What's your thoughts on bike geometry?

Victor I

aka Ridgehog
I don't know what length the crank arms on my Hightower are, but what I found worked for me was to just put extra air in the shock and keep it on firm most of the time. Obviously you then don't get to use the full travel, but you gotta make some tradeoffs or hit your pedals on every rock on the trail. Or I guess you could learn how to ride a bike and try to time your pedal strokes, but nobody's got time for that.
I have the same issue with my Hightower but rarely get peddle strikes on my Hardtail. Everything has trade offs. Never thought about suspensions or geometry until the past couple of years. Old school bikes didn’t handle as well but didn’t have to think about much other than try to avoid an OTB.
 

Jmann

Well-Known Member
I am 6’3” with an even split between legs and torso. I ride XL bikes. The latest geometry (short headtubes, short stems) puts me way too low in the front relative to proper saddle height and way too cramped. How is it that an XL FS bike with a 20-21” seat tube, 13” BB height, comes with a zero degree 50mm stem and two spacers? Feels like early 90’s NORBA XC geo 🤨. I wish manufacturers would leave more steer tube to play with so I didn’t always have to find 100-110mm, 20+degree riser stems to get the bars closer to level with the saddle, which puts me in a more balanced position for technical riding rather than feeling that I’m going to go over the bars on the next technical descent.
I have the same issue. Santa Cruz is especially bad with really short steerer tubes. I hate the look of riser bars or a positive rise stem, but without it I’d have a 5” saddle drop to bars. I have to remember to specifically ask for the fork to be cut high on new bikes.
 

JDurk

Well-Known Member
Just went down this rabbit hole of reach/stack as I was looking at the new Pivot Trail 429. Early conversations with the LBS was being told I should be on a L because frames run small, all my bikes are M with me being just shy of 5'8" and almost a 32" inseam. Looking at Pivot's size recommendations, small: 5'4" - 5'9", medium: 5'8" - 5'11", large: 5'10" - 6'2". Obviously I'm not a L.

My current 3 bikes are all old school, XC race geometry 29" wheels, 100mm FS, 100mm HT and rigid SS. Have all the cockpits pretty much dialed in to the same dimensions and feel very comfortable on all. Here's the comparison.
FS: Stem=90 TT=593 ST=17.5" Stack=611 Reach=412
HT: Stem=90 TT=593 ST=17" Stack=603 Reach=414
SS: Stem=80 TT=609 ST=16.4" Stack=620 Reach=425
Trail 429
Sm: Stem=?? TT=595 ST=14.5" Stack=593 Reach=430
Md: Stem=?? TT=628 ST=15.5" Stack=604 Reach=460

Based on this, looks like I would be on the Sm 429 with a long stem and shitload of seatpost sticking out or a med with a short stem. For the type of riding I do, leaning more towards a Mach 4 SL with a 120mm fork if I decide to get a new bike.
 

stb222

Love Drunk
Jerk Squad
Just went down this rabbit hole of reach/stack as I was looking at the new Pivot Trail 429. Early conversations with the LBS was being told I should be on a L because frames run small, all my bikes are M with me being just shy of 5'8" and almost a 32" inseam. Looking at Pivot's size recommendations, small: 5'4" - 5'9", medium: 5'8" - 5'11", large: 5'10" - 6'2". Obviously I'm not a L.

My current 3 bikes are all old school, XC race geometry 29" wheels, 100mm FS, 100mm HT and rigid SS. Have all the cockpits pretty much dialed in to the same dimensions and feel very comfortable on all. Here's the comparison.
FS: Stem=90 TT=593 ST=17.5" Stack=611 Reach=412
HT: Stem=90 TT=593 ST=17" Stack=603 Reach=414
SS: Stem=80 TT=609 ST=16.4" Stack=620 Reach=425
Trail 429
Sm: Stem=?? TT=595 ST=14.5" Stack=593 Reach=430
Md: Stem=?? TT=628 ST=15.5" Stack=604 Reach=460

Based on this, looks like I would be on the Sm 429 with a long stem and shitload of seatpost sticking out or a med with a short stem. For the type of riding I do, leaning more towards a Mach 4 SL with a 120mm fork if I decide to get a new bike.
I am surprised you run such a short stem on the XC geo, a long stem is usually the tell tale sign of “old” geo.

