Climbing Rubber Friction test link

Search
Go

Discussion Topic

Return to Forum List
This thread has been locked
Messages 1 - 50 of total 50 in this topic
minexploration

Social climber
Whitefish Montana
Topic Author's Original Post - Nov 20, 2008 - 08:10pm PT
Interesting link on climbing rubber friction.

http://www.spadout.com/r/climbing-rubber-test/
WBraun

climber
Nov 20, 2008 - 08:18pm PT
That's a poor test setup.

Totally static in a controlled temperature environment on a polished smooth slab with nobody in the shoe.

They've always done it this way and it proves nothing except some numbers on a sheet of paper.

Croft could climb in a pair of roller skates that all those rubbers couldn't.

There's your start ......
Fletcher

Trad climber
Norman Clyde's napsack
Nov 20, 2008 - 08:24pm PT
I was about to post the same link. Had the same reaction as you, Werner. Seems contrived to a certain very specific set of circumstances.

I'm such a plonker I can't tell the difference anyway.... 5.10 dot rubber seems best for me!

Fletch
Indianclimber

Trad climber
Lost Wages
Nov 20, 2008 - 08:34pm PT
What about the Acopa rubber?
murcy

climber
San Fran Cisco
Nov 20, 2008 - 09:36pm PT
i am opposed to these tests, as, for me, the principal use of climbing rubber is to serve as an excuse.
Euroford

Trad climber
chicago
Nov 20, 2008 - 09:41pm PT
i better go gets some mad rocks... when i flail around i can use this paper as backup to my story.


Elcapinyoazz

Social climber
Redlands
Nov 20, 2008 - 09:44pm PT
Obvious first problem with the test is that it doesn't address deformation of the rubber from having a climber's bodyweight on it.

Maybe a softer rubber with lower coefficient of friction deforms and spreads out more, thereby gaining more contact area than a harder rubber with higher coefficient and thus ends up with higher friction overall.

Second obvious problem is that it only did test runs at a single temperature.

This test is way too simplistic, and looks more like something a sophomore engineering student would set up rather than a CERN guy.


JLP

Social climber
The internet
Nov 20, 2008 - 10:06pm PT
A wad of bubble gum would have come out as #1.
Karl Baba

Trad climber
Yosemite, Ca
Nov 20, 2008 - 10:41pm PT
I smell BS as well. Somebody did a rubber coefficient test once and scientifically proved that rubber sticks just as well on wet rock as on dry rock.

I was stunned. Anybody who ever climbed wet rock has got to know the practical difference.

Peace

Karl
murcy

climber
San Fran Cisco
Nov 21, 2008 - 12:22am PT
nah, the (bad) joke was that i need to have the excuse of bad rubber, so that tests would show my excuse to be crap. in fact i climb badly because of a hard gym session the day before.
Mighty Hiker

Social climber
Vancouver, B.C.
Nov 21, 2008 - 12:26am PT
Peter was awful happy when the Fires came out, and took the place of EBs. I'm pretty sure he never tried roller skates - it would be more Canadian to use ice skates. Though they don't get a lot of ice in Nanaimo.
ß Î Ø T Ç H

climber
Last >>
Nov 21, 2008 - 12:38am PT
" What about the Acopa rubber ? " I remember seeing a video of John with his own little portable micro-slab for testing shoes . That's been a few years tho .
bachar

Gym climber
Mammoth Lakes, CA
Nov 21, 2008 - 03:44pm PT
Wener's right...

This test is absolutely worthless.
Ed Hartouni

Trad climber
Livermore, CA
Nov 21, 2008 - 11:26pm PT
Not sure I'd call it worthless, but certainly limited and only a part of the whole picture.

Wikipedia [url="http://en.wikipedia.org/wiki/Coefficient_of_friction"]Coefficient of Friction[/url] is not bad on this:


While it is often stated that the coefficient of friction (COF) is a "material property," it is better categorized as a "system property." Unlike true material properties (such as conductivity, dielectric constant, yield strength), the COF for any two materials depends on system variables like temperature, velocity, atmosphere and also what are now popularly described as aging and deaging times; as well as on geometric properties of the interface between the materials. For example, a copper pin sliding against a thick copper plate can have a COF that varies from 0.6 at low speeds (metal sliding against metal) to below 0.2 at high speeds when the copper surface begins to melt due to frictional heating. The latter speed, of course, does not determine the COF uniquely; if the pin diameter is increased so that the frictional heating is removed rapidly, the temperature drops, the pin remains solid and the COF rises to that of a 'low speed' test.
minexploration

Social climber
Whitefish Montana
Topic Author's Reply - Nov 22, 2008 - 10:56am PT
I posted the original link. The responses got me thinking. I am a physics professor at the local community college.

