Find the actual weight of the Arkels.  I am pretty sure they weigh more than my current panniers, tent, sleeping bag and pad combined.  Really.  You could bring a cooler full of beer and still save weight by ditching those for a couple drybags lashed on the sides.  And it will carry more solid.  However, I generally also recommend replacing the beer with a sensible single-malt for a better buzz-to-weight ratio.

I am done with pumps.  Sometimes I use Aqua Mira and some powder or tablet to flavor.  Mostly now I use some variation of this gravity setup.  MSR DromLite bag (6L for me) 5.7 oz with cap and tubing, Sawyer squeeze filter 3.3 oz, Sweetwater Siltstopper prefilter 2.8 oz, and less often, a GravityWorks carbon element for taste 1.3 oz.  Total if I use it all is 13 oz.  I use the different pieces based on where I'm going and what I expect the water sources to offer.  The prefilter almost always.  Gravity works as well as any pump with zero effort.  Another less obvious weight savings is that you can leave the unfiltered water in the Drom and carry just one bottle, refilling as you go.  Probably not for racing, but I'm rarely in a hurry through my favorite places.  I used this setup for an 8 day trip with 3 people this past summer and on a 12 day trip with my wife this winter and several other lesser trips.  It is well tested served us all very well.

Mathieu, Do you have a good idea of your route into NW Washington? Or will you go up into BC from Colville?  I live in Bellingham, WA and would be happy to share what I know of my area, and I know the east side of the state a bit too.  I can also offer a campsite if you need one around here.  Sounds like a very cool trip, except that it's going to be really hot.

If you want an ultralight tent where you can get up on your elbows, or just sit bolt upright, check out the Six Moon Designs Skyscape series.  I have the Trekker, which is the middle price, middle weight option.  I can't say enough good about it.  Quite roomy for one, I can sit straight up and change clothes, bring gear inside, or under the vestibule.  25 ounces for the tent and 3.6 ounces for a pair of carbon poles.  Cuben and $$$$ saves 10 ounces off that.  I carry 3 stakes as well, with the foot end tied off to my bike.  Bug net almost all the way around for views when it's not raining.  Deploy the sides for rain.  There's a bunch of good tents, and as someone already said above, no single right answer.  But this one works great for me. 
http://sixmoondesigns.com/tents.html

One of the biggest ways you might lose weight with a rack and pannier system is to ditch the panniers.  I used to go this way some time ago and my panniers weighed over 5 lbs (Jandd Large Mountain).  I replaced them with a couple of stuff sacks and 3 web straps per side.  Fill the bags and lash them on.  Free if you already have some sacks and straps around.  Even better, the load carries much more securely.  Most pannier systems have compression straps that snug the bag up but they don't do anything to snug the bag to the rack.  I have been very happy with this system.  Even better since I started putting a piece of 1/8" plywood inside to keep stuff from bulging through the rack side.  Only down side is they're a little less convenient to get into on the trail. 

You should also consider that when you put a rack on the rear end of a FS bike, that weight is "un-suspended weight".  This means that your suspension will become MUCH less active.  Put 45 pounds back there and you will be riding a hardtail.  http://en.wikipedia.org/wiki/Unsprung_weight

Two other general thoughts on saving weight:

Buy a scale.  Without one, all of your efforts are basically guesses.  My food co-op sells a little digital unit for $15 of so.  It has transformed my base weight.  My base weight for an 8 day, high country, bikepack trip last summer was under 13 pounds and I actually DO carry a tent.

And, 23 years ago, as I prepared to ride across the U.S., I read this little piece of advice and it has always stuck with me.  In advance, gather all of your gear.  Divide it into three piles.  One pile is stuff that is ABSOLUTELY essential (think sleeping bag).  One pile that is probably pretty reasonable to bring (spare tire).  And the third is stuff that is a little indulgent.  Leave two piles at home.  IOW, skip the lantern and bring a really good tire boot.

I have re-tightened them many times.  Easier with the proper tool.  But, plenty doable with a nut and bolt.  If the brand is one that a local shop carries, I would go by there and see if they wouldn't consider snugging it up for you.  It takes just a minute or so and in any shop I have worked in it would have been considered under the frame warranty.  Good luck.