FWIW, I think most people ride a size too large on these modern bikes.
 

JDurk

Well-Known Member
I am surprised you run such a short stem on the XC geo, a long stem is usually the tell tale sign of “old” geo.

FWIW, I think most people ride a size too large on these modern bikes.
I tried 100mm stems on both bikes and felt too stretched out.
 

Ian F

Well-Known Member
I got used to pedal strikes from my DH racing days. I ran my M-1 so low and slack that it was rare when I didn't have at least one strike per run. That was another reason I ran clipless as well. And that was with 165mm cranks.

My Spot came with 170 cranks OEM. I have 170 cranks on the Chameleon. The Megatower had 175 cranks when I built it, but I have a set of 165 eeWings to go on it when I switch it to 12 spd (maybe this weekend since it looks pretty wet...).
 

jimvreeland

Endurance Guy: Tolerates most of us.
Just went down this rabbit hole of reach/stack as I was looking at the new Pivot Trail 429. Early conversations with the LBS was being told I should be on a L because frames run small, all my bikes are M with me being just shy of 5'8" and almost a 32" inseam. Looking at Pivot's size recommendations, small: 5'4" - 5'9", medium: 5'8" - 5'11", large: 5'10" - 6'2". Obviously I'm not a L.

My current 3 bikes are all old school, XC race geometry 29" wheels, 100mm FS, 100mm HT and rigid SS. Have all the cockpits pretty much dialed in to the same dimensions and feel very comfortable on all. Here's the comparison.
FS: Stem=90 TT=593 ST=17.5" Stack=611 Reach=412
HT: Stem=90 TT=593 ST=17" Stack=603 Reach=414
SS: Stem=80 TT=609 ST=16.4" Stack=620 Reach=425
Trail 429
Sm: Stem=?? TT=595 ST=14.5" Stack=593 Reach=430
Md: Stem=?? TT=628 ST=15.5" Stack=604 Reach=460

Based on this, looks like I would be on the Sm 429 with a long stem and shitload of seatpost sticking out or a med with a short stem. For the type of riding I do, leaning more towards a Mach 4 SL with a 120mm fork if I decide to get a new bike.

I'm in the same size range. For drop bars I size down and run a long stem, for MTB I size up to the Medium and ride a shorter stem. My most XC setup uses an 80mm stem. My Spearfish had a 60mm.
 
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JDurk

Well-Known Member
I'm in the same size range. For drop bars I size down and run a long stem, for MTB I size up to the Medium and ride a shorter stem. My most XC setup uses an 80mm stem. My Spearfish had a 60mm, same as my new REEB.
So you know who may be interested when you're ready to sell.
 

jdog

Shop: Halter's Cycles
Shop Keep
Just went down this rabbit hole of reach/stack as I was looking at the new Pivot Trail 429. Early conversations with the LBS was being told I should be on a L because frames run small, all my bikes are M with me being just shy of 5'8" and almost a 32" inseam. Looking at Pivot's size recommendations, small: 5'4" - 5'9", medium: 5'8" - 5'11", large: 5'10" - 6'2". Obviously I'm not a L.

