Touring - Question about generic S, M, L frame sizes

Hello,
I'm currently thinking about buying Specialized Sirrus and traveling for several days/weeks on it.
One thing confuses me. I read through this forum and see experienced cyclists with great bikes saying how a 2 degree tilt of the saddle, or a 1 cm higher than usual seat made their riding uncomfortable and painful until they re-adjusted the bike. At the same time, in the touring section people express their happiness with a Specialized/Trek preassembled bike from the shelf and how it makes 100+ km rides a breeze.
I'm wondering which is closer to truth - that I will need to adjust everything +-0.5cm, or that I will be just fine with any good bike, given that the frame size (S, M, L) fits me about right?

(I have an assembled bike that I can ride 40-50km, but not without some discomfort in hamstrings; I have never figured out how to make it better - already changed a frame, front shocks, saddle and adjusted saddle and stem tilt and height many times. It feels much better when I try Sirrus bike at LBS).

Thanks in advance for you opinions!

Some ppl are lucky enough to be proportioned just right for the standard bike sizes and configurations. Most others aren't, thus all the tweaking. When you're in the saddle for hours each day, each mm does count.

My body is so out of standard for cycling that, over the years, everything but the frame has been customized just for me. No way I could buy an off the shelf bike and ride it far. Thus, rather than buy the latest and greatest, I just stick with what I know works.

Don't forget that even with a perfectly fitting bike that you still need to use decent form.

Also, while the Sirrus might feel better at the LBS, does your current bike feel comfortable when you ride it around the block, or does it only appear after some time into the ride?

Thanks to the threadless, open face stems being easy to change, the one that came out of the carton

is not the one you have to keep, a competent professional bike dealer will swap one for another length for cost or below. at point of purchase , time of sale ,
they may do a swap at the time of your new bike after sale tuneup.

the setback of the saddle is adjusting for Femur length [upper leg bone] and personal preference ,

setback affects the Body's weight bias on your arms

the saddle height to pedal distance is to get a good leg extension.
but not too much, at the bottom of the pedal stroke.

One thing to keep in mind is to let your body have time to get used to the bike whenever you tweak something. If you keep changing something about the geometry every ride, no amount of tweaking will make it comfortable.

Also +1 to SBRDude's comment on good form. Your knees should pass very close to the top tube during each pedal stroke, and your elbows shouldn't be locked (except when braking hard).

I can't really adjust the bike at the time of purchase, because I can only know how it fits after riding for 50+km.
And with my current bike, 50km is about how long I can ride before my hamstrings become uncomfortably sore. This is what's not right about my bike - my hamstrings and only my hamstrings get tired, sore and tight after riding. My calves and quadriceps don't feel anything and don't do any work.
Riding base model Sirrus for 30 minutes, I felt that my legs are in a better position, with knees going higher with each stroke, and my calves doing some work as well as other muscles. Also, it's just lighter and faster than my bike, so it felt nice. I don't know if this feeling would extend after riding 50, 100+km.

I've changed every major part that affects geometry on my bike already, trying each setup for a day or two. One thing I feel is always the same is my legs, knees not going high enough while pedaling, and I feel it's connected to sore hamstrings. I sometimes come back home from a 50km ride with stone hard and tight hamstrings that I have to massage, while my calves and quadriceps feel just like if I sat on a chair for all this time.
Maybe you could tell me what's the problem here?

seat height needs to be within a few mm for most cyclists. Setback, reach and drop have a wider range. The frame size is only loosely related to these contact points. That's why manufacturers can get away with so few sizes. It's nothing new, back in the vintage days it wasn't uncommon for manufacturers to only sell 21", 23", and 25" for a given model.

Huh, I can't help much, but I tend to feel soreness in my hammies when I'm pushing a slightly too high gear up a hill.

I have to think your problem is related to your seat position or cranks. I would say that most people wouldn't notice the difference between 172.5 and 175mm (for example) cranks, but maybe you are an exception. Something to try if you've really exhausted your seat position options.

For anyone researching similar questions - I got rid of most of discomfort by lowering the seat that was way too high. It felt at first unusual to pedal just like with pistons in this lower position, instead of simply pushing down in the previous higher position.

For anyone researching similar questions - I got rid of most of discomfort by lowering the seat that was way too high. It felt at first unusual to pedal just like with pistons in this lower position, instead of simply pushing down in the previous higher position.

If all your'e doing is pushing down on the pedals, then you are relying heavily on your hamstrings. Work on smoothing out your pedal stroke to more of a circular motion, which will involve the quads and lessen the stress on your hamstrings. Foot retention can help in this regard, in addition to good bike fit. Good luck!

Also check out some of the competition other than the Specialized. Off the shelf bikes like that can sometimes have fit issues for your particular body but other makers of almost identical bikes will have a slightly different fit and might suit you better. Thus, with off the shelf bikes make sure you shop around to find one that fits you well without too much adjusting. With more expensive bikes adjustments are a given.

