Once more, trendy small frame size

Discussion in 'Cycling Equipment' started by rubencito30, Nov 26, 2006.

  1. catlike

    catlike New Member

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    How can i tel that frame fits me if i dont know seat tube (virtual) lenght. Inseam x 0.63= (virtual) seat tube lenght (c-c). I know it is approximate, but still it is better that to trust the salesmens opinion to what would fit me. It is hard to find out the virtual seat tube lengt for compact frames unless manufacturers doesnot show it (but most of them show). Is there a similar formula that shows the frame size according to persons measurements for top tube?
     


  2. artemidorus

    artemidorus New Member

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    Don't worry about formulae. Try all the sizes that look about right, and don't buy one that doesn't feel good over a good few minutes on the road or on a trainer. I'm not being facetious - there is no other way.
     
  3. oldbobcat

    oldbobcat Well-Known Member

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    This is what I did. Get a feel for your size range by trying bikes that generally fit you. I did this through 40 years of trial and error, but always ending up in the same place--seat tube around 60-61 cm c-t, top tube 57-57.75 cm c-c. The top tube length would be complemented with a quill stem in the 110-125 mm range.

    When shopping for a modern bike, I looked for a top tube in this range and then verified that I could get the seat and handlebars high enough safely. Since most 60s now have top tubes well in excess of 58 cm, that put me on a 58. Ask the salesperson to let you measure any frame that interests you.

    By the way, with todays fat and variable tube diameters, c-c measurement of seat tubes is virtually meaningless.

    Also, your position on the trainer will not necessarily match your position on the road. I found that when pushing air aside I automatically lower my upper body by bending the elbows more.
     
  4. catlike

    catlike New Member

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    If i only could try diferent frame sizes... In area i live in there is no choice of road bikes (contrary MTB bikes) in shops. There are usualy one bike for brand in one size (witch usualy isnt mine), each negoations about frame sizes ends with "we can order one for you, put the deposit in". Maybe i am spoiled, but if there is shop, i want to try diferent size frames, otherwise there always are online shops (lower price). What if frame dont fit me well? I can order one online with same success.
     
  5. oldbobcat

    oldbobcat Well-Known Member

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    Now I'm hearing you. Here's another starting point to getting a good fit. Competitivecyclist.com has a fit calculator that gives you three different kinds of fit--Competitive, Eddy, or French. Have a friend measure you as directed by the program and then select your fit. If you're a relative beginner I suggest the French fit, but if you're tall and/or lanky (like Eddy), try the Eddy.

    The program will give you a range of lengths for seat tube, top tube, crank, and stem, plus saddle setback. This thing works pretty damn well, although I found that for a short torso with long arms it helps to reduce top tube and stem lengths and make up some of the difference by lowering the stem.
     
  6. HUMP DIESEL

    HUMP DIESEL New Member

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    Alright guys I wanted to get back in on this topic, because I have some more info that some on here will say "I told you so." See my other post about what bikes I have raced this past season.

    Toward the end of the season, I was riding the 53 Bianchi, which basically a 50 the way they measure. I had a 130 mm stem, the seat post maxed, and still felt like I was fighting the bike. I even got to the point where I was so far over that I was causing acid reflux.

    Here is the deal...I got off that bike and grabbed my Dad's 853 steel Lemond. It needed some TLC, and since it is getting to be winter, he would not be riding it.

    The kicker is, this bike is a 55 c to c, 57 c to top, with a 56 to 56.5 top tube, depending on how you measure. It has a 120mm quill stem, so easy adjustment. My first forays were spent getting the seat height right, but even though it was not, I had a revelation...I am riding base right now, but some of the hills around here before would have my heart rate up, now I can still go up them at about the same speed and my heart rate is staying low...Bonus. I also found that when standing, the bike felt very stable, not that it was going to be twitchy, but like fluid. I could feel that I could put the power to the pedals without uneeded exageration.

    I have been on this bike now for three weeks. I have got the saddle back up to a height that I could not achieve on the smaller bikes. The saddle to bar drop is not near what it was, but I can ride in the drops now without kicking myself in the chest.

    So you say "HUMP, What are you trying to tell us?"

    Guys what I am trying to say is...."I stand corrected on my assumption." I do not think any fitter would have fit me on this bike, because if you take my height this bike is too big, I should be on a size smaller, but my body does not lie, this bike feels good, I am much more comfy, but I am also faster, even just riding base. My pedal stroke has significantly smoothed out, I could tell that on the trainer tonight, the hum was steady, not sporadic.

