Bike selection

[Done]

So, I guess for the time being, I'm still lead to believe that my original statement about a hard tail being more efficient is accurate.  When I sit down and look at the basic forces applied to the bike a suspension system is going to absorb energy and turn it into heat.  I think there's only two places to get energy on a bike, stored kinetic energy at the top of a hill, and the person riding the bike.  Any energy that is used to heat the suspension is energy that could of been used to propel the bike forward.

Agreed: soaking up bumps absorbs energy, which is dissipated as heat. With a full-suspension bike, the shock  absorbs the energy and gets hot. But doesn't the same thing happen on a hard-trail, but instead of a shock it's your legs (and butt, arms, and back) that soak up bumps and dissipate energy? I wonder which is more efficient--my butt or my shock?

Without bumps, I agree that a smooth climb requires less energy with a hard-tail. Less weight and peddle bob.

[bartspedden]

I think you are mostly right Toby, and that's probably why I ride a fs.  But where my mind starts to wander is on the question of efficiency.  Here's a pretty understandable definition of efficiency

        % efficiency = useful energy produced x 100 / total energy used

In bike terms how efficient a bike is, is equal to the amount of power a rider applies minus the amount of energy used not propelling the bike forward. In a weightless, frictionless world our bikes would be 100% efficient.  But here on earth power can be used in things like heating bearing grease, overcoming the drag from the tires or air or dragging break pads, or... heating the suspension.  Anyway you can reduce these inefficiencies, the more efficient your bike will be.  That's why see products like ceramic bearings, pro-pedal platforms, frame designs that limit pedal bob, tires will lower rolling resistance.  

It's hard for me to understand how adding something like a rear shock could make the mechanics of a bike more efficient, but maybe I'm not thinking about this correctly...  maybe I'm missing something...

regardless, I do know from experience that a fs bike sure makes riding the miles more fun for me!

[caseygreene]

If you want to read a mag that will get yer mind spinning about the physics of a bike, i suggest Bicycle Quarterly: http://www.bikequarterly.com/vbqindex.html
Don't tell anyone in missoula but its my favorite. They actually do real world tests (kinda), and even if i dont agree with a conclusion, I still respect their approach. They also delve into historical approches (sometimes a bit too much). Its not all about sponsors and advertising and the newest greatest thing.

Also, more physics stuff: http://www.tonyfoale.com/

[bartspedden]

Aesome caseygreene!  Thanks for the insights.  It looks like those sites will be a good match for me.  I'm also going to talk with a guy that I work with who has a degree in physics.

[cpblue]

Again, thanks for all the responses about bike selection.  After much research on not only the bike, but where I'm going to ride and what I'm going to carry, I believe I'm headed for a hardtail.  The choices seem to be endless and I hoping after some test rides I can narrow the pool down some. 

When I make a selection I'll be sure and post a picture.  Thanks again.

[WWOOF]

what wheel diameter is best for bikepacking - 26 or 29?

[Done]

what wheel diameter is best for bikepacking - 26 or 29?

Uh oh, now you've done it--you're going to get a whole bunch of people all riled up over wheel sizes. Fact: People successfully bikepack with both sizes. My opinion (for what it's worth): Ride what fits, feels good, and gets the job done!

[WWOOF]

Uh oh, now you've done it--you're going to get a whole bunch of people all riled up over wheel sizes. Fact: People successfully bikepack with both sizes. My opinion (for what it's worth): Ride what fits, feels good, and gets the job done!

Yea hahaha I know it is definitely a touchy topic, but I haven't been mountain biking in a while and I want to get the inside scoop on what the pros and cons are of each type specifically for bikepacking

[AZTtripper]

Yea hahaha I know it is definitely a touchy topic, but I haven't been mountain biking in a while and I want to get the inside scoop on what the pros and cons are of each type specifically for bikepacking

You'll want to ride what all of the cool kids are riding obviously.

Here in AZ that's 29r Scott M and Chad B both race directors here AZTR and AES are both on 29rs as well as both finishers of the AZTR last year. Its all about being trendy don't cha know.

