofo (Feb 29, 2004)

What's too much? You can get longer posts that will work fine. But I had an Easton EC90 Zero setback in a 330 length that will be more than sufficient. I haven't measure the amount of post showing but you have my saddle height measurement which should help. BTW - I'm running a Specialized Toupe saddle.

Here's a picture for reference (with the 120 stem).


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## unknownrash (Dec 25, 2005)

Hey C-40, 

I did measure my inseam countless times with the book shoved "way" up there. I think my numbers are fairly accurate. I did measure my saddle height on my old road bike a while ago and it did correspond pretty closely with the recommended height. I'll have to measure again when I get home. Thanks for the responses so far.


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## C-40 (Feb 4, 2004)

*here's a pic...*

Here's a 51cm with a 73cm saddle height.


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## oneslowmofo (Feb 29, 2004)

Dave - that is a blingin' RED bike. What a beauty. :thumbsup:


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## unknownrash (Dec 25, 2005)

Well I just measured my saddle height from the center of the BB to the top of the saddle and it is exactly 73cm. I kind of had a gut feeling that a 53 would be a better fit, I feel better now that I have some feedback from some Look riders. 

By the way what should a proper stem and spacer setup look like anyways?


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## C-40 (Feb 4, 2004)

"Proper" means different things to different folks, but I think it's 2cm or less of spacer and a standard 73-84 degree stem. The picture I posted is a 51cm frame with a 73cm saddle height, a 110mm x 84 degree Ritchey 4-axis stem and only 5mm of spacer under the stem. It produces a drop in the 9-10cm range.

If you get a larger 53cm, you'd have to use a 73 degree (horizontal) stem to get that much drop, or a different headset with a shorter 5-6mm top section instead of the 15mm one provided by LOOK.


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## C-40 (Feb 4, 2004)

*thanks...*



oneslowmofo said:


> Dave - that is a blingin' RED bike. What a beauty. :thumbsup:


I do get a lot of double takes from riders going the opposite direction. I've never seen one like it. I toned down the red with black bar tape.


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## sb37 (Jul 25, 2007)

I'm 183cm with 85cm inseam (relatively short legs, long torso). Curent saddle's a tad above 75cm. How would you size me, C-40?


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## 1speed_Mike (Feb 16, 2004)

Checkout https://www.xcontario.com/bikeCAD.html. You can input all of the bike specs (frame angles, tubing diameters, everything...) as well, your body specs (the dashed-line at 775mm represents my cycling inseam), to get a virtual bike. Very cool! So, I plugged in the Small and Medium numbers and here are my virtual 585s. You can alter pretty much everything, from stems lengths/rises, saddle setback, number of spacers, etc. It should give you a good idea of what different frame sizes will do. Have fun!

Small (51cm):









Medium (53cm):


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## C-40 (Feb 4, 2004)

*short legs..*



sb37 said:


> I'm 183cm with 85cm inseam (relatively short legs, long torso). Curent saddle's a tad above 75cm. How would you size me, C-40?


You've got some really short legs for 6' tall. When a rider has a really long torso, the frame size can depend on how the leg is proportioned. 

Most likely, the best option is to select the 55cm frame with the 56cm TT. 

More information on your current setup would be required to make a well-informed suggestion.


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## sb37 (Jul 25, 2007)

hey c-40. i went with the XL, actually, i was just interested in your recommendation as you seem to know your stuff, and usually recommend "smaller" frames. In the end, I felt cramped with the top tube of the 55/L and didn't want to have to run an ultra-long stem. still trying to dial it in though, so maybe i'll ask you some more questions.


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## sb37 (Jul 25, 2007)

by the way, which measurements would be helpful? I'd be interested in making sure I have the right crank and stem length, and determining if my spacer setup is correct (thinking i should drop stem height a little more).


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## C-40 (Feb 4, 2004)

*measurements...*

I would have picked the samller 55cm, so that could run a long stem. As long as a 130 was long enough and the HT was long enough (it's 33mm taller than mine), the smaller frame should have been OK. A comparison with your old bike would tell.

The said, you've only got 2cm more saddle height than I do, but 5cm more head tube length. With an 84 degree stem and only 5mm of spacer, you'll have a conservative 6cm drop from the saddle to the bars. If you want more than 6.5cm of drop, you'll need less stem angle. I'd have to know the TT length, the seat tube angle, the stem length and angle of your old bike to predict a stem length for the frame.