I have been a professional mechanic for several decades.  I have installed a lot of riv-nuts, including on my own bikes.  You should know that it will void most any warranty.  You should consider the location, material and likely stresses carefully.  In a couple of cases of the very lightest of aluminum frames coupled with poor choice of location, out of fear for shop liability, I declined to do it.  I would never put one in a fork.  Make darned sure the riv-nut goes in tight to the tube.  Not just the hole size, but the compression you apply with the tool.  The vast majority of riv-nuts that I have installed were replacements for factory nuts that weren't tight enough and spun when the owner tried to pull a over-torqued or corroded bolt.  This creates a challenge for removal, some much tougher than others.  To help prevent that trouble, use anti-sieze or grease and get a little under the head of the bolt as well as the threads.  A washer under the head also helps with this.  I like steel riv-nuts more.  Occasionally, the force necessary to get an aluminum one tight enough not to spin, the threads can get pulled out.  And I would second all the pointers already given.  Not trying to discourage, they are often a very handy solution.  It's just that I have also seen them cause considerable trouble and expense when used without proper care.

I have been carrying a GorillaPod Original for at least a dozen years.  Weighs 1.6 oz.  Works great.  Grabs your bike or anything else.  Cheap too.  Use a releasable zip-tie to put it on your bike somewhere for a quasi-permanent bike mount.  Endless options.

http://joby.com/gorillapod/original/#features_specs

I have a pair of X-Alp Drifts, size 45, gray, brand new, still in the box.  Make me an offer? 

I have been happy with one of these: http://www.rei.com/product/799192/cocoon-hyperlite-pillow

Initially it was quite bulbous and my head would tend to roll off.  I made one simple mod to it that helped a lot and may help a lot of other inflatable pillows.  With it deflated,  I draped it over a button at it's center and, from the other side, tied a small piece of thin cord TIGHTLY around the pillow/around the button.  Makes a depression in the center to cradle my skull.  I also put it under my air pad so it stays put.  Call me a wuss, but I love having a pillow.  2.4 OZ is a small price to pay for a happy neck in the AM.

I also have a Thudbuster.  I love it for fire roads and commuting.  It is no replacement for true rear suspension off-road, but it is awesome for comfort for long miles on rough surfaces.  You might also consider your rear tire width and pressure.  Could you go wider?  Could you go lower pressure?  I find that people frequently want to ride super hard tires for some imagined efficiency.  Only on the smoothest surfaces is this practical.  For anything else let them down a little.  Torture is not efficient.  A smooth ride is less fatiguing and therefore more efficient.  Good luck.

Can't recall which brands, but a couple of companies make a cheap little riser just for that purpose.  Minoura might be one, maybe Topeak.  Not sure on those, but check at a local shop and suggest they look in their QBP catalog.  They DO exist.

1 vote for the LHT.  I have worked around all three of these bikes in shops.  The 520 just isn't burly, lacks disc brakes, lacks clearance for wider tires, and is a dated design cockpit-wise.  The Tri-cross might prove frustrating for heel clearance if you have big feet and want to use panniers.  Haven't looked it up, but I bet it has the shortest chainstays of the three.  I also think it's a little on the light side for loaded, off-pavement riding by a big guy, or even a medium guy.  The LHT is just what it says.  Fatties fit fine, discs if you want 'em (which you do), bomber and comfortable ergos.  But, the bottom line is:  get whatever and ride the shit out of it.

I have used one for several years for mountain biking, bikepacking and commuting.  It's still in fine shape and currently on my Superfly.  I love it.  That said, it's no substitute for full suspension.  But if you're riding a hardtail, it's a great thing, IMHO.  Reduces fatigue and improves comfort.  I'm a total weight weenie and I think the extra ounces are well justified.

Hey all, thanks for the replies.  Chad, I'm afraid that I can't figure out now which file is the one I started with, cuz I've modified it so much to make my own route that whatever I started with is long gone, but I do think that it might be yours.  It's just called KMC130m.kml in my GoogleEarth.   Mark, your trip sounds like it was a bit wet.  I've been watching the weather a bit and am hoping that mid-September will put us a little post-monsoon, but AZ is way out of my element, so what do I know.  We live in the Northwest, so rain gear we have.  I think we will be taking the detour off the plateau around the burn, but thanks for the tip on that.  It sure helps to confirm the choice to do the big climb back up.  But the cold Tecates will be so close by then.