[bartspedden]

So I chatted with the physics major (he forced me to remember differential equations as they apply to absorbers - it was painful  ) and did some more reading and slept on it to let my mind chew on the new info. It turns out I WAS thinking about things incorrectly.  The path Toby was on was exactly correct. On a smooth surface there's no doubt, a hardtail is more efficient. As the terrain gets rougher (a la sergeants mesa) a FS is more efficient.  The reason (as I understand it) is actually 2 fold:

• A rear shock will keep the tire in contact with the ground more than a hardtail will, therefore more of the energy supplied by the rider can be transferred to ground thereby propelling the rider forward.
• The angle of deflection will be reduced while going over obstacles thereby requiring less energy to overcome the obstacle. While this saps energy from forward motion, it turns out that the energy to compress the shock is less energy then would be applied on a hardtail assuming optimal shock settings.

This explains why on paved uphills I lock my shock.  On mild to aggressive uphills I'm in the pro-pedal setting.  And on obnoxious uphill I've got the shock wide open with no pro-pedal.  Without understanding the "why" my body was telling me which setting was most efficient because each different setting maximized the ground contact and minimized the angle of deflection which helps me get up the mountain with the least amount of energy sucked from my bones. 

A little geeky, sure. But it does explain (I saved you all from the bad math I was doing) why the answer to these types of questions is always "it depends".  Sorry for dragging everyone into my brain fart! I hope it wasn't to boring 

[Done]

A little geeky, sure. But it does explain (I saved you all from the bad math I was doing) why the answer to these types of questions is always "it depends".  Sorry for dragging everyone into my brain fart! I hope it wasn't to boring 

Hey, I think that this has been an interesting topic--so I guess that makes me a geek too. But we're in good company, as this sport seems to attract people who obsess about stuff like this!

Thanks for pinging your physics major friend. And thanks for excluding the math!

[Marshal]

So I chatted with the physics major (he forced me to remember differential equations as they apply to absorbers - it was painful  ) and did some more reading and slept on it to let my mind chew on the new info. It turns out I WAS thinking about things incorrectly.  The path Toby was on was exactly correct. On a smooth surface there's no doubt, a hardtail is more efficient. As the terrain gets rougher (a la sergeants mesa) a FS is more efficient.  The reason (as I understand it) is actually 2 fold:

• A rear shock will keep the tire in contact with the ground more than a hardtail will, therefore more of the energy supplied by the rider can be transferred to ground thereby propelling the rider forward.
• The angle of deflection will be reduced while going over obstacles thereby requiring less energy to overcome the obstacle. While this saps energy from forward motion, it turns out that the energy to compress the shock is less energy then would be applied on a hardtail assuming optimal shock settings.

This explains why on paved uphills I lock my shock.  On mild to aggressive uphills I'm in the pro-pedal setting.  And on obnoxious uphill I've got the shock wide open with no pro-pedal.  Without understanding the "why" my body was telling me which setting was most efficient because each different setting maximized the ground contact and minimized the angle of deflection which helps me get up the mountain with the least amount of energy sucked from my bones. 

A little geeky, sure. But it does explain (I saved you all from the bad math I was doing) why the answer to these types of questions is always "it depends".  Sorry for dragging everyone into my brain fart! I hope it wasn't to boring 

Humm, your main point sort of assumes a HT never has the ‘optimal’ rear suspension when in reality for ‘some’ off road conditions it could—ie: tire flex and frame flex could also work to achieve tire contact and optimal angle of deflection

Oh and what about the inherent weight penalty with FS—a big factor in climbing, and what about----

All this is of course a never ending debate, which is probably why we don’t all ride the same bike

Personally the best bike for me is the one I now use—till the next one comes along

(I guess I be a bit bored right now to be sucked into engaging in this one, ahhhh, oh well--it is bike stuff and bike stuff is fun- )

[Chad B]

You'll want to ride what all of the cool kids are riding obviously.

Here in AZ that's 29r Scott M and Chad B both race directors here AZTR and AES are both on 29rs as well as both finishers of the AZTR last year. Its all about being trendy don't cha know.

Actually, I am going back to my Rocky Mountain Vertex and Fleece blanket days....It's not what is "cool," it's getting ideas from those around you. I went had the opportunity to go to interbike one year and sit on tons of bikes, 29er and 26ers alike. What I came away with...I enjoyed a bigger wheel.