If the climbers do not like this test. Help me design a test that would satisfy the climbing community. I am willing to take my time and budget to run, document the results, and publish the results on this site.

What I would like is to use this thread to develop some sort of consensus on what you would like for the test. I will then develop a procedure and testing protocol based on the ideas and what is considered standard testing protocols (ASTM maybe?). Then, I will post the procedure on this site for critique, and after review, run the test.

Dr. JRW
Ed Hartouni

Trad climber
Livermore, CA
Nov 22, 2008 - 11:46am PT
if you read the responses, you can see what most climbers feel are the unmeasured variables in the simple "tilt test" done in that article. Climbers have an empirical notion of what controls friction, and they learn to use that control to achieve the required support for their moves.

 Suppleness of the sole of the shoe.
 Large, flat, smooth contact area.
 Geometry of contact.
 Clean surface.
 Temperature and humidity.
 Type of rock, and surface condition.
 Kinetic coefficient - to - stopping.

These all seem to play some role in "sticking" your feet to the wall. There may be more. As the Wikipedia article said, these variables are "systemic" rather than "material" properties, so it might take a while to investigate.

Also, it might be necessary to actually use a human foot (living) in the shoe to perform the tests. This is because the biomechanical aspects of sticking a foot hold are very important to the use of the shoe, where the shoe's stickieness is only one aspect of shoe performance.

Shoe tests are done with expert climbers who use their experience, and a series of demonstration climbs, to validate the shoe design.

Good luck!
klk

Trad climber
cali
Nov 22, 2008 - 11:59am PT
Ed: "Type of rock, and surface condition"


Yeah, this is really important. A test run primarily on low-friction surfaces (i.e., the two chose for the test you linked)probably tells us less than we need to know about climbing-shoe rubbers.

A series of different surface textures would be more useful.
bachar

Gym climber
Mammoth Lakes, CA
Nov 24, 2008 - 12:00pm PT
Ed said,
"Also, it might be necessary to actually use a human foot (living) in the shoe to perform the tests. This is because the biomechanical aspects of sticking a foot hold are very important to the use of the shoe, where the shoe's stickieness is only one aspect of shoe performance. "


Bingo!


Try Formula 1 tire rubber on that test and it will kill all other climbing rubbers - but climbs quite poorly on real rock.
minexploration

Social climber
Whitefish Montana
Topic Author's Reply - Nov 24, 2008 - 12:21pm PT
After reading several of the reply's. Do people want a way to test shoes or the rubber friction? From John's statements and others as well as my own climbing experience. I know that the system of climber + shoe + rubber = foot sticking on the hold.

Completing a test like was linked in the first post is easy. Trying to replicate a system and get results that mean anything is the tough part.

Thanks for all the comments so far. I am currently looking at the testing literature and lining up students to work on this project. Any more ideas would be helpful.

JRW
mcdoodle

Trad climber
temecula, ca
Feb 27, 2009 - 11:19pm PT
First of all, All the test claimed to validate was coefficent of friction (COF).Which admittedly is only one aspect of climbing shoe performance. Second, read the test!! The granite was the BOTTOM SIDE of a counter top piece which is much coarser. Third, several of the rubber manufacturers tout a COF test as claim to their products superiority. Fourth, not only will heat, temperature, humidity, weight, contact patch size, angle, and deformation affect performance technique is a major contributor. Rubber design is a compromise of all these variables and may vary according to the style of climbing and type of surface being scaled. you will find that no one shoe or rubber will be suitable for every circumstance. So cool your jets and take the test for what it is and not as a claim of the BEST rubber for all purposes.
rgold

Trad climber
Poughkeepsie, NY
Feb 28, 2009 - 01:50am PT
Rubber friction is a very complicated thing. Have a look at

http://www.tr.ctw.utwente.nl/Research/Publications/PhDTheses/thesis_Deladi.pdf

for example. There's just a tad more to it than the naive model obtained from Amonton's two laws, which are probably best for two different polished metals. For example, the thesis notes that the microgeometry of the rubber plays a substantial role in the observed coefficient of friction. We don't know whether the variations in this microgeometry are bigger within one particular brand or between brands of rubber. And that microgeometry is influenced by the size of the normal load, with the result that different frictional "laws" may apply at different loads.

