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The all important fit!(28 posts)

The all important fit!elrey
Jun 14, 2002 8:57 AM
I posted this on Bicycling.Com, but I wondered what your thoughts are.

I have been looking at and trying out some bikes. My plans are to buy one by the end of summer. So much is made about fit, so I have some questions. I tried a Lemond Zurich and was properly fitted. I am about 5'11" and have a 33" inseame(if any of that makes a difference). The salesman selected a 53cm bike. The salesman then put me on a trainer to make final adjustments. When all the proper adjustment were made, the saddle was pushed as far back as it could go and I had an 80mm stem. The salesman said I had a large femur. I also feel I have a short torso. So, I have a few questions. Is having the front of your knee in a verticle plane with pedal spindle all that important? Am I screwed as far as finding a good fit? Is the Zurich a bad bike for me? Finally, since the sadle, crank arm and stem can be adjusted, is the geometry of the bike all that important? By making these adjustments aren't you changing the ride geometry? Any recomendations or opinions are greatly appreciated.
re: The all important fit!Jekyll
Jun 14, 2002 9:05 AM
Sounds like you may want to try something with a bit shorter top tube. Lemonds are known for being longish in the top tube, something more square (more euro geometry) should feel a little better. Something with a shorter top tube and a little less seat tube angle (maybe more set back on the post as well) would probably fit better. The Zurich is a very nice bike but don't buy it if it does not feel and fit correctly.
re: The all important fit!elrey
Jun 14, 2002 9:12 AM
If i get a bike with a shorter top tube and a steeper seat tube angle, wouldn't that put my knee infront of the spindle? Is that a bad position to be in?
re: The all important fit!Jekyll
Jun 14, 2002 9:57 AM
that's why i said less seat tube angle - puts you back further on the bike. roughly for every degree of difference in seat tube angle your saddle will more around a cm fore or aft. knee over pedal is a good place to start saddle positioning. if your body type really does not fit standard sizing you may want to look into custom as well (not nearly as expensive as it would seem).
re: "Is having the front of your knee in a verticle plane with"cyclejim
Jun 14, 2002 9:09 AM
"Is having the front of your knee in a verticle plane with pedal spindle all that important? "

To my understanding, the Lemond geometry is DESIGNED to put your knee further back from the "normal" fit which would be to have your knee more or less over the center of the pedal spindle. So, this is totally normal for the Lemonds. I found it to feel a little wierd for me. If it doesn't feel right......
Sounds too small to meMcAndrus
Jun 14, 2002 9:31 AM
According to LeMond's website, a 53cm Zurich has a 54.5cm top tube. If I understand the geometry correctly, a LeMond's slacker seat tube angle might extend that top tube length, effectively, to a 55.5cm length.

Now, I'm 5'11" with a 35" inseam. I ride a Euro proportioned Giant (not compact) with a 61cm c-t seat tube and a 58.5cm top tube. These are roughly the same dimensions I've ridden for decades (don't ask how many).

With a 33" inseam you'd have a longer torso than I but even at that I think you should be on at least a 57cm Zurich.
Sounds too small to mekoala
Jun 14, 2002 9:53 AM
I have a 33 bike inseam and a short torso. I was fitted at 55 c-c or 57c-t seat and 54 top tube. I went custom and ended up with a 10 stem and 73 degree seat angle. 53 c-t will push the limits of seat tube and on a threadless setup will make a long drop to the bars if you are not a racer with lots of flexibility. It seems the short stem on a 53 (if that measurement is right) would indicate the lemond top tube will be too long for you in 57c-t.
Sounds too small to mekoala
Jun 14, 2002 9:56 AM
I have a 33 bike inseam and a short torso. I was fitted at 55 c-c or 57c-t seat and 54 top tube. I went custom and ended up with a 10 stem and 73 degree seat angle. 53 c-t will push the limits of seat post and on a threadless setup will make a long drop to the bars if you are not a racer with lots of flexibility. It seems the short stem on a 53 (if that measurement is right) would indicate the lemond top tube will be too long for you in 57c-t.
Sounds too small to meTrux
Jun 14, 2002 10:08 AM
I concur. I'm 5'10.5" and my Lemond dealer put me on a 57cm Zurich. I came off a Euro 56cm frame and now the new Zurich feels great.
Actually a slack toptube makes the effective toptube shorter.elviento
Jun 14, 2002 8:46 PM
This assuming you want to achieve the same riding position, such as knee above pedal, etc. This is because if you want to maintain the same effective seattube angle, you have to push your saddle to the front on a Lemond, by doing that, you shorten the seattube.
Actually a slack toptube makes the effective toptube shorter.unchained
Jun 15, 2002 6:37 AM
Unless you cannot achieve the correct knee position with the steeper bike (the saddle has been positioned all the way back and requires more setback).
53cm??B2
Jun 14, 2002 10:31 AM
I'm no expert on the subject, but it seems to me that your dimensions would suggest something in the 55cm to 57cm range (c-t). I would start there and see what tweaking needs to be done with one of those frames.

