A Hard Lesson in Bike Geometry

Last weekend I learned a lesson in bicycle geometry.

At my UBI frame-building class, we learned the basics of why almost all bikes have fairly similar geometry (or "virtual geometry" in the case of compact-style frames), at least within their class -- road, MTB, cyclocross, BMX, hybrid, etc., etc.  As a frame builder, you can experiment with changes ... but will usually quickly find out why your novel geometry just does not work for its intended purpose.

So for the Yamabushi, I followed the traditional geometry pretty carefully, starting with frame measurements from my last two road bikes, and adjusting for a cyclocross build -- with slightly longer chain stays, 425mm instead of 405-410mms, and allowing for a longer fork.

I built up the bike with a Ritchey cyclocross fork, which has a vertical measurement of 391mm from the fork crown to the axle, and an offset (rake) of 45mm.  This is a bit short for a cyclocross fork (they range 390-410mm), but noticeably longer than a standard road fork of 365-375mm.  The extra length allows for fatter tires and mud clearance, of course.  Anyway, the Ritchey works perfectly, and the result is a bike that is comfortable to ride and handles well.  The Yamabushi is not as nimble as, say, my 2007 Cervelo R3-SL was, but it is stable, and it responds well, going just where I point it, when I point it.

Last weekend I put on the bike a new fork with disk brake mount, attached the new Avid BB-7 disk brake and my recently built wheel with a disk rotor.  I  added "The Plug II" (USB charger off the dynamo hub), and was excited to find that everything seemed to work.

I went out for a spin.

The brake is great -- much more control, and better stopping power, than the V-brakes I have been using.  The new front wheel with 50mm carbon clincher rim feels very fast.  The Schwalbe Ultremo 700x28 tires roll fast and are very comfortable with the extra air volume -- perfect for a Brevet that will go over good quality roads.

But the bike seemed to steer oddly.  It felt as if I was steering a boat, with a very little rudder pushing against a strong current.  At first, I thought something was wrong with the headset or the fork installation -- too tight, or too loose?  Or maybe the disk brake cable was gumming up the steering?  After eliminating these choices, I decided to compare the new fork with the one I had removed.

Left side -- a fork too long. 

Sure enough, the new fork has a crown-axle measurement of 410mm, 19mm longer than the Ritchey, and at least 10mm greater rake than the Ritchey.  The longer fork pushes the front end of the bike up, resulting in a reduced head tube angle.  This, plus the added rake/offset, push out the front axle noticeably ahead of the steering axis.

The feeling was odd.  Very odd.  Size does matter.  And shape.

I will try again with another fork as soon as it arrives.

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UPDATE:  I got the new fork, which has the same rake as the Ritchey (45mm) and is in between the two in length 400mm).  The handling is no longer boat-like.  The wheel seems very fast and the disk brake very nice.  The steering is more Cadillac than Porsche, but that seems very stable, and fine for most uses.  Tomorrow I will ride it to work and if all is well, give it a real test the coming weekend.

UPDATE2:  As an experiment, I switched back to 700x35 cyclocross tires (Continental "Speed" version -- for hard packed dirt and pavement, roll reasonably well) from the 700x28 slicks I had tried before.  This increases the effective diameter of the wheel and this the "trail" of the wheel's contact point a bit more, and the handling shifts from Cadillac in the direction of Porsche.  It is a bit odd that fatter tires with more tread result in nimbler handling ... but that is so.

Still, the cyclocross tires definitely roll slower than normal road tires.  I ordered some 700x30 Grand Bois touring tires that randonneurs seem to rave about (distributed in the U.S. by the rider who completed Cascade 1200 with the fastest time this year ...  so they may be fat, but they're not slow!)

UPDATE3:  I noticed that the FSA headset I have had on the Yamabushi (used, removed from frame I rode 2001-2006) was noticeably gummed up.  Some lubricant helped a bit, but still the steering seemed a bit resistant.  Maybe this was at least a contributing factor to the "boat" feeling.  In any event, I put on a new Cane Creek headset I ordered last month.  Yes, I have a headset press and a removal tool,which have now pretty much paid for themselves by getting their first use!  With the new headset and the Grand Bois tires, the front end us very responsive, slightly toward the "twitchy" end of the spectrum.  But when I put an Ortlieb handlebar bag off the front, the handling seems really perfect -- as close as possible to "neutral".  I will ride this combination on a cold 400km Brevet tomorrow.