To begin to get anywhere, such tests probably have to be conducted with a human being (the same human being) in the shoe(s). And it isn't clear to me that a static slab friction test, even if more properly carried out, is the best measure of anything beyond absolutely pure friction climbing, which was probably never a central ingredient of climbing practice and certainly isn't today. It may well be, as JB emphasized, that the stickiest rubber in the slab test will have qualities of flexibility, conformability, edging ability, and durability that make it a poor performer overall.

From my very old-school perspective, the thing that makes modern rubber significantly different from the older rubbers is that in modern shoes you can move your feet on the holds while the holds are weighted, and indeed a certain amount of modern technique involves pivoting on weighted holds. Try some of those maneuvers in the shoes of yore and you'd be off the footholds and out in space in an instant. So some of what makes modern rubber "sticky" is its ability to conform over and adhere to macro features while moving under a load, and this may well be quite different than the ability to adhere to the micro features of a relatively smooth slab. Unfortunately, this type of conformable adhesion is almost certainly influenced by shoe construction, so it may be hard to discern the role that the rubber is playing, even if a suitable test could be created.

Finally, a word about statistics. The tests do measure something, namely the ratio of one particular fixed normal force to the corresponding frictional force for one particular size and shape of rubber on one particular material. But without some measures of variation and confidence intervals to go with the means, we have absolutely no idea if we are looking at significant differences.
Omot

Trad climber
The here and now
Feb 28, 2009 - 02:51am PT
Dr. JRW,
Go for it! But please consult with a polymer chemist or two. Physicists tend to simplify the situation, as the NWU/CERN guy did. Every tire company must have a bunch of chemists and material scientists studying rubber friction on a bunch of surfaces and there must be a vast literature on the subject. Not the exact same application, but a good place to start to see what's been done and what is understood.

Also, please add error bars (a pet peeve of mine)! Looking forward to seeing the results.

Enjoy,
Tomo
sb4

climber
Mar 12, 2009 - 05:54pm PT
Bottom line is I'd like to know if certain shoes would help me climb. The problem is we can't afford money or time to try every shoe for a few weeks, and even then your energy level could change, making comparison difficult. It's a tough problem. But a realistic rubber test might be a rough guide to shoes that perform a little better. I'd prefer to hear that all shoes are about equal and forget about it. But if some shoes significantly reduce slipping on rock, I'd have to be interested.

If I had to rig a test, I might try this. Get a vertical slab of granite, or go outside and find a suitable rock.

Rig up a 175 pound weight on top of a pole. At the other end, put the rubber in the shape of a piece of a large ball (sphere section) to keep the same contact area as we change the angle. Maybe some kind of a swivel joint would allow a flat section.

Attach a rope to the weight end, with the ability to keep it approximately perpendicular to the pole. Place the end with the rubber piece against the granite wall.

Lean the weight out at an angle to where friction keeps it from falling down. It should resemble a climber on a rappel.

Slowly pull in the rope to reduce the angle to the wall. At some point, the rubber will slip off. Measure the angle. Repeat many times.

Problem: how to keep the pole from swinging sideways toward the wall. Maybe instead of a single pole, make a fork with two poles each with a rubber "foot" against the wall. Or some kind of low-friction guide.

That's my 2 cents.

Regards,

-SB
tolman_paul

Trad climber
Anchorage, AK
Mar 12, 2009 - 06:09pm PT
The funny thing is you mentioned what can have an effect, the shoe, and then you get hung up testing rubber which IMHO doesn't have that much of an effect, with what is currently available.

Shoes do make a difference, sometimes. I've had most itterations over the years from the glove like boreal ninjas which you could smooch into things nothing else would fit, the scarpa lemenstral which you can stand on nickle edges because they are so incredibly stiff, to many in between.

