Tuesday, January 15, 2008

Broken Record

Unfortunately work and weather has limited my shop time. No more work on chain stays or the Path Racer - no more pictures for the moment - sorry.

But, my new Sapim spokes came in and I was able to finish lacing and truing the light-rando wheels. They look pretty good. With the weight coming in so low, I'm considering using velo-plugs instead of rim tape. They're supposed to reduce weight a bit. But, I'm wondering if a light tape (not rim tape) might accomplish the same thing. The low pressure tires don't work so hard on the spoke holes, and the spokes are sized so that they don't stick out past the nipples. So, I guess that its time to experiment and weigh (literally) the options.

The other big news is Craig's List. I've been watching it and eBay looking for a lathe and a drill press - not thinking that I could possibly buy both. I have a small counter-top drill press, but it isn't heavy enough for the table to hold an angle while I miter a tube (using Joe Bringheli's miter jig). I know that the jig works, because I used one in his shop on one of his drill presses. So that's want #1. Everywhere I look, anything that looks adequate is outside of my budget, considering I can continue mitering with a hacksaw, grinder & files. But, I have a good space for it in the shop.

A lathe is a beautiful thing. That's a famous saying (started by Darrell Llewllyn - a great frame-builder in Australia). Ultimately, what we need is like a 12-13" swing and 24-30" between centers. This allows one to mount a fork, and cut the crown race seat on the lathe, which is more accurate than using a hand seat cutter. But that's just one thing the lathe can do. It can be used to cut miters, with the right fittings it can be used as a small milling machine, one can turn down tubes, and make a variety of parts and tools.

A big lathe like that needs a lot of space, often takes a 240v circuit or even 3 phase 240v - which would mean rewiring the shop and getting a whole new feed & panel installed for the house. It'd probably cost a grand for an old one with a little life left for frame building - but $3,000 would probably be a better amount to invest. And, it'd be hard to move around or ship. Right now, that's not in the cards for me.

However, somebody right here in town, had a 6" and a 9" lathe for sale on Craig's List. The first is a Sears/Dunlap, the second is a Central Machinery (Chinese - not the best brand of same, IMHO). The prices seemed attractive, so I called and visited 'Otto' (his Craigslist name). Otto takes me down to the basement, and it turns out that he likes to 'putter'. In his shop he has a beautiful Southbend Heavy 10. Very nice!!!! But, he has a variety of tools he's collected and tuned up - for sale. In fact, we haven't even made it down the stairs and he asks if I'm interested in a drill press?

Now, aside from not being able to fit or afford a big lathe, I have no experience with a metal lathe and will have to learn to use one. My first goal is to turn down (thin or reduce the gauge) some tubing - maybe 6" long. The small lathe is plenty big for that. Plus to learn on and make some small fittings, maybe even some tools etc.

It's got a new motor, probably over-powered by the size. The beds look nice, and there doesn't appear to be any lash in the cross slide. No center for the tailstock, but two sizes of jacobs chucks (one may work on the headstock). No face plate or 3 jaw chuck, but a nice 4 jaw chuck. Not a lot of change gears, but I can fill them out over time from eBay. A few other little bits and such. All tuned up, fresh paint, mounted on a nice board. It's low speed isn't very low, but I can probably come up with countershaft and slow it down a bit - plus with the small swing, the speed of the face is already sorta low. Small enough for the garage shop or basement. Asking $350 - let's me know it's negotiable.

So we talk, and look at stuff and I ask about the drill press. It's out in the garage, we go back up stairs and its tucked in tightly between a big Buick and the wall. It's from Taiwan. I don't recognize the brand (which is Taiwanese), but it's a nice, heavy sturdy piece of iron. Not new, but obviously well cared for. Looks like the best I could find for much under a Grand (I see a big jump up from what is available for $300 and what's available for a grand - lots in between with very incremental improvement - but I may be proved wrong). Anyhow, this looks very cool.

I ask him how much for both the lathe and the drill press, he thinks and says how about $300? I was figuring he'd want $500 or more and I'd be stuck. But... for this price, how can I go wrong? The drill press obviously won't fit in my car, but he has a mini-van. So tomorrow, I'll become the owner of a nice drill press and a good small engine lathe. How cool is that? Well, unless you're a bike building geek like me, it might not seem all that hot. But believe me, in my world, this is a grand slam. Yipee!