    Lance may have been onto more than just how to train and race. He knew he had to be on that bike for a long time, and he knew that it had to be comfortable.

    So now that I have said this, you guys can rag me all you want, but I know my next bike is going to be a bigger one that more matches the Lemond.

    For review of a different bike fit up, look at Rasmussens Colnago on cyclingnews.com. He is riding a bigger bike size.

    Cheers.
     
  7. alienator

    alienator Well-Known Member

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    Glad you found something that worked....but......it's best to ignore whatever a given manufacturer lists as frame size. The things you need to know are seat and head tube angles, top tube length (or virtual top tube length), and head tube length. These are the numbers that will tell you if a frame is in the ballpark for you or not.

    I'm to lazy to go back and read how this thread has developed, but go write down the dimensions I mentioned above and put them someplace you won't forget.
     
  8. BiggMakk

    BiggMakk New Member

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    Great comments. I enjoy that fact that you (H. Diesel) are so analytical about your riding.

    I had an interesting revelation myself about 4 weeks ago. My sit bones were killing me. Riding was a painful experience; I blamed the saddle. I went shopping for a new saddle at a high-end bike shop and the manager (a guy I've now known for a while but was still wary of the impending "upsell") suggested it may not be my saddle but my fitting. Reluctantly I brought my bike in and he put it on a tainer.

    Apparently I did not need the set-back seat stem I was riding. He replaced my old stem with a Thompson sans the set-back and proceeded to lower my seat. Voila! Amazing difference. I'm telling this long-winded description to say all of a sudden my 54cm frame is now a joy to ride. What I once considered too big is so comfortable. I love being in the drops. No butt aches, no foot aches, no hand aches. I don't have a trendy seat-to-bar drop but who cares. I'm still damn aero when I ride because I'm so comfortable.

    Lesson learned: Comfort trumps trendy.
     
  9. oldbobcat

    oldbobcat Well-Known Member

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    Beg to differ. Merckx rode the drops when he needed to reduce his wind resistance, which could have been considerable in consideration of his size relative to the rest of the peloton of that time. When climbing he used the hoods and did not use the tops as much as many of today's riders do.

    vintagevelos.com has a photo of his 1973 Giro de Italia De Rosa. The site says its 58.5cm c-c (60cm c-t), with a 57cm top tube (short by today's standards), with considerably more than a fistful of seat post showing. The seat tube length is confirmed by other sources and the top tube is certainly plausible given Merckx's lanky build and the growing Italian fashion for shorter top tubes.

    My point is that Merckx was already lowering his position beyond what was then standard, most likely to adapt his height and build to a more nimble frame and reduce his frontal area. A more traditional fitting would have put him on a frame 1-2cm larger with a shorter stem. For a reference, check photos of Coppi, also tall and lanky, on his 59cm c-c Bianchis.

    By the early 80s Cyril Guimard had his entire Renault-Elf squad using his adaptation of this position. For contrast check out photos of Sean Kelly (an old school anachronism), especially when he's riding next to guys like Phil Anderson and Steven Roche (definitely new school).

    LeMond and Armstrong both used their adaptations of what Merckx started. They used longer top tubes because their skeletal proportions are more average, but their positions were definitely more conservative than today's norm.
     
  10. 531Aussie

    531Aussie Well-Known Member

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    I've tried it 3 times (smaller frames with longer stems) and I didn't like it. In fact, I've just pulled one of the bike to bits today. I've had two 56s and a 56.5, all with 140mm stems.

    What I REALLY didn't like was mashing off the saddle; it felt like ALL my weight was way over the front wheel, and the forks and front wheel seemed to flex like crap. I improved it a bit with stiffer forks, but I loved getting back on my 58s. The steering also felt a bit weird off the saddle

    I dunno how the pros do it. Maybe they have better techniques and don't weigh 85kg :)
     
  11. HUMP DIESEL

    HUMP DIESEL New Member

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    oldbobcat, thanks for that information. I will look at that. What is the deal with most frames having the top tube longer than the seat-tube? Sometimes it would seem best to have a taller seat-tube, but have a shorter top tube.

    Anyway, I was feeling the same way on the smaller frames, I had times when trying to sprint that the back tire would hop and not get traction, and then when climbing, I felt the same like the bike was twitchy. I accomodated it mentally, but I really do not want to have to think about that when I am racing.

    I feel the bigger frame is working for me, now I have to make sure that I get all the dims written down so that I can transfer the measurements.

