Once more, trendy small frame size

I think "proper place" for a saddle is becoming more difficult to identify. I always was told to go with the plumb line of knee to pedal spindle, for instance, but I've seen time trialists/triathletes with their knees so far forward it would make your ears ring, and when one considers a person on a recumbent has their plumb line messed up, I really don't think it's a teribly important factor.

If you feel stretched out and your rails are as far forward as possible, you could always buy a different seat post-some are specially made to allow substantial forwarding of where the seat is in regards to the seat tube. http://www.profile-design.com/2006_product_pages/seat_post/fast_forward.html

 

This in a way verifies what I was saying.

You say that you feel stretched even with a shorter stem. I would say then that the small frame would have been a better fit. If you have the seat slid forward all the way, that tends to make me think the same thing, unless you are running a certain stem length for look and compensating with the saddle fore and aft, which I do not recommend. The first thing that you should set up is the engine, then you worry about the front end. I was doing the same thing on the bigger bike, but ended up getting chafed and my knees started to hurt, so I moved the seat back and down to get the engine right like I said, now, no chafing, and if you drop the plumb line, then I am behind the saddle. I do not feel that the plumb line from the knee works for everyone, it was something that was noticed over viewing many people that it kind of averaged out that this is where people end up. Like you said also, a recumbent throws that out the water.

I had to put a 100mm stem on the 54 to get it to feel right, and that is with moving my saddle back. Now I can get a frame that is two sizes smaller and get back to the longer stem that I prefer. Check out the latest pics from the Dauphine on cyclingnews, they show one T-mobile rider who is running a 140. I have a friend who runs 130 to 140 all the time.

I feel that my arguement still stands in the fact that shops are there to sell bikes, and they get in a number of bikes based on the average of what people are riding. That is why you will see more 54 and 56 size frame more than any other. Very rare is the shop that carries a large number of frame sizes, because it is just too expensive to sit on that kind of inventory.

If you can get on a size cycle, that would be a good way to experiment with the different set-ups before laying down the coin and find out you are not right.

HUMP

 

No no, my saddle is not all the way to the front, as a matter of fact there is plenty of adjustment towards the front. The saddle has been adjusted by the good old plumb line of knee to pedal spindle.

I could go one down on the sterm, as I am running a 110mm; and its "perfect" judging by the hands on the drops, and not being able to see the front hub "theory".

 

Well, in that case the bike probably fits you pretty well, you could have ridden the small, but if you are comforatble then the one you have should work.

Are you running spacers under your stem?

I am by no means a guru on this fit stuff, only a more than casual observer looking for answers.

There is something going on for so many people (Pros and the like) to able to ride the way they do and put out the power that they do, I know good climbing pros are putting out steady 400 watt measurements on climbs, and when I was racing the 52, I had a ten minute climb locally that I could do that on, so there is something to it.

HUMP

 

Well, yes on paper I am riding the bike that I am supposed to (sort of, because of the Giant S\M\L measurements might be a tricky thing); and its been configure\set to my body measurements\position. The thing is that riding on the brake hoods does not comes naturally when riding at slow speed\cadence; now if I am going "at it", riding the hoods is no problem at all.

BTW - I do have spacer under the sterm, but I still could raise it about a 1/4 of an inch.

Ohh and thanks for the info\help

 

Alright, On my bike which is a Cervelo Soloist aluminum. It is a 54cm, I am 5'-8"
I have the seat set at 7mm behind crank centerline, my handlebars are as low as they will go with the Thompson 100mm stem. I also have the saddle set at 73.5CM from center of crank to top of saddle along the seat tube. I will let you know how that feels after tommorow, because I am trying something new cleat wise...I moved my cleats a good way behind the pedal spindle via turning the base plate for the Speedplays backwards...an idea I got from cyclingnews.com...I went out a few minutes ago, and it immediately felt more comfortable under my feet.

I will keep you guys posted..

Cheers

HUMP

 

Do you realize that the rule of thumb of not being able to see the front hub is just a rule of thumb and arbitrary?

If you feel your saddle height and fore/aft is close to right you can certainly shorten your stem quite a bit. 100 is very normal, 90mm is perfectly OK, in fact some people use an 80. Of course you can get various rises or set them more or less horizontal.

You should find a shop that can set you up on a trainer with a fitting stem.