Seldom is the rubber the limiting factor, and how well a given rubber performs depends on how clean it is, how fresh (not oxidized) ambient temp, type of rock, etc.

donini

Trad climber
Ouray, Colorado
Mar 12, 2009 - 07:26pm PT
I think the friction characteristics of rubber is overrated. If rubber is too soft it rolls instead of holding an edge.
bachar

Gym climber
Mammoth Lakes, CA
Mar 12, 2009 - 07:41pm PT
All I can say is that if the rubber doesn't feel right to me, I ain't gonna be doing any free soloing with it.... just saying.
donini

Trad climber
Ouray, Colorado
Mar 12, 2009 - 08:15pm PT
John, I agree with you. Obviously, you and I were around for the advent of sticky rubber. I'm saying that sometimes climbers get into micro differences about the stickiness of rubber and that, for me , there are other characteristics of rubber that are also important in making the shoe "feel right."
bachar

Gym climber
Mammoth Lakes, CA
Mar 12, 2009 - 08:29pm PT
Definitely. Hardness is one and the other is "static" vs. "dynamic" coefficient of friction.

Some rubbers have a high static coefficient of friction but low dynamic coefficient of friction - they hold but when they pop, they pop quickly. Other rubber that has a little higher coefficient of dynamic friction will hold but slide slowly when it pops. The latter has a lot more "feel" to me and I can definitely tell a difference between the two.

It's very hard to test the differences between most rubber now days. I have my own testing system that I trust, others have theirs. When you get ten or twenty different rubber samples from different chemists it's good to have a test that will tell you what is best!
tolman_paul

Trad climber
Anchorage, AK
Mar 12, 2009 - 08:34pm PT
The only time I've been unhappy with a climbing rubber is when it has rolled off of edges. I can't think of any time where I felt that a slightly stickier rubber would have helped signifigantly.

I'd rather have 1/2 dozen different types of shoes that excelled at different footwark, then 6 pairs of the same boots or shoes with 6 differen types of rubber.

I started climbing in the Fire age, so I've never known a non sticky climbing shoe.
TradIsGood

Chalkless climber
the Gunks end of the country
Mar 12, 2009 - 08:45pm PT
Good reactions here.

To the physics prof. As Ed mentions, trust no climber to believe your results.

There was a test that showed conclusively that chalk reduced the coefficient of friction between skin and rock. That does not sell chalk. It does not get industry funding.

Skin properties are quite well studied in industry and support the conclusions of the friction test.

Your even above average climber is not educated enough to understand the studies, and he is also biased enough that even if he firmly believes that he understand climate change to be perfect science will pooh-pooh the study that shows chalk to be a hindrance.

Conformance, as rgold mentions, is an important property, not only for rubber but skin as well.

I bought a pair of Evolv's a few year's back. They apparently demonstrated to sales people to show that shoes were so "sticky" they would adhere to vertical surfaces. Trust me, under load, it does not happen! Shear, or deformation, plays an important role.

There is a lot more to the "equation" than friction coefficient. That is most important on slab climbing and least important on edging. But even slabs are not really linoleum or polished granite.
jstan

climber
Mar 12, 2009 - 08:47pm PT
First the coefficients of both static and dynamic friction are of interest, unless your name is Croft.

Secondly, the rubber's hardness helps determine its purchase on edges. Here you need to design a surface texture you think is representative of the rock on which you will be using it and you have to use a representative normal force. There may be several textures and you may have different normal forces with different people. Face it. You have to design and prove each texture represents the designated rock and you have to cover the full range of expected normal forces.

An approach to designing the representative texture:
The presence of a foot in the shoe, I suspect, can be reduced to agreeing that the normal force is not constant over the entire area in contact with the rock. So come up with a model texture (above) that sort of agrees with what a person in the shoe can do on an inclined plane of the rock in question. Once the model is qualified forget about putting feet into the equation. Then vary normal force over all of these textures.

In defense of rationality a final comment. Shoes are cheap enough and they wear out fast enough so that everyone goes through many pair. Whatever the study shows I suspect the majority of people will still be going out and trying different shoes. They will be doing this even after all the manufacturers have independently done this study to make their product better than that of their competitors'.

I don't bother to mention the manufacturers will also be designing both smearing and edging models.

EDIT:
I did one of the early tests on the effect chalk has on effective coefficient of friction between the rock and skin. Early 70's as I remember.

When there is little chalk on the rock, chalk does indeed promote increased friction.

However when the remnant layer gets too thick the friction is reduced.

This is why for decades now people have carried toothbrushes so excess chalk can be brushed off, when encountered. I would say anytime you see the surface has a very consistent white appearance you are getting into the region where friction has been decreased. If you can see obviously chalked holds in photographs you are probably already in this regime.

