TMB

You would be well served to understand the subject. The posters here have been discussing a seat tube measurement in the classic style - centre of bottom bracket to centre of seat tube.

Trak bikes do NOT measure their bikes this way. Trek bikes are measured centre of bottom bracket to top of seat collar, a 58 cm Trek is between a 54 and 55 cm measure in the classic style of measurement. The more important figure on the Trek geometry charts is the Effective Top Tube (c-c).

On a size 54 Trek the Top Tube is 54.6 cm. On a 56 cm Trek it is 56.1 cm and on a 58 cm Trek it is 57.2 cm.

pigmode

You're right. Trek's designated size is noticably bigger than if they were measured c-t-c. And by the latter metric (as your numbers show), they do have longer than average TTs.

biker7

It is you who would be well served to understand the subject before weighing in. As with many that only have a fragile grasp like yourself, you fall into the category of focusing on a particular aspect of Trek's frame geometry when it comes to their sizing. The Trek 58cm bike rides equivalent in sizing to other 58cm c-t-t frames out there in spite of your misconception regarding the relevance of seat collar and therefore true c-t-t seat tube length which is less then 58 due to the presence of a seat collar as you say. Your argument is no more relevant than comparing compact bike geometry with much shorter seat tube length to conventional horizontal top tube bikes when each bike has equivalent 3 point contact.
Here is the pecking order:
- length of Top Tube
- length of Head Tube
- seat tube angle and not length

It is the above three dimensions that matter most when it comes to frame sizing. If you study and/or compare a Trek 58cm to many other 58cm c-t-t virtual or conventionally sized frames you will discover a Trek in size 58 rides no smaller then any other 58cm bike out there because Trek builds their frames close to square in L/H and with ample head tube length per their sizing.
George

pigmode

George is right too. Center-to-top is a more a rational comparison factor, given the wild variations in TT diameters these days. Trek TT lengths still come in a bit longer by any measurement.

oldspark

Now you guys got me scratching my head-I though Trek's TT were fairly standard in length compared to the "normal TT".

toomanybikes

Oh dear.

Another of the boy racer, learned it all yesterday types.

Clearly you are not able to understand what I wrote.

However, my life is simply too short and my time far too valuable to be the slightest bit interested in "arguing" over the internet with yet another of your type.

One of the things I like a great deal about these forums is the ability to populate an ignore list for the most insulting of internet denizens.

To the OP - good luck.

biker7

I understand exactly what you wrote, you are simply wrong. If I wanted to take the time I could demonstrate my point graphically by superimposing one of many other frames over a 58cm Trek geometry demonstrating why you are wrong but I too believe it is a waste of time because you have no rebuttal to what I wrote. If your time is so precious why waste our time in the first place but putting forth a false assertion? BTW, I don't have an ounce of boy racer in me...lol.
For those interested...here is a further link to Lance's 58cm Madone:
https://www.cyclingnews.com/teamtech0...ikes/usps_trek
For those not visually challenged...take note of the profile of Lance's bike. Focus on two things. True to Trek's sizing...their 58cm has a very typical and not short top tube length at 572mm. Now visualize something the disparaging poster couldn't fathom...that of having a top tube directly on top of the existing top tube in effect being convergent with the top of the seat tube and not having the collar above the seat tube that the maligned posted is wrongly fixated upon. Translation?...the 572mm top tube is in effect longer then 572mm if it were to intersect the seat tube at the end which is more traditional and the basis for the 58cm sizing. And the final subtle point that tmbs failed to comprehend. Trek is a bit unconventional in how they attach their head tubes on their CF bikes as they run the same head tube length as most traditional 58cm frames. Note the asymmetry of how the head tube is connected to joining top and down tubes. Trek elects to derive an ample head tube length by having a great portion of head tube length beneath the down tube. In summary, a 58cm Trek bike rides every bit as big as any other name brand bike out there sized c-t-t.

Lastly tmbis...you could have couched your comments in the good spirit of the rest of this thread and my response would have been more conciliatory...but you elected not to. So you are in effect wrong on two fronts...the initial insulting tone of your post which started this exchange and then you putting forth a technical assertion that is inaccurate which you likely don't appreciate being reminded of. The reason for this forum is exchange of ideas. You can play nice and put forward your views right or wrong or do it your way.
Oh dear indeed.
George

pigmode

You're right about how in a comparative sense Trek measures a virtual tt where the actual tube is lower. If you compare to say, the C50 and the Dogma, they are all in the same ballpark with Trek still a little longer.