UPDATE4 (February 3):  I have now used the disk brake and 400mm fork on the 400km Brevet, and since for almost 3 weeks of commuting and riding in the city.  I have come to the conclusion that the bike handling issues I had were at least significantly the result of the gummed up, very old FSA headset.  The bike handling has been just fine with the new headset, with any of 3 sets of tires, with or without a handlebar bag.  If I get some extra time, I might even try swapping back in the 410mm/more rake fork just to see if it is more rideable now with the new headset ... but no time right now.

Off Season Rest

With short, cold days, some wet weather, plenty of (domestic Japanese) business travel and work, I have not gotten in many long rides since Jerome and I did an intense Brevet in early October.  This has been my "off season", from late October until early January ... with riding to start the new year depending on schedule and weather.

I have at least been working on my bikes and reading a Google-hosted U.S. randonneur discussion board, which has focused over the last few days on a Mayo Clinic study announced in June and published in "Heart" magazine that suggests too much intense exercise over too many months and years, can damage the heart and lead to increased incidence of early death.

A Thanksgiving week Wall Street Journal article sensationalized this, with a headline suggesting runners had "one foot in the grave".  (The article is available here ... behind the WSJ paywall.)

One key is to be sure not to exercise at too high an intensity for too long a period.  Brevets require very extended effort, but the intensity level is quite low -- and the key to riding a longer Brevet is to know how to continue to make the greatest forward progress with the least effort.  Managing intensity levels is very important for proper training.  Short bursts of intensity -- intervals, hill climbs -- are crucial.  And books such as Younger Next Year (co-written by the doctor younger brother of a former colleague of mine) suggest a big mistake older people make is to avoid intensity altogether.  But training at too intense a level for too long a period will certainly grind down an athlete and it seems reasonable that it could damage the heart muscle.

Another key is to be sure to allow adequate recovery time after any kind of extreme event.  As much as a month is required for full recovery after a marathon, a longer triathlon, or a weeklong cycling event such as Transalp.  A Boulder Colorado newspaper article provides nice balanced report.

So does riding a longer Brevet or randonee damage the heart?  I do not know.  It probably depends on how one rides the event.  If the Brevet can be completed at moderate intensity, without extreme sleep deprivation, and with adequate recovery, then I doubt it is harmful.  And riding these or other multi-day events is an acquired skill.  The first time I did Tokyo-Itoigawa, I could barely get out up off the floor the next morning.  Now it seems like just a regular hard single day.  After trying PBP in 2011, I felt as if I had put myself through a brutal punishment.  But after subsequent long events, I get through without nearly the degree of suffering, and I recover much more quickly.

If exercise involves extreme intensity and punishment ... and is followed too soon by other similar events, rinse and repeat, then yes, it may not be good for one's health.  Is that really a surprise?

Long Term Road Test -- Japanese Punctureless Tire Tube

There was an era, back in the 1960s and early 70s, when American cars had a very short lifespan.  The manufacturers did not mind -- in fact, they wanted it this way, since customers would want to buy a new car every 2 or 3 years.  Planned obsolescence.

The only problem with this strategy was that American cars got a reputation for being very poorly made.   Japanese cars won a place in the U.S. market because they lasted a long time.  A Toyota, Nissan or Honda would run trouble free for a decade or more.  The Honda Civic or Toyota Corolla with over 100,000 miles and 10 years was a standard "graduate student" or even "junior faculty" car at many U.S. universities.  U.S. manufacturers eventually got the message, and their quality improved, eventually closing in on the Japanese manufacturers.  Today, the average car on the road in the U.S.A. is something like 11 years old -- the oldest ever.  Even as population increases, the U.S. does not need as many new cars each year.  Little wonder that GM and Chrysler needed bail-outs back in 2009.

The same thing is happening around the world with light bulbs.  We used to have incandescent bulbs that lasted maybe 1000 hours on average and consumed 60 watts.  Now we have LED bulbs that last 50 times as long, and consume 10% the wattage for the same brightness.  Yes, LEDs are much more expensive, but it is nice to put one in a light socket and know that it should last as long as I am in my house.  Without any light bulb changes, it is only a matter of time before the end of light bulb jokes.

Could the tire tube be about to undergo a similar transformation?

After my speech in May 2011 to the bicycle usage promotion study group run by Shigeki Kobayashi, a Chiba-based inventor named Suzuki-san came up and started to tell me about his latest award-winning invention -- a tire tube that is nearly puncture proof (well, he markets it as "very difficult to puncture" -- not wanting to overstate his claim).

I was pleasantly surprised to receive, a week or two later, a package in the mail with a gift of two of his patented, award winning Isshin Tasuke tire tubes, plus some explanatory material.  

The tubes felt heavy -- they weigh around 250 grams, as opposed to 90 for a regular Vittoria 18-25x700 road bike tube.  I was not sure I would want to use them.  And I am not sure you want to hear about them either -- tubes are not the most exciting piece of equipment on a bicycle.

