New-Old-Stock Bertin Road Frame and Fork (57 cm) With Butted Steel Tubes... Black/Yellow Enamel Finish (One of Three Slightly Different Models) Thank you for your interest in this item and please visit our store for other offerings. A fellow Ebayer has been kind enough to direct us to a website dedicated to everything Bertin.
It's really an interesting site with a lot of information about the company and their products. Of particular interest to us, is a webpage focused solely on Bertin road bikes from the 90's. We mention this webpage specifically, because we noted a few pictures of this exact frame...This offering is for a new-old-stock Bertin (made in France) road frame and fork with a black and yellow color scheme. We believe it's a mid to late 90's model and possibly one of the last production models coming out of the Bertin factory in France. As I scan the frame for markings, I noticed the following somewhat faint stamped alpha/numeric sequence (which will not show up in a picture) on the underside of the bottom bracket shell...
And I assume these markings represent the serial number. The frame and fork weight (noted below) gives some indication it was built with butted steel tubing (although we are not sure what brand/model tubing). The frame tubes are TIG (Tungsten Inert Gas) welded and the down tube appear slightly oversized, while also retaining a somewhat aero shape i. We should also note the matching fork is a straight-bladed steel model with a 1 threaded steerer tube. Having said the above about the frame, I should also point out this particular offering is one of three slightly different models we have available with the same paint scheme.Some noteworthy frame characteristics (that are shared by at least one of the other two frames, but not both of them) include the built-in seatpost clamp (w/o the binder bolt), a traditional (round) top tube and down tube shifter bosses not to be confused with dual control brake/shifter lever cable guides on the bottom of the head tube... Which are also present on this frame.
I suppose having both the down tube shifter bosses and the aforementioned cable guides is a bit redundant, but for those that still want to use the dual control brake/shifter levers on this frame, there is still the ability to use the guides and then the shifter bosses as cable housing stops. Now the cable housing stops that mount on these shifter bosses are not included here, but I believe them to be a fairly common part that may be acquired from another vendor (or even recycled from another frame no longer in use). I guess there is still the option to use vintage down tube shifters on this frame, but then the cable guides at the bottom of the head tube would go unused (so something else to think about from a cosmetic standpoint). 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.
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): 57 cm.
Weight (frame and forks): 7 lbs 4 oz (frame weight is 5 lbs 12 oz and fork weight is 1 lbs 8 oz). Rear dropout spacing: 130 mm. Top tube length: 58 cm. Head tube angle: 74 degrees.
Seat tube angle: 74 degrees. Chain stay length: 41 cm.
Head tube length: 18 cm. Head tube inside diameter (for headset): 30.2 mm.Seat tube inside diameter (for seatpost): 26.8 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 guides on the bottom of the head tube (for cable routing when dual-control levers are used), brake cable housing stops on the top tube, shifter bosses on the down 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, a stamped/pre-drilled hole on the underside of the bottom bracket shell for cable guide block (not included, but inexpensive part to obtain) and a built-in seatpost clamp (without the binder bolt, but another inexpensive part to obtain).We understand there are other frame/fork measurements or characteristics that impact ride qualities and performance, but the above specifications should provide for a good starting point. We also ask that you scan our notes that follow, as we have attempted to provide some general commentary that supplements/supports the above information. Please understand we are only trying to make some very basic observations. We understand our comments may not hold true under all circumstances and that we barely touch on a couple of topics...
But we still hope our notes provide some assistance when considering this offering. We believe most would agree that head tube and seat tube angles have a fairly significant impact on ride qualities... With the emphasis on the head tube angle. These angles may range anywhere from 68 degrees to 75 degrees. The shallower the angle, the more stable and comfortable the ride should be at lower speeds, while steeper angles promote a more responsive/rigid feel that generally handles better at higher speeds (but is usually less comfortable).Not as comfortable as a frame with shallower angle measurements. The wheelbase measurement also appears to impact ride qualities. 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. 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. 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 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... 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. The joints of a frame, while reducing overall frame weight by thinning the tubing walls at lower stress areas i. 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).
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. 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. 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 butted 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.
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 black and yellow frames is not perfect, so please expect some blemishes (scratches, scuffs and painting blemishes) on each offering. We will do our best to point out significant cosmetic flaws, so there are no real surprises, but please keep in mind there are going to be some blemishes on each of these offerings. Having said this, as we inspect this particular frame and fork, we do not see heavy or numerous scuff or scratches. Most of the more visible frame blemishes and scratches are located towards the bottom of the left seat stay (as best illustrated in the last handful of pictures to the left). I see a few scratches/scuffs, as well as some painting blemishes. The latter are best described as areas on this seat stay and a lesser degree on the left chain stay, where the frame does not appear to have been properly cleaned/prepped before painting. We see this on a number of these Bertin frames, but we still like to point such blemishes out on each individual offering. Then there are some scratches/rub marks on the fork blades.
Please also note these frames will generally have paint chips around the dropouts too, but these blemishes do not seem to bother most folks as much, since the wheels will clamp down in these areas (although we still thought this was worth noting). Overall, the frame and fork shows fairly well, but keep in mind there are some blemishes upon close inspection. You may visit our store by clicking on this "Store Home Page". Link and please note the product categories on the left side of our "Store Home Page".We have also moved our "Terms and Conditions". You may navigate to this page by clicking on the link on the left side of our "Store Home Page". The item "New-Old-Stock Bertin Frame and Fork (57 cm) withButted Steel Tubes. Black/Yellow" is in sale since Thursday, August 17, 2017. This item is in the category "Sporting Goods\Cycling\Bicycle Frames". The seller is "bicyclists_retreat" and is located in Argonia, Kansas. This item can be shipped worldwide.