Anyhow, I'll be busy but try to keep you all updated and get the Path Racer pictures up here soon. Cheers

Monday, January 07, 2008

Brief Post

Only a little to report today. Yesterday I brazed the track forks to the stays and threw them into water to soak off the flux. The day job limited progress today, but I got the basement cleaned out, and reorganized, to prepare for doing carbon work inside (where its warm). Keep tuned for more info and related pictures of some test layups.

Speaking of warm,
it hit 60 degrees farenheit yesterday, and today was darn close to that. Hard to believe it was 10 degrees only a few days ago, and I should make hay while the sun shines. Tomorrow looks to be another busy work day, but i hope to make it into the shop yet.

Meanwhile, my Grand Bois tires arrived, so it's time to finish the path racer and then get some pix of the completed bike. I have to say, the new Grand Bois look and feel the part of a fast, supple tire. Along with the 700Cx30s for the Path Racer, there is a pair of 650Bx32s for upcoming rando bike.

My next task is to
clean up the chain stays, and some pix of same to share with you. From there, I have to miter the chainstays for Paul's bike, then set up the jig and tack it all together.
So with luck, we'll have some more pictures to view before the end of the week, then it'll be on to completing Paul's bike.

See ya soon

Sunday, January 06, 2008

New Pictures

Vote on the right for your favorite frame material. BTW, hemp only works when its encased in epoxy (like carbon). :)

I've promised some pix from the build of Paul's new track bike. The tubing is SLX, which is like SL with reinforcing rifling in key joints. Below on the left is the end of the chain stays, and on the right is the bottom of the seat tube. In both pictures the rifling is pretty obvious. The yellow dust in the stays is paint from the hack saw blade, I took about a CM off of each end. The stays themselves are ROR (round/oval/round), so it shouldn't be necessary to crimp them to make room for the tire to fit. It is important, however, to position the forks so that the tire fits nicely in the ovalled rand for the stays across the full range of rear axle positions.

The bottom bracket shell is a Cinelli road shell with spoiler., If you enlarge the pictures and look closely, you'll see the filler in the cable tunnel. What you won't find is the casing stop that used to be their.

Next comes a rear and front view of the stainless fork crown. Originally the front had a flat land for the brake, like on the back. I'm almost finished rounding off the front, which I think will look better on a track crown. Then its the slow process of polishing the crown.

Finally you can see the the track fork being fit up to the chain stay. The fork has a bend in it near the end of the stay, so that the faces will be parallel. As a consequence, the inside miter is much shorter than the outside on. As you can see, the stays have a large overlap with the forks. In face, the overlap is more than an inch long. This probably isn't necessary, but on a track bike it's nice to make this intersection as rigid as possible.

At this point, I have one miter left to clean up. Then it'll be time to set up the jig, tack things in place, and get ready to braze this up. More pictures once we have more progress.

Thursday, January 03, 2008


Time is running out. Vote on the right for your preferred frame material!

It's 10 degrees Fahrenheit in the shop (garage) , so still no more work there and still none of the promised pictures. Instead, a few other pix and further discussion around building a light Rando bike. First a spy shot of the oh-so-close-to-done path racer. In the tradition of spy shoots, its dark, grainy and hard to make out. But, sharp eyed viewers will
get a sense of how the finished product will look (as always, click to enlarge pix)
One Honjo is partially fitted and one to go. Tape and shellac the bars, replace the tires and change the chainring for a TA 1/8" track ring (although that Stronglight ring looks mighty pretty to my eyes).

I'm getting itchy to put this one on the road, but not until they're cleaned up a bit.

Next come some pictures of the wheels that I laced (not trued or tensioned yet) yesterday. More on that in yesterday's post.

The rims are made by Velocity, using the extrusion of the Aerohead. If you don't recognize the label, it's because the distribution rights to this rim (which is a 650B or 584 ERD size) belong to an Australian outfit called Chainring Transit Authority (or CTA). They fronted the money for having this size manufactured and got an exclusive on it. That said, their prices (even shipped from AUS) are quite fair, they offer extra services (want a hand polished rim? How about a customized drilling pattern?) and I enjoy doing business with them. Most likely, these rims will be the light-weight standard for 650B wheels for some time to come.

Here is the 100gm H2 front hub from White Industries. Lots of other hubs might have worked, but these combine lots of attributes that I like: finely polished; sexy shape (with a traditional look); nicely 'engraved' logo; nice sealed bearings, low weight, & made in the USA.

Here's the business end of the rear-hub. That's a titanium cassette carrier which helps the complete wheelset (using Sapim spokes w/ brass nipples) to weigh in at 1515gms. Not bad eh?

