Ryder1

Sorry, but the fundamental problem is your math skills are lacking, as repeatedly demonstrated by your previous posts. You even admitted not understand how Reach is measured (!). I'm not being harsh; everybody has their strengths and weaknesses, and math is simply not your strength. Fine. I *suck* at learning foreign languages. And I acknowledge that. Man up and acknowledge your weaknesses instead of engaging me by mindlessly repeating your misunderstanding of what the "INDUSTRY" means by Reach. Note: people don't *decide* what "Reach" means, math does. By themselves, numbers are just numbers. People who understand math analyze the numbers in the form of calculations. That's what I've painstakingly done above, but your math skills and/or ego won't allow you to understand. I even self-verified my data twice by performing 2 alternative calculations. Then I showed you a thread where the same debate was covered and resolved (in my favor). Yet you persist with the sole point of "just compare reach vs. reach."

I can design a bike that's 5 feet long and another that's 100 feet long, and they could both have a 1" Reach. Or I can make the Reach of the 5 foot bike *longer* than that of the 100 foot bike. I could even give the 100 foot bike a negative Reach. Follow? It would be nice if there was a single number we could rely on, but it's a bike, not a dress.

Sorry if I sound condescending, but you're being willfully stubborn. When you read a bunch of numbers and you don't understand them, you can recoil in fear and cling to your ignorance, or you can admit there's maybe something you're not quite grasping. Even Trump has acknowledged having failed to understand the complexities of North Korea and health care policy.

Please re-read the link in my last post, to see how this debate normally ends.

AnthonyG

Ryder1, I'm sorry that If by saying that I didn't know how reach was calculated, that this has led you into claiming that you did. I was just being modest.

"Reach" and "Stack" were INVENTED by the bicycle INDUSTRY as an agreed upon method of making certain calculations so that anytime a bike manufacturer quoted "Reach" and "Stack" that those measurements were calculated the same way and were directly comparable.

"Reach" and "Stack" are NOT the methods used by an Independent arbiter and are NOT up for INDEPENDENT interpretation. All angles and variables are taken into account in order to quote "Stack" or "Reach".

I've been involved in bicycle racing since the late 70's. No one was talking about "Reach" and "Stack back then. Back then it was top tube length and head tube height. As you are well aware these measurements are susceptible to many variations dependent on many other factors.

"Reach" and "Stack" are the Bicycle Industries agreed upon methods for making certain calculations so that all relevant factors are taken into account and are directly comparable between manufacturers.

Ryder1. You did not invent, "Reach" and "Stack".

Ryder1

I never said I invented anything. You've put words in my mouth about 10 times, yet ignored my numerous valid points. Why is this? Are you pulling my leg?

Look, this is simple math. 10th grade stuff, if that. Stop being intimidated by it. You don't need to consult the high priests of "THE INDUSTRY." Yes, they created the "stack and reach" sizing system, but no, they never said you could directly compare Reach vs. Reach between bikes. And it's pretty stinkin' obvious if you'd bother to take 30 seconds, look at a bike geo drawing, look at how Reach is measured, and see how Stack impacts Reach (because HTAs are never 90*). See that? IT'S REALLY SIMPLE IF YOU JUST TRY. As Stack changes, it impacts Reach. And so you can never merely look at Reach vs Reach. That's all I'm saying. It's not debatable. That's what the other thread concluded also. That's what I've seen concluded every single time this issue comes up. Because it's true. Do you honestly disagree, or is your ego all amped up? IT'S REALLY SIMPLE IF YOU JUST TRY. Have you done this? Why don't you do this and tell me what you think? Will you? No. You crack me up.

AnthonyG

Yes you CAN directly compare "Reach" and "Stack". That's the whole point to "Reach" and "Stack'. To come up with figures that CAN be directly compared.

"Reach" and "Stack" are measured from the centre of the bottom bracket (BB) to the centre of the top of the head tube (CTHT).

I undertand the concepts well but I was just being lazy in claiming I didn't because I didn't want to look up the details to quote them.

