Monday, August 9, 2010

Goat Rocks Backpack

Went to the goat rocks wilderness area this past weekend. Very nice! The sign posted on the trailhead said it was by far one of the most popular backpack areas (I had last been there 10 years ago... ) and they weren't kidding. the parking was full and we passed or saw perhaps 60 plus hikers on Saturday... But it's a big area and we found a nice place to camp and it still felt nice and private, and the views were fantastic.

If the clouds would have cleared it would have even been nicer, because Mt Rainer, Adams and St Helens would have been visible. We didn't go super far, but still probably managed 2 mile Friday evening, 10 miles on Saturday, and 8 miles out on Sunday, a nice weekend getaway, that if you subract gas money(to get there) and initial tent, packs, sleeping bag etc, was totally free.

2014 comments: Wow, 5 years since our first trip to Goat Rocks. Since then we've been back once and we will definitely be back again. It's great place. But recommend not going on the weekend, its too busy :)

Thursday, July 1, 2010

Breaking Spokes on Tandem

In past posts I have written considerable amount about bicycle wheels. I am a proponent of high spoke tensions and do believe if you build the wheel correctly (stress relieve etc) the spokes should never break.

So imagine my surprise when I had two broken spokes on the drive side of tandem wheel (36 spoke 30mm deep rim). Did I put too much tension into the spokes? The answer is evidently yes, for the spokes used. For some reason I didn't use DT, wheelsmith or Sapim spokes, etc, but some other stainless db spokes I happened to have. My thinking must have been, "well if stress relieve correctly they will be fine."

Pic above: Broke spoke, Unbroke bad "poor" spoke, Proper Wheelsmith spoke (notice the nice filleted transition into the head). [what is a little concerning is I noticed some DT spokes have the same sharp edge...]

The spoke head was formed quite poorly, and that is what broke, more like "popped" off. The 'elbow' certainly didn't break. There is quite a sharp edge transition from the spoke wire into the head. This stress concentration spot is where a crack must have formed.
As expected for spokes that are going to break, they started breaking well under ~ a year of riding. Under the 'magic' 1e6 cycles.

I replaced all the drive spokes last week. Last night a non-drive side spoke broke, so it appears as though I will be replacing those spokes this weekend.

2014 comments and review:  As far as I can remember, I re-did the wheel and it has been perfect since.  the Tandem is now sold and we have a new lighter tandem (by tsunami ).  The new wheels for the new tandem are h plus son 43 mm deep rim with 24 spoke rear (2to1 pattern).  Its been great as well !  I used "rim bed washer" (custom made out of aluminum, yes that was lot of hacksaw and file work) to spread out the high spoke force.  The deep rim is nice for heat sink and for convection of heat during heavy braking. 

Wednesday, February 17, 2010

Earth Democracy

With the new digital TV, occasionally OPB runs shows from Oregon state university. Flipping through the channels on a Saturday evening a couple weeks ago, this lecture was on. Very good, I couldn't help but sit and listen to it. Very well spoken. Discusses farming, seeds, etc. Not to be missed !! 44 minutes. I found the video online also, it is here.:

Click the high quality to get a better video.

There is a second video (part II) with the questions and answers.

A google of Earth Democracy and/or Vandana Shiva (the lecturer) brings up more links..

2014 comments:  With the new age of netflix, youtube etc, things like this seem to get lost in the sea of information... 

Tuesday, January 26, 2010

new history book to read.

heard this on NPR the other day. Looks like a good book to pick up read.
Bomb Power: The Modern Presidency and the National Security State (Hardcover)

The comment on that page by john hamilton is right up the alley with what james kunstler writes in "the long emergency":

"...The future does not bode well for the kind of system we have now - infinite growth of economic output, increased spewing of greenhouse gases, increased attempts at futile empire building, increased degradation of the environment, and infinite growth of population. All of these things take place in concert, in a synergy of dysfunction for the planet. It won't last."

2014 comments:  Hmmmf.  I don't think I ever finished that book, need to check it out again.  Kunstler:  I occasionaly visit his blog, if and when i remember.... 