And if you break a spoke, any decent shop should be able to fix your wheel!

As is always the case, once you start weighing things in real life, they add up to more than theoretical weights. Also, at this point in the process I'm trying to be fairly conservative.

So let me explain theis chart. In the build kit, every item was weighed on a digital scale unless it is highlighted in yellow. We don't need the full length of the seat post and can probably get it down to its spec'd weight of 188 grams. Also, its easy to sub in a Sella Italia SLR for the
Arione. This would net a reduction of about 0.2 pounds. But, in reality for a Rando bike, we might go with a Brooks saddle for an approximate weight gain of 0.7 pounds. And, I don't know what handlebar tape we'll use, or its weight.

However, the rider at hand likes the Arione so that's going to be the basis of our computation. The wheel weight is probably going to go down a little once the rear gets re-spoked - which should compensate for the h-bar tape. And who wants to cut seat-posts?

So the real open question is frame and fork weight. I may have under-estimated here, but don't think so. The fork will have relatively short legs and a rather short steerer, so I anticipate it coming in at around 700 grams if a fairly light crown is used. I don't think that it will be a problem to hit 700 grams. The frame itself has bigger question marks. First of all, let me note that the tube set weighed in right to the gram of the Columbus spec: 1420 grams. Using BikeCad, I determined the length of each tube, center to center, and created a ratio of that to the uncut tube length. So, if a tube, C to C, is 92% of its uncut length, then I multiply 92% times its weight. In reality, the tube weight should be less than this for two reasons: 1) the tube is butted, and all trimming comes off the much heavier ends; 2) the ends aren't cut square - they are mitered and really don't quite reach to center of a joint even at their longest point. So, my calculated final tube weight is probably well over the actual cut lengths.

This takes us from an uncut weight of 1420 grams to a cut weight of 987 grams. To this I've added the 108 gram raw weight of the rear dropouts and 132 gram raw lug weight. These will also be reduced, but not by much. In any case, the cut tubes, lugs and dropouts come to 1227 grams - well under the weight of just the uncut tubes. There will be a cable guide under the BB, some cable stops on the TT, a housing stop and a chain catcher on the chain stay, and a brake bridge. I've estimated these at 5 oz, bringing the total frame weight to 1369 grams. You might note that I haven't accounted for filler (silver) or paint. So I may have under estimated total weight. But then again, I've over estimated the tube, lug and dropout weight.

The net of this is that it looks like this bike, with 32mm tires will weigh about 16.75 pounds. I'd say not bad - but not a record holder. Also we have to mount a good front rack, a bag, fenders, and a light set. Ideally the light set will be generator based. So there is still work to do. But it looks like we're on the right track. And we aren't engaged in a weight contest, just trying to keep the bike as competitive as possible without compromising its performance. That's it for tonight.


Wednesday, January 02, 2008

It's late

It's late and I'm tired, so this will be short.

Laced up the wheels today. White Ind. H2 hubs, Velocity Arrowhead (w/ OC rear) 650B rims from CTA, Sapim 14/17ga 32x3-cross front, 14/15ga 32x3-cross rear.

I should note that I miscalculated the rear spokes and will be re-lacing with shorter spokes.

Anyway, the total weight of this wheel set (less rim tape and skewers) is 1515 grams. Not bad eh?

Good night

Tuesday, January 01, 2008


Now there's a heavy topic. We've been trained to believe that weight is one of the most key criteria regarding bicycle performance. It makes sense logically, one can even calculate energy saved over a course based a on certain weight saving. As a consequence, the importance of weight takes an impregnable position in our imaginations.

I don't subscribe to this point of view. There is no question, that if the differences are great enough, weight will slow us down on the bike. But how much is too much? As Richards Sachs points out, we don't bench press bike frames, and frames don't contribute to rotating weight. So is a super light weight bike really a performance advantage compared what was available in the early 70's. For those of you who weren't around then, a 22 pound bike was pretty competitive. Considering the UCI allows bikes to weigh as little as (approximately) 15 pounds, we're looking at a 7 pound difference between then and now.

Well, if you're as big as me, that seven pounds is something like 3% of the combined weight of bike and rider. Which sounds like it might make a difference. The studies that I've seen, however, don't seem to show that results vary based on weight. It seems like a disconnect, but when time counts, ability and attitude appear to outweigh weight.