Ryder1 you have made a fundamental mistake in claiming that front centre to distance is what you need to read. The front to centre distance isn't the arbiter of Reach, its the result of changes made to Reach and Stack.

Lets take the 60cm frame and note the Reach and Stack measured from the BB to the CTHT. Now lets say we take the exact frame geometry + fork and ONLY lengthen the Head Tube (HT). Imagine you have simply fitted a TALL stem. Something that was easy to do on older bikes. The effect of this change would be to increase the Stack but REDUCE the Reach. The HT angle is leaning back towards the rider(BB).

Lets for the moment assume the same HT angle and Fork.

In order to have the SAME Reach but more Stack with a taller head tube you would have to increase the Front to Centre distance to accomodate this. If you wanted to increase the Stack AND increase the Reach as well, then YES, the Front to Centre distance IS going to increase quite a bit just to account for a modest increase in Reach.

Its just the Maths/Geometry.

In the old days frame builders would change HT angle and fork rake for each different size. HT angle is still adjusted sometimes but nowadays with carbon fibre forks the fork rake stays the same.

Now of course stem height and length plays a role in where Reach and Stack may effectively be but for the sake of comparability bike manufacturers quote FRAME Stack and Reach using the same methodology and the numbers ARE directly comparable.

79pmooney

Yes. I have two. I rode a Merlin MTB almost 30 years ago and knew from that quick ride that a custom road ti bike was, for me, "it". Took years to land the job and situation to justify going that route (and kept seeing all the stock ti bikes as very expensive class B fits). When that day came, I already had framebuilder make me several stems (TiCycles). I got to see quite a few of his bikes; in process at his shop, at a shop that fitted customers for custom TiCycles and on the road. I liked what I saw and heard.

So, when that day came, I brought in a steel bike I really liked, had him measure it up, told him of the changes I wanted (higher BB; I was tired of scraping pedals, slightly different front for reach and stem and a couple of equipment requirements. I love the bike. It fits! As nicely as anything I have ever ridden. Loves to climb. Comfortable all day.

But at the same time I was putting together an el cheapo fix gear as my first light. fast fix gear. Too much fun! (I wouldn't ride it in the hills. (The frame had been though a lot before I bought it for $20.) At 8000 miles, I knew Ii needed to retire it before it broke on me. Got this a crazy idea to copy it in titanium, with a custom road dropout that opened forward, then down, making the entire slot usable AND allowing a wheel with a very big cog/very tight chain to be taken out easily. Had it built. Way, way too much fun. It's a real 1980s racing bike in a fictional world where freewheels and gears were never invented.. Despite the ride and feel of a pure race bike, it was no hardship to ride it 16 miles to a century then ride home.

So, yes, it can be done and it can work very well for you. Now you may well want to take a different approach. I've been riding a very long time and stumbled on a bike that was very close to a perfect fit 40 years ago. So I could with confidence approach TiCycles and say I want "this" and either show them the bike to pattern the new one from of send him drawings of what I want. And TiCycles is a little unusual in that they will build anything you want if you can convince them you really know what that is.

Ben

Ryder1

We're beginning to agree! I agree with most of this. But you're saying I wrongly delved into front-center, but like wb, cs, ett, hta, I only referred to fc in relation to wb and cs to confirm, in a separate self-confirming calculation, my initial 7+3 effective-reach-delta calculation of 10mm (in contrast to your 3mm).

I agree! But...all the above explains exactly why this statement

is not true. You can't have it both ways. In the former, you're saying Stack affects Reach, and in the latter you say you can directly compare Reach vs. Reach. Which is it? Answer: You can't compare Reach until you've accounted for Stack, just like you explained. How much does Stack affect Reach in the Domane (60 vs 62)? 7mm (per an online bike calculator). So, 7mm must be added to 3mm (off the spec sheet) to get 10mm. Which is why there is a WB difference of 10mm (not 3mm).

I think that sows things up, yes? Time to go ride in this 118* heat.