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## sb37 (Jul 25, 2007)

I think I'd like more drop, as much as 10cm if that could be possible, although my short legs make it hard. the stem i have on the 585 is 110m/84 degrees. If I switch to a 73 degree stem, how more drop will I get? thanks very much for your help. I'll look for the specs from my old bike, which was a Cannondale CAAD5 frame in size 56(c-c). It was a very similar geometry to the Look XL, although I'd like to get a slightly more aggressive ride than I had.


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## uscsig51 (May 7, 2006)

C-40, here is the opposite issue...184cm height and inseam is 88.90cm (relative long legs and short torso proportions).

I've been switching between a 100cm and 110cm stem to try and find the right balance on my XL frame. My saddle height is around 81cm and I'm currently using a 84* stem, however no matter what, I always get "tired/cramped" at the back of my neck. Saddle to handlebar is 54cm.

Any suggestions/solutions?


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## sb37 (Jul 25, 2007)

i could trade some of my torso for some of your legs and we could both have perfect proportions. C-40, any suggestions on how much torso i should give up? how do you feel about surgery? is this UCI-legal?


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## C-40 (Feb 4, 2004)

*drop..*

If you switch to a 73 degree stem, it will increase the drop by 2cm, so you should be able to get about 9cm. You can change the headset to one with a shorter top and just about get the 10cm want.

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=34&pid=452

http://www.canecreek.com/is-6.html

If you'd chosen the smaller frame, you could have used a 120mm stem not had that problem. That's why I alwasy ask about the amount of drop desired. The HT length can be as important as the TT length. The larger XL has 19mm more HT length, but a reach that's only about 8mm longer, due to the difference in the STA. You got a small amount of reach you didn't need and fouled up the stem setup.


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## sb37 (Jul 25, 2007)

the difference in reach is more than you think - the L has a 56cm sloping top tube, and the real 'virtual length' is 55cm. The XL is 57.5 without slope, so 2.5cm longer, and i'm still gonna end up running a 120mm stem (110 now, but probably will replace with the 120/73) to get desired reach. On a L, i'd have to run a 140mm+ stem to get proper reach, which goofs up the handling. This way, with the XL frame, I'll have 9-10cm of drop, which should be fine, and preferable to the 140mm stem. I'll have the right reach, and standover height isn't a problem. Thanks for doing the math for me - that's exactly what I needed to know.


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## 1speed_Mike (Feb 16, 2004)

sb37 said:


> the difference in reach is more than you think - the L has a 56cm sloping top tube, and the real 'virtual length' is 55cm. The XL is 57.5 without slope, so 2.5cm longer, and i'm still gonna end up running a 120mm stem (110 now, but probably will replace with the 120/73) to get desired reach. On a L, i'd have to run a 140mm+ stem to get proper reach, which goofs up the handling. This way, with the XL frame, I'll have 9-10cm of drop, which should be fine, and preferable to the 140mm stem. I'll have the right reach, and standover height isn't a problem. Thanks for doing the math for me - that's exactly what I needed to know.


Take 10 minutes and input the frames you are considering, as well as, the bike you have now to see how things are impacted by STA/HTA, etc, into http://www.xcontario.com/bikeCAD.html. There's no math involved and it gives you a real-time virtual image of what the differences are doing to reach, drop, etc. C-40 is bang-on, but this will give YOU the power to get the info yourself.


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## sb37 (Jul 25, 2007)

sorry, correction on my part. i think the difference in reach is a little under 2cm, rather than the 2.5 i said before.


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## C-40 (Feb 4, 2004)

*the difference...*



sb37 said:


> sorry, correction on my part. i think the difference in reach is a little under 2cm, rather than the 2.5 i said before.


The difference in the horizontal or "virtual" TT lengths, the B dimension, is 15mm (575-560).

The difference in the reach, which determines the stem length required, is another 7mm less, due to the slack seat tube angle. The total differene is about 8mm, just like I said the first time. The smaller frame only need one size longer stem to fit the same, once the saddle is in the same position relative to the BB.

It's common when looking at different frame size to either ignore change in fit caused by the STA, or to get it backwards, thinking that a slack STA makes the reach longer. The only problem the steeper STA on the smaller frame might create is the need for a seatpost with 10mm more setback.


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