Custom built frames
As
mentioned above, all Jackson frames are built using Reynolds or Columbus steel tubes.
Reynolds TI is the oldest manufacturer of tubes specifically designed for
bicycle frame building. Reynolds currently offers 5 different qualities of
tubing, 525, 631, 725, 753, and 853. Of these 5
varieties many different configurations can be realized. Bob Jackson Cycles
builds main frame tubes with the top 4 qualities only.
Hi tensile steel should best be reserved for plumbing pipes and should not even be considered for a bicycle frame. Jackson will not build with either of these materials.
No longer produced by Reynolds, due to its inability to be tig welded.
REYNOLDS 631 / 631OS info
No longer produced by Reynolds, due to its inability to be tig welded.
REYNOLDS 725 / 725 OS info
Reynolds 725 Chrome moly tubing can be used to build a complete frame or can be used as seat and chainstays to produce either 631 or 853 frames. The 725 is an up grade over 525 when used as a stay material. It offers increased strength without an increase in weight.
REYNOLDS 753 / 753 OS
No longer produced by Reynolds, due to its inability to be tig welded.
This was the benchmark by which all high performance bicycle frames have been judged for the last 20 years. Possessing a 195,000 psi tensile is among the strongest tubes currently available for the manufacture of high performance, light weight, ultra responsive road frames. This tubing uniquely combines terrific power transmission ability, lively ride, responsiveness and a high degree of comfort, while producing some of the lightest frames available.
BICYCLE GUIDE tested a sub 20 pound Bob Jackson 753 in their June 1995 issue and used such terms as "The four pound Jackson floated up longish canyon climbs", and "your back just doesn't get sore on this bike".
Unfortunately 753 frames will never be seen in great numbers. Frame builders having access to this material is closely controlled. Builders must be certified as to their proficiency in low temperature silver brazing 753 by Reynolds. Only after having passed a structural test on their work will they be certified and sold these tubesets. Another drawback is the cost of silver brazing material as compared to that of brass, approximately $150.00 per pound compared to $9.00. Having to keep the area to be joined at a maximum of 1200 degrees, tig welders are immediately ruled out, along with their ability to mass produce 753 frames. It is primarily for these reasons that 753 frames are not offered by the bicycle giants. Highly skilled labor and time consuming hand work are not the direction large companies wish to move in.
753 OS This is an oversize version of 753 featuring even better power
transmission abilities than normal sized 753. A special 753 Anniversary tubeset
has been created for Bob Jackson Cycles to commemorate the sixtieth anniversary
of Bob Jackson Cycles and the introduction of 531 tubing. It features specially
drawn short butts, reduced wall thickness, oversize seat stays and oval
chainstays. Only 60 of these set have been manufactured by Reynolds, once they
are gone no more will be produced. Unfortunately
all of these have been used.
REYNOLDS 853 / 853OS info
Reynolds 853 is a high strength, 210,00 psi, heat treated, air hardened steel
alloy. Careful control of the alloying elements combine to give these tubes
enhanced mechanical properties surpassing other materials currently available.
The main advantage of Reynolds 853 is its ability to air harden after joining, a characteristic not shown by other chrome molybdenum / manganese molybdenum materials presently on the market. When building frames using either TIG welding or high temperature brazing, above 1600 degrees, the joints increase in strength as the frame cools to room temperature.
LUG CONSTRUCTION IS THE PREFERRED METHOD OF JOINING 853. It allows a much larger area to be heated than tig welding which concentrates the heat to a very small area at the weld. This completely goes against the “AIR HARDENING” building philosophy of the material and adds nothing to the strength of the joint. It is however a much cheaper joining method, requiring less time and skill to perform.
Jackson will build to order any of its frames using virtually any Columbus tubing. Columbus has pushed the envelope of tubing thickness to .38mm on some of their tubesets, approaching the weight of Aluminum. info
With the exception of a few special models, all Bob Jackson framesets feature lug construction. In this day of tig welding there is still something beautiful and functional about an expertly built and finished lug frame. Despite claims of lighter weight (more on this later), the main reason for manufacturers championing tig construction are the cost savings to themselves and the ability to use less skilled labor in their frames construction. Also see enclosed sheet on 853 properties and lug construction vs. tig welding.
TOURING FRAMES
ROAD FRAMES
These frames are designed
for serious cycling and as such come in many different configurations to
best suit an individual rider’s needs
and wishes.
631 / 525 FRAMES (available in
2 different models)
MESSINA,
built with Messina lugs, these are conventional long point lugs, frame
is built with a uni crown fork & cast bottom bracket shell.
3 WINDOW,
These Prugnaut lugs feature ornate cut outs on the head lugs and seat
lug and are therefore refereed to as 3 Window lugs, These frames are built with
a cast bottom bracket and Cinelli crown. These lugs are a no cost option on 531
Messina frames, and are the standard lug used on the Grand Prix, Vigorelli 531
track frame & all touring frames.
631 / 725 FRAMES (available in
3 different models)
3 WINDOW,
built with 3 Window lugs described above, cast bottom bracket
shell & Cinelli style crown.
SUPREME / LUGANO,
built with
cast long point lugs, cast bottom bracket shell and Cinelli style crown.
ARROWHEAD,
built with more ornate fully cast Arrowhead lug set, again with Cinelli style
crown.
725 FRAMES (available in
4 different models)
NERVEX PRO,
these are the legendary
lugs used on the finest frames built some 20 to 25 years ago. Frames will be built
with these lugs until the supply is gone. Frame includes a very rare Nervex bottom bracket shell and
comes standard with a Cinelli
style
crown.
853 FRAMES (available in
5 different models)
OVERSIZE ROAD FRAMES
SUPREME / LUGANO
lugs in an oversize version are standard on all oversize road frames.
ARROWHEAD oversize lugs are available on any 631, 725 or 853 oversize frame.
MUSCLE
CARBON FIBRE
filet brazed Reynolds or Columbus tubing bonded
to a carbon fiber rear triangle.
VIGORELLI
track frames are built
with either 3 Window or Supreme / Lugano
lugs, your choice. Other lug sets are available.
Standard crown is a flat cut out crown with no provisions for brakes.
Can either be built with
3 WINDOW, SUPREME / LUGANO lugs or fillet brazed. The PROMETHUS time trial frame must be fillet brazed. Any combination of wheel size is available with these frames.
LEGEND, SUPER
LEGEND
both of these
frames are built with hand cut lugs fabricated in Bob Jackson’s shop.
Additional ornate work can be done on these frames (Price on application).
Standard tube set is 631 / 525, however any other tubeset can be used for the main
triangle. The rear end must be constructed of 531 if the Curley rear is to be
retained, otherwise the rear triangle can be constructed of any material.
Oversize tubes are not an option with these frames.
TANDEMS
TOURIST TANDEM,
RACING TANDEM
are built with either 3 WINDOW or SUPREME / LUGANO lugs. The LEGEND
(Curley) Tandem uses hand cut lugs as the Legend / Super Legend frames. Frames
are available in either 531 or 631 in standard size or oversize versions.
SMALLER RIDERS
Any Jackson frame can be built utilizing 650 (26”)
wheels. This change allows for the restoration of correct geometry, usually
compromised in smaller frame sizes, and enables us to further shorten the top
tube length, a definite plus for woman riders who usually have to settle for a
frame designed for a male rider’s body proportions. Due to the toe clip
overlap issue, a frame utilizing
700C rims is hard pressed to get a top tube under 52 cm, even at this size the
geometry is seriously compromised.
For more information on
these frames please contact us. There is NO additional charge for frames built
this way.
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