I found that a "basic" quick and dirty fitting helped me a lot. He verified that my saddle position was good, I thought so because I'd set it up with the normal rules of thumb and had tried 20-25 mile rides with various small adjustments. By the way, I think that saddle set up is entirely within a normal person's ability to set up and experiment with tweaks. Stems are a different story, unless you have access to a variety of different examples. Stems can't be adjusted like saddles

So, this basic fitting involved replacing my stem with an adjustable fitting stem and letting me ride on the trainer for a while between changes. This stem could be set to various lengths and rises. I found a definite sweet spot with a 90 mm with a slight rise (it's called a 7 or 8? degree rise). It also felt pretty good flipped to horizontal. The 100, less than 1/2 inch longer, defintely felt too stretched out. The 80, too cramped. As I get more flexible, I'm going to flip the 90mm down, and see how it feels.

On another issue of whether to go a little small, vs. a little large if between frame sizes. I agree that saddle height, fore and aft, and reach can be adjusted quite a bit and get pretty much the same dimensions for different frame sizes. On the other hand, assuming only a moderate rise in a stem, the saddle to bar drop is an important factor and is a reason to go "large" on the frame if a person doesn't want or tolerate a large drop.

 

Alright, another look at this. Go on cyclingnews.com and check out the write up on Iban Mayo's Scott Addict.

He is my height and weight....Take a look at this frame size.

I tell you, there is something to all this.

HUMP

 

This thread is several months old. I'm not sure how I came across it but based on what I'm currently experiencing, Hump Diesel is very correct. I'm no racer, but I do put in a lot of time on my bike. I'm 5'9" and currently ride a 54cm with a 110mm stem. Ironically I am more uncomfortable on the hoods than I am in the drops. And even on the drops I am only comfortable holding the lower end of the handle bars. My weight is much better supported by my bones and there's a lot less stress on my seat. I kept thinking I need a shorter stem (and in fact, I cannot really change the 110 b/c my knees are barely clearing the handle bar when I climb out of the saddle). Had I had a smaller frame, my weight would be better distributed and I would enjoy a lower profile that I find more comfortable. I would require a longer stem for knee clearance, but this would improve the handling.

 

It's all fashion, when I were a lad, Eddy Merkx was there with a slow cadence and a 'slow' frame. Everyone had big big front chain rings, and laid back geometry. Nowadays the fashion is for high cadence and compact geometry, so everyone has small front chain rings and tight casettes and frames where their knees nearly touch the bars...

Fashion, is everything with cycles. So sad.

 

i'd also say it's a fashion riding small frames or why would there be that "standard" frame size chart depending on your body measurements. There must be researches done to it to which frame size is a better choice for which kind of person.

sometimes it looks weird you see a huge rider with a small bike or a seatpost extended to the max. looks more likely riding a BMX instead of a road bike

 

Gee. The simple answer is to buy what works for you and ignore outside input. Fashion is only a factor to fashionistas and the uninformed.

As for chainring sizes, laid back frames and all that, bollocks. What Merckx rode has got sod all to do with what works for me.

 

Fashion....Let me think? Yes it could be, but what prompted the switch? If you look at the riders of yester year, they did ride different bikes. One thing that you will notice more is that riding on the hoods was not something that was done often. Merckx was in his drops most of the time, because the hoods were only there to hold the brake levers, therefore the handlebars had to be higher and thus the top tube was higher for a given person. The old way was to have a fist full of seat post. Not to say that these racers were not fast. Today the majority of time for a racer is spent riding on the hoods, very little in the drops, even when riding hard on the front, many will not get into the drops. I have ridden multiple frame sizes this season. I am back on a 53 Bianchi at the time, with a 130 mm stem and the seatpost maxed out, so I could more than likely go to the next size frame up which would be a 55. I have noticed that riding in the drops is not a problem on this frame, but the majority of my time is spent on the hoods while riding or racing. I went thru a time at the first part of the season where I was running the seat low to compensate for the frame, now I have about 20-25mm of spacers under the stem, and like I said I raised the seat back up to what was recommended by a fitter within .5mm. I have found that I do not have to worry about my feet having hotspots, or my knees aching after a hard workout. There are many views on set-up, but I think that smaller frames are still the way to go.

HUMP

 

Maybe for you, but there is no way to generalize that idea. It doesn't work. Full stop. What works for a person is what fits them best, makes them comfy, and encourages them to ride. Big frame, small frame, in between frame.......none of those is empirically better than the other. To think so is only a religious belief.

 

Interesting thread. The last time I purchased a bicycle, I was tempted to try a smaller frame, but didn't because I had pretty consistent fit information from both an independent paid fitter and an online fitter that I needed bigger. Next time I will try test riding a smaller size and see how it feels. On another note, I just happened to be looking at the Trek catalogue for 2004 models yesterday, and noticed that inside it makes reference to the fact that LA rides a 58 cm, which is NOT on the small side. He is generally listed about 177 cm tall---under 5 foot 10 inches.

