The following pictures are for illustrative purposes to show one of these frames/forks seated on 700c wheels (note the sloping top tube). Please understand this offering does not include the wheels pictured.

We do want to emphasize the frame was built with straight gauge tubing, so it will be heavier relative to most other steel tubed road frames. Although, if there is a potential benefit to having thicker/heavier tubing (especially with larger frames), it's the unlikely event that such heavier frames will ever develop the "wobble effect" that can sometimes show up at higher speeds with frames that employ butted design features to the extreme (please refer to our general notes below for more details).

We were not provided any information with these frames, but please still review the detailed notes that follow, as we have taken some measurements to help assess fit and function. Please also understand that while the measurements below are not factory specifications, we have tried to be as accurate as possible using the various measurement tools available to us (i.e., calipers, protractors, rulers, tape measures, scales, etc.). Some of these measured specifications include the following (and please note all length measurements are center-to-center): 

• Frame size (seat tube length): 44 cm

• Weight (frame and forks): 7 lbs 15 oz (frame weight is 6 lbs 0 oz and fork weight is 1 lb 15 oz)

• Rear dropout spacing: 130 mm

• Top tube length: 51 cm

• Head tube angle: 78 degrees

• Seat tube angle: 81 degrees

• Wheelbase: 97 cm

• Chain stay length: 39 cm

• Fork rake: 50 mm (least amount of confidence in the accuracy of this measurement to the nearest mm...so probably an error factor of +/- 5 mm)

• Head tube length: 9 cm

• Head tube inside diameter (for headset): 30.2 mm

• Fork steerer outside diameter (for headset): 25.4 mm (English threaded) with 26.4 mm crown race step-up...so ISO spec'd

• Seat tube inside diameter (for seatpost): 26.2 mm (measured by inserting a seatpost sizing rod and noting the first visible marker above the seat tube)

• Seat tube outside diameter (for clamp-on front derailleur): 28.6 mm

• Bottom bracket shell: 1.37" x 68 mm (English threaded)

• Braze-ons: Dual control brake/shifter lever cable stops on the down tube (for cable routing when dual-control levers are used), brake cable housing stops on the top tube, shifter cable housing stop on the right chain stay, water bottle cage mounts on the down tube and the seat tube and chain peg on the right seat stay

• Other notes: Semi-vertical rear dropouts with built-in derailleur hanger, recessed brake caliper mounting holes and a stamped/pre-drilled hole on the underside of the bottom bracket shell for cable guide block (not included, but inexpensive part to obtain)

Other measurements...
The wheelbase measurement also appears to impact ride qualities. A general rule of thumb is that a longer wheelbase results in a more comfortable ride at lower speeds (similar to the shallower angle discussion noted above), while a shorter wheelbase will promote a more responsive/performance oriented feel that generally handles better at higher speeds (but the drawbacks are predictable in that improved high-speed handling qualities generally result is less comfortable overall ride characteristics). In an attempt to provide some basic guidelines, wheelbase measurements generally range from around 100 cm (or less) to nearly 110 cm...with ride qualities described above dependent on where a measurement is positioned on this continuum. 

The chain stay measurement is a component of the wheelbase, so it's not surprising to note a consistency between the two measurements. In other words, a shorter chainstay measurement will shorten the wheelbase and generally translates into more responsive/performance oriented ride characteristics with better acceleration and climbing qualities. The drawbacks (to a shorter chain stay) are consistent with the discussion above in that such positive handling qualities at higher speeds will generally result in a less comfortable ride at lower speeds. A longer chain stay measurement, similar to a longer wheelbase measurement, will usually improve overall ride comfort, while conceding some of the high-speed responsiveness achieved with shorter dimensions. Lastly, in an attempt to provide some additional guidelines, chain stay measurements generally range from around 40 cm to 45 cm (or possibly longer) with ride qualities described above dependent on where a measurement is positioned on this continuum. 

Fork rake, like the chain stay measurement, is a component of the wheelbase...but to a lesser degree. A longer fork rake, as in the case of a steel touring fork with exaggerated curves, will generally provide fairly significant road dampening qualities. From our own personal experience, we always noted the way a touring-style fork will literally bounce up and down around the dropouts, absorbing the bumps in the road, but this feeling never made it up through the steerer (or at least to the degree noted at the dropouts). We realize there are other factors at work here, but we still wanted to provide one example of the impact fork rake may have on ride comfort. Another thought regarding fork rake is it's impact on the "trail" of a bicycle. This could turn into a lengthy discussion by itself, but the general concept is the "trail" measurment of a bicycle significantly impacts the stability of the ride, or said another way, the bicycle handling properties that promote straight ahead steering. Generally speaking, the longer the "trail" the greater the inherent tendency the bicycle will track in a straight line. A shallower head tube angle and a shorter fork rake are probably the most significant contributors to a longer (and preferred) "trail" measurement. Our general assumption here is that frame manufactures have long since incorporated the preferred "trail" measurements in their frame and fork designs, so the fork rake and head tube angle should compliment one another in this regard. 