AnthonyG

Stack and Reach are what they are. Stack and Reach are measured on an X,Y axis with the centre of the BB being the 0,0 point. When manufacturers quote Stack and Reach you can count on them having been measured on an X,Y axis and they CAN be directly compared.

What riders do later with stems to position their effective Reach and Stack is up to them but they are based on the frames Stack and Reach as stated by the manufacturer. If you look at your current frames Stack and Reach you CAN directly compare it to a prospective frames Stack and Reach to see what changes there will be, in front of the BB, between frames.

Regarding the 60cm and 62cm frames we were discussing. The 2 frames had different seat tube angles. The 62cm frame nominally moves the saddle back however when you place the saddle at exactly the same position on both frames in relation to the BB then the 62cm frame was only 3-5mm ( I haven't got the specs in front of me at the moment) longer in Reach than the 60cm frame. It's not much difference.

The frame geometry is a bit of a Red Herring in regards to Stack and Reach and I'm sorry if I bought into it earlier. Stack and Reach work perfectly well to compare similar types of frames. If you were comparing a beach cruizer to a TT bike there may be some errors but who does this anyway.

Ryder1

I do! I ride and shop all kinds of on/off road bikes, including rapidly evolving full-suspension bikes with nutty actual-vs-effective STAs, options for different fork lengths and wheel sizes, sag, dynamic sag, widely varying stem/bar set-ups, frame "chips" that alter geo, anti-squat %, etc. -- waaay more complex than this roadie stuff. And gravel bikes are sorta different esp. with their longer forks and purpose. Or installing straight bars or alt bars on a frame originally designed for drop-bars, etc.

But even within road bikes, it's helpful. Consider: if the Domane 62 had another 10mm of stack (via HT), it's Reach would be listed as identical to the 60. The casual observer might think they're the same "length" but it's just not the case.

AnthonyG

Your still not comparing fit between off road bikes and road bikes. Different riding postures and handlebars which renders any comparison meaningless. Reach is only measured from the BB forwards to the centre top of the head tube. When comparing two bikes you assume that the seat is positioned exactly the same on both bikes and that your stem and handlebars are the same. The Reach and Stack measurements inform you of where the handlebars will be in relation to each other. Now when I assess frames I do take the seat tube angle into account to get an idea of where it may or may not be possible to locate the saddle but this is different data.

What Reach and Stack tell you ARE directly comparable measurements. If you change the seat position, the stem or the bars then that's other changes that YOU have made.

Reach and Stack is very specific information for use by those who understand what it means.

AND the total length of a bikes wheelbase is completely irrelevant to fit. Fit is measured inline with the saddle/handlebars and its ONLY the distance here that's relevant. Not the wheelbase. If a 60cm frame and a 62cm frame have the same Reach then they have the SAME Reach.

Ryder1

In addition to my initial calculation (7+3=10mm), and two corroborating calculations, I also gave lots of examples to illustrate my point: Reach is not interdependent of Stack, and so Stack must be accounted for (which was the "7" part). I can't make it any clearer.

Meanwhile, you keep talking "around" the issue, and making odd statements (are you using a language converter, or is English your second language?- no offense), which suggests you still don't understand. If you do understand, please provide an example of what you mean by comparing Reach "directly." Above you said 386-383=3mm (well, actually you said it was 5mm before I corrected your subtraction effort). Is this the entirety of your analysis?

Ryder1

I just saw this. You really haven't yet grasped this stuff, have you? Good grief, dude. Just accept that math is not your bag. Maybe one of your kids can help you with it.

elcruxio

You really are not getting the whole reach and stack thing are you?
Reach is reach.
Stack is stack.
They refer to the frame measurements.
They are the exact measurement as pointed out in the geo graph.

Now a 60cm and a 62cm frame can easily have the same reach, say 600mm. But the difference usually in these cases is that the seat tube and head tube of the larger frame is longer, hence stack is higher on the 62cm frame. But the reach can still be the same in the frame.