 My wife and I like to take our time and wander off on foot here and there and generally linger for as long as such beautiful places warrant, so our routes and speeds tend to be a little different.  We took five days just to do the White Rim.  It's nice out there.  But our approach makes water a rather big factor.  So, I'm still wondering about the springs that are on the KNF map, and on the 2Epic site (http://2-epic.com/maps/311map.html?map=kmc200full.kml&index=10).  Namely, Big Saddle Tank, Quaking Aspen, Kanabownits, Parissawampits.  It doesn't sound like Mark went by these as they are a bit off the 125 route.  But they are going to be critical to us.  One of them better have water, or I sure hope we run into someone who likes to share.  If anyone has any recent data on these (possible) sources, I'm all ears.  When I get back I will try to figure out how to post my route and a little trip report.   Cheers, Dan

I have ridden the White Rim twice, both times clockwise.  One was a three day, self-supported and the other a five day.  I like to go slow.  It is well worth riding.  I really can't think of any particular reason why one way or another would be better.  Except maybe this:  I think the Colorado River side is a little more spectacular visually.  So maybe having that later in the loop (going CCW) would be a nice booster for the one-day rider.  Either way, you have a healthy climb to finish with.  People often seem to do this loop by leaving a car at the JCT of Rt 313 and the Mineral Bottom Road/Horsethief Trail.  A modest variation that I have used is to camp and park at a small 6 or 8 site campground a couple of miles south of there on the west side of 313,  it's really easy to miss.  A double track goes right out of the campground west to a point a few miles down the MBR/HtT.  Saves a little pavement and a little of the MBR, which is kind of busy with trucks going fast and boats and other dust and noise makers.  Worked for me anyway.  Have a great ride, it's a wonderful place.  ABSOLUTELY do not miss the spur out to White Crack.  Lousy sandy climb, but not to be missed.

My wife and I are heading out to do a KMC 125/200 hybrid (skipping the 200 portion north of 89A, adding the loop to North Rim) as slowly as possible around September 8-12.  I was wondering if anyone had any current info on water, especially in the neighborhood of the Rainbow Rim Trail, give or take 20 miles?  Has anybody by chance taken the route south into the Park on 268B?  We will be heading that way and are hoping to find water at Big SaddleTank/Point, Parissawampitts Spring, and/or Kanabownits Spring 2 or 3 miles before we reach the Point Sublime road.  My Kaibab NF map shows that as a through route, as do the KMC200 route notes, but no other source (G-Maps, etc.) confirms that route as existing, so I'm digging around.  Anything else noteworthy?  Thanks in advance for any info.  -Dan

Hey Markphx (or anyone else), my wife and I are heading out to do a KMC 125/200 hybrid (skipping the 200 portion north of 89A, adding the loop to North Rim) as slowly as possible about September 8-12.  I was wondering if you had any current info on water, especially in the neighborhood of the Rainbow Rim Trail, give or take 20 miles?  Did you by chance take the route south into the Park on 268B?  We will be heading that way and are hoping to find water at Kanabownits Spring 2 or 3 miles before we reach the Point Sublime road.  My Kaibab NF map shows that as a through route, as do the KMC200 route notes, but no other source confirms that route as existing, so I'm digging around.  Anything else noteworthy?  Hope your trip was great.  Thanks in advance for any info.  -Dan

I have never used any GPS.  I will soon have an Android 2.2 phone.  There are GPS apps available that use satellites, not cell signals, so it should function anywhere.  I would be curious to know if anyone has any experience using such a setup and especially if there is any compatibility between such a setup and the many trip data sets (tracks?) already compiled?

Hey all, I happen to live just north of the PNT.  I have ridden and slept on the first three mountains east of the sound many, many times.  A lot of clear cut forest and some great climbs and fine views of the Islands, Olympics, Canada and the Cascades and the odd bit of righteous singletrack.  If you have any specific questions about the Whatcom and Skagit county portions, fire away.  It's my backyard and I love it.