Please note the dimensions (wheelbase, chain stay, etc.) on this particular offering are fairly short, so consistent with the angle measurement discussion above, this frame should be fairly responsive and perform fairly well at higher speeds, but it probably will not be as comfortable (relative to a frame with longer dimensions). We do not view the fork rake as having a significant impact on the ride qualities of this particular offering (in the sense that it will not influence handling or performance to the degree of the other noted specifications). 

Materials...
We are not going to do this topic justice, but will still try to provide a few general/basic observations. 

Most vintage frames were made with steel tubes and although there were different brands/types...this was the preferred material for many years. Steel is generally the heaviest of the material choices, but some still prefer the ride qualities of a steel frame. Generally speaking, steel frames may retain several desirable high-speed ride qualities...responsiveness, good acceleration, etc...while the inherent dampening qualities of steel help to alleviate some of the rigid/uncomfortable ride characteristics that usually accompany high-speed performance. 

Maybe the most significant historical advancement made with respect to steel frames was the idea of butting the tubes. The motivation behind this concept was to maintain structural integrity of a frame by reinforcing the tubes with thicker material at stress points (i.e., the joints of a frame), while reducing overall frame weight by thinning the tubing walls at lower stress areas (i.e., the tubing sections away from the joints). Butted steel frames are still going to be heavier (in most cases) relative to frames made with other materials (aluminum, titanium, carbon fiber, etc.), but weight differences are generally not as significant when butted tubes are used. 

Like just about anything however, too much of something is not always a good idea. In the case of butted tubes, we've noted some examples (especially in larger frames) where the tubes become so thin in lower stress areas that a frame will literally begin to "wobble" at higher speeds (and this can be especially unnerving on descents). I am sure there are several factors a work here, but this undesirable characteristic seems to be more prevalent with lighter (and larger) frames that have possibly taken the butted concept to extreme limits. Please understand, we still much prefer a well designed/manufactured butted frame over a straight gauge frame, because the ride qualities are not compromised and a lower overall frame weight is still attainable.

Aluminum frames were probably next to achieve some level of commercial appeal...and while it's a lighter material, aluminum frames are generally stiffer and provide a harsher ride (relative to a similarly constructed steel frame). Having said this, aluminum frames generally retain many of the high-speed ride qualities and superior climbing qualities (due to their light weight) desired by more competitive cyclists. Some would also note that aluminum frames are generally a good candidate for lighter riders, while heavier/stronger riders that generate a lot of torque may want to look at other material options.

Another design feature that gained popularity, while the aluminum frames were being introduced, concerned the idea of oversized tubes. The underlying motivation here was similar to that of butted tubing noted above...maintain structural integrity and desirable frame characteristics, while further decreasing the overall frame weight. This was accomplished by increasing the size (diameter) of the frame tubing while also thinning the tubing walls. As most will attest, this concept can be taken to the extreme (similar to the butted discussion above), which may also result in undesirable frame qualities. Although, well designed and oversized frame tubes in just about any material are still widely accepted and available on many current frame offerings, which lends support to the merits of this underlying concept. 

More recent frame materials gaining popularity include carbon fiber, titanium, or some combination of various frame materials (and regarding the latter...an aluminum frame with carbon fiber seat stays and a carbon fiber fork has become a popular option that is still somewhat affordable by today's standards). While frames made with these materials are generally more expensive, there are many that believe their basic properties (in addition to their light weight) help to achieve the most desirable combination of ride qualities (i.e., high-speed performance/responsiveness, while still maintaining comfort and low-speed stability). We believe there is merit to this claim, especially when considering the resources frame manufacturers are dedicating to research and development. 

Having said all of this, please note this particular offering is a steel frame with straight gauge tubes, so some of the inherent road dampening characteristics (of steel) noted above, may translate into a slightly more comfortable ride, even though this frame also has relatively steep angles and short dimensions. We should also note the relatively heavy frame weight is the result of straight gauge tubing...so uniform material thickness throughout the tubing walls. This tubing should help prevent the "wobble" effect from occurring, as discussed above, but the trade-off is the heavier overall frame weight.

Condition...
All of these Bertin frames and forks are new and unused...and came to us bulk packed with some cardboard dividers and packaging to help preserve their cosmetic condition. Still, the condition of these bright yellow frames is not perfect, so please expect some blemishes (scratches, scuffs and other cosmetic imperfections) on each offering. In general, the finishing work is not as clean as it could be...and this could be in the form of welds not as clean as they could be, frame tubing not properly prepped before painting, or there could be a problem with the painting itself (i.e., uneven application of the enamel in some areas). I do not see any functional problems with these frames/forks, but the aesthetic workmanship is not as nice as I would've liked. Listing Update...This is my last one of these frames/forks in this smaller size. Unfortunately, it shows a fair amount of shopwear (scuffs and scratches), which is why I held it back and made it available as my last offering. Functionally, the frame and fork is fine and clearly new-old-stock with no evidence of having any parts ever installed on it. Although, cosmetically there are a number of scuffs/scratches, as illustrated in the pictures (on the top tube in multiple places, the right fork blade, the left seat stay, etc.). I don't mean to dissuade anybody from considering this last small frame/fork offering, but at the same time I want to be honest when I say this last one does not show as well as the others that have preceded it.