I kind of get what you're probably trying to say. With the lower stacked bike you need to put more spacers under the stem to get the same stack as with the higher stacked bike and thus due to the head tube angle you are effectively making the reach of the handlebar shorter. But this has NOTHING to do with the frame stack and reach which are what they are.

So the dilemma we have here is between 'actual' and 'effective'. If you use a high spacer stack (like I do) then you have a shorter effective reach to the handlebar even if the frame reach is what it is. If I were to use a bigger frame with the same reach but higher stack on the frame I'd need to shorten my stem to I could get my handlebar in the same position it is now.

AnthonyG

Ryder1. Your the one who has not grasped it.

If a 60cm frame and a 62cm frame have the SAME Reach, then they have the SAME Reach. You can take it to the bank. Is the front centre distance different in order to achieve this? YES!

But still, if the Reach is the same, the Reach is the same. There are NO geometrical calculations used to calculate Reach and Stack. They are measured on the X,Y axis from the centre of the Bottom Bracket to the top centre of the head tube.

That's it. Nothing more, nothing less.

Ryder1

Do you think I'm ********? Of course I get it. Who doesn't? They're friggin' frame measurements. I've simply gone a step further by APPLYING THOSE MEASUREMENTS INTELLIGIENTLY to the task of bike fit, Domane 60 vs. 62 in this instance. This confuses some and makes them think I don't know how a bike's geo is measured and reported.



Agreed. The seat tube length has nothing to do with it, but whatever.


Agreed. The frame numbers are what they are. How could then not be? But those stem spacers will impact the size/fit of the bike (for a given rider), which is why you introduced the word "effectively" when describing Reach.


Agreed. You understand how a frame is measured, but you're also APPLYING those measurements to how a bike will fit you, which can be useful. And you intuitively understand that, while frame measurements obviously remain static, Reach is not interdependent of Stack when comparing different bikes (which is why you again invoked "effective" reach).


Thanks for chiming in. You started by chiding me, but then came around.

Ryder1

I don't disagree. That's all obvious. But when comparing one bike to another, you have to control for Stack variances between the two. Otherwise, you're not holding the other variables static. Once you control for Stack variance, THEN YOU CAN COMPARE REACH DIRECTLY. But not until then. That's why 3mm is a misleading number, which is I corrected you two agonizing weeks ago.

AnthonyG

Ryder1. Please stop giving advice on fit to other people. What you do for yourself is up to you.

You are giving incorrect advise to the Original Poster in this thread or others who may read this thread looking for advice. You just don't understand Reach and Stack. Reach and Stack are numbers to be used by people who understand them. On there own, Reach and Stack don't mean anything much at all. Reach and Stack ARE numbers to be used to compare two similar frames to understand the differences between the two in regard to the reach and height of the head tube.

Nothing more, nothing less.

https://www.trekbikes.com/us/en_US/b.../1460000-2017/

This is our reference.

the 60cm frame has a 579mm effective top tube. The 62cm has a 593mm effective top tube. You could be forgiven for thinking that you will need to reach 14mm further forwards to the handlebars yet the Reach says different.

The 60cm has a 383mm reach. The 62cm has a 386mm reach. Only 3mm longer.

How? If you look at the specifications you will find that the 62cm frame has a more relaxed seat tube angle. Its moved the seat back. Also, as you are harping on about, the longer head tube length has move the top of the head tube closer.

Guess what? I don't need to work out the geometry to know this. Its a figure that has been measured for me by the manufacturer and its called, "Reach" or "Stack".

Who knew?

What this information tells an EXPERT is that after locating the saddle in the same place on both bikes in relation to the BB then the Reach forwards to the top of the Head Tube is only 3mm longer on the 62cm than on the 60cm.

I don't know why we have had to argue for a page on this.

This information can be used in lots of ways. Someone may have found their perfect fit but are using a really tall/long/short stem to get there. Using Reach and Stack figures they can assess how a different frame may alter the stem they need to use.

Regarding the Original Poster. The OP was concerned that the 62cm would have a really long Reach in comparison to the 60cm frame. I read the specs and it doesn't. Once the saddle is placed in the same spot on both bikes negating the difference is seat tube angle then the reach forwards is only 3mm further.