Bryan

BTW - If that's what the shop recommended: get a new shop. (Unless you have some really strange physical proportions)
That set up...jtolleson
Jun 14, 2002 10:43 AM
sounds all screwed up.

First he puts you on a 53cm, which sounds unusually small for your height. Then he slams your saddle all the way back to achieve KOPS, then he puts an 8 stem on it to address a reach issue (I know you mentioned an 8 stem when you posted this question at Bicycling.com).

He's a dork. Go to a different LBS.
I agreeklay
Jun 14, 2002 10:55 AM
...he's a dork with a 53 cm bike he's having trouble selling.

I'm 5'11 with a 33 cm inseam. I find I have been most comfortable on 56x56 marinoni (74 degree seat tube angle).

K
the sales guy sucks for oneishmael
Jun 14, 2002 10:46 AM
You said that there was an 80cm stem on the bike and they just compensated by putting the seat back, thats retarted. There really are now proven fit theories, knee over the pedal included, if its comfortable its good. Get the seat height right, a truly comfortable seat(may take awhile), and decide the distance between seat and bars that fits you best. When you have this number try buy a frame that allows you to have a stem thats no shorter than 10cm or longer than 12cm. The bars can be raised so I wouldnt worry to much about this seeming downside of a smaller frame. And different bars have different distances of up to a cm or two so keep that in the equation also. Maybe you should put the knee over the pedal at first to get an idea of how to judge where to start the measurments.
the sales guy sucks for oneelrey
Jun 14, 2002 10:51 AM
The bike didn't have an 80mm stem on it. I was all the way back on the saddle to get the front of my knee over the pedal spindle. After he did that i was too streched out and needed a 80mm stem to fit.
okishmael
Jun 14, 2002 10:59 AM
So you want a short top tube and lemonds are kinda long. If he did the knee over the spindle thing, which I guess is a good idea, and you ended up way back on the seat thats strange because lemond geometry should put you back there anyway without needing to move the seat back. If he did the knee over thing right, then ok, now take that out on the road with a good seat and see how it fits to make sure the distance from seat to grips is right (raise them or not after a bit) and then find something that allows you to get a stem thats between 10 (or maybe 9) and 12. You may be in a similar boat to me, I ride a lot and am sure of my fit and I like a really short top tube and long headtube. I looked for that and found that compact geometry frames fit best.
re: The all important fit!jmr986
Jun 14, 2002 11:03 AM
I'm 5'6" ( 30" bike inseam) and a 51 Zurich fit me best, the 53 was too long. Sounds like it might be too small for you.
Fit equation:MXL02
Jun 14, 2002 11:21 AM
as used by most shops for Frame size is:
inseam (cm)*.67= frame size c-t
or inseam (cm) * .65 = frame size c-c
so for your measurements, 33in * 2.54 cm/in *.67 = 56.15cm
This of course, is just a starting point and may go 1cm in either direction, but a 53 cm frame sounds way too small. As had been said in other posts, the bike shop person is either ignorant or dishonest...either way you need to go someplace else.
look for a different shoptarwheel
Jun 14, 2002 11:51 AM
This frame sounds way too small to me. I am the same height and inseam as you. A 53 LeMond would be way too small, and the 57 would probably be the best fit. LeMond's also have a longer than usual top tube, which is why I didn't get one. the Zurich is a good value for the money and a nice frame, but their geometry is not for everyone. If I were you, I would find a shop that does Serotta bike fittings (or something comparable) and get some solid recommendations on sizing. It might cost you $50-100, but it's money well spent -- and if you buy a bike from the shop that does the fitting, they probably won't charge for it.