My current 3 bikes are all old school, XC race geometry 29" wheels, 100mm FS, 100mm HT and rigid SS. Have all the cockpits pretty much dialed in to the same dimensions and feel very comfortable on all. Here's the comparison.
FS: Stem=90 TT=593 ST=17.5" Stack=611 Reach=412
HT: Stem=90 TT=593 ST=17" Stack=603 Reach=414
SS: Stem=80 TT=609 ST=16.4" Stack=620 Reach=425
Trail 429
Sm: Stem=?? TT=595 ST=14.5" Stack=593 Reach=430
Md: Stem=?? TT=628 ST=15.5" Stack=604 Reach=460

Based on this, looks like I would be on the Sm 429 with a long stem and shitload of seatpost sticking out or a med with a short stem. For the type of riding I do, leaning more towards a Mach 4 SL with a 120mm fork if I decide to get a new bike.
I had a large on the old 429. and I got a large on the new one

Staring at the numbers alone I At 5 foot 9 1/2 was ready to buy a medium. At the last minute I decided to get another large just to see what a longer bike would feel like. On the old 429 I had to run a 65 stem to be comfortable and on the new one I’m running a 40 mm stem. The modern bikes just work better in my view with the shortest time you can run on them. I happen to think that running a longer stem than normal can somewhat compromised ride handling.

I’ll add here that this bike reminded me immediately of the Mach 4 sl 120 when climbing. And of course it feels a lot like a switchblade when Descending. I’ve ridden all three of these a fair bit and this by far is my favorite of the bunch. I’ll also add that there’s no more M4s to be found this year unless you can find one somewhere already built on the shop floor. I shouldn’t speak about things that I am only guessing to be true, but if you look deeply into where this bike is actually made and see the unrest is going on in that country, the writings on the wall in terms of when these bikes will be made again. It’s not the only factory that Pivot uses.


this is The first bike I’ve builtwith a mixed wheel size. I’m running a 27 x 2.8 on the rear and a 29 x 2.35 on the front. It sounds like it would be fucking crazy to ride but it’s really nice. It feels totally normal now and a 29er rear wheel.actually feels really goofy. The traction when climbing Is superb. Most of what I didn’t like about a true 27+ bike is erased with a 29er front wheel.

I have heard from a few really good sources that this (mixed wheel size) is going to become more common place in the next couple years. It’s already happening on eBikes in a big way. DH bikes too

Ignore my stupid looking saddle. In my Dumbass 24 hour racing days, I completely destroyed my prostate. I had a really rough run of prostatitis and this is THE saddle that allows me to have zero pressure on my taint.
4F1D6583-F398-4F04-9AEF-1D8B3D20CA4D.jpeg
 

JDurk

Well-Known Member
I had a large on the old 429. and I got a large on the new one

Staring at the numbers alone I At 5 foot 9 1/2 was ready to buy a medium. At the last minute I decided to get another large just to see what a longer bike would feel like. On the old 429 I had to run a 65 stem to be comfortable and on the new one I’m running a 40 mm stem. The modern bikes just work better in my view with the shortest time you can run on them. I happen to think that running a longer stem than normal can somewhat compromised ride handling.

I’ll add here that this bike reminded me immediately of the Mach 4 sl 120 when climbing. And of course it feels a lot like a switchblade when Descending. I’ve ridden all three of these a fair bit and this by far is my favorite of the bunch. I’ll also add that there’s no more M4s to be found this year unless you can find one somewhere already built on the shop floor. I shouldn’t speak about things that I am only guessing to be true, but if you look deeply into where this bike is actually made and see the unrest is going on in that country, the writings on the wall in terms of when these bikes will be made again. It’s not the only factory that Pivot uses.


this is The first bike I’ve builtwith a mixed wheel size. I’m running a 27 x 2.8 on the rear and a 29 x 2.35 on the front. It sounds like it would be fucking crazy to ride but it’s really nice. It feels totally normal now and a 29er rear wheel.actually feels really goofy. The traction when climbing Is superb. Most of what I didn’t like about a true 27+ bike is erased with a 29er front wheel.

I have heard from a few really good sources that this (mixed wheel size) is going to become more common place in the next couple years. It’s already happening on eBikes in a big way. DH bikes too

Ignore my stupid looking saddle. In my Dumbass 24 hour racing days, I completely destroyed my prostate. I had a really rough run of prostatitis and this is THE saddle that allows me to have zero pressure on my taint.
View attachment 155281
@jdog thanks for info. Haven't really done any research about availability of the Mach 4. Will probably just stick with my current ride and look to do something next year with Steve at Caffeinated.
 