On another note, something to be aware of for any newbies, is that companies measure that seat tube length in different places. Even Trek, Klein and Lemond, which are all owned by Trek, take that measurement in three different places---Trek-center of crank top of seat collar, Klein-center of crank to top of top tube, and Lemond-center of crank to center of top tube. So when comparing a Trek and Lemond, at least in 2004 anyway, a 55 cm Lemond, was similar to 53 cm Trek, in seat tube length anyway. And then of course the top tube lengths and the rest of the bike geometry may be completely different as well. And now comparing sizes across manufacturers is even more complicated with compact frames, sloping top tubes and "effective" or "virtual" sizes. The good news, imo, is that it seems possible through experimentation, changing seat height, seat setback, changing stem length and height, etcetera, to generally get comfortable on two or three frame sizes, up or down, so perhaps you don't have to hit it right on head with the one right frame size for you.

But from what I am reading here, dialing in the right frame size and setup to maximize racing efficiency is a whole another ballgame altogether, and the "right answer" may even change with each race? I suppose a power meter is useful in this endeavor---that you find you are able to generate more power in some positions on certain frame size and setups than others? And what about aerodynamics? Is your most powerful riding position consistent with good aerodynamics or are these two entirely separate things? Sorry to be rambling here, but I haven't got beyond the step of being able to buy a bike and to be able to get reasonably comfortable on it ---which for me was an important accomplishment in and of itself.

The whole process of selecting and setting up a bike to maximize racing efficiency, which racing I am doing occassionally now at the entry level, is a very complicated mystery to me, with seemingly moving targets! I think I like Alienator's take on this subject.

 

Seat tube length is one of the least important dimensions to know. It really doesn't matter. What is important is top tube length. And there is no variation on how it's measured. Actual Top Tube length is measured along the tube, from the center of the seat tube to the center of the head tube. Virtual Top Tube is measured parallel to the ground from the axis of symmetry of the seat tube to the axis of symmetry of the head tube. Simple. Virtual Top Tube is the number you want, if you're looking at compact or semi-compact frames as it is the number that would be the analog of the Top Tube length on a standard frame. After that, head and seat tube angles, head tube length, and possibly for leg length challenged riders, stand over.

 

That makes sense, but then why do bike manufacturers determine the size of a frame, and refer to the size of a frame, by seat tube length? Why not quote frames sizes by effective top tube length?

 

I think very few manufacturers size by seat tube, now. Definitely fewer are sizing this way. I'm not sure why a company would size by seat tube. The only reason might be legacy from the old days. As it is seatube lengths can vary a great amount between bikes with the same virtual top tube. If three bikes have the same VTT, but one is a compact, one is a semi-compact, and the third is a standard there could be a 10cm or greater difference in seat tube lengths. Definitely with the emergence of compact and semi-compact road frames, sizing by seat tube has become anachronistic.

 

Alienator: I do agree with the idea that seat tube length is arbutrary, with the compact frames and most frames measuring virtual.

I also think that most people can ride a frame size bigger or smaller, depending on the items you put on it. Lance did ride a 58, and yes he is about 5'-10". He also has a condition in his back that would not allow him to fully lay over a bike the way most people would lay over a bike. Notice the pronounced hump in his back. He also rode forward toward the crank, and spun the pedals like a demon. That is why I say that people can ride frames larger or smaller than what would typically be their optimum. Optimum is also specific to discipline. Most racers prefer a stretched position, 120mm stem minimal, some running 130 and 140. If you were a century rider, your position may be different, and if you were just riding for basic fitness, then again, your position would be different.

I know that I raced and won on three different frame sizes this season. I started on a 54 Cervelo, then a 52 Cannondale, then a 56 Cannondale (because I crashed the 52 in a crit and my teammate loaned me his to finish the stage race), then I went back to a 53 Cannondale, now I am on a 53 Bianchi. On all these bikes, the minimum stem length was 120, with the Bianchi having a 130. I am thinking about trying a 55 Bianchi or equivalent to see if I can get rid of spacers.

HUMP

 

For most normal people, yes. You may experience sore neck and shoulders, numb hands, impaired breathing, and reduced effectiveness while climbing. It also makes my helmet droop over my eyes a la Beetle Bailey.

On the other hand, it gets you on a lighter, presumably stiffer frame, gets your upper body out of the wind, and is a way to compensate for the longer top tubes currently in vogue.