BTW, my fitting showed that I needed a frame with a relatively short top tube -- exactly the opposite of Lemonds. I shopped around and found several different brands that fit the bill. A lot of Italian brands (Gios, Colnago, Tommasini, Viner, De Bernardi) have relatively short top tubes as well as Eddy Merckx (Belgium). Keep in mind that a bike with a more relaxed seat tube angle (72-73) fits "shorter" across the top than one with a steep angle (74). In other words, if you have two bikes with the same size top tube, the one with the more relaxed angle will fit shorter (about 1 cm per degree). Although Lemonds have a relaxed seat tube angle, their top tubes are so long that they still fit long.
smaller frame = steeper seat angle.rufus
Jun 14, 2002 12:45 PM
there was a thread below about how trek lemond's have gone away from the extremely laid back seat angles that greg's bikes always had, and are now sized quite similar to most other frame geometries.

if so, then a smaller frame usually has a steeper seat tube angle to properly position the smaller person over the pedal spindle. this is probably why the seat has to be slammed all the way back for your longer femur to achieve the correct position. a larger size would have a bit slacker seat angle, and probably fit you better.

my inseam is about 31.5 inches, and i'm on a 54 cm c-c, and really only have about an inch of standover. but my torso is a bit longer in relation to my shorter legs. i'd think you would need at least a 55-56 cm.
makes no sense....C-40
Jun 14, 2002 12:46 PM
Lemond geometry is currently no different than a dozens other brands. I don't think a single person responding to your question has noticed the 73.25 degree seat tube angle on the 53cm size. This is not the laid-back seat tube angle that Lemond claims to have. The top tube length is also on the short side at 54.5cm.

I suggest that you start by rechecking your inseam carefully. Then take a measurement from the floor to the center of your kneecap (in bare feet). This will help determine if you have an unusually long femur. My inseam is only 1cm less than yours (83cm) and the center of my kneecap is about 19.5 inches or 49.5cm above the floor. Compare your dimensions to mine (which produce a good fit on most 54-55cm frames with 73 to 74 seat tube angles).

Using a bike to check inseam is a good technique. If you block up the wheels (with boards or books) until you get saddle-like crotch pressure when standing over the bike (in bare feet & cycling shorts), the distance from the floor to the top of the top tube will be an accurate cycling inseam.

3-5cm is the common range for standover clearance. More clearance may create a problem with the handlebars being too low due to the short head tube length. Clearance could be reduced to as little as 2cm, but then you get a very low saddle, which produces a tourist or "Fred" look. As a quick reference, measure from the top tube to the top of the saddle, after the saddle is adjusted to the proper height. 16-20cm is a common range.

If your inseam measurement is correct, (almost 84cm), a 53-54cm frame measured center to center (like the Lemond ) or a 55-56cm frame measured center to top would be the appropriate size range. The 53cm Lemond would certainly be the smallest frame that you should consider. You also have a fairly long torso, if you are 5'-11" tall in bare feet.

Long torso riders usually have to ride the largest frame that they can straddle, to get enough top tube length, without resorting to a 130mm or longer stem. Moving the saddle back all the way will add about 2cm to the reach (or effective top tube length, which should help you to obtain a better fit. It doesn't make sense that you would need only an 80mm stem on a frame with a 54.5mm to tube, even with the additional 2cm of reach from moving the saddle back. I'm four inches shorter, with only 1cm less inseam. If I were on this bike with the saddle all the way back, I would probably still use a 90mm stem. I would expect that you should be able to use at least a 110. Perhaps the dealer set you up with a very short "beginners" reach. One functional check for adequate stem length is knee to elbow clearance, when riding in the drop section of the bars, with fingers in reach of the brake levers and the upper back in a horizontal position. Overlapping knees and elbows is not desirable.

If you do have long femurs that require a slack seat tube angle, try a LOOK or Merckx frame.
low saddle produces a tourist or "Fred" lookkcd
Jun 14, 2002 4:41 PM
A good observation. Awareness is important but I may have to change my name to Fred after looking closely at my bikes.
Low saddle not unheard of in pro peleton (4 smaller riders) nmunchained
Jun 14, 2002 6:51 PM
nm
makes no sense....koala
Jun 14, 2002 4:56 PM
When I plug in Lemonds own fit formula I get 54.5 c-c which is a long cry from 53 c-t. I same inseam and have over 5 inchwes of seatpost on a 55 c-c. Thoughts?
oh, come on.funknuggets
Jun 14, 2002 2:08 PM
The secret is to get the smaller frame... but get much longer cranks. That would give you the proper knee to spindle alignment that you are looking for... NOT. This guy is a quack. Move on.
Let me guess...Scot_Gore
Jun 14, 2002 4:21 PM
....there was only one Lemond remaining in inventory and whatta you know, it fits you. :-0

Could be wrong, but the secret of retail is inventory control and sometimes it's a dirty little secret.

Scot
You will be sorry if you buy this bike!crosscut
Jun 15, 2002 9:02 PM
It is very much too small for you. I got burned once by a bike shop
who sized me incorrectly. Later, the salesman admitted they wanted
to "move" the bike so he sold it to me. Don't get suckered.