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Curious about what size you think I(27 posts)

Curious about what size you think IChronofiend
Jan 4, 2002 10:06 PM
need. I won't say what size frame I ride now as to not skew results. I am 5'11" with a 32.5 inch inseam (cycle shorts and book wedged in measurement).
What range of sizes measured c-t should I be looking at for my next road bike?
What is the smallest frame you think I could ride comfortably with a t-t in the 55.5cm range?
What is the cut off for an absolute too large a frame for me?
re: Curious about what size you think Igtx
Jan 4, 2002 11:39 PM
I'm 5' 11" with about a 34" inseam and comfortably ride bikes 56 - 58 c-c with 73 - 72.5 STAs and tts from 56 - 57.3 w/11cm stems. I'd imagine you'd want a longer top tube than me, but who knows. I'd say frames in the 56 - 58 c-t range.
no standover clearance....C-40
Jan 5, 2002 5:49 AM
With a 32.5 inch inseam, he could barely standover a 56cm, which typically has a standover height around 32 inches. A 58 would be out of the question.
no standover clearance....gtx
Jan 5, 2002 10:12 AM
obviously depends on bb height and STA. I said for him 56 - 58 c-t. My 58 c-c Merckx (low bb and slack STA) has a standover clearance of about 32.25 inches, which is about the same as the standover on the 56 c-t Soulcraft Groundskeeper cross bike that I want right now, which obviously has a much higher bb. I'm sure he'd have plenty of standover on a 56 c-c Merckx (roughly 57.5 c-t). You are wearing shoes when you ride, and it's not such a danger issues like it is with mtbs.

Anyway, I'm wondering if this is the same guy who posted last week with very simular dimensions. I'd be worried that he's going to end up with a bike that's too small (like so many people I see out riding). Maybe a compact frame would be the way to go.
long torso....C-40
Jan 5, 2002 6:03 AM
You have a long torso. Your optimum vertical size would be a 55cm (c-t), the same as I ride. You could (barely)standover a 56cm, if you are looking at brands that only offer even sizes.

You're also 4 inches taller than me. A 55.5cm top tube works fine for me (with a 73 STA), but would be shorter than you should use, unless you like a 130-140mm stem length. Despite what people say, their are no stock frames that have the top tube length that you need (57cm +) with the small vertical size that you require. One of the new compact frame designs might provide a solution for your problem. The sloping top tube could provide the additional standover clearance you need, in a larger frame size, that will have the appropriate top tube length. The head tube might be a little long, but you wouldn't need any steering tube spacers.
c-40, how about this...koala
Jan 5, 2002 6:19 AM
Since you seem to conceptualize fit so well; Seven says (I spoke to them directly) that the sloping top tube helps eliminate toe overlap but I cant see how. Can you explain?
Jan 5, 2002 8:19 AM
If they are talking about a "stock" sloping TT frame. The sloping design would permit a larger frame (with a longer top tube tube) to be used. The longer top tube will lengthen the wheelbase and reduce toe overlap. A shorter stem will also be required.

The other method of reducing toe overlap would be to use less head tube angle, combined with more fork offset.

Seven should be able to build any top tube length desired, reagardless of whether it's a horizontal or sloping TT. In this case, it does not make sense. The same fit can be achieved with either design.
How about aChronofiend
Jan 5, 2002 3:24 PM
55cm (c-t) frame with a 55.5cm tt and a 120mm stem?
I think this could be ideal or is a 56cm a better fit?
Is it apples and oranges at this point if we are only talking 1/2 cm in that I can tweak that out with a stem adjustment etc?
not understanding...C-40
Jan 5, 2002 4:47 PM
As I stated earlier, the 55cm should be a perfect fit vertically, it's the 55.5cm top tube that is shorter than optimum for someone that's 5'-11". I would be surprised if a 120 stem was long enough. I'm four inches shorter and use a 110mm on this size frame. I would expect a 130mm or longer might be required. That's why I mentioned a 57cm or longer top tube, which would allow you to use a mid-length stem.

If you are looking at a brand of frame that is available in 1cm increments, the only difference in the fit between the 55 and 56 will by 1cm less standover clearance, 1cm longer head tube, and probably .5cm longer top tube.

