Stem question

Mansmind said:

Does anyone know the proper way to measure a stem length? Is it center to center or something else?

I haven't been able to find what size my bike came with or I could figure it out. I think I want to try a slightly short stem as it seems I'm stretched out a tad too far. I don't know what size to go to however, until I know what size I actually have.

I would think center to center, but I know don't know for sure...thought some of you may know.

Thanks,

John

Yep. Center to center along the extension.

Mansmind said:

Does anyone know the proper way to measure a stem length? Is it center to center or something else?

I haven't been able to find what size my bike came with or I could figure it out. I think I want to try a slightly short stem as it seems I'm stretched out a tad too far. I don't know what size to go to however, until I know what size I actually have.

I would think center to center, but I know don't know for sure...thought some of you may know.

Thanks,

John

If it's threadless or quill a type that is tig welded,it's c-c along the side of the extension. Older quill types that were cast or forged aluminum were c-c along the top of the extension with a few exceptions.

meehs said:

Yep. Center to center along the extension.

Check above. Type makes a difference whether it's along the side or top.

boudreaux said:

If it's threadless or quill a type that is tig welded,it's c-c along the side of the extension. Older quill types that were cast or forged aluminum were c-c along the top of the extension with a few exceptions.

Thanks guys, looks like (I'll measure again when I get home) that I have a 120mm stem. That's good news in that I have quite a bit of room to move should I choose to.

I would also think that with the shorter stem, I'm going to get a quicker feel to the steering also, make sense?

Incidentally, I have a 58cm '04 Specialized Allez Comp Double that came with their Flip Flop Road Stem. It just feels like I have a little too much weight on the bars when on the hoods. My LBS seemed to think my perception was wrong, and not having ridden the "racier" road bikes before, I didn't see a big reason to disagree. After logging about 400 miles though, I still think it's a little off. Height seems correct, just a little too far forward.

Any particular recommendations on what I should replace it with? FSA, etc.? 31.8 clamp needed.

Thanks again,

John

boudreaux said:

Check above. Type makes a difference whether it's along the side or top.

I saw your reply. I didn't realize there were different methods used for measuring. I thought it was always c-c along the center of the extension. Can the bike industry standardize on anything? :o

meehs said:

I saw your reply. I didn't realize there were different methods used for measuring. I thought it was always c-c along the center of the extension. Can the bike industry standardize on anything? :o

Of course not.. that would make too much sense!🙄

Actually, I suspect using the centerline on the side of the stem makes it a little more accurate due to the angles involved when measuring along the top.

the angle between the actual stem, and the headset clamp would theoretically introduce some error when measuring a long the top of the clamp.

I certainly don't know if that's the reason or not, but it seems a better way to do it IMO.

John

Mansmind said:

the angle between the actual stem, and the headset clamp would theoretically introduce some error when measuring a long the top of the clamp.

No it doesn't.Stem length is stem length. Angle is a separate conept,but has to be considered since if you change the angle, you change the reach to the bars, as well as the height of the bars.

boudreaux said:

No it doesn't.Stem length is stem length. Angle is a separate conept,but has to be considered since if you change the angle, you change the reach to the bars, as well as the height of the bars.

I agree with what you're saying, except the actual horizontal difference between the clamps changes as the angle changes. The only way to prevent this would be changing the length of the extension part of the stem.

My point was, due to this variable, it is more accurate to measure stem length along the side, along the center-line of the extension itself. In this way, you automatically take the angle into account. Measuring from the top, while technically possible, would be much more difficult in trying to match the angle.

Granted the difference is relatively small, but my point was in it's accuracy.

I have no idea why companies would choose one over the other, and in some respects, I can see why it would make more since to only measure the actual horizontal distance.

I've attached a drawing (scaled) that indicates what I'm saying.

Mansmind said:

I agree with what you're saying, except the actual horizontal difference between the clamps changes as the angle changes. The only way to prevent this would be changing the length of the extension part of the stem.

My point was, due to this variable, it is more accurate to measure stem length along the side, along the center-line of the extension itself. In this way, you automatically take the angle into account. Measuring from the top, while technically possible, would be much more difficult in trying to match the angle.

Granted the difference is relatively small, but my point was in it's accuracy.

I have no idea why companies would choose one over the other, and in some respects, I can see why it would make more since to only measure the actual horizontal distance.

I've attached a drawing (scaled) that indicates what I'm saying.

There is a convention for measuring stems. The drawings are meaningless in the real world of stem buying. It's also center to center....Move on.

Again, does anyone have any reccomendations as to what "brand" stem I should get? Are any particular manufacturers better than others.. etc.?

I see a lot about FSA, but I have no personal experience with them to draw from. I also see some CF models, anyone had experience with those?

All input welcome!

John

Mansmind said:

Again, does anyone have any reccomendations as to what "brand" stem I should get? Are any particular manufacturers better than others.. etc.?

I see a lot about FSA, but I have no personal experience with them to draw from. I also see some CF models, anyone had experience with those?

All input welcome!

John

One general opinion to share with you along those lines. You can spend a LOT of dough on a stem that will hold your handlebar securely without creaking and squeaking or you can spend a relatively small amount of dough on a stem that will hold your handlebar securely without creaking and squeaking. Now there's definitely something to be said for the "cool" factor of the spendy, exotic stems but that's really all you're paying the extra money for (that and possibly a few less grams). I'd rather put the money into something that will actually have an impact on the performance or comfort of the bike.

boudreaux said:

There is a convention for measuring stems. The drawings are meaningless in the real world of stem buying. It's also center to center....Move on.

