I finished brazing up the front triangle tonight and I’ll work on the rear end over the weekend.  I still neet to do a little cleaning and filing of the lugs but all in all I’m pretty pleased with the results.

Looking pretty pimp with the Ritchey fork

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BAM!!!

Posted: December 9, 2011 in Uncategorized

The Ritchey Carbon Pro cyclocross fork just showed up.  I need it to set up the rear triangle of the bike and get my BB drop and all those kind of measurements right and I didn’t think it was going to get here in time to work on the bike this weekend but it just showed up so it’s on!

So as per the instructions in the book (Lugged Bicycle Frame Construction, A Manual for the First Time Builder) I bought me a cheap little MAPP gas torch for about $60 bucks.  It works fine and accomplishes what it is supposed to but I was only able to get about two and a half lugs brazed up before the oxygen tank went empty.  No biggie but the tanks cost about $10 at the Home Despot so that will be about $30 worth of oxygen per bike.  I also did not like that the flux would get all sooted up before it heated up to temperature.  So I just when down to AirGas and bought me a little Oxy-Acetylene torch for $160 and a little oxygen and acetylene tank for $120 (first fill on each was free).

WORLD OF DIFFERENCE!  No soot and it heated things up WAY faster.  You can really control where the heat is going a lot better with the oxy-ace.  I brazed up the bottom bracket/seat tube and the down tube/head tube.  As you can see from the picture below the results were markedly better.  Less silver all over the place and a much cleaner appearance.  There is a little blob on the bottom point of the DT lug and then a little gap at the point but I’ll just flux and heat up the point and move that blob down there (in theory).

On a completely different note – one issue has been my eyesight.  I’m getting long in tooth and I wear bifocals. But in reality I don’t really use the bifocals and just look over the top of my glasses.  When using the MAPP gas torch the flame wasn’t very bright so I was using my prescription sunglasses as safety glasses.  The problem was that they are not bifocal so I couldn’t get in close to see clearly what was going on.  However, the oxy-ace is lots brighter so I needed to use the supplied goggles and now I can just leave my glasses off and get in close enough to see what is going on.

Anyway, I submit for your approval the foray into using the good lugs and tubes…

Just got to dress that bottom point up a bit.

I guess I’m as ready as I’ll every be so I started on the real deal today.  I spent the day mitering tubes – measuring and remeasuring.  The frame is going to be a 61cm.  I don’t ride a 61cm, I ride a 53cm.  But there is a method to my madness.  I want a little more practice before I plop my rearend down on something I made so  I’m making this as a suprise for someone (I got another guy that is super tall and has a hard time finding bikes that fit him lined up – he just has to buy the tubes and lugs and I’ll build one for him too).  I got online and got the geometry/measurements from the manufacturer of guy #1’s frame so the front triangle will be identical to his favorite bike.  Since I’m making him a Cyclocross bike the chainstays will be a little longer and a longer CX fork will shallow out the head tube a tad but otherwise it shold ride pretty much like his bike.

Below you see the tubes all mitered up except for the ST and DT at the bottom bracket.  I’ll probably finish that up tomorrow (after reading the “Front Triangle” chapter one more time) and then start brazing.

All mitered up and no place to go.

73 degrees

I did up lug number three and four and I think I’m starting to get the gist of things and can see what is going on and understand why now.  I did however go a little overboard on the amount of silver I used this time but I figure too much is better than too little as far as the strength of the joint is concerned.  I think I’m ready to tackle the real deal now so I’ll start mitering up the Columbus tubes and turn to.  I’ll keep you posted on progress.   Wish me luck.

Not too shabby for a noob - I think

Practice Lug #2

Posted: November 29, 2011 in Lugged Bicycle Frame Construction

Thanksgiving and the dry weather kept me busy getting miles in out on the road.  While I didn’t do any frame work I did manage to come out of the other side of Thanksgiving lighter than what I went into it.

Last night I did lug #2.  As you see from the picture below I over (under?) compensated in my attempt to control the silver better.  While things looked good during the process – less burnt up flux, less silver where I didn’t want it, etc. – after cleaning up the lug it became apparent that I didn’t use enough silver.  With hindsight the fact that I didn’t use nearly as much brazing rod as on the first attempt should have clued me in but I was so focused on being neat and tidy that it didn’t click.  In the image you’ll see an obvious lack of silver between the lug and tube.  I’m pretty sure I just need to re-flux the joint up and add some more silver so that will be an exercise in learning too.  However, in light of the realization that practice make perfect I’m going to order a couple more “cheapo” tubes today to utilize the remaining lugs from the “cheapo” lug set so I can have a couple more practice sessions before I start on the actual project.

Neat & tidy but not nearly as good a joint as the first one.

First Lug Work

Posted: November 21, 2011 in Lugged Bicycle Frame Construction

So after many days/weeks of deciding whether or not I could do this or if I was just flushing money down the toilet I got my ducks in a row and ordered my tubes and lugs and as noted in the previous post they showed up Friday.  Then I had to go and buy the rest of the stuff on the materials list.  Stuff like a vice and grinder, some threaded rod and angle steel, etc.  I had a little epiphany in that a cabinet Lazy Susan base just happens to be the same dimensions as the vice I bought.  The Lazy Susan base is rated at 500 lbs so I thought “Why not?”  It’s pretty cool being able to easily spin the vice around while brazing up a lug.  I don’t really feel like running power out to and insulating/sheetrocking the little detached garage that will eventually become my shop in the middle of winter so for now the enclosed back porch has become my shop.

When I bought all my tubes and lugs I ordered an extra tube and a cheapo set of stamped lugs for something to practice on.  Below are the results of my first actual lug work.

I used the “Tube Notcher “ program on Nova Cycles to get my miter right.

A nice miter

Here’s a dry fit of the head tube/top tube.  When it came to the actual brazing of this joint I left the head tube out because 1.) I wanted to be able examine the penetration of the silver through the lug and 2.) I didn’t have a head tube for that lug set.  The head tube in the image below is actually the down tube for the oversized tube set that I will make the actual frame out of.

If only it looked this good after the brazing.

Here are some shots after the brazing but before the clean up.

Now here are some shots after cleaning everything up.

Left Side

Ride Side

The right side is definitely cleaner than the left.

Top

You can also see that I got a little build up of silver at the point on the lug on the top of the top tube.

But here are the important shots – the inside of the lug.

Inside

Another inside shot

You’ll notice that the silver penetrated all the way through and around the lug.

So if I understand the concept correctly this would be a strong, acceptable joint.  The only issues would be the wasting of a little silver on the outside of the lug and the time wasted in filing/sanding to clean up the lug.

All in all I’m pretty pleased with the first attempt.  I still have some practice tubing and the seat/top tube lug from the cheapo lug set so I give it another go tonight (if I’m not too zonked from sitting on the trainer after work).