Not to argue, but in terms of headtube length, I don't see your point about its relationship to the upper downtube junction. If you follow from the front axle to the top of the tire, to the top of the fork crown, to the top of the headtube, then you can see that the junction point of the DT has no practical bearing on the length of the HT and is not a variable in determining its length.

But anyway, I'm way out of my league as a layman more interested in comparing prospective frames in order to get a precise personal fit.

markwebb

Whoa there Biker 7 - this was a nice decent discussion about stem lengths and relatiion to top tube lengths and the effects on climbing position - I'm the original poster - the OP here. I am interested in finding out about different stem lengths and how to improve my climbing position by lengthening my stem length - please read my original query and the GREAT responses to the subject and the very helpful advice.

Your post is not really appropriate to the purpose of my OP and does nothing to help me - it's just argumentative and really no one really cares about how Trek measures frames - has nothing to do with my question. So please if you have nothing positive to add to this thread don't bother posting anymore. Thanks in advance for your cooperation.

markwebb

And George - a 55-57cm bike is probably the most common size for folks 5'10-5'11". 56 is definately NOT a small bike for this size person. You get up above 56-57cm on a standard bike without a sloping top tube and the stepover height starts to exceed 33" which - for the average build of persons 5'10" to 5'11" starts to become too tall and "dangerous" and potentially painful : ) ifyaknowwhatImean

Because you made this one universal statement I would have to discount any other advice you would give out.

oldspark

Hey markwebb-some posts just go to he!! with a hand basket on their own, nothing you can do to save it. LOL

markwebb

Yeah...but it was a really good discussion up to that point.

You know another reason us old guys like a bike they can more easily step over - as we get older we get less flexible and it's just easier to straddle a 32 inch stepover with less effort. If I were to ride a 58 or 59 seat tube I'd have more trouble getting off the darn bike with a 33 or 34 inch stepover !!!

My new Mercian King of Mercia (perhaps arriving at my house by 1/6/06) is a 55.5 seat tube c-c 56 c-t with a 57cm c-c top tube. Based on this thread I am buying a 100mm stem - that combo will increase top end by 2cm over my current bike. That should be good for the cramping!!!

I like the post about seeing the front hub - that really helped. Had it not been for that post I probably would have gone with a 120, but using that rough estimate I may only need the 100mm stem.

I'm now trying to decide - with a 55.5 seat tube - how long should the quill length be (it''s a Chorus threaded headset). My 56cm bike has 3.5 inches of length showing, so with a .5cm shorther seat tube I'll need to pull seat post up about 1/2 inch or so and move bars up as well. From my calculations, my new Nitto stem will allow up to 4.5 inch rise from top of headset and still have about 70mm inside head tube - is 70mm inside a safe amount on a 190mm quill? Anybody know where the minimum insertion mark is on a Nitto 190mm quill stem?

oldspark

Couldn't you convert it to a new style stem with an adapter, lots more choices with the stems and much easier to change out. I have done this with no problems what so ever.

markwebb

New = threadless? The bike uses 1" threaded, so need to use quill stem. I like them better, because you can adjust the height and dial them in easily, unlike threadless.

cyclezen

not in an argumentative frame, but for many decades the common sizes for 5'10 to 6' would have been 58 for most to even 60 for some riders, and 57 for others. There are still many who ride bikes in these dimensions and have no problems with 'dangerous' or 'painful', and actually perform quite well. The reasons for these sizes are too numerous to really go over, but they range from the extremes of 'what was' to 'fashion' to 'equipment limitations' to 'good positional sense'.
So now the current fashion is to use a smaller frame, so a 55 or 54 is no longer 'too small'. For a majority of riders this is moot. Ultimately the key consideration will be 'position', and many (maybe even most) riders can get there on a range of frame dims - some of which will affect bike handling in positive or negative ways. Then stem length and seatpost length/position in part compensate for the 'new' fit.
A problem, as I see it, is even though riders are 'downsizing', manfacturers are still spec-ing finished OTR bikes as if they were being sized the 'Old-fashioned' way. And to some extent the original question of the post shows that. Given that except for a few manus (like Lemond, Merckx, a few others) the majority give you a frame that is at best matching TT to ST; most undersize their TTs in the seat dims we're talkin about by 1 and even 2 cms. And when they spec components, the 54-56 bikes will get 90-100 stems (like the bad old days and what is intended to fit someone 5'6" to 5'8"), rather than the 120-130-140 a 5'10", 5'11" rider will likely be using as a minimum. So you get cramped...
Numbers are illusory anwyay. What counts is how well you can breathe, put power to the pedals, not hunch your shoulders, and retain the stamina, flexibility and supplness to do it for a few miles. Everything else around that is fashion.