Hopefully you are aware that there are variations in seat tube angle, top tube length and head tube length among the many different brands of frames available in a 55cm size. One brand's 55 may fit more like another brand's 56. Got anything specific in mind?
How about what the experts think?Kerry Irons
Jan 5, 2002 4:53 PM
Try one of these sizing calculators, and ignore the comments about what my uncle's cousin's sister rides, since she's about the same size as you.
I thank you guys, but c40 is rightChronofiend
Jan 5, 2002 6:49 PM
a 55cm c-t is right on for my inseam, but a 57cm top tube is way too long. I have a 56.5 cm tt now with a 120mm stem and the reach is long. That is why I think I can get away with a 55.5cm tt and stay with the 120mm stem. And this is a 55cm so the standover will be perfect.
I am interested in the Vortex by the way and LS tends to have longish tt. I can go custom with the Vortex, but if I did, I would probably go with the same geometry as the Palmares they made last year in a 56cm. All this would give me is a .5cm longer tt than the 55cm stock frame. Is that a big deal? I assume that can be tweaked by stem length alone.
I think most people are on too large a frame rather than to small. I want the smallest frame I can ride in comfort as I want a more aggressive bike that is stiffer. A custom Vortex with a 55cm c-t with a 56 tt would be ideal, but is that .5cm worth the hassle of customization??
You guys (gals) are knowledgeable but there is a great deal of variation in theory here and it gets confusing.
I thank you guys, but c40 is rightgtx
Jan 5, 2002 7:08 PM
yeah, it is confusing. I'd recommend a long test ride on a LS 55 w/12 cm stem before you buy, though. Good luck and enjoy!
better to compare the "new" to what you have....C-40
Jan 6, 2002 7:25 AM
Remember that you can't directly compare the TT length of a new frame to your old one, unless the seat tube angles are the same. A one degree change in STA will change the effective TT length by 1.2cm.

If you currently have a 56.5cm TT, how do figure that a 57cm would be "way too long"? With a 110mm stem, the reach would be shorter than you have now (assuming the STA is the same on both frames).

You've made this process way too hard. If you had posted the STA, TT length and head tube length of you current ride, it would be easy to predict the changes needed to duplicate your current fit on a new 55cm Litespeed.
C40 Thanks for inputChronofiend
Jan 6, 2002 9:21 AM
My current bike is a 73 STA, a 56.5TT and a 14.0 head tube length.
The Vortex in a 55cm frame only differs in the Head Tube Angle as it is 73.5 and the HT length is 14.3 as it has the new integrated headset design. So it seem the difference is only the .5 in the HTA.
I agree that a 75cm TT wouldn't be out of the question, but such a TT lenght would put me on an overall entirely too big a frame as my shorter legs need more standover.
How will that .5 difference in HTA affect bike fit difference between what I have now and the will the HT length be ok as they are almost identical?
Right now my 56.5 TT with a 120mm stem gives me a very long reach to the bars and my arms are locked when on hoods.
And that one test of handlebar obscuring front hub doesn't pertain to my current setup as my handlebars are easily more forward when I am in this position.
C40 Thanks for inputgtx
Jan 6, 2002 10:06 AM
keep in mind, too, that if Lance Armstrong, who is also 5' 11", used your approach to bike sizing, he'd be riding the 56 OCLV, but he's riding the 58. I recently rode my friend's Serotta 55 c-c w/55.5 TT and though it felt ok in terms of cockpit with the 12cm stem, it just felt WAY too small, which was especially noticeable on fast descents. Though you would have only about 1/2" standover, I still think the 57 LS would feel a lot better. Maybe consider the LS Siena in size Large--same at the other LS 57s but with a sloping top tube. Anyway, that's it for me. Over and out.
Jan 6, 2002 10:09 AM
actually, using your method Lance might even be on the OCLV 54 (74STA and 54.5tt)--same effective cockpit as LS size 55 (73STA and 55.5tt). LOL!
totally off base!!!C-40
Jan 6, 2002 5:08 PM
How did you come to such a weird conclusion about frame sizing?? Without any knowledge of inseam, I'd never make any predictions about frame size based on height alone. Height has nothing to do with frame size, if you consider that the "size" is strictly a vertical dimension relevant only to inseam. Frame size says nothing about top tube length.

Knowing that chronofiend has a short 32.5" inseam, limits the vertical size that he can safely straddle to a maximum of 56cm (c-t). With his 5'-11" height, he obviously has a long torso. The stock frames that he can straddle will generally have TT lengths that are on the short side, requiring a 120 to 140 stem, unless he also has long femurs that require the saddle to be pushed way back. This would reduce the stem length required.

As far as the frame size that Lance rides, it's obviously 2cm smaller than most people would select. He's got a lot of post showing and uses a lot of head tube spacers. I would recommend a frame that was 2cm larger, whatever size it might be. A 2cm larger Trek would have a 1cm longer top tube. A 10mm shorter stem and very few, if any, head tube spacers would be used.