Manufacturers are busy lobbying the UCI to lower the minimum weight allowed for a bike. Given that all the teams and riders have access to similar equipment, this shouldn't change the quality of competition or the order of results. But it will give manufacturers bragging rights for a few more years of product cycles. And, fundamentally, the bicycle business has long been one of product cycles. This wasn't always so. There was a time when changes came more slowly, but Shimano made this one of it's key tools to survive the various bicycle market booms and busts - as did their clients: the bike manufactures.

Now days, many folks get the itch to buy on a regular basis. For some folks this happens annually, for others every x number of years. Don't think for a moment, however, that bicycle sales are based primarily on a combination of bikes wearing out, or becoming fundamentally obsolete, and new cyclists joining the market. There is a huge segment of move-up and replacement (which may be merely an addition to one's stable) purchases that drive the market, especially on the upper end.

Let's face it, our modern economy puts lots of emphasis on growing consumption - often at the cost of product longevity. So what I've described clearly isn't unique to the bike sector.

Having said that, I prefer to build something that will survive through multiple generations. I think, that for this to happen, there are three things that must be right about a product: 1) It has to be durable; 2) It must be inherently functional; 3) It needs to exhibit a fundamental aesthetic that lasts over time.

As a result, my bikes generally won't be the lightest in the market, even when I use carbon fiber. That doesn't mean that I don't experiment with light weight frames, nor that I won't deliver something light to a client. But I do want my frames to last and build them accordingly.

Before and after WWII, top French builders competed in technical trials where their bikes were tested and judged for functionality, durability and performance. The best examples weighed in somewhere around 16-17 pounds with fat tires, fenders, racks & bags, front and rear lights, and pumps. Today, except for a couple of preserved examples from those contests, I am unaware of any bikes today that are that light while being so fully equipped. After all, its hard to build a bike that capable and that light. And frankly, one should presume that such a bike wouldn't have a very long life under daily use. In fact, those same French builders generally sold the public similar bikes, but at weights starting at 21-22 pounds.

Bicycle weight has long been viewed as a performance issue, but low weight reduces longevity.

Having said all of the above, I remain intrigued by bike weight. More and more, I consider how everything, apart from the frame, contributes to the total bike weights we see today. This too is much like what the old French builders did. As part of their program to reach low weights, they'd replace steel bolts with aluminum, or cut a dish into the heads of bolts, they'd cut away pedal cages, and make their own brakes or stems to lose weight.

Today builders have to consider legal liability when modifying components. And we have to consider how many components are made to work as part of a system - where changes to one piece could throw off functionality of everything. On the other hand, we can select from components and groups to achieve low weight in ways the old French builders generally couldn't.

Today, its possible to purchase a pair of wheels that weighs less than a Kilogram. That's darn light. The new Red group from SRAM is claimed to be less than 2 Kilo's. Given that, it should be easy to build a bike today from commercially available products that weighs less than 5.5 Kilo's, or around 12 pounds. Will this make you a faster rider? Personally, I doubt it. But all this drives me to wonder what a reliable steel-framed bike should weigh.

In a smallish size, I think that a 650B based frame, built up with Columbus Spirit for lugs might come in around 3 pounds. Add another pound and a half for the fork, and we're at 4.5 pounds. What do you suppose we can do with this?

Well, I've been weighing some components lately. I'll be publishing the results in another post - but by and large SRAM seems to offer accurate numbers. Preliminary results suggest that my build kit will weigh in around 12.4 pounds, which combined with the frame and fork totals 16.9 pounds. Frankly, this doesn't seem believable to me, so it looks like a test is in order. But first let me describe the build kit so you can see that I'm not planning to do anything crazy or radical.

The core will be a SRAM Force drive train including: braze-on front derailer, rear derailler, 1090R chain (weighed in its heavy packaging), SRAM OG-1070 steel cluster in a 12-25 configuration, Dual Control levers (weighed with full cables and casings), and carbon compact crankset with the normal Exo-Drive BB cups. To this add: Thomson Elite seatpost, Fizik Arione saddle (a Sella Itala SLR would save 0.2 pounds), Tektro Quartz CR720 cantilever brakes (w/ hardware), 650Bx32 tires and a set of hand built wheels comprised of White Industries H2 sealed bearing hubs, laced 32 x 3-cross to a set of CTA Razor rims using Sapim spokes (front 14/17 ga, rear 14/15 ga). There you have it. None of this is cheap stuff, but it's not esoteric, flimsy, or hyper expensive either. Seems doable - I'll share more info as progress is made.

Vote Now!

Don't forget to vote on the right for your favorite frame building material!