markwebb

Sage advice. I would think that sizes for 5'10" to 6 feet riders would be in a range of 55-59, with the 58-59 for someone 6 feet - to 6'1", and the 54 for someone 5'10" preferring a slightly small bike.

I myself tried a 54 a year ago but it was noticably too small with a 54cm top tube. That's why I am going for A 55.5 SEAT TUBE WITH A 57CM Top Tube on my new Mercian. I'll get a 32" standover with a little longer top tube, and with going to a 100mm stem I will have an effective 2cm longer length on top than my other bike - I'll still have a tourist ride position but I will be a little more stretched out up top, while having to raise my seat post only about 1cm higher than if I were riding a 56cm seat tube. It should be just the right combo and with the 100cm stem should eliminate that cramped feeling. I feel the 57cm top tube will give me the right length, but if needed I can go to a 110 or 120 stem. With the 56cm top tube I would be looking at 130 or 140 if I maxed out, which would be an awfully long stem. The 57cm top tube and 100 or 110 stem should be good for this old racer converted to tourer !

What I marvel at with a slight chuckle are the ridiculously small and odd combinations I see used by some weekend warrier racer wannabes with extra long seat posts that are 4"-6" higher than the bars - man for anything other than trying to achieve an aero position for a time trial that seems just silly and uncomfortable. I'll agree with you that absurbly small frames are not really a god idea.

This continues to be a good thread with good info - it's still for the most part on target as to my original post and folks giving me advice on sizing the stem and other considerations in order to eliminate my cramped feeling up on top and the reasons for it/solutions to the problem.

Thanks to all - and Happy New Year.

cyclezen

I tend to be less critical of what I see on bar drop. Mainly cause a person with a shorter torso than avg (for their size) and longer arms will likely be using a greater drop (thatz me). Why? Cause even a longer stem doesn't rightlly compensate for the positional problem a long reach causes. Even with a significant deep elbow bend, and a 4" drop, my torso ends up in a fairly upright position. If I went to a 2" drop or (dog's blood) a level bar, I'd be virtually upright, which would not only be less powerful or efficient, but greatly less comfortable and not rideable for any time/distance. I tried it for a while (whole month) some years back and really hated it.
The stem extension assures a nice open reach and stretch, with a curve to the back. The bardrop aids that and also keeps my torso angle at a good combination of power and comfort. With not undue pedaling effort, and hands on the bartops, the 4" drop assures my upper body weight is countered by the pedaling force and I feel a very light weight on the bar tops. With a 'higher' bar position, and under stronger pedal loads I'd actually have to pull lightly on the bars to keep the body from lifting and straightening - not a good thing.
The drop works for me. For someone with a longer torso and less long arms, also using a similar length stem, a higher bar position might work best for them.

BTW - I don;t think I'd use or recommend using the old "bar obstructs the front hub view" method on any setup that isn't traditional frame sizing and adjustable quill stem. Lotza reasons... But in a nutshell, outside of the traditional stuff and frame sizing, with the newer frame sizing and stuff you can still get to this 'convention' and have the body angle and reach be completely out of wack.

oldspark

Mark-this is what I am talking abouthttps://www.performancebike.com/shop/Profile.cfm?SKU=1594&item=00-5369&slitrk=search&slisearch=true was not sure if I would **** but it works very well and you can adjust it just as as quick a quill stem plus you have all the options of the stem angles and lengths. I can change a stem in about 5 min plus move it up or down like a quill. Sorry it is not a click on-I'll try to change that if I can figure it out.

oldspark

https://www.performancebike.com/shop/...slisearch=true

toomanybikes

Congrats, The King of Mercia is a BEAUTIFUL bike.

I like the Mercians a great deal, still intend to get a Mercian someday, probably the KoM, the lug-work and paint jobs are simply gorgeous.

You will have many happy years together - enjoy it.

oldspark

I need to pay more attention to the threads-sorry for suggesting to put that adapter on your Mercian. Art work deserves better.