Tuesday, January 5, 2010

Book Review

Just got done reading "The Long Emergency". Very well written and thought out. Learned a lot ! We might have to go back to horsepower. No not that horsepower, like a real Horse, with four legs, Power.

Started reading "How to talk so kids will listen & listen so kids will talk". Wow a very practical useful book. Not just for people who have young children. Published in 1980 ! Where have i been that i missed this book... ?

Both books recommended to me by my sweetie Harriet. How nice to have such a clever girlfriend !

Happy new year everybody. I have been quite busy. Hope to get some bicycle engineering posts done in the future. Meanwhile i will just post general happenings and such.

2014 comments: Whoa !  Harriet is now my wife :)

Tuesday, November 17, 2009

busy month

Been pretty busy the last month or so. First went up to Edmonton for a week of work at Sulzer service center. Nice service center, nice people. It was cold (below freezing) and yes snowed as well. Very car-centric. Would have been nearly impossible to go for a walk.

Went to the huge indoor mall in edmonton. The indoor roller coaster was quite impressive! But the mall itself.. I don't know... the whole concept of it seemed somewhat depressing. I did bring ice skates and went skating for an hour at free-skate.

I flew back into PDX on Fri and flew out again that night for Chicago and Class reunion in Michigan. The reunion was great! I was able to visit with a lot of old classmates and teachers. It was hard to believe it had already been 20 years, some the teachers hadn't seemed to have changed. Saturday night we visited at Love Creek Nature center. A lot children.. :

I had forgotten how nice, tranquil and beautiful berrien county is, very little change in 20 years, which is good (although there did seem to be more vineyards). I managed to drive around on some of the roads i use to ride. Brought back good memories of the beautiful fun cycling we use to do. I also managed to visit with big Al Muldoon for a couple hours in St Joseph. He still riding very strong and look as young as he looked 20 years ago.

Baby-sat Harriet's children for a morning and carved pumpkins for halloween. They both were non-squimish and got their hands right into it!

Installing new windows in the house. doesn't take long, but what a mess !

Modified loose tight for riding to work. I really like these.. They were a very loose and are a very thin nike dri-clime ? material.. Like some warm- up pant. By sewing in a knee patch and by sewing up the side to make them less loose, they make a perfect riding tights / pants. Very light, and thin they can't hold much water. since they are loose they are much warmer than a on-the-skin-type tights, but cooler on a warmer day as well. Also they come on and off much quicker then a normal tight making them perfect for comutting.

Right now I am down in La Porte Tx and another Sulzer service center. Nice weather, but wow talk about car-centric living. Makes me happy to be in portland where at least there is more freedom !

2014 comments:  the house is sold and we are now in Hillsboro in a rented "townhouse".   Those damn tights / pants  I still have and still use ... :)

Friday, October 9, 2009

Cannondale Fork mod

Recently picked up a cannondale racing frame and fork off of ebay for $230. It is light, by far the lightest bike i have ever owned. It is fairly stiff also. It had some issues: slight misalignment issues, wore-out dropouts, a bunch of corrision spots under the paint. But, for the most part a well made frame that rides nice and is fun to ride, and will make an excellent racing bike..

It came with an integrated headset. It seemed like something was missing, like there should be some sort of "fork plate" (some called it a "base plate"?.. ). No-one could tell me, nor could i find anything that said or showed what needed to go there. Most said the Bearing just goes right on the carbon fiber.

The engineer in me said no-way, poor design.. i don't like high point loads into "plastic"... So i managed to make an aluminum "base" on my lathe. It was very delicate machining. Had to keep it thin and get the angles correct. Came out nice ! I took some short carbon fibers (made by "trimming" carbon fiber cloth), mixed with epoxy and used that under and in between.

I also added slight shim from a soda can.

2014 comments.  The baseplate is still on the fork.  the soda can diametrical shim ?  silly :)  The frame and fork I still have.  A few more dents and dings...:)  Its been hanging up for a year or two, but its about to come back into service....  

