What's your thoughts on bike geometry?

Jefflenosky

Active Member
Hey everyone,
I'm curious to get a solid east coast perspective on bike geometry. There's some really aggressive trends in the bike industry right now that are driven by the west coast and I recently made this video talking about why some of them might not work for us. It also talks about why my hardtail in particular is definitely not "on trend". Check it out and let me know your thoughts!
 

Victor I

aka Ridgehog
Trends are constantly changing and helps keep it interesting. If you ask 9 out of 10 people, slack will probably be the choice. I like how you touched on FS vs Hardtail geo in your vid. I obtained a hardtail a few months ago with a 67.4 head angle(not on trend either) and ride it more than my FS. Love the efficiency and am surprised how well it works on tech. Many people prefer ultra slack these days but much easier to flick around a moderate length/head angle bike at places like Jungle, High Mountain, Ringwood, Sterling... I’m actually faster on this bike and am having more fun. To me having fun is the best part of riding.
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jdog

Shop: Halter's Cycles
Shop Keep
A-plus on the stack and reach drawings. Many customers I’ve dealt with lately talk about these dimensions but don’t actually understand what they are measuring.
 

-YETI-

Active Member
I thought this was really interesting about how ideal reach differs between HT and FS. I haven't ridden a HT in years- but was always surprised by how 'short' the geo charts were in comparison. Great explanation of this with the marker on the wall!
 

Ian F

Well-Known Member
The biggest adjustment I've had to make (and still have to constantly work on) is leaning a modern geo bike as much as steering it, in order to get around tighter corners. However, this isn't easy sometimes when riding janky, rocky and generally slower East Coast trails.
 

pygmypony

Well-Known Member
great vid and explanations...it also prompted me to head over to the R.A.D video you mentioned and do some measuring there...

prompted me to order a shorter stem for my Pivot 429 FS, which has been awesome, but has felt a bit long...based upon the measurements for RAD, my 52mm stem may be a bit long
 

a.s.

Mr. Chainring
I've been saying for years how these new geometries are not ideal for our NE trails. The bike shops and manufactures are pushing people to “size up” but I agree with you @Jefflenosky. If you’re in between sizes, go for the smaller one. It’ll handle better on our twisty, technical trails.
 

jdog

Shop: Halter's Cycles
Shop Keep
I've been saying for years how these new geometries are not ideal for our NE trails. The bike shops and manufactures are pushing people to “size up” but I agree with you @Jefflenosky. If you’re in between sizes, go for the smaller one. It’ll handle better on our twisty, technical trails.
I sort of disagree here. I’m 5 foot 9 1/2 and most brands put me on a medium. I have short legs and long torso. On a medium I have to run a longer stem,Which can negatively impact handling. I’ve tried both and I keep landing on a large with a shorter stem. This feels better going downhill for sure.
 

ebarker9

Well-Known Member
I sort of disagree here. I’m 5 foot 9 1/2 and most brands put me on a medium. I have short legs and long torso. On a medium I have to run a longer stem,Which can negatively impact handling. I’ve tried both and I keep landing on a large with a shorter stem. This feels better going downhill for sure.

It seems like at least two different things are being discussed. There's the stack/reach/RAD discussion about fitting the contact points of the bike to your body size. That seems like it can be done "mostly" independent of the types of trails being ridden. The "RAD" approach outlined in the Joy of Bike video makes a lot of sense to me. That sizing is based efficient movement for aggressive riding and making the distance between the feet and hands optimal for power generation when pumping, jumping, dropping etc. The comments about maneuverability on tight trails, to me, sounds more like a wheelbase, chainstay length, HT angle etc discussion. They're obviously related but have somewhat separate implications. Certainly not a straightforward thing.

At least from my experience, I can see where having a shorter bike on tighter trails makes sense, but I've really only found advantages to the more modern geometry. Even on tighter tech trails, feeling more balanced and in the middle of the bike gives less of a sensation of fighting going over the bars and allows you to be in a consistently better riding position and "attack" the trail more vs surviving. I haven't found much of a hinderance to making tighter corners although I'm sure there's a learning curve.
 

Tim

aka sptimmy43
I sort of disagree here. I’m 5 foot 9 1/2 and most brands put me on a medium. I have short legs and long torso. On a medium I have to run a longer stem,Which can negatively impact handling. I’ve tried both and I keep landing on a large with a shorter stem. This feels better going downhill for sure.
I'm in the same boat. 5'10 with long arms. I've found through trial and error and geeking out over bike fit over the past 3 years that I prefer a large with a short stem. I stumbled across the RAD video a couple weeks ago and used that to check my fit and low and behold I was right on the money.
 

serviceguy

Well-Known Member
I sort of disagree here. I’m 5 foot 9 1/2 and most brands put me on a medium. I have short legs and long torso. On a medium I have to run a longer stem,Which can negatively impact handling. I’ve tried both and I keep landing on a large with a shorter stem. This feels better going downhill for sure.
Same here, I'm in between sizes, but when I tried a medium I felt definitely 'squeezed in'. Going with a longer stem seemed counterproductive in terms of maneuverability so I've always gone with a large. So far so good.