My first bike was a Giant FRC3 which is very similar to the Specialized but fit me better. Also look at the KHS Urban Express which are often overlooked but are inexpensive and have all the right stuff for touring!

I can't really adjust the bike at the time of purchase, because I can only know how it fits after riding for 50+km.
And with my current bike, 50km is about how long I can ride before my hamstrings become uncomfortably sore. This is what's not right about my bike - my hamstrings and only my hamstrings get tired, sore and tight after riding. My calves and quadriceps don't feel anything and don't do any work.
Riding base model Sirrus for 30 minutes, I felt that my legs are in a better position, with knees going higher with each stroke, and my calves doing some work as well as other muscles. Also, it's just lighter and faster than my bike, so it felt nice. I don't know if this feeling would extend after riding 50, 100+km.

I've changed every major part that affects geometry on my bike already, trying each setup for a day or two. One thing I feel is always the same is my legs, knees not going high enough while pedaling, and I feel it's connected to sore hamstrings. I sometimes come back home from a 50km ride with stone hard and tight hamstrings that I have to massage, while my calves and quadriceps feel just like if I sat on a chair for all this time.
Maybe you could tell me what's the problem here?

your first comment doesn't quite make sense in that the folks at the shop can adjust the bike to fit you properly at time of purchase.
I don't understand the comment about liking the Sirrus because your knees can go higher. Either the seat height is adjusted properly for either bike or it isn't. The only way I can see having "knees higher" feeling good is if your old crank arms were very short and the Sirrus are longer but both bikes should have the bb-seat height about the same.

The only reason I can think of for sore hamstrings is that you're not relaxing in the top part of the stroke and you're fighting your own muscles. Are you using clipless pedals and shoes or are you pedaling on a plain platform pedal?

Some ppl are lucky enough to be proportioned just right for the standard bike sizes and configurations. Most others aren't, thus all the tweaking. When you're in the saddle for hours each day, each mm does count.


I'd say that you have it the wrong way 'round. Most people are proportioned just right for standard bike sizes and configurations. That's why they are standard. Gaussian distribution and all that. Some people are out on the tails of the distribution and thus fitting is more difficult.

All of the other adjustments that people make are for individual preferences and to take into account slight body variations.

SlowRoller, basically that's what I did. I lowered the seat, and now my quads are doing a lot of work pedaling, I'm even thinking my hamstrings now are too idle, but I'll ride it for a couple of days first to decide.
zeppinger, I only have Giant, Specialized and Trek stores around here, checked both Sirrus and Trek FX line many times. Both fit ok from a 30 minute ride perspective.
LeeG, like I've just mentioned, I feel much better now that I lowered the seat. I'll see if it's too low after a couple of days. I'm using plain platform pedals.

SlowRoller, basically that's what I did. I lowered the seat, and now my quads are doing a lot of work pedaling, I'm even thinking my hamstrings now are too idle, but I'll ride it for a couple of days first to decide.
zeppinger, I only have Giant, Specialized and Trek stores around here, checked both Sirrus and Trek FX line many times. Both fit ok from a 30 minute ride perspective.
LeeG, like I've just mentioned, I feel much better now that I lowered the seat. I'll see if it's too low after a couple of days. I'm using plain platform pedals.

Paul,
You haven't said whether your legs are longer, or your torso is longer, or neither. This might help analyze your situation from a physique perspective.

I can't speak for others, but my hamstrings tend to begin a ride tight and loosen up after a bit. Then I stop for stretching once warm, and continue. (I'm over 50 years old.)

Having your hamstrings knot up after exertion says that they're working against the setup or against your other muscles (as suggested by a previous poster).

Is it possible that you have your seat set too far rearward to gain better reach, when a longer stem might be the right answer? WIth the seat too far back, you're having to engage too much of the hamstring in the downward part of the stroke, sort of like a sprinter's strain. Maybe your LBS can look at femur length and torso length to find a better compromise here?

Just a hunch...

Phil

Hey Phil,
I heard people say I have long legs.
Like I've mentioned, after lowering the saddle my hamstrings are quite idle and I'm doing much more with quads. Also, I've noticed slight knee pain sometimes after rides 30-50km long.
I now think that something should be done about the horizontal setup - stem length, saddle position, etc. I occasionally want to have the handlebar closer to my torso, but don't know if it's right. Also, my stem is 90mm, I don't know if there are shorter stems available.
Before, I used to have a 16" frame which was obviously too small. Then I took height and inseam measurements, checked several size charts online and switched to 19" frame based on that information. I am 178cm tall, and I've already forgot my inseam, it was either 89 or 84 cm, slightly longer than the average. One of more experienced riders I know thought 17.5-18" would be better for me (his opinion after taking a look at my new frame).
LBS around here are not like US or EU stores, they are not more professional than an average experienced cyclist. They may give me some advice from another point of view, but it won't be a guaranteed solution. That's why I want to hear more opinions here.