This is the type of setup that I ride. The top of my saddle is 17cm above the top tube. I use no head tube spacers to yield a 10cm bar to saddle height difference, with a standard 80 degree, 110mm stem. I also have 3.5cm of barefoot standover clearance. Nearly perfect fit, IMO. Take a look a the latest issue of Cycle Sport magazine. My C-40 is setup very similar to Eric Dekker's.
totally off base!!!gtx
Jan 6, 2002 6:02 PM
all I can say is that if chronofiend (who I think may have posted under a few names recently) is 5' 11" with a 32.5 inseam and thinks he's gonna get a good fit on a bike with a 55.5 tt and 73 STA, he a) has the weirdest proportions I've ever heard of b) has major flexibility issues c) doesn't ride much d) is smoking crack or e) all of the above. And honestly, I don't care.
totally off base!!!Chronofiend
Jan 6, 2002 6:12 PM
Why are you taking your frustration out on me??? Just because someone else disagrees with you, and to boot you displace onto me. Geeze!!!!!!
I can see that fit is a topic that no one can nail down with any certainty and I wouldn't expect that anyone can. It is not a true science as their is subjectivity involved in what one may think is a perfect fit.
Man, are you the kinda guy that gets yell at by your boss and goes home and kicks the dog?
totally off base!!!gtx
Jan 6, 2002 7:44 PM
I apologize if you think that I was leveling any kind of criticism toward you--not what I intended. I was trying to help with my earlier comments. I'm sorry if I failed to do so. Good luck.
can't understand english???C-40
Jan 6, 2002 6:53 PM
I've said numerous times that a 55.5cm TT is probably too short, requiring an excessively long stem. What the heck have you been reading?

You obviously don't understand the first thing about fitting a frame, or the differences between the various terms like "size" compared to top tube length. They are entirely different.
can't understand english???Chronofiend
Jan 6, 2002 7:32 PM
Man O Man what is up with you guys??? I do understand and agree that the 55cm LS fits me vertically but the 55.5cm tt is pushing the short end of a decent fit.
My current ride is the same geometry as the Vortex but has a 1cm longer tt. Is that 1cm an insurmountable obstacle??? I feel a 56cm c-t frame with a 56cm tt would be a compromise for me as my standover would be better and the tt closer to ideal.
My current ride is similar in set up to your ride with very little standover in barefeet and 16cm from tt to top of saddle. I have 41/2 inches of seatpost to the rails showing. The drop to the bars from the saddle is about 3 1/2 inches as well. It is very comfortable and with shoes, the standover is better.
If I measure my inseam like they say with a book rammed in their, I can get a measure of 32.5- 33inches. It is not an exact science and I am not sure what is a realistic amount of pressure to use to take measurement.
Is that 1cm difference in tt to what I have now that big of a deal? I understand english but you have given me a lot of information, but have not answered that question. No need to get pissy though. I can understand sometimes why Mountain bikers call roadies pricks. Too anal-retentive.
can't understand english???gtx
Jan 6, 2002 8:00 PM
as I mentioned in other post to a similar inquiry, I'd look at the Hampsten bikes

gtx "LS Vortex question" 1/2/02 4:04pm
reply was to gtx...C-40
Jan 7, 2002 4:22 AM
My "can't understand english" was to gtx. He didn't seem to grasp what was clearly sstated and went off on a tangent about sizing Lance Armstrong's bike.

The 1cm difference in TT length shouldn't be a big deal. You may need a 130 stem, but that won't hurt a thing. Check that knee to elbow clearance and make sure your current setup is long enough. Apparently you feel that it's plenty long now. If that's the case, the answer is simple, 1cm isn't a big change.
can't understand english???gtx
Jan 6, 2002 7:42 PM
"I've said numerous times that a 55.5cm TT is probably too short, requiring an excessively long stem."

I'm glad we agree. I'll leave it at that.
C40 actually, I thinkChronofiend
Jan 6, 2002 10:28 AM
the Vortex may even have a 73HTA as well. It is listed on their current website as a 73.5 but past 2 years catalog has it as 73HTA. I don't think they would have changed it so it is probably a typo.
So the geometry is the same as my current ride but with a 1cm shorter tt and of course the 2cm standover difference which I could benefit from. I know I am 5'11", but can the length of my neck and size of my head (don't laugh) throw my measurements out of wack?
I mean, I have short legs, but my torso may not be that much out of proportion as it may seem if I can gain an inch or so in height by my large looming noggin. I never thought of my torso as being particularly long and that is why on my current 56.5tt with a 120mm stem is too long for me. That is why the 1cm less of tt doesn't seem unrealistic to me with same stem.
Possibly a 55cm c-t with a 56.5 tt would be ideal as I can go with a 110 stem but a 120mm stem isn't pushing the envelope at all is it? I was told a 130mm stem is ok too but that is maximum.
stem length, head tube length....C-40
Jan 6, 2002 2:49 PM
If you are comparing the head tube length of a frame that uses a conventional threadless headset to one that uses one of the intergrated designs, don't forget to include the difference in the stack height of the headsets. The conventional headset is about 3cm longer than the integrated design. The head tube length on the 55cm Litespeed shouldn't be a problem though. Your saddle height will be no higher than mine. With 4 inches of additional height, you should have plenty of arm length to avoid using many head tube spacers.

Your comment on stem length doesn't make a lot of sense to me. The arms can always be bent just by leaning over a bit more, regardless of how long your stem is. No one should be riding with their arms locked out on the hoods. If you can't hold a lower position you may lack abdominal and back strength.

One way to evaluate stem length is to check for knee to elbow clearance when riding in the drops. As long as your knees and elbows don't hit when you're back is flat and level, it's long enough. A longer stem doesn't have any advantage. If you want a lower position when riding on the hoods, stem height, not length, should be adjusted.