How Much Reach is Too Much Reach?

Has anybody given any thought on how handlebar height (effective stack?) and the reach play along with each other?

Of course?

And?

I find a higher stack to be more comfortable.  Especially if you like to ride with a body position towards the rear of the bike or are riding truly steep trails.  However there is a limit before you can’t weight the front properly.  So reach/ head tube angle, and chainstay length are all a factor in how high you can go.  Longer wheel base with a reasonable reach number like a transition spire can definitely allow a lot of additional stack height compared to something with more conservative numbers.  But whether that’s a good thing really depends on your riding style.  You can always run spacers or a bigger fork and an angle adjust headset but you can’t shorten a head tube.

The reason I'm asking I've now done two rides on a 55 mm rise bar instead of the previous 35 mm and I moved a 1 cm spacer from above the stem to below the stem (additional rise). And added a 35 mm step to replace the original 40 mm, but that was caused by a necessity, it wasn't done intentionally.
oupled with a bigger upsweep and backsweep angle, the grips are quite a few cm higher and a bit more backwards as well. The bike does have a fairly short headtube, 120 mm in XL, so the grips weren't particularly high for an XL before, despite a 35 mm rise bar. 

I've come to think the long reach of the bike by itself wasn't an issue, the cockpit height might have been the driving factor as my torso was leaned over horizontally too much, giving me the wrong posture. I recently started feeling like I can't lean my bike over with me keeping upright and coming to a conclusion (because of skiing in part and discovering a few details about the technique there as well) that a more upright position might be beneficial at the same (frame) reach value, not just by reducing the reach.

It's early days, I've done two rides on the setup so just getting to grips with it, but there are some 15-year-old-bike (Commencal Meta from 2008) vibes to it for some reason. Can't comment on how it handles yet, but it does feel like it's a bit easier to flick the bike around. I do worry that with the arms not being outstreched as much as before I'm going to hit a hole or jackknife under a rock/root and get packed onto the bars, but for now it's just a worry. Will see what more riding will bring about.

Cannot give short answer and I don't have energy for a litany. The shortest version I can come up with is the obvious(hopefully), that what it does to reach/stack depends entirely on what bar roll you prefer. Some people think it's preferable to run higher bars instead of stem spacers, which MIGHT be true. But if I was going to bet, I would say more people than not run bars rolled so far back that it does pretty much the same thing as stem spacers would. I prefer bars rolled either vertically (the "rise" section of handlebars is perpendicular to the ground from side view) or slightly forward from that depending on where I ride and how my shoulders feel. For someone with similar preference, running high rise bars is actually viable option for reach preservation while adding stack. 

Uuum... playing with bar roll to achieve reach/rise correction will likely get you into a heap of different problems to put it lightly. And I never mentioned bar roll, I specifically mentioned a higher rise bar, so a different handlebar, of a different shape. And handlebar height in general.

I think you need to try it then, because bar roll is as legitimate tuning option as anything else mentioned. What makes you think that the same bar roll you use on typical trail ride is the best option for a weekend in bikepark? Also, you cannot separate rise from roll, just like you cannot separate head angle and fork offset or reach and stack in the first place. Is it a can of worms? Sure, that's why I didn't want to answer in depth lol 

I'm experimenting with it now. My range has a high stack (650mm) 25mm under the stem, had a 40mm stem and 38mm deity riser bar. Was excellent setup and felt at home.

Bored one day, I swapped a 35mm length stem over, the stack height of the stem was a bit thinner so made up the difference with another 5mm spacer to keep theoretical stack height the same, but reach reduced 5mm. Bar roll was exactly the same (neutral according to the markings on the bars)

Went out for a ride and I couldn't get weight on the front end as good, just that 5mm change threw me off. I went down 5mm of spacers and slightly better but I felt my hands were too low.

I was really surprised how such a minute change really threw me off. Maybe it was placebo or something, but definitely didn't feel "right"

In my experience, longer reach setups require higher bars to get a similar bike feel as shorter reach/lower bar setups, assuming you liked your front to rear balance on the shorter reach bike. So when I'm on a shorter bike, it typically has slightly lower bars, and vice versa. So Primoz, your experience lines up with mine. If I swap to a longer reach bike and keep bars at the same height, I feel stretched out with my weight on my hands and over the front of the bike. YMMV

I'm not trying to say bar roll is not important, far from it, just that (I think) tuning reach and/or stack through bar roll will cause a much bigger change in upsweep and backsweep (or transform into frontsweep or downsweep even) much sooner than a change in reach or stack will occur. Even more so once you take into account different up and backsweep options between different bars.

Biggest caveat to all of it? @brash mentions 'neutral roll'. What exactly is neutral roll? I mean, yeah, the zero degree roll where the backsweep and upsweep are what it says on the box. But how that translates into a 'global', on the bike upsweep and backsweep depends on the headangle. What a rider actually needs depends on the cockpit length (not reach!), saddle height and body proportions.