When your hand is extremely sweaty and you grab a heavily chalked hold, the chalk itself becomes slippery.
Splater

climber
Grey Matter
Mar 12, 2009 - 10:12pm PT
"There was a test that showed conclusively that chalk reduced the coefficient of friction between skin and rock."

It was a nearly useless test.
The main purpose of chalk is to minimize the reduction in grip caused by moisture/sweat/greasy skin. The reduction in friction due to chalk is much less than the reduction in friction due to sweat.

Try this test sometime:
Go climbing on a hot day.
Grease off handhold without chalk.
Hold on by using chalk.
TradIsGood

Chalkless climber
the Gunks end of the country
Mar 12, 2009 - 10:22pm PT
Apparently you did not read it, Splater.
bachar

Gym climber
Mammoth Lakes, CA
Mar 12, 2009 - 10:25pm PT
"The main purpose of chalk is to minimize the reduction in grip caused by moisture/sweat/greasy skin. The reduction in friction due to chalk is much less than the reduction in friction due to sweat. "

Got to agree with Splater...
Splater

climber
Grey Matter
Mar 12, 2009 - 10:49pm PT
This abstract?
http://www.cababstractsplus.org/abstracts/Abstract.aspx?AcNo=20013081469

I do not see that they tested the difference of "sweaty fingers on dry rock" (1) without chalk and (2) after using chalk as a climber would.

"alternative methods for drying the fingers are preferable"
Which methods would those be? The sweat glandectomy method?

more discussion halfway down this page:
http://www.theshortspan.com/features/friction.htm

http://www.spadout.com/r/climbing-chalk-test/
Our primary assumption is chalk's primary purpose is that to absorb moisture, not increase the friction between someone's hand and the rock. Therefore the test measures the absorption ratio of each type of chalk.
Splater

climber
Grey Matter
Mar 12, 2009 - 10:56pm PT
jstan,
Yes caked holds are greasy.
That doesn't mean they'd be less greasy without chalk.
When I climbed at a place that didn't allow chalk, the holds were even worse. They were covered in an oily slime mixture of sweat, dead skin cells, and dirt.
jstan

climber
Mar 13, 2009 - 01:14pm PT
Since it was so difficult to quantify I did not in the 70's attempt to simulate various degrees of sweatiness.

At Carderock in DC we used to have 95/95 weather which did in fact make an observable difference in the sweat on one's hand. Even under those conditions and with unbroken streams of people going up and down routes using mica crystals all sloped the wrong way I don't remember chalk being used particularly. If by some accident someone did something amazing at Carderock we all were pretty sure Ken Wilson would not be there the next day giving interviews. I worked right next door to the Blue Plains Sewage Plant. If we all had been using chalk I might have decided simply to work nights at the Lab. Carderock would have been uglier than Blue Plains.

On a more interesting note. When I went to my first Facelift, out of nostalgia I went over to look at Sunny Side Bench following an absence of almost forty years. Its surface texture has been changed totally. The natural texture is entirely gone and it is smooth and coated deeply with rubberized DNA from all the bodies that have been dragged over it.

This is not to say that is altogether bad. After all climbing is only an activity wherein you walk up to whatever problem is there, and you amuse yourself by seeing if you can figure it out. Nothing deep or significant is going on. When we chalk up a problem all we are saying is that we are not interested in doing the problem that was there when we first walked up.

Other than the ugliness that is created I am not even saying it is wrong to avoid the problem that is really there.

Rubberized DNA can present some really interesting problems.

If you happen to be one of the first 100 parties to do a route that week chalk did help get you up it. No question.

An idle observation. The OW threads have apparently identified Basket Case as being perhaps one of the hardest off widths. With all of this notoriety and given judicious placement of several anxiety reducers(SAR's) rubberized DNA may even find its way to that august location.
noshoesnoshirt

climber
dangling off a wind turbine in a town near you
Mar 13, 2009 - 01:45pm PT
Interesting article from the January American Society of Mechanical Engineers journal.

Highlights:

"• Friction force is NOT proportional to load, NOT independent of area, and NOT independent of speed.

• Friction coefficients from tables represent specific conditions. Your results may vary.

