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PLEASE help with my fit all you experts....I'm freaking out!(16 posts)

PLEASE help with my fit all you experts....I'm freaking out!Zonic Man
Aug 19, 2003 4:12 PM
I'm scared a 51cm bike is just too small for me. With all the talk about "standover" not being that important, i'm worried i'm getting too small of a frame built for me.

New Bike Custom Specs:

Seat tube length-51cm
tt length-53cm
head tube length-111.7mm
head tube angle-72
seat tube angle-73
tt angle-0
head tube above tt-17.7mm
Fork offset 5 cm
length 372mm

wheelbase 97.5cm
standover 77cm
trail-56.9mm
chainstay length-410
Front center 578.4

This matches up with the following numbers that I use:

Saddle Height: 73.6cm
Saddle Setback: 6.6 cm
Saddle to stem drop: 5.5cm
Saddle to handlebar 53.5 cm

I was fitted by Dr. Massimo Testa and a PhD in excercise physiology (and a Cat 2 racer and USCF elite coach) at the UC Davis Sports performance clinic.

http://www.stevelarsensports.com/training/pages/m_testa.html

This was further backed up by Myke Berna at Wheelworks in Davis.

Fitting was done by static size measurements and on a Serotta Fit Cycle in a 1 hour workout, measuring EKG and VO2 outputs, including wattage and power transfers at intervals via Power Cranks.

Fit was constantly tweaked on the fit cycle.

Plus, I supplied the designer of IF with all that info, as well as my static measurements, and he came up with the numbers.

The weird thing is, I'm 5'9", with a cycling inseam of 31.5"/81cm.

Help me out, I'm freaking out. I'm probably just listening to too many other people!
FWIW......coonass
Aug 19, 2003 5:01 PM
I'm only 5'-8", 30" inseam and the first bike I purchased (ca 1980) was by the '2-finger' method and for years, I never adjusted to the 52cm frame (s/t and t/t too short). In 1998 I got measured by the Bio-Racer system and purchased 2 custom Waterford 2200s; 55cm S/t and 55.5tt, etc.....absolutely beautiful fit; couldn't have been better if I were to have been at the shop and they measured me every day....I may not understand your computer-generated stats, but is the saddle height of 73cm compute to being 22cm above your seat-lug?? Go to a shop and ask to see a similar sized frame and see how it fits....
I think you'll be fine...airwreck
Aug 19, 2003 6:40 PM
it's such a learning experience, but maybe you should be applying your mtb fit to the initial setup to ease the transition. Paying attention to achieve a similar saddle to controls position and bar height. Also make sure your seat fore and aft puts you over the pedals the same as your mtb.

It was interesting how after many years I compared my cockpit specs and found they were remarkably similar without a conscious effort to produce that result. Needless to say my stem length had shrunk and my bar height had risen since my young foolish days.

Anyway, factors such as where you like to be on the saddle, where your hands are on the bars the majority of the time will become clearer and tweaking will take place.

And if that don't work out....sounds like the IF is a good fit for me;)
Very strange...and a rant, since you asked...peter1
Aug 19, 2003 7:02 PM
I'm 5'11" and ride a 56 cm IF; could have fit on a 57 cm too, but I'm partial to more standover clearance, a hangover from my mtb days.

I saw your earlier post but didn't read it too closely. Frankly, IMNSHO, 51 cm for someone 5'9" seems way too small unless you've got freakishly short arms and legs. Did you try a standard IF size first? They go up in 1 cm increments.

Now, my rant. I think that unless you're REALLY tuned in to what you ride (that includes pro racers) or have some sort of body part that's on the edge of the bell curve, custom doesn't make a lot of sense.

A lot of people are happy with custom bikes, but I see a lot posts on this board from people who ordered a thoroughbread and received a camel (horse designed by committee...). I rode with a fellow this summer who had a custom Seven Ti, probably cost him nearly $6K, and he wasn't happy with the standover height, feeling it was too tall even though he'd been "professionally" fitted.

Bike geometry is something that evolved over the years, and when you order custom, you're reinventing the wheel every time. There are at least a dozen critical measurements, and as soon as you futz with one, the others have to change, too.

The whole custom thing sort of reminds me of my surfing days. I always wanted a custom board, so I saved up the scrach and went to a famous shaper in Santa Cruz. I went to the great man's shaping room and told him the exact dimensions that I wanted. Six weeks later, I got my board, and it was the exact dimensions that HE wanted.

Needless to say, it worked perfectly. Not sure what the moral is...

End of rant. Have you actually ordered the bike? Have they started on it yet?
custom boards...airwreck
Aug 19, 2003 7:28 PM
are a different story. I'v never had a custom bike but have had scores of custom boards. And I never tell my shaper what I want, he makes all the calls. Helps having a half dozen different boards, and replacing them yearly. My bikes seem to last longer, although I do have several.
numbers don't add up...C-40
Aug 19, 2003 7:10 PM
A saddle height of 73.6cm with a cycling inseam of only 81cm can't be correct.

My inseam is 2cm longer (but I'm 2.5 inches shorter) and my saddle height is 2cm lower. That's too big a discrepancy.

If your saddle height is 2cm higher than mine, you're going to need a lot of steering tube spacers or a high rise stem to achieve a saddle to bar height difference of only 5.5cm with such a short head tube. If you buy a custom, you should get the proper head tube length to eliminate most or all steering tube spacers.

The head tube on my Fondriest is almost identical in length. With a 2cm lower saddle, I have a 9cm drop to the bars with a 5mm spacer and 84 degree stem. You would need either need 6cm of spacer or a 100 degree stem angle with 3cm of spacer to get the bars up that high. Either one would look stupid.