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Monkey Soup

Angry Wanker
Most people are riding bikes that are too big and long. Interesting article, read through the fluff and get to the part where the pros are sizing down and riding narrower bars:


Bike industry is like any other, creating solutions to problems they created. Your long, slack, low bottom bracket having big-wheeled sled was the best thing ever last year. Now they need to sell more bikes (that they can’t even make yet), so the solution to getting your agility back is mullet bikes? Get out of here. Maybe ride a bike that fits you, and not what fits the latest trends?
 

Ian F

Well-Known Member
Most people are riding bikes that are too big and long. Interesting article, read through the fluff and get to the part where the pros are sizing down and riding narrower bars:


Bike industry is like any other, creating solutions to problems they created. Your long, slack, low bottom bracket having big-wheeled sled was the best thing ever last year. Now they need to sell more bikes (that they can’t even make yet), so the solution to getting your agility back is mullet bikes? Get out of here. Maybe ride a bike that fits you, and not what fits the latest trends?
I don't know... amusingly, the bike I have (Santa Cruz Megatower) isn't part of that test, for whatever reason. I rarely see that bike mentioned in discussions about enduro bikes, for better or worse. Not entirely sure why... I've been happy with it. It's a big, long bike, but that is what I wanted as the intent was to replace a full-on DH bike, but can get pushed into trail duty once in awhile. It has served that function well.

For once, none of the new bikes out there make me want to move on from the bikes I currently have.
 

Monkey Soup

Angry Wanker
I don't know... amusingly, the bike I have (Santa Cruz Megatower) isn't part of that test, for whatever reason. I rarely see that bike mentioned in discussions about enduro bikes, for better or worse. Not entirely sure why... I've been happy with it. It's a big, long bike, but that is what I wanted as the intent was to replace a full-on DH bike, but can get pushed into trail duty once in awhile. It has served that function well.

For once, none of the new bikes out there make me want to move on from the bikes I currently have.
I think that long bikes definitely have their place, they’ve proved it in the DH world, but DH is more a sprint than a marathon. It’s probably more tiring to muscle around an overly long bike on a longer trail ride vs. something a little more moderate, especially in our neck of the woods. I would imagine those pros at the pointy end of the spear experimented with long, short, mullet, etc. before they settled on their current sizes. Interestingly, one of the primary effects of mulleting a bike is shortening the reach.
 

Gene

The Dancing Machine
Great video, but I disagree with going shorter.

I had a conversation with @jdog after I demo’d a Large Kona.

My only bike today is a Niner Jet9 Large which I purchased from Halter’s many, many years ago in a faraway plaza that no longer exists.

Riding that Kona in today’s world of Large frames made me feel like I was going over the handlebars.
 

one piece crank

Well-Known Member
This is a good video @Jefflenosky. I have not gone down the latest geometry trend path, partly because I only ride HT and rigid bikes, but also because at 6’4” I have a different perspective on frame size and find I prefer a slightly smaller frame.

When I set-up a bike, in addition to considering stack & reach, I also measure the BB-to-grip-center and the rear-axle-to-grip-center, which I adjust through seat post, stem & riser-bar selection. These fixed HT dimensions translate directly to my riding style, desired cockpit fit and feel, and are easily transferred from one bike to another. I do measure wheelbase, but to be honest, it is simply the result of what I’ve built. With the exception of my Fat Bike, I like smaller wheels too - a faster, more responsive feel is totally suited for 90% of the East Coast trails I ride, you know, up/down/rocks/off-camber/roots/logs/drops/stream-beds/etc (i.e. not flat, sandy/gravelly stuff).

Will this work for you? Who knows, but this process comes from decades of riding what “I” like.

Also, thanks for not bringing up head tube angle…
 
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