• High friction and high wear do not always equate."

http://memagazine.asme.org/Articles/2009/January/Theres_Rub.cfm

(I'm such a geek I have this on the back of my toilet with the Playboys, a copy of Rock'n'Road, and a book on numerical methods called ironically, "Relaxation Methods for Scientists and Engineers")
MH2

climber
Mar 13, 2009 - 02:29pm PT
A guy let me try a pair of the new Firé shoes at UW rock. There was a concrete slab with embedded granite rocks that varied in angle. I just stood in my EBs on a section steep enough for them to slip slightly and then tried the Firés in the same place. The Fires were clearly stickier. Sticky isn't the best word for what we want, though, because you want the shoe to lift up without having to scrape bubble gum off the bottom.

I've been waiting almost 30 years for a better rubber but haven't seen any great leap like the EB/Firé horizon.

noshoesnoshirt

climber
dangling off a wind turbine in a town near you
Mar 13, 2009 - 02:52pm PT
I'm holding out for this
TradIsGood

Chalkless climber
the Gunks end of the country
Mar 13, 2009 - 11:06pm PT
Thanks, splater.

Looks like you confirmed what I said. You did not read the article, but just the abstract.
MisterE

Trad climber
One Place or Another
Mar 15, 2009 - 01:07am PT
bump
MisterE

Trad climber
One Step Beyond!
May 1, 2009 - 12:07am PT
This is what started the climbing rubber chicken craze
SteveW

Trad climber
The state of confusion
May 1, 2009 - 12:47am PT
Those damn chickens are all rubbery at dinners. . .
cahuac

Boulder climber
Mexico
Jul 9, 2011 - 04:48pm PT
I am searching the web and everybody talks about chalk reducing friction and how many experiments they made. BUT. I have not found the most important fact, the static friction coefficient of hands-rock types. this data would be a result of such trials and experiments, so I am thinking... mmmmm maybe those researches are wrong or fake.

Anyways, i was searching for this data because I am making a Forces diagram to know how much forces hands and toes need to do in some layback positions.

if some one has done these, please publish, I will be very grateful.


Albert Verdugo
nutjob

Gym climber
Berkeley, CA
Jul 24, 2012 - 05:32pm PT
Dr JRW, any updates on the climbing shoe rubber test project?
nutjob

Gym climber
Berkeley, CA
Jul 24, 2012 - 05:43pm PT
Alright locker, next time I burn holes in the toes of my Mythos (mostly from heel-toeing in wide stuff) I'm sending them your way.

Is there a trick to making thicker rubber to improve longevity for heel-toes but keeping the toebox profile slim for thin cracks too?

Of course I'll keep practicing to better implement the standard wisdom (don't move your feet after you place them).
TrundleBum

Trad climber
Las Vegas
Jul 25, 2012 - 12:47pm PT

I'm with Werner:
...
It aint the shoes per se'
I bet Jimi cud'a shred a tune with a $20.00 ukulele

and with noshoesnoshirt:
I want shoes with Geckskin

Or how about a pair of Curchill swim fins for thin hands cracks ?
Rolfr

Social climber
North Vancouver BC
Jul 26, 2012 - 02:02am PT
The most important stickiness factor is really mental attitude. All things being equal, Slab/Friction climbing should show the nuances of differing rubber, but usually it is the head game that causes loss of contact with the rock not the rubber.

What ever shoes give you the greatest confidence are usually the stickiest, just watch a hesitant or anxious runout friction climber, usually they peel off because fear forces their body closer to the rock. In a fearful stance your knees come closer to the rock, a defensive posture that actually puts less contact area on the rock, as opposed to maintaining a good 12" of distance between your knees and the rock, which creates a larger contact area over the balls of your feet.

I find when climbing at my limit, any modern rubber has its limitations if you hang around too long on tenuous holds. Sometimes you just have to move and believe the rubber will stick.

Unfortunetly the older I get the worse the rubber seems get!
nutjob

Gym climber
Berkeley, CA
Jul 26, 2012 - 06:54pm PT
Rolfr, that is a good point.

My intellect knows about normal force and how to maximize it, but when I'm on lead it's harder to convince that little boy inside me and make him commit! And if I try to force it without his buy-in, he gets all trembly and sketched and then we blow it.
Messages 1 - 50 of total 50 in this topic
Return to Forum List
 
Our Guidebooks
spacerCheck 'em out!
SuperTopo Guidebooks

guidebook icon
Try a free sample topo!

 
SuperTopo on the Web

Recent Route Beta