Scraping House

Here's what i was up to in September. Takes way too much time! Looks really nice now with paint on it though !

This side was really bad, and the paint was really thick and cracked, so I took it all off. I have two huge garbage bags full of paint scraping just from this side of the house and only about 2/3rds up. Some of the siding needed repair also...

The rest of the house will get a normal scraping and paint!

2014 comments.  The house was sold last summer, and where I "scraped" with the Infared heater, and repainted: the paint was still perfect !  So probably worth the extra work in the long run.  By the way that was Fir siding not Cedar.. 

Thursday, October 8, 2009

Fixing a Rear Dropout

Fixing a rear dropout does not require replacement. This method is quick, and precise and strong. Timewise, shouldn't take more then 15 minutes to 30 minutes. This one took a little longer because i also drilled out the helicoil thread repair and brazed in a proper 10x1mm "sleeve" made from a nut.

Here is a pic after i straightened it best i could. I considered welding the crack as is, but i wouldn't have been able to get it straight.

Here i broke it. The big advantage then was i was then able to fix the thread and also face it in the lathe.
Next came proper alignment achieved by using two axles, nuts and visegrips.

Next i simply stick welded it with. Weld very hot and fast, chipped slag, and hit it again, and repeated 3 or 4 times until it looked good. Filed it flat (not shown) and was done. Will now work perfectly. This will be my sweethearts bike someday.., an old but cute and sturdy Bridgestone RB-1 road frame that i picked up for $40..

2014 comments.  As I look back at some of the things I did, this one was actually really good work, a great quality repair... .  I ended up not doing anything with this frame, and finally sold it, and hopefully it is being ridden around by a Portland hipster :)  

Monday, August 17, 2009

Tandem !

Bought an old burley tandem for $400. ~15 yrs old ? but lightly used and sensibly made (i like the internal shifter cables..). Fairly heavy, but sturdy.
I added my new tandem wheels (the original tandem wheel had a bent axle even from light use). I re-machined the front bottom bracket eccentric to take a 110 mm spindle rather than the bowlegged length of 126 mm.

Added V-brakes which of course are huge improvement over cantilevers, especially for the rear brake (with its long cable). [Note must use "v-brake" road levers and not say a travel agent with normal road levers, to get the advantage of less force in cable and subsequent less "sponge"]. We did a couple max-stops and yes can almost slide the tires ! Its stops like single racing bike. Kool stop pads of course. The rims are a fairly inexpensive Alex Rim, wide but 30mm deep , so plenty of aluminum for a "heat sink" or at least i hope. Panracer 35c tires; way wider than i expected. Should have went with 32 or 28.

We did the Portland sunday Parkway and rode up mt tabor. Felt great both going up and coming down. The steering is a little strange and will take some getting use to.

2014 comments.   This was a great tandem.  It is sold now and we have new Tsunami frame, which I also built new wheels for (which I will do a new post on...)

Tuesday, August 4, 2009

Shelves and Shaper

Been making some nice garage shelves. The secret to making them fast and accurate is to Dado cut (shelve slots) the fours corner posts all together. In this particular case i had a 2x8 that I slotted, then i ripped into 4 pieces. With subsequent bracing makes for a lightweight and strong shelves.

Finally got the metal shaper body hauled away to Metro Metals. 740 lbs. Using a pry bar, 4x4's and jacks and a cable winch it took an hour plus to load without injury... The tailgate barely handled it, and is now slightly bent.

It was unloaded in all of 5 seconds by a big magnet (which for a second or two, when only holding on a corner and about 5 feet above, thought was going to let go and really bend up the the pickup..)

2014 comments:  still have the shelving, and since have made _a lot_ more shelves (especially for the new rented townhouse that has no built-ins...).  The Pickup has long been sold, but was of course a great little vehicle. 

