bike geometry for up and down hill---------

[chrisx]

There are hills, and there are HILLS.
Down hill bikes are not made for going up hills. 
Where is the balance?
If you wanted a new frame what would you look for?
Say for a month long ride on a trail.

[harryonaspot]

Relaxed geometry ie a slightly slacker head angle, maybe longer seat stays and rugged. Reliable easy to fix components and a seat that fits

[wahday]

No, downhill bikes are definitely not for bikepacking. Any XC (cross country) bike is well suited for a wide range of terrain and load. I have bikepacked with my Klein Attitude 26”, Salsa El Mariachi 29er and a Gary Fisher Hoo koo e koo 26” rigid and every one has handled what I threw at it just fine. The El Mar is my favorite, though (the Klein is a close 2nd – a very comfy ride)

[chrisx]

Relaxed geometry ie a slightly slacker head angle,

Read that a lot,          relaxed geometry.               Could mean anything.

If you pedal in 22, 36 for a long while, then approach the limits of your brakes on the way down?

[harryonaspot]

Relaxed geometry generally refers to a slightly slacker head angle than the standard 71 degree country race bike head angle. You can be a little more casual about you riding not having to watch the bike on a long day in the saddle. I don't understand what you are asking about in reference to your granny and brakes

[chrisx]

There is a legal limit to the grade of a road.  Most any bike can be go up and down on a 20% grade.  When you get off the road, there are trails and such with more incline than the the roads.  Lumps, bumps, ruts, etc.  I am not asking which bike goes up and down hills.  I am asking what geometry is good for going up and down HILLS.

No, downhill bikes are definitely not for bikepacking.

   

[mbeardsl]

Whatever bike feels good to YOU going up and down hills.

It really depends on what you mean by hills and the type of terrain. A bike built to climb 20% grades won't be the same bike built to descend -20% grades.  And those wont be the same as bikes meant for chunky singletrack.  Trade offs in between to find a happy medium for everything above.

[chrisx]

Thanks for helping define the question.  now if someone knows the answer. . . . Please note, 20% is a hill not a HILL

Whatever bike feels good to YOU going up and down hills.

It really depends on what you mean by hills and the type of terrain. A bike built to climb 20% grades won't be the same bike built to descend -20% grades.  And those wont be the same as bikes meant for chunky singletrack.  Trade offs in between to find a happy medium for everything above.

[mbeardsl]

You're talking in riddles.  What exactly are you asking?  Regardless, go out and ride some bikes and see what works FOR YOU.

[chrisx]

What exactly are you asking? 

I am asking about bicycle geometry 
http://en.wikipedia.org/wiki/Bicycle_frame#Frame_geometry

what geometry makes a bike good on up hills and down hills

go out and ride some bikes and see what works FOR YOU.

how do you ride 10 different bike for a few days each to see what works

[mbeardsl]

What do you mean by hill?  6% grade paved roads? 20% rocky descents with big drops? Vastly different things.

Many shops have demo bikes that you can rent/borrow. Similarly sized friends will sometimes let you borrow.  Demo events held by bike shops/bike brands.  The big 3 do them pretty often. Etc.

[Adam Alphabet]

One bike to kill em all.
Steel hard tail, (or ti if you've got the funds)
*29"wheels with room for 2.35" rubber minimum.
*68 to 69 head tube angle
*73ish seat tube.
*16.5" to 17.5" chain stays, adjustable/interchangeable dropouts for different drivetrain preferences.
*12.5" to 12.75" BB height
*Top tube that fits you with room for stems 50mm to eeesh 100mm
*Rigid fork for touring, 100-120mm fork for shredding.
*Balance of light and strong where you need it so it's not a slug uphill and not a princess down.

Works extremely well for me for ALL the riding I do.

[chrisx]

Could not help but notice;
Vancouver , BC Is surrounded by hills.

[Area54]

Frame geometry is not the only thing to consider, you have to look at it wholistically.

Take the new Fsi 29 from Cannondale. They've re-written their book on what a fast and efficient 29 should be, slacker head angle (there's that slacker word again) but have mated it with a fork rake and length that matches the frame geo to meet their handling objectives. Shorter stays and an offset rear (think pugsley/moonlander) for stiffer rear wheel build and chainline improvement. System integration is what they call it, but I look at it as 2 components that are designed together. I'm not a dyed in the wool Cannondale fan, but I respect their engineering for performance based outcomes.

Head angle geos mean nothing if the fork is not matched to create a neutral handling front with positive caster.

[Adam Alphabet]

Could not help but notice;
Vancouver , BC Is surrounded by hills.

True, but it's the same bike I through rode the Colorado trail on, same bike I toured 2000km in Chile on (Carretera Austral included), same bike I've raced up and down the Sea to Sky Corridor (Vancouver, Squamish, Pemberton), same bike I've road toured through BC on. Same bike I'll be taking on a road trip this summer to ride the best trails Washington, Oregon, Utah, Idaho and Montana have to offer. Works well for me and my style(s) of riding with enough overlap that I don't need (or want) a garage full of 5 or more niche bikes.

[chrisx]

t I don't need (or want) a garage full of 5 or more niche bikes.

The Canadian guy seems to understand the question.

May need a dictionary and a tutor and some time to figure out what the Australian guy is talking about.  Be patient I'll figure it out.
http://www.epinions.com/content_951820420?sb=

[chrisx]

how far is too far
http://www.bikeradar.com/mtb/gear/article/recent-progressions-in-mountain-bike-geometry-39736/

[Area54]

ausglish

[Michael_S]

everyone has different preferences, slacker head angles mean better control at high downhill speeds, a steeper head angle means quicker handling in singletrack for me.
My 29er custom hardtail has a 72d head angle with a 51mm offset fork. I like the faster handling and maneuverability.  The reduced "trail" allows you to steer the bike from the bars instead of with your body.

Seat Tube angle is really a comfort thing. Most 29ers are ~73d because of the big wheels. I use a 72d to get me father back for climbing and fit.  

If I was to buy a production bike I'd get a Singular Swift and 51 mm offset suspension fork.

mike

[Area54]

Another thing to look at now if considering 29+ is rake and trail. Nope, not talking trail building here, talking about rake (the forward offset of the axle to the centreline of the steerer tube) and trail (the measurement on the ground of the projected pivot point (caster angle) of the steerer and the centre of the tyre contact patch - lets call it caster distance)

Increase the height of the tyre and the caster angle of the fork steerer moves forward, increasing the caster distance and changing the handling. More to it than just angles

Also factor in sag of a suspension fork too, this will change the caster angle significantly with 'slacker' head angles. Doesn't change so much with 'steeper' head angles.

All has to work in symbiosis.