Kevin,
Thanks for the comments and update on current European builders. I tried to choose my comments carefully so as to not raise any hackles especially since I have no experience with present day custom builders over there.
The accuracy employed by many American frame builders especially in mitering main tubes and tube alignment far exceeds what is necessary to build a functioning frame. I was guilty of that myself when I built some frames back in the mid 70s.
When we started building frames our goal was not to get into the custom frame business. We explored building bikes and components here in the US.
After the US Bike Boom craze ended the demand for entry level "10 speed" bikes fell off. The market for midrange bikes was starting to grow as cyclists were looking for better quality second bikes.
There was a shortage of midrange to better quality European bikes both because of the unfavorable exchange rate at the time and many European makers didn't have a US presence after the Bike Boom ended: Raleigh, Peugeot and Motobecane were that main players with Bianchi to a lesser degree.
The frames that I built were intended to get a first hand understanding of how changes in geometry affected ride and handling. In addition I was developing processes for building production frames and also how to train workers in frame building.
As you mentioned about jigs, I was concerned about residual stresses after brazing too. Our jig was custom built for us by a machinist who was also an avid cyclist. He modified the design several time for us. I learned to loosen some of the tube clamps before moving to the next joint so as to prevent stress buildup.
My negative comments were based on having to realign poorly built frames from many top name European builders.
When I was figuring out frame building (there was no one to learn from) I started by doing autopsies of wrecked frames. Once I cut open a totaled mid 60s frame built by a premier Italian house. For starters it was a 50cm frame made with heavy gage tubing, probably Columbus SP. The biggest surprise was there was no mitering on the frame tubes at all! There was a 1/4" (6mm) gap between the ends of the top and down tubes and the head tube. Someone just cut off the tubes and stuffed them in the lugs.
I witnessed an ex-pat European frame builder make a frame freehand one Saturday afternoon. We were headed to an out of state race that day and one of the rider's bikes fell off the bike rack at 65 mph; his frame was totaled. Lucky for him the builder was located in the town where the race was being held. He raced on the frame in the morning, even though the paint wasn't completely dry.
It's easy for a craftsman with 20 plus years of frame building to "eyeball" the tubes for length but 2-3 lick with a file doesn't constitute mitering in my book. The only measurements taken on the frame were at the end when he "aligned" the dropouts with Campy dropout tools before the frame was painted.
Granted it was a rush job but that seemed to be the person's standard procedure.
Several years ago I bought a 1988 Colnago Technos frame from a local frame builder (OT but KOF). He said the the original owner complained that the bike handled weird. My friend realigned the forks which were quite a bit out but that didn't help. The owner ended up trading in the frame for a custom built one.
I checked the alignment before starting to assemble that frame. The rear triangle was off to one side by 7/16" (11mm). We put the frame on a layout/alignment table and found that the head and seat tubes where out of parallel by over a 1/4" in each direction (1/2" total). That frame should have never left the factory in that condition!
I have dozens of horror stories like that but I'll spare you...
There are many beautiful bikes that don't handle well; frequently because the frames are misaligned. The point I wanted to make, is that these frames were made by the hands of men not divine spirits. There is no excuse for these kinds of things since it's so easy to eliminate the problems during brazing!
Chas. Colerich Oakland, CA USA
kevin sayles wrote:
> Sent: Saturday, October 31, 2009 4:11 AM
> Subject: [CR] Frame Alignment: Ugly scratches and Useful bike tools
>
> Hi Chas,
> Naturally my attention was grabbed by your statement below..........
>
> Whilst I can't speak of other European framebuilders, I know I'm more
> than happy with the standards I set myself.
>
> It is true that many of the established European builders methods leave
> a lot to be desired.....but then I can say that about certain American
> framebuilders, some with a almost 'God like' following adopt certain
> methods that I wouldn't choose to emulate.
>
> A frame made in a jig doesn't automatically mean it will be superior to
> one made 'freehand'......infact I would argue by saying a jig is prone
> to imposing built in stresses.
>
> My method is to set up the frame on a table, which, even though it is
> accurate is only used for setting and not for alignment, the frame is
> continually checked for track during the process of brazing each
> individual joint, but I do have custom made apparatus that enables tubes
> to remain in alignment during brazing.
>
> We used to have a Italian made jig, which I hated, every frame that came
> off it was always out of track.......eventually we sold it, and I went
> back to using a setting up table....which is how I was taught by Danny
> Foster at Bob Jackson's.......which promts me to question the statement
> about a chainstay being 1/2" shorter!.......that's a huge ammount, the
> wheel would probably have been so far to one side that the tyre would
> have touched the inside of the chainstay!
>
> Chas, my intentions with this message are, certainly not to be
> arguementative, or nasty, but to merely 'put up some defence' for
> European framebuilders.......though between you and me, some do fall
> into the category that you refer to, as I'm sure some American builders
> do. [like you say, 'most' American frame builders]
>
> Its just that whenever I see reference to American frame builders being
> so much better than anyone else it naturally hits a 'nerve'......I'm
> sure you can understand this.
> [tell you what you are good at though, and that's the paint
> jobs!!....Keith Anderson, Brian Baylis etc........superb!]
> Regards......Kevin
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> Chas wrote;-
> I agree completely with several posters that most American frame
> builders set a quality standard that has rarely been met by ANY of the
> European builders.
>
>> Many famous name European frames were (and still are) built without
>> the benefit of a jig or any fixturing. Tubing fit was "eye-balled" and
>> a lot of frames were assembled with main tubes that weren't even
>> accurately mitered. After brazing, the frames were cold set to an
>> approximation of proper alignment.
>>
>> In a properly aligned frame the wheels should be parallel on a
>> horizontal and vertical plane with the centerline of the bike. The
>> dropouts should be equal distance from the centerline too. Head and
>> seat tubes should be parallel. Fork blades should be equal length and
>> have the same amount of bend and rake or trail. The front axle should
>> be parallel to the front of the fork crown and the rear axle parallel
>> to the bottom bracket.
>>
>> A well aligned frame doesn't have any pull to either side and tracks
>> well through corners especially when descending.
>>
>> While there are other elements of frame geometry that come into play,
>> a properly aligned frame will handle better than one that's out of
>> alignment.
>>
>> Anecdotal tale in reference to the growth of mail order sales in the 70s:
>>
>> In 1977 someone brought a brand new all Campy Bob Jackson bike into
>> our shop. It was beautiful, black and tan with crisp decals,
>> pinstriping and a shiny clearcoat. It was one of the nicest finished
>> frames I've ever seen.
>>
>> The "customer" had just received it from mail order house in Southern
>> California that was pushing a lot of Bob Jacksons, Colnagos and other
>> well known brand frames.
>>
>> He complained that the bike was "pulling". I took it out for a test
>> ride and brought it back in less than half a block. It was pulling was
>> an understatement! It wanted to go in circles!
>>
>> I put it up on the stand and immediately saw that one chainstay was
>> over 1/2" shorter than the other. I showed him the problem and
>> politely sent him on his way.
>>
>> The term "Hand Crafted" applies to many of the bikes that are the
>> topic of the CR group. None were created by divine touch!
>>
>> As such these creations are rarely going to be perfect but they should
>> at least ride and handle well by intent not accident.
>>
>> Chas. Colerich
>> Oakland, CA USA