First of all, the original question posted was about manufacturer's not "standardizing" on anything, since it's apparent some use one method, and other's use a different method. My original post to the question was a theory as to WHY it might be different.

Secondly, there IS a difference, and my drawing was a method of communicating that difference...center to center or not, it remains true. This was in response to your indicating that it doesn't make a difference. For their purpose, those drawings are not "meaningless" as you indicated. I didn't draw them as a tool for buying stems.

Thirdly, everyone has their own ideas. I have mine, and you have yours...apparently in this case they're different. It's usually more productive to discuss differences (perhaps we both might learn something, which is what these forums are/should be about). I have no interest in starting a "war" here, I have better things to do. I also don't appreciate being called "wrong" when I'm not, and when I AM wrong, I like to understand why.

Enough said...

John

🙂

meehs said:

One general opinion to share with you along those lines. You can spend a LOT of dough on a stem that will hold your handlebar securely without creaking and squeaking or you can spend a relatively small amount of dough on a stem that will hold your handlebar securely without creaking and squeaking. Now there's definitely something to be said for the "cool" factor of the spendy, exotic stems but that's really all you're paying the extra money for (that and possibly a few less grams). I'd rather put the money into something that will actually have an impact on the performance or comfort of the bike.

Makes sense to me! Thanks for the input. That's exactly what I wanted to know. I didn't know if there was any REAL difference in performance from one to another (within basic design group). I'm not chasing grams, but I'll probably choosed something that doesn't increase weight, even if it doesn't decrease it.

Mansmind said:

First of all, the original question posted was about manufacturer's not "standardizing" on anything, since it's apparent some use one method, and other's use a different method. My original post to the question was a theory as to WHY it might be different.

Secondly, there IS a difference, and my drawing was a method of communicating that difference...center to center or not, it remains true. This was in response to your indicating that it doesn't make a difference. For their purpose, those drawings are not "meaningless" as you indicated. I didn't draw them as a tool for buying stems.

Thirdly, everyone has their own ideas. I have mine, and you have yours...apparently in this case they're different. It's usually more productive to discuss differences (perhaps we both might learn something, which is what these forums are/should be about). I have no interest in starting a "war" here, I have better things to do. I also don't appreciate being called "wrong" when I'm not, and when I AM wrong, I like to understand why.

Enough said...

John

🙂

You asked a simple question and got the correct simple answer.Now you seem to think you are the expert. Some things are not about 'opinions' or what one 'thinks',and 'discussions' will not change what exist as to how it's done. Get over it.

boudreaux said:

You asked a simple question and got the correct simple answer.Now you seem to think you are the expert. Some things are not about 'opinions' or what one 'thinks',and 'discussions' will not change what exist as to how it's done. Get over it.

You're correct... opinions are opinions and don't change anything.

Facts however, are facts.

It's apparently a fact that they're measured center-center. This I learned.

It's apparently also a fact that some measure it along the top, while others measure it along the side. Which means the industry isn't consistent on how this measurement is taken.

It's a fact that depending upon the up/down angle, you can get different measurements between those methods. (this is apparently where we disagree)

I'm FAR from an expert, and haven't made any claims to be. I do however, have an excellent of simple geometry.

There's nothing to get over, all I've done here is stated some very simple facts, and to the extent those facts where questioned, attempted to explain them.

If you don't agree with them, that's your right. If you don't want the discussion, then stop participating in it.

Mansmind said:

It's apparently also a fact that some measure it along the top, while others measure it along the side. Which means the industry isn't consistent on how this measurement is taken.

It''s consistent with respect to THREADLESS,and quill types that are Tig welded!! That's new school stuff, and covers alot of current territory.Cast and forged quill is old school. Bicycles go back over 100 years.How do you go back through that kind of history and standardize? Next time ask about bar clamp diameter and I'll tell ya about old scholl, new school,road mtb,standard and oversie,and we'll see if you can get your head around that one. Wanna talk about JIS and ISO standards too while we're at it?

boudreaux said:

It''s consistent with respect to THREADLESS,and quill types that are Tig welded!! That's new school stuff, and covers alot of current territory.Cast and forged quill is old school. Bicycles go back over 100 years.How do you go back through that kind of history and standardize? Next time ask about bar clamp diameter and I'll tell ya about old scholl, new school,road mtb,standard and oversie,and we'll see if you can get your head around that one. Wanna talk about JIS and ISO standards too while we're at it?

Look, I understand why it isn't consistent.. I picked that up from your earlier post. I'm not even saying that it's a realistic idea that it would be consistent given the history. I have no doubt that you know that history very well.

The only reason I started down the measurement road was in response to (Meeh's)? comment regarding the standardization. "Wrong" or "right" had nothing to do with it, it was just an idea as to PERHAPS why the method of measurement is different for different types. It had nothing to do with your explanation of which types are measured "how". I found that information very helpful.

I obviously didn't know what the proper convention (and didn't want to assume) was or the thread would have never been started, and as a result of asking the question, I got what I needed to know very quickly and appreciate the responses.

I took your "No it doesn't" to mean that the angle of the stem has no affect whatsoever on the measurements using one method vs. the other. Perhaps I misintrepreted that statement. If I did, I apologize.

I do understand that any given company (or type) will measure the stems they manufacture consistently... regardless. Stems having the same "advertised" length, but measured in a different way... could actually give you two different length stems however, assuming the angle is steep enough (I've seen as high as 16 degrees advertised).

Regardless, I certainly don't want to start debating ISO standards, I deal with them too much already. 🙂

LOL.. I must admit I'm sort of curious as to what the push toward the larger 31.8 diameters are. I understand there would be some extra strenth, etc. ...does 31.8 offer something that 31 or an even 32 woudn't have though?