Saturday, July 11, 2009

Crank Brothers Eggbeater Pedals

If the little bearing on end of the pedal fails the pedal body can come off the spindle. The rest of the ride will be one-legged (if your lucky, if un-lucky a bad crash and ambulance ride) . Now i have had this happen to me, but not with an eggbeater, and I was lucky and didn't crash.

To help prevent this from happening an extra bearing can be added. In addition to another bearing (686 sealed, vxb sells cheap), Will need a longer 4 mm bolt (local hardware) and a washer overlapping the inner seal lip, helps shield from the elements (since rubber end cap now can't be used..). Place 2nd bearing in after clip. Note will not work with all eggbeater spindles. (some use nuts rather than bolts to hold bearing in / hold pedal body unto spindle. )

Also will need to use thread lock or have the bolt bottom out perfectly without putting too much preload on outer bearing. Also should probably have a washer in between the two bearings the same or slightly greate thickness than the snap ring clip. Ok possibly if you get the spacing correct on the in-between-washer (not shown below), you might not need thread lock, etc.

2014 comments :  Hmmmm.  I havent' done this in years..  I don't even know if its possible . I am still riding Candy's though. 

Hauling Steel

Been taking steel to Metro Metals. They have a pretty nice and fast process and helpful and friendly people. Weigh on the way in, dump steel, weigh on the way out, they print a check a give to you.

This was $50 worth of steel,(I added a couple more items, and had 700 lbs of steel !)

Disassembling the metal shaper, still need to get the body hauled. Maybe next weekend if my little truck can handle the weight.

Building Tandem Wheel

Some pictures of working on tandem wheel.Here are the spokes, the nipples, the washers, nut driver. The nut driver bit had to make myself, with a file, brazing and then turning on the lathe. It is square to fit over the end of the nipples. The nipples took a long time to prep. I had to lathe-turn each one to get rid of the slot and to put a slight curve to them.

Here is a picture of the Wheel half-laced.

And here is a picture of the nipple (flipped) and washer inside the rim, to help spread out the load. Higher spokes forces are possible with lower peak stress onto the rim and nipple. Fatigue life should be improved with a stronger wheel. Also improved aerodynamics with hidden nipple. Fortunately with these rims, the rim bed was nearly flat for 9 mm od of the washers, So the washers are only slightly taco shape. The ideal is to have enough surface area in between the under force components that everything stays elastic.

2014 comments. since been sold.  New tandem wheels are only 24 spoked, but built using the same principles... 

Spoked Wheel - Part 4 - Elbow Strength

From previous post , the tensile strength and cross section areas are
233 ksi (2.34 mm) 0.0066658 in*in
240 ksi (2.0 mm) 0.0048695 in*in
245 ksi (1.8 mm) 0.0039443 in*in

Then it follows that:
The ultimate tensile load of 2.34mm spoke is 1553 lbf
The ultimate tensile load of 2.0 mm spoke is 1169 lbf
The ultimate tensile load of 1.8 mm spoke is 966 lbf

The spoke is predicted to break in tension at those forces. But for infinite spoke life, what we are interested in is is fatigue strength. For ductile steel, fatigue strength (or endurance limit) is approximately 0.5 of tensile.
Taking the elbow as the limiting factor, which we assume to be in shear we want the shear fatigue strength. Using distortion energy (von mises) failure theory, this is 0.58*tensile fatigue strength.
To summarize the max force that should be put into a spoke:
2.34mm: 233*0.5*0.58*0.0066658 = 450 lbf (2004 N, 204 kgf)
2.0 mm : 240*0.5*0.58*0.0048695 = 339 lbf (1508 N, 154 kgf)
1.8 mm : 245*0.5*0.58*0.0039443 = 280 lbf (1247 N, 127 kgf)
What this means is that for a spoke that has 1.8mm elbows, if the force in the spoke is kept under 280 lbf, the spoke should have infinite life.
In the elbow, the force transitions from an axial force into a shear force . Someday I may model this with FEA to see the stress contours. If there is bending stress in the elbow, which is definitely possible from not adequately stress relieving the spokes, then the stress in the elbow could be above the fatigue strength, and thus infinite spoke life will not be achieved.