The 一新助け(Isshin Tasuke) Tube weighs 247 grams

A Vittoria standard road tube weighs 91 grams.

But the next time I changed to a new a tire on my Bianchi (commuting bike) rear wheel, in June 2011, I tried out one of Suzuki-san's tubes.

I recently changed a threadbare rear tire on the Bianchi for the second time since then.  I put the same Isshin Tasuke tube right back in this third tire.  No flats for almost 18 months of mostly urban riding.  

True, I have not used the Bianchi as much this year as in 2010 and 2011 -- less daily commuting, and more urban riding on the Yamabushi this fall.  But still, no tube punctures in what must be thousands of kilometers, through the entire life of 2 normal road bike tires (both Vittoria -- supple, light, good grip, and high TPI, but nothing extraordinary in terms of puncture protection).

I have never understood the explanatory material that Suzuki-san provided.  Either a lack of Japanese or of technical knowledge.  The tubes have some kind of little loose granular items inside.  You can hear these rolling on the inside as you spin up at the start of a ride ... but they are silent once you have been riding for a minute, and do not seem to cause a noticeable change in rolling resistance.  Yes, the tubes are heavy, not recommended for a hill climb race, but the road feel is acceptable, and for normal riding the convenience certainly more than compensates for the additional weight.

After 18 months, the loose granular substance seems to be forming into lumps on one side of the tube, but it is certainly still useable.  I plan to ride it until it finally punctures.

I just put the second tube from Suzuki-san on the rear wheel of the Yamabushi.  If all goes well, I will use this rear wheel, with the new road disk brake/carbon clincher front wheel, on a 400km brevet in mid January around the Seto Nai Kai.  It will be a bit different than the usual road bike setup, but it is not a hilly course, and it will be worth it if I can avoid changing even one or two flats while out riding in the cold this winter.

Is this a better approach than the Air Protect Max goop that Hutchinson makes, or the Stan's No Tubes sealant, for insertion into a tire?  I do not know.   The sealants add around 100 grams of weight to the tire, if properly used -- not much different than the Isshin Tasuke approach.  I tried the Hutchinson goop a few times on my road tubeless tires 4 or 5 years back, ... and it seemed to end up oozing out under the tire bead and hardening on the back of the seat tube, where needless to say it did not serve its purpose.  Others like the sealants -- David and Juliane used them in the 2011 Transalp in their tubulars, and made it through the week without a flat.

You can order the Isshin Tasuke tubes (Japanese language only) online at 

http://tasuke.ocnk.net/product-list/4

or via fax at 04-7132-2415.

They are not cheap -- at 2850 yen for a road bike version.  Then again, if they last as long as 5 or even 10 regular tubes and save you from all those flat tire incidents, they are not expensive either.  The same concept as the LED light.

Looking forward to the next 20 years

I had the honor of riding the Cascade 1200 and Rocky Mountain 1200 this summer with Ken Bonner, one of the most decorated endurance/Brevet riders around.  According to the BC Randonneurs homepage, he has recorded over 178,000 kilometers of lifetime Brevet distance.  (The BC Randonneurs have established a separate award that is reserved for riders who record long distances "other than Ken", to make sure others get some kind of recognition and he does not monopolize things.)

More accurately, I should say that I had the honor of riding the first ninety minutes or so of the Cascade 1200 with or near Ken... then did not see him again, as I slowed to a more sustainable pace, bonked on the first day's late afternoon long climb, stopped each night, etc., while Ken just "rode through", then returned home for some grandparent duties.

Likewise I did not see him on the Rocky Mountain 1200, where Ken's group started 6 hours later than mine, and finished 18 hours+ sooner.  I think he probably passed at Jasper while I was sleeping.

So I was interested to learn that Ken just celebrated his 70th birthday by doing 70 hours of riding ... another 1600 kms.

Most important, he looks happy!

Cyclepedia to PDX

Last year I got the book "Cyclepedia", which is essentially a catalogue of the most impressive collection of bicycles in the world, the Embacher Collection in Vienna.  It covers an incredible range of history, bikes from all over the world, all eras, all genres -- road, mountain, track, touring, tandem, folding, cargo, urban, and other designs.  The common themes among the 100 bikes are innovation and stylish design, indeed, iconic design.

The book is available on Amazon.com, and the content (plus 360 degree photos) is now also an ipad app.

Now, I am told that the collection will be on show from June 8 to September 8, 2013 at the Portland Art Museum, Portland, Oregon.  Another great reason to be in Portland at some point during the summer months.