So, TL;DR, if people that know a thing or two about the effects try things out and don't have concrete answers, what is the industry supposed to do when it comes to newbies and 'set it and forget it' crowd to improve their riding? How to get people to test things out if they don't even know what to look for? You can just ride along and be blissfully ignorant of it all, but based on trying out different skis in the past season as a newbie it was eye opening how much of an influence on the skills and body posture different equipment has. So much so that it finally pushed me into the same on the bike.

I wish it was possible to quote just part I' m replying to but oh well. The issue with "neutral" bar roll is not that hard to fix, I actually mentioned it above, your reference point is flat ground, if the main bend of the handlebars is perpendicular to the ground, that's when both up sweep and back sweep are what they are supposed to be and if you change rise, you are only changing stack, while maintaining reach. Caveat is, the reach and stack are not really what matters in the real world as was discussed before, call it "spread" or whatever is what always changes even if the textbook reach is the same. Btw I don't agree necessarily that neutral bar roll as defined above is really neutral to riders upper extremity, the way I look at up/backsweep is that the back sweep should aim at the origin of the arm, aka shoulder. For most people it aims somwhere between belly button and crotch.

Looks dialed.  time = 5:08
 

That's Bronson Moore's stem. 

https://nsmb.com/articles/most-interesting-dude-sea-otter-2022/

Seth discovers stack

That Revel Rascal, I presume in a small has a stack of 600mm and a reach of 424mm. Reach with that stem would be in the 300's for sure now.

What is better for new and learning MTB ride, who is 174cm? shorter or longer reach?

It is between 444mm Medium and 464 Large. dont know what to choose.

 

I'd go on Large, 464mm is not THAT large. But if there's a stack of 630 that could be too much...

Medium and Large have same stack 636mm

What kind of a bike are we talking about? My Large is a 510 mm reach... 

Yt capra MX 

Ah. Reach wise I would tend to go larger (just because of their sizing), stack wise... If you like higher bars I think it will be alright. I have the same stack on mine and it's quite an exercise to get bars high enough.

There's probably no chance to try either variant? 

No, and she is starting to ride, till now 2 times on DH bike

So a virtual reach (the calculated reach at 600mm stack, a thing I found useful some years ago) is at about 482mm for size Large and 462mm for size Medium. With it in mind I'll go with Medium for 1m74.

But like Primoz said, 636mm stack could be a touch too high depending of the handlebar and what the future rider likes. Happily there is a lot of choice on the market so I think it'd be fine.

Tnx, so i guess Medium is better choice.

Figured I'd share my current experience with reach and stack going to extremes that feel like almost too much even at 6'4". I've been riding a bike recently with a 522mm reach and a pretty sizeable headtube. I don't have all the geo info yet, but it's the size the brand recommended for me. The stack is plenty tall with room to go higher, and I'm not sure if I want to.

Being rearward and upright is nice, but when the reach gets super long, the front wheel feels planted but distant. I figured going taller on the bars would help, but in this case laying the bike over into turns begins to feel more like pulling against the front wheel rather than being able to place my weight on top of it because the bars are so high. In tight turns, it feels more like sitting next to the bars while the front wheel is in a different zip code.

The rear center is just under 440mm but with I think around 20mm of rearward movement so the front wheel doesnt really feel light at all and the bike growing makes it feel like even more of a handful when trying to tighten up turns. I feel like this bike would be sweet if my average trail speed was around 30mph, but with super technical terrain where I live I think I'm going to be experimenting with different bar heights for a bit. I'm wondering if going lower will help lighten up the rear slightly to help with cornering. 

I'm in your size range but a bit taller at 6'6". My G1 had a 535 reach but only a 659mm top tube and 140mm head tube with a 79 ESTA and a massive 1350 wheelbase. I didn't like this that much.
I switched to an XXL Megatower that's only has 520 reach but a 670 top tube which effectively moves me forward on the bike but has a longer cockpit which is accomplished by the slightly slacker seat tube I think. The WB is only 1333 but that makes a huge difference for riding. The G1 felt like a battleship but the Mega is pretty agile. The Mega has a huge 150mm head tube when paired with a 170mm fork is borderline too tall. I've got a 0' rise stem and I'm looking at switching my 15mm rise bar for a 0. In most ways the Mega is a little less extreme than the G1 but I find it so much more useful. Kudos to the bigger bike for providing me with a huge bike when no other company would but it looks like Santa Cruz really did their homework and nailed the happy balance. 

I can agree that the Megatower geometry is among one of the most comfortable Ive ridden. I prefer the XL personally but I could see being just as comfortable on the XXL. I’m also able to run a lower 25mm bar than my usual 38mm rise on that bike with only 10mm of spacers below the stem. Trying a taller bar on that bike put more weight on the rear wheel than Id like so I can imagine the XXL has even more of that feeling. 

I think the telly tale sign that the reach is too long is when you see a load of headset spacers under the stem