The real cool people ride SS, rigids....

[AZTtripper]

Actually, I am going back to my Rocky Mountain Vertex and Fleece blanket days....It's not what is "cool," it's getting ideas from those around you. I went had the opportunity to go to interbike one year and sit on tons of bikes, 29er and 26ers alike. What I came away with...I enjoyed a bigger wheel.

The real cool people ride SS, rigids....

Don't for get to reuse that broken seat if your ass isn't rubbed raw you aren't really riding. I am stuck with the big kid wheels for now as I can't afford to switch back.

[Michael_S]

Kinda new to this site... but how come no one mentions the more touring oriented MTB's like the Fargo?  I understand the hype on full suspension ( I've had a few) and a number of hardtails ( 29er too) but seems to me the Fargo or the Rawland is the perfect bike for a lot of Bikepacking?  Sure if your intention is fast rocky descents a Full sus. bike is best but how many of your Bikepacking trips just do that?

not trying to stir the pot, just curious.

~Mike

[AZTtripper]

Mike it just depends on the course you want to ride. There are those who like the Fargo type bikes but they seem best for gravel grinders. A few die hard types ride them on ST but most prefer to have at least front suspension and MTB geometry.

Maybe if we stir hard enough the Monstercross riders will come out and give us some good reasons to ride a less comfortable bike. If you don't stir the pot the soup will burn. 

[DoctorRad]

The FS vs Hardtail question was tested in MTB Pro (now defunct UK) magazine in 1997 by two acquaintances of mine.

Same riders keeping as close as possible to the same riding heartrate on FS and Hardtail bikes weighing the same amount. From one of the authors: "On a smooth Tarmac climb the FS was consistently 5% slower IIRC. On a gravelly but generally not that bumpy climb there was nothing in it. We hypothesised that a rougher climb would see the FS go ahead but it proved tricky to get enough clean runs on a harder climb".

[Michael_S]

Having owned and ridden all of the above ( not Bikepacking though) including both a steel 29er hardtail and a full suspension bike with the Horst link ( considered the best design by many and bought and patented by Specialized) I have some non-scientific conclusions.

Decending... full suspension w/o a doubt is the best. I can still recall yelling at my friends after the 1st long downhill on the Titus Motolite " this bike is worth every penny".  Slow climbing, IMO and even on rocky trails... fully rigid is way faster. I started on these in early '80's and raced one for 10 years. The best compromise... steel 29er hardtail. The combination of materials and big wheels really make you feel like you've got some suspension in the rear. Slower on descents but you can make up for it on climbing and rolling terrain. oh, and with a fork lockout.  Done the monstercross thing too, which I love for mixed terrain rides ( dirt and street).

Now I've come full circle and am building a rigid drop bar 29er, a steel Singular Gryphon. I had a local frame builder add some better cable routing and rack braze on's as well so I can try some Bikepacking on it.  Planning on the 1st trip this spring.

~Mike

[Marshal]

Kinda new to this site... but how come no one mentions the more touring oriented MTB's like the Fargo?  I understand the hype on full suspension ( I've had a few) and a number of hardtails ( 29er too) but seems to me the Fargo or the Rawland is the perfect bike for a lot of Bikepacking?  Sure if your intention is fast rocky descents a Full sus. bike is best but how many of your Bikepacking trips just do that?

not trying to stir the pot, just curious.

~Mike

FS/HT and Drop Bars

Regardless of the pros/cons of FS vs HT I am sure a lot of backpacking riders do not build up a bike ‘just’ for bikepacking.  So whatever bike they pick, it might also be their every day ride bike.  So the FS vs HT decision/preference will also address the every-day-ride question.

But you asked about a Fargo style bike, which usually means a set up with some type of drop bar.

A drop bar vs a straight bar is a much much bigger factor for riding single track than FS vs HT. 

I think the drop bar approach might very well be the way to go for gravel road touring, mixed with light/buff single track. 

But without a doubt the straight bar provides several advantages in more technical single track terrain.

In the end I suspect the ‘expected terrain’ is dictating most readers decisions about using a Fargo ‘drop bar’ type bike for bikepacking.