Nothing much at all.

Ryder1. You think your right because others have stoped arguing with you. On one hand I SHOULD stop arguing with you myself. You know how the saying goes.

However. This is a public forum and people come here for good advice.

Ryder1. STOP giving advice. Your wrong.

Ryder1

Why would anybody care where the top of the head tube is? I don't grip the top of my HT, I grip my grips. And I will place my grips where I want them, irregardless of where the top of the HT is. The upshot of this is, when comparing 60 vs. 62, you must mathematically dismiss of the extra 25mm of HT length on the 62 because it's perverting the Reach difference between the two bikes (by 7mm). But you're not doing this, which is why you're getting the misleading number of 3mm (or 5mm, depending on your subtraction skills on a given day). I've made this AGONIZINGLY clear in my previous posts. I'm afraid you just don't understand the math.

Once you place the bars/grips in the same place, you get a 10mm delta. This is the distance that the HT has moved forward in space on the 62 vs. the 60, as measured at the *BOTTOM* of the HT, or at 100mm up the HT, or at 200mm up the HT (which is FAR superior than measured at the top of the HT, which is a random place that won't affect actual rider fit, see?). 10mm is the critical measurement when comparing the two bikes because it actually speaks to how the rider will *FIT* differently on the two bikes. Websites like Stack and reach calculator make these comparisons easy. Give it a shot. Play around with it.

I just don't think you grasp the math and instead hope you can find intellectual shelter under the ALMIGHTY BIKE INDUSTRY's magical "Reach" number. But direct comparisons of Reach between two bikes is not possible because Reach is a function of a whole bunch of variables (nearly as many as ETT). It's not like chain stay or seat tube length. It's only marginally better than ETT, and actually more dangerous because stack tends to vary more between bikes than STA. I think you'd actually be better off if you stick to comparing ETTs - LOL! In this case, you would have only been off by 4mm instead of 7mm.

AnthonyG

Your making things FAR too complicated and you really don't get it Ryder1.

Here's where your going wrong. Placing the handlebars in the same place, ISN'T what Reach and Stack are about principally. Its about placing the SADDLE in the same spot and calculating where the hands will move to assuming the starting position is the SAME bars and stem.

Could you use Reach and Stack to figure out what changes would be needed on a new frame to place the bars in exactly the same place as an old bike? Yes!

Yet, if you were doing that then you would straight up rule out any frame that wasn't close in Reach and Stack to you old frame. That's just how you would use Reach and Stack.

So back to the case in hand. The OP WANTED to increase handlebar height without increasing the stretch to the bars.

The Reach and Stack figures showed that the Stack would be increased considerably with only a minor (3mm) increase in Reach.

You can't see this yet you insist on offering incorrect advice. I really shouldn't have to convince you of anything Ryder1. Your the one who needs to learn Reach and Stack.

DaveSSS 

It would help for the OP to post his actual saddle height, from the center of the crank. Then you don't have to wonder about the inseam measurement.

AnthonyG

Maybe but then again I'm not telling the OP how he HAS to fit on a bike. The OP wanted higher handlebars (edit WITHOUT) an extra stretch to the bars. The Reach and Stack figures showed that he could have extra height with only a marginal extra stretch (3mm) with the 62cm frame.

Ryder1 is overthinking it and just refuses to accept where he's going wrong even when its clearly pointed out.

Yes, if you measured from the BASE of the head tube back to the BB then the 62cm frame is a bit longer but this isn't about where the BASE of the head tube is, its about where the TOP of the head tube is. Ryder1 knows this already but still doesn't get it. Its the measurements along the plane of the handlebars and the saddle that count. Measurements along any other plane don't matter at all to fit.

EDIT: and I'm going to have to edit this because some still won't get it. Its about the handlebar MOUNTING point. Yes the bars themselves may be curling forwards and down yet Reach and Stack are nothing more than a COMPARATIVE measurement for where the handlebar MOUNTING point is.