You don't mention the intended stem length, but a 53cm top tube is pretty short for a guy who's 5'-9" with a long torso. My Fondriest has a 53cm TT and I use a 110 stem. I would expect that you will require a 120 or 130. Is that what you want?

After looking at the numbers, why buy a custom frame? There's nothing custom in the dimensions that I can see. A stock Fondriest 51cm would fit the same.
Crap, I'm an idiot.Zonic Man
Aug 19, 2003 8:39 PM
My saddle height is 72.0 (I used to have it before the fit at 73.6, was reading the wrong numbers) and measuring again, I'm a 32in inseam as well.

I did the cursory "wrench science" fitting deal, and they recommend a 63 cm "total reach"....right there with what IF was building for me.

FWIW, I'm running a 110 84 degree stem as well.

Oh yeah, IF does custom at no charge too. I'm going semi-compact as well (the reason for a "51") duh.

And if it means anything, I told them I wanted a pretty racey crit type bike. I talked to another buddy who owns a bike company (another steel bike company, but it'd take about a year to get one of his...blah!) and he said they're shorter in the TT typically than an all day Euro-style bike....

Thanks a ton for the information, seriously!
just wondering....divve
Aug 19, 2003 10:05 PM
You say it's going to be a semi-compact. I assume this means the top tube is slightly sloping, although the specs state the tt angle to be 0 degrees? The 72 deg. head tube angle also seems rather slack for a crit bike or even a regular race level road bike for that matter. What's the motivation behind this? Thanks.
I dunno.Zonic Man
Aug 19, 2003 10:44 PM
I looked at that with the IF guy. I looked at another IF crown jewel Ti today that was very similar in spec, and damned if the TT wasn't sloped just a LITTLE bit. That's where I got that figure from. As for the other measurements, I just cut and pasted.

As for the HT angle, man, I know, eh? Wass up with that? I really don't know what their theory is, I just hope it all works!
still need more head tube...C-40
Aug 20, 2003 5:06 AM
Your numbers make more sense now. The type of pedal/shoe combo you choose can make up to 1cm difference in saddle height. I use speedplay/sidi for one of the lowest stack heights.

Two things still don't seem right to me. The 110mm head tube would have to be a lot longer if you really intend to keep the bars 5.5cm below the saddle. For reference, try measuring from the floor to the top of the bars. Mine are about 87cm above the floor on my Fondriest. The saddle is about 96cm above the floor, for a 9cm difference. The head tube is 105mm with a 3cm headset, a .5cm spacer and an 84 degree Ritchey WCS stem. To get the bars to the height that you've listed, the bars would be around 91cm above the floor. 4cm is a huge amount to make up. Flipping an 84 degree stem to 96 will only gain about 2cm. Don't make the mistake of buying a "custom" and end up with a high rise stem and 2cm of spacer.

The 72 degree head tube angle is definitely not criterium geometry. A 73 would be more like it, with 45mm of rake. I also wouldn't get 50mm of rake on the fork. Not many forks available with this much rake.
still need more head tube...pedalAZ
Aug 20, 2003 1:05 PM
I just went through a similar fitting and walked out with a bike spec that includes an allowance of 3.8 cm of steerer tube spacers above the headset. The reasonf or this is that I was assessed as having to little flexibility in my hamstrings and glutes for a racers style drop. This way, as I improve in my flexibility, I can just lower the stem and lose a spacer, without having to cut the custom frame.

I don't know if Zonic's got a similar background for his geometry, but that sure made sense to me.
OK...C-40
Aug 20, 2003 3:34 PM
If you're a beginner, it's likely that you will change your setup as you become more experienced. Beginners have no business buying custom frames that "might" fit properly some day in the future, IMO.

Keep in mind that as you remove spacers, you also increase the reach to the bars. After removing 3cm of spacer, the stem will need to be 1cm shorter to produce the same reach.
OK...so beginners shouldpedalAZ
Aug 20, 2003 4:18 PM
buy bikes that don't fit well, so they can experience the worst road biking has to offer? If I can afford it, why shouldn't I be getting a bike that fits? I may be a beginner on the road, but I am an experienced mountain biker and am getting advice from some pretty solid folks. At the suggestion ofthe bike builder, I went for a 100mm stem, so that I could shorten to 90 if and when I dropped the spacers - thanks for confirming that suggestion.
Don't freak...-JC-
Aug 20, 2003 8:08 AM
Yo man, what's up? I haven't seen you since Cool.

Anyway, I just went through a little of what you are going through now. I was riding an old Colnago I got cheap here on RBR. It is a really nice bike but I never felt totally comfortable on it. It always seemed a little small. I couple months ago I decided on a new bike so I got fit by Terry over at Shaw's in Santa Clara. Terry spent more than two hours with me measuring, watching me ride, measureing some more...

At the end he told me that the frame was fine but my bar didn't have enough reach and my cranks were too short. After going over the numbers from the fit, I bought a 54 C-C Coppi Foco (super nice BTW)to replace the 56 C-T colnago master light. If anything, this frame is a little smaller but with the proper cranks (same size stem) and bars, the bike fit perfectly.

I guess my point is that at some point you just have to give up on your intuition and trust the experts. That's why you went to them in the forst place, right?

Good luck with the new ride.

JC
Is this Foster?Zonic Man
Aug 20, 2003 8:24 AM
Sorry...who is this?
Didn't you see the initials?dzrider
Aug 20, 2003 11:27 AM
It's a crisis; you're walking together and leaving only one set of footprints.