I did not perceive @Jefflenosky 's argument being about size choice as much as pure geometry within the same size, which is more of a subtle subject and would definitely come into play when having a custom bike built (also more of a 'shades of gray' rather than 'black and white' type of debate). That said I really enjoyed the video as it clarifies very well the geo parameters and how they may affect our rides (even though I must confess that most moves in the video are way out of my league anyway). Would be interesting adding to the comparison a fully rigid bike, whaddaya say @Mitch ?
 

Paul H

Fearless OOS Poser
I am also in between sizes and I wish I can choose a size based on how it rides but boo hoo me... my back prefers a larger bike and that overrides how a smaller bike rides better.
 

dmkalemba

Well-Known Member
Agree with the long torso guys. i am 6' 1: with just over 32" inseam.. while these freakish measurements are good for swimming and body surfing, it always makes bike fit a pain in the ... back. I always feel more comfortable on the next bigger size bike. I think the slacker head tube helps as well, i feel much more comfortable in turns. In rock gardens the steeper head tube and smaller frame put me way to far out front, especially when the suspension is compressing. Thanks @Jefflenosky for the demonstration, now i know why :)
 

Ian F

Well-Known Member
I've tended to be between a M and a L for years and would often choose a M based on my BMX background. It was only when I started riding modern bikes did a L start to feel "right". Previously, they always felt too big. Although less through thought process and more blind luck, my two F/S bikes are L and my one HT is a M.
 
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Jmann

Never gonna let you down.
The biggest advantage for new school geo for me was the steep seat tubes. I run a lot of seat post and when bikes had 72-73 seat tubes it put my butt way too far back. Steep climbing was miserable, even with all my weight forward I would wheelie out on steep switch backs.

The “rad” measurement doesn’t work for me. My rad measurement was 3 and 3.5 inches shorter than the rad on my hardtail and full sus. I’ve had a lot of bikes and know what works for me. My Chromag has a 65 HA, 76 SA and a 483 reach, and it rides great even on tight trails (Allaire, mahlon, jungle). Of course this is my personal experience.

What doesn’t work great for me with new school geo is the low bottom brackets and pedal strikes. Also why I tend to prefer hardtails. My yeti has a higher than average bottom bracket but I still have to work at avoiding pedal strikes.
 

JimN

Captain Wildcat
Team MTBNJ Halter's
What doesn’t work great for me with new school geo is the low bottom brackets and pedal strikes.

This. I don't know anything about bikes or geometry, but I really liked my Hightower. I really couldn't get over the pedal strikes though. Sucks that they design bikes out west where there are apparently no rocks.
 

a.s.

Mr. Chainring
This. I don't know anything about bikes or geometry, but I really liked my Hightower. I really couldn't get over the pedal strikes though. Sucks that they design bikes out west where there are apparently no rocks.
Yes, agreed. I got bucked off my Orbea twice due to a nasty pedal strike. Now I’m constantly aware when I go through rock gardens and try to time my pedal strokes accordingly. It’s a little distracting and nerve racking when I’m going full tilt.

I read a review somewhere where the tester crashed from a pedal strike. He recommended going with 165 or 170 crank arms. I think that’s the norm for these new bikes?
 

JimN

Captain Wildcat
Team MTBNJ Halter's
He recommended going with 165 or 170 crank arms. I think that’s the norm for these new bikes?

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.
 

stb222

Love Drunk
Jerk Squad
I sort of disagree here. I’m 5 foot 9 1/2 and most brands put me on a medium. I have short legs and long torso. On a medium I have to run a longer stem,Which can negatively impact handling. I’ve tried both and I keep landing on a large with a shorter stem. This feels better going downhill for sure.
I am almost the same exact height as jdog but the opposite proportions, long legs, short torso. That being said, when I went from a 54 to 56 on my road bike, I also added 10mm to the stem 🤷🏼‍♂️

for the mtb, I get the best of both worlds, shorter bike and a short stem. The down side of those is I can’t run my dropper slammed all the way in (still lots of post out) , which is negative style points.
 

icebiker

JORBA: Morris Trails
JORBA.ORG
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.
 
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