Also note that just because this much force can be put into the spoke, doesn't mean it should be. The rim and nipple strength might not match. In the days of box section rims, the amount of spoke tension was determined by tightening the wheel's spokes to within a half turn of the onset of rim buckle. With today's deeper profile and/or sturdier rims, buckling is not the limiting factor. I have only experienced it with a very light box section rim, long ago...

Also of course, in the future, will look into the nipples and rim. The goal is to have as highly tensioned spokes as possible with infinite fatigue life of the spokes, nipples, and rim.
2014 comments:  Ahh this is good stuff. I still use this, my own blog post,  as reference :) 

Spoked Wheel - Part 3 - Fatigue Cycles

How many revolutions should a wheel last (need for fatique calcs)? Infinite is great of course, but what is reasonable? 10-20 years ? Rim-braked rims wear thin of course, so... For now I will go with15 years. Say 25 miles per day. 9125 mile per year. 210 cm (0.00130488 mile) circumference wheel (700x23c). 9125 miles/0.001305 miles per revolution = 6,992,882 revs per year or ~ 7 million wheel revolutions per year.
In 15 years, 105 million revolutions.

For a racing wheelset: 2 or 3 races a month, maybe 200 miles for 9 months a year. 1800 miles a year. Keep only 5 years. 6-7 million wheel revolutions.

However, typically the knee for fatigue life or endurance limit for steel is right around 1 million cycles. In other words, if the steel component being dynamically stressed doesn't break after 1 million stress cycles, it probably will have infinite life.

One issue is that Aluminum does not have an endurance limit.
Summary: Wheels see enough stress cycles that they should be built for infinite life.

Saturday, June 27, 2009

Inexpensive Tandem Hub

Since I am too cheap to buy an expensive tandem hub (at least for the cheap tandem I am working on), i modified a track hub. Dual threaded for freewheel and drum brake. The Miche hub worked nicely for several reasons.
1. More threads, more nicely done, than other track hubs. As many threads as on a normal hub. I don't want to "strip" the threads with the extra power of a tandem.
2. 12x28 bearings. The bearing are large enough to handle the extra weight of a tandem, while still leaving enough aluminum thickness on the hub, and allow a 12 mm axle. Any other size and you in danger of burning out bearings, breaking the hub shell, or bending axles.
3. Allows the use of an inexpensive but strong freewheel. I know freehubs are great, but since the ratchet pawls are at a smaller diameter, they can't take the same amount of abuse a freewheel can. Obviously a phil wood hub would work great, but they are over $400.

Made an axle for the hub. Not hard to make, other than having to be ultra careful to get the axle to bearing a slight slip fit. The non drive end I made of aluminum. The axle ends, still needing a trim, I silvered into thick tubed 1/2" 4130 tubing, that i then machined down to 12mm.

2014 comments..  Hmmmf.  looks great, but didn't work out in the end.  My favorite tandem rear hub now is siply the $40 or so Shimano 29er (629 ?)  cassette hub.  With 10mm steel axle.  Has held up great for us.  Drum brake ?  sold long ago.  Just not necessary for us..

Friday, June 26, 2009

Pa and Oh visits

Been in Allentown PA for interaction / training with the Pro Pump Services guys. Been here nearly two weeks. Visited two Powerplants, a foundry, and our Sulzer service center. Here we are at Cogentrix plant in Northampton that burns waste coal (basically coal that was "dumped" and is sitting in piles around Pennsylvania).

Here we are measuring vibration on a booster pump (a small pump, yes relatively, this is a small pump). I have the blue hardhat on.

I managed to make a quick trip to Ohio for the weekend to see Joel Sharon Caleb and Cameron. Here are the boys playing golf. A lot of fun. Here Caleb is getting the ball back to the green after launching if off the tee well beyond the the green and into a hay field. This was Cameron first time swinging a real golf club and he did quite well! Even managed to skip the ball off the water.

2014 comments :   These guys are big boys now ! 

