Re: [CR]BB Shells and Dave Bohm

(Example: Framebuilders:Cecil Behringer)

From: <"brianbaylis@juno.com">
Date: Wed, 7 Jun 2006 14:11:50 GMT
To: norris@norrislockley.wanadoo.co.uk
Subject: Re: [CR]BB Shells and Dave Bohm
cc: classicrendezvous@bikelist.org

Norris,

Thanks for putting forth your view and thoughts on framebuilding. It is interesting to note the differences between UK builders and American bui lders. One thing that must be noted is that Dave Bohm is more an excepti on than a rule in so far as American builders go. There are a few builde rs here who focus on the bike frame as art, so to speak. John Murphy of Columbine comes to mind and also Vanilla Bicycles and Glenn Erickson, wi th a few others trying to follow suit. Excessive Art Stump-like framewor k turns me off also but to some degree there is a market for it.

Another school of thought here in the states has more to do with refinem ents and doing very clean work, but not neccessarily super fancy and ove rworked. I did a few overworked frames as a fledgling builder like many do, trying to set the world on fire and gain some experience and fame fr om all of it. I appreciate craftsmanship and expert design and finish wo rk, but the excessive cutting is too much for my taste. The full stainle s fancy foo foo frame at the framebuilders show felt ice cold to me. I a ppreciate the time someone spent, but I would spend the time in complete ly different ways, as I'm sure you would also.

I don't like to critizise other builders artwork, but I honestly feel th ere is a limit, and if the bike starts to look like jewellery then you s hould wear it around your neck. The other thing about extensive artwork is that often even though there is a lot of work and it appears fancy, m y eye almost always finds poorly perportioned parts and awkward curves a nd such. Putting in a lot of work making something not quite right makes no sense to me. If you mess with the bits there should be harmony and a theme that binds the set together. When I see long points on lugs that have been cut leaving very thin lines I never like the look. It's a case of a lot of work but the effect doen't look proper to me. I believe tha t clients here in the states demand the level of work we produce as Amer ican builders; but there are cases of overdone frames that maybe would b e better off with more time spent studying classic design perportions fo r curves and so on. A balance of style, design, and craftsmanship are th e best combination in my opinion. Bikes for the sake of art turn me off.

Brian Baylis
La Mesa, CA


-- "Norris Lockley" wrote:


It's been a difficult day so far..and it became even worse when I saw

Wayne's contri about Dave Bohm's reworking of the RGF bottom bracket

shell and the Bocama lugs. In retrospect perhaps I am over

reacting..it's just that the contri caused me to revew much of the work

I have done on bike frames for nigh on 50 years and to revisit some of

the principles on which my working procedures have been based.

Like many frame-builders I have always been more than happy to use RGF

cast bracket shells because they are accurately made, the castings are

sound, the threads are usually well-formed,and they contribute to a

stiff and responsive frame. I have never known one to ovalise in use or

to crack or deform in any way, being ultimately very dependable and

suited to the purpose for which they were made. They were often the

first sign of a quality frame made by a builder who knew his materials.

I have never thought that they were "rough", just in need of a little

cleaning and smoothing, but far far better than the cast brackets of the

50s. in all respects.

Similarly Bocama lugs were always robust, well thought out for the

purpose in hand, but did require some refinement in terms of filing down

and profiling...but never anything drastic.

The purpose of this email is not in any way to criticise Dave Bohm's

skills because he clearly has immense talent with his jeweller's saw and

needle files, but instead I wish to ask quite simply "Why?" Why take

that bracket shell and lugs and then set about wholesale alterations,

alterations that although rendering the components more artistic, might

in fact lead to them being weaker than they were at the outset thereby

jeopardising possibly the integrity of the construction and the ride

quality of the finished frame? Would it not have been more sensible to

take a blank one or if none were available, to weld one up, and then

cut the profiles.

Most Bocama lugs arrive with a ring of metal attached to the headlugs,

in the same way that Nervex Pros did That ring has a function - to help

to prevent the ovalisation of the head bearing sockets, thereby reducing

or removing judder. Dave appears to have removed those rings. If they

appear slightly ugly, it is always possible to run a bead of weld

material along them and then file them into an elegant concave curve

that not only enhances their appearance but strengthens the headlugs

against ovalisation even further.

The removal of the outer tube socket walls on the bracket shell and

their replacment with longer tangs seems not a bad idea, but if those

tangs are only brazed or bronze-welded into place rather than fusion

welded thereby producing at least a semblance of homogeneity and

structural integrity, it does bring into question whether the end result

was worth all the effort. My own experience suggests that such tangs as

these and those brazed to the lugs are little better than

window-dressing.."ars gratia artis". Presumably Dave will use

silver-solder when he eventually "brazes" the frame together, otherwise

there would be a risk of the added-on tangs, floating off under the

torch. Should the frame be chrome-plated there would also be a risk of

the acid etching slightly into the tangs' b/o joints, and of

under-cutting the filed and dressed weld.

I came across this contri about two hours after I had put to one side

the Bernard Carre-built Sauvage -Lejeune frame that I had been cleaning

up. This is the 1965 frame that carried Henri Anglade to the French

Champion's jersey and to 4th on GC in that year's Tour, together with a

number of high placings in top-ranking races.

Coincidentally this frame has an RGF bracket shell, but neither the

shell nor any of the Prugnat short-point lugs have had any reworking

nor, I suspect ,even the stroke of a file gently across their surfaces.

The front and rear drop-outs and their joints into the blades and stays

are just as the torch left them.

Membership of the List and the privilege of being able to read all the

contris has made me very much aware of the vast gulf that exists between

perceptions of a custom frame in the States and those held in the UK.

Clearly the clientelle for custom frames over there demands and is

willing to pay for far more "art" than a British builder could ever hope

to find stepping through his workshop door. Perhaps that is the

difference..American builders have studios and British ones have

workshops...I suppose, on reflection I am firmly rooted in the "form

follows function.." school of framebuilding.

Norris Lockley, Settle UK