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Messages - vanvalks

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Routes / Re: San Diego to East Coast Route advice
« on: April 05, 2010, 10:29:57 am »
My only advice since i haven't done either route is to go to and read some journals.  There are literally thousands of journals posted there, most with more info than you can absorb.


Gear Talk / Re: Bicycles for off-road riding
« on: March 25, 2010, 08:18:51 pm »
For anything you ever wanted to know about recumbents and more, go to  It is a very active board and the regulars between them know everything about recumbents.


General Discussion / Re: Artificial knees
« on: March 20, 2010, 10:59:01 pm »
I certainly didn't mean to imply that being overweight was the only cause--merely one of the most common.  If you're tall, you put more stress on the knee joint because there is a longer lever arm--think of the knee bent to 90 degrees.  A light weight on the end of a long femur puts the same stress on the joint as a heavy weight on a short femur.  The total pressure on the cartilage in the knee can exceed 2,000 psi when a heavy person does a deep knee bend.  There just aren't many materials around that can stand up to that sort of repetitive pressure for many years.  Running or any other trauma can damage the cartilage and start a positive feedback system of more damage causing more loose particles, which causes more damge, and so on.  The problem is that cartilage grows so slowly, once damage gets started, it is hard to reverse the positive feedback cycle 


General Discussion / Re: Artificial knee's
« on: March 20, 2010, 12:09:00 am »
As far as knee replacements go, there are usually four pieces:  1) a metal piece that is glued to the femur(thigh bone) 2) a plastic tray that is roughly 3/16" thick 3) a metal piece that is glued to the tibia (the big bone of the lower leg) and 4) a plastic button that is glued to the underside of the kneecap.  The plastic tray sits between the two metal pieces.  The rounded end of the femoral component rides in a dished out area in the plastic tray, which is locked into the tibial component.  In some knees there is an upward projecting metal stud at the back of the replacement which serves as a lock to keep the joint from bending the wrong way, but usually the posterior ligaments are left intact, and they do that job.  Riding a bike will put very little wear on a new knee joint--what wears them out is being overweight.  The male human knee, regardless of how tall the person is, is just not large enough to handle more than 200-250 pounds.  It is a case of too many pounds per square inch of pressure.  With women, the upper limit is probably nearer to 180-220 because of the smaller surface area of the joint.   If one wants their new joint to last a long time, the best thing to do is to get the weight off, and non-weight bearing exercise like cycling is a good way to accomplish that goal

Bob (retired MD)

Gear Talk / Re: Specialized Tricross Comp 2010
« on: March 15, 2010, 12:42:45 pm »
See the reply I wrote in the other thread on the TriCross bike.


Gear Talk / Re: Tri-Cross
« on: March 15, 2010, 12:40:25 pm »
Get the new edition of "Bike Touring:  The Sierra Club Guide to Travel on Two Wheels" by Raymond Bridge.  It is the best $18.95 that you can invest in getting started in bicycle touring.  The author devotes about 150 pages to discussing touring bikes and what are good and bad features to look for.  He also gives good, common sense recommendations for packing and other touring scenarios.  Altogether a 5 star book, even if you have done some touring.


General Discussion / Re: Google Maps Bicycling
« on: March 12, 2010, 05:08:24 pm »
I just tried using their program for a North Cascades loop yesterday.  For the most part, it worked pretty well.  It did route me on bike trails wherever possible, but it also put me on dirt Forest Service roads for some of the mountain pass sections.  The ACA routes and Google's were not the same in quite a few places even when I forced the issue by setting waypoints at specific ACA turning points.  For instance, Between Mazama and Winthrop Google uses Hwy 20, ACA uses Goat Creek Road; between Rockport and Marblemount ACA uses Rockport Cascade Road, Google again uses Hwy 20.  Generally, Google seemed more willing to route you onto busy roads or dirt roads that were shorter in mileage than the ACA routes.  In one case in my local area, Google routed me onto a busy highway that I would NEVER try to ride, instead of using a very low traffic back road that only adds about a half mile to the total distance of about 20 miles.

That said, for a beta edition, it did very well overall, and if Google really does accept the feedback of those of us out here with the rubber on the road, it has the potential to be a great addition to our planning aresenal.


Another possible option:  a tandem trike.  My wife and I ride a Terratrike tandem, and she loves it.  Advantages:  No coordination problems when starting, especially on hills; no worries about doing an Arte Johnson; the stoker has a fabulous view of the surroundings, not the back of the captain's jersey; the trike disassembles in about five minutes to fit into a much smaller space; there is an Independent Pedalling System available, so the stoker can just relax if he/she feels like it; adjustments for different heights is easy and a wide range can be accomodated (I've ridden with my 6 year old granddaughter and my 6'5" son--though I did make an extra bracket to accomodate him); very stable for high speed descents (we've had ours to over 50 mph and it is rock solid).  Disadvantages:  like any other recumbent, since you can't weight shift and can't stand up, it is slower going up hills (but you can go as slow as you want without falling over); it is heavier; ready to ride, it is over 10' long; large turning radius; almost have to use a trailer for touring as there is only room for rear panniers; cost more.

My son and I have ridden back to back centuries with it in perfect comfort; my wife loves the reclined mesh seat--she thinks it is as comfortable as any of the chairs we have in the house.  We have a Tandem Talk intercom whihc we don't always use, but does make sure that no one needs to shout (the stoker's head is about 5' from the captain's.  There are two major makers of tandem trikes:  Greenspeed from Australia and Terratrike in the US.  The Terratrike is about 60% of the cost of the greenspeed.  Go to for lots more info


Gear Talk / Re: 10 speed vs 9 speed for touring
« on: February 18, 2010, 11:30:05 pm »
FWIW, I run an Ultegra 52-42-30 fd with an 11-34 cassette with the XT long carge RD and have no problems going into either the 30-11 or the 52-34 combos.  Just set it up so the 52-34 works; the 30-11 may be noisy (mine isn't), but you won't hurt anything

Pacific Northwest / Re: ACA forum members from PNW
« on: February 01, 2010, 06:56:12 pm »
I'm in Snohomish, north and East of Seattle.  There is a 17 mile  (soon to be 30 mile) paved MUT about 5 miles from my house that I ride regularly.  I ride a recumbent trike most of the time, putting about 2500-5000 miles a year on it, depending on which tours I do.  This year I plan on doing Cycle Oregon and the North Cascades route, with the possibility of doing the Olympic Peninsula in there as well.   I hope to do the Northern Tier one summer, but I'm not sure when.

Bob Van Valkenburgh

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