Friday, June 5, 2009


With the new digital TV, I was able to watch the Giro. I noticed slideouts occurring on corners with dry pavement. Watching the riders go down, it was apparent what went wrong: Not enough weight on the front wheel.

If you watch carefully, just prior to the front wheel slipping, the rider's weight is back on the saddle. One can find all kinds of information on how to corner, the majority of course good advice, but I have yet to see emphasis on, or to keep awareness of the weight balance between your wheels. I do have personal experiences as well (e.g. a crit in michigan in 1993? second to last corner my front wheel start sliding. In hindsight I am pretty sure I was pedaling/pushing so hard that I also pushed back into the saddle. I did stay upright, but scared the guy behind me .)

With a tweaked front geometry and by coming out of the saddle a little on corners, I have found I can corner better, and have hit nearly 60 mph on roads in west hills here in portland ( only possible if you stay in a full tuck, don't touch brakes in corners, and of course weigh as much as me...)
From BLOG Pictures

If you take a motorcycle training class, quite a bit of emphasis is put on cornering. One key point is that in most situations if you lean the bike over (done by an initial countersteer) and look into the corner, the bike will turn. And that speed (within reason) is not the issue, if you lean it, it will stick. (Assume dry pavement...I am always wary of wet roads ! )

The same with a bicycle. If you lean it, look into the corner, you will stick. But that assumes you have the front wheel properly loaded. It is easy to transfer weight to the front wheel, come out of saddle and put weight on the pedals. Inside pedal, outside pedal doesn't really matter, likewise, what is happening to your weight side-to-side, or up-down doesn't really matter compared to your fore-aft weight. Weight on the pedals means most of your weight vector is now at the bottom bracket which is nearer the center of the bike, and viola, with the rest of your weight on the handlebars, your front wheel will be sufficiently loaded with weight and slideouts should not occur. (on dry pavement and assume no pedal clip.)

Saturday, May 23, 2009

Large Pulley

Ever wonder what is up with the large pulleys recently showing up on the inexpensive shimano derailluers? Decent engineering. Fairly common knowledge since the 18th century days of mechanical clock making*, to minimize friction loss, the ratio of axle diameter to wheel diameter should be minimized. ( e.g. the axle/bearing diameter as small as possible, the wheel/pulley as big as possilble).

For rotational systems, power (or power loss, in this case) = torque * rotational speed. Torque = force times a lever arm. If the lever arm, or radius of axle approaches zero, well of course so does the torque and so does the power loss. Or for identical axle diameters, if the Pulley diameter increases, the rotational speed decreases, and thus also power loss.

10 tooth ~ 32 mm dia
11 tooth ~ 36 mm dia
13 tooth ~ 44 mm dia
15 tooth ~ 52 mm dia

So by going from 10 tooth pulley to 15 tooth pulley the friction loss is nearly halved (to 60% 32/52)
Another advantage is the chain isn't flexed as much, albeit not saving probably a huge amount of energy, but some nonetheless.

Obviously if you have frictionless pulley bearings (i.e. standard deep row ball roller bearings), then this is not as big of deal. Yet it still applies since many bearings have tight rubber seals. I have seen where this seals have way more friction than standard bushing pulley, and regardless of what is claimed, they don't "loosen" up all that quickly (these are not electric motors spinning at 6000 rpm).

So if you are going to use sealed pulleys, pick those with smaller bearings, where the seal friction acts at smaller diameter. I personally use shielded bearings, but for a lot of wet weather or washing (..ccx..), it might pay to use simple bushing'ed large diameter pulleys.

On subject, how about Ceramic bearings for Pulleys? Not logical, since the way ceramic bearings save energy, is that they don't deform as much under load (hertzian contact...). And if the load is next to nothing to begin with, such as in a Derailluer pulley, then the relative energy saving will also be nothing. If they seem like less friction, it is probably only because the seals are really light. Don't waste your money!

*Book about John Harrison: Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time).

2014 comments.  Friction Facts now has tested pulleys (among other things) and actually measured this.  Go to their site and support them !