    I to went back to riding a no-setback seatpost, and that took care of the same problems with saddle comfort, and my feet, go figure.

    HUMP
     
  12. scirocco

    scirocco New Member

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    Small frame sizes are a necessity for those of us blessed (cursed) with long legs and short torsos. With modern bike geometry tending to long top tubes, we have to go down a size or two from what might be considered normal for our height. This is simply to avoid having to run 90mm or smaller stems (which do adversely affect handling, I don't care if anyone says different).

    The downside is that you are then left with having a stack of spacers under the bars (unless you want a time trial position!) But that's preferable to the short stems or extremely stretched out position you're forced into with larger frame sizes.
     
  13. Eden

    Eden New Member

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    I agree and disagree - I'm longer legs, shorter torso, especially arms too and I ride a smaller frame than most want to put me on. I'm also very small all over so even though I'm on a 44cm frame I have to have an 80mm stem on it and it handles just fine - keep in mind that it is proportional to the frame though. I would actually prefer a little *more* drop, but you just can't get it on a frame as small as mine.

    The thing is you have to forget about everything else and find something that fits YOU. If that means a smaller frame than typical good, if it means a bigger one good too. As long as it fits you properly, you can be comfortable and efficient on it then all is well. As far as the pros go, I'm sure fads come and go, but still few of them are going to be willing to sacrifice speed and power for trendiness, so what ever they are doing it must be working or they won't do it for very long.
     
  14. oldbobcat

    oldbobcat Well-Known Member

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    Of course, a trendy position didn't seem to slow Alberto Contador. On the other hand, it looks as though he could get a little more oxygen into his lungs if he came up a centimeter or so.
    http://images27.fotki.com/v966/photos/1/108147/5118232/Tourst20Sirotti003-vi.jpg

    For reference, here's the cannibal on the tops, looking quite aero except for the elbows:
    http://www.france-cyclisme.com/nicolas/merckx75.jpg

    And here he is on the hoods:
    http://www.richardpettinger.com/cycling/eddy_merckx/merckx.jpg

    And here's Kelly catching wind next to a sleeker Stephen Roche:
    http://www.longscycle.com/images/signs kelly roche 3_small.jpg

    I should talk, too. After a professional fitting that had me flipping my stem, I'm back to my old ways, somewhere between trendy and Eddy. With the higher handlebar I was always on the drops trying to get out of the wind and relieve the pressure on my ass.
     
  15. zaku

    zaku New Member

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    i often see huge guys with a 52cm (or even 49cm since the guy looks huge compare to its bike). it's weird to see the seatpost fully extended specially on a road bike :rolleyes:
     
  16. alienator

    alienator Well-Known Member

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    Soooooooo.......what if the frame fits them and is comfortable for them?
     
  17. zaku

    zaku New Member

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    who knows how they feel. might or might not be comfortable.
    i'm just saying it's looks weird to me so it gets my vote as a "fashion"

    and.. otherwise why would there be so many standard sizes on many things that is a "recommended" and designed for the specific user fit? not only for bikes but for example shoes, helmets, clothes, etc.
    the bike factory could always had designed a single sized frame (let's say only size small since it's the fashion these days) and not to care about the rider's comfort and they would have saved much more money in the building process.

    in "general"
    a badly fitted bike will cause muscle pain, injuries, etc in the long run.
    same as a badly fitted helmet might cause injuries or not efficient as designed or a badly fitted shoes might not be comfortable or decrease its designed performance too.

    my 0.02 cents
     
  18. alienator

    alienator Well-Known Member

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    Well, there you go. My view is that I don't know what fit needs they have, what skeletal or other medical conditions might exist, or what feels good to them, so I don't even consider how they're fit. I tend to worry about only myself on my bike and how my bike and I work together. I tend to believe it's a bit presumptuous of me to assume that anyone else is falling prey to fashion.

    As for the effects of bad bike fits......no kidding? Really? They can cause pain and injury? Sarcasm aside, those possibilities are obvious. What is not obvious is, when viewed from a distance, whether or not someone is necessarily fit correctly on their bike.
     
  19. HUMP DIESEL

    HUMP DIESEL New Member

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  20. oldbobcat

    oldbobcat Well-Known Member

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    I'm built lanky, too. When I started racing in the 70s my bike setup used to confound everyone who tried to coach me, including Mr. Fit Kit himself, Bill Farrell. It turned out my proportions and weight (way back when) were very close to Merckx's, and I would do best to pattern my setup after his.
     
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