Turn your steel frame into a World Travel Bike with GroupJ's Bicycle Frame Couplings (BFCs)
GroupJ Bicycle Frame Couplings
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For less than the price of a few components, GroupJ’s Bicycle Frame Couplings (BFCs), Figure 1., converts a steel frame bicycle into an elegant travel bike that can be packed into an airline legal case, allowing you to take your high quality bike with you wherever you might go. GroupJ BFCs provide an economical solution for those wanting a full size, airline transportable bike. If you are an avid cyclist, you know that the time and expense you have invested in the build-up and fitment of your bike really makes a difference to your ride experience. Even a high-end rental bike will not be as satisfying as having your own bike. Now, with GroupJ’s BFCs, you can build a custom bike that you can take around the world. Such bikes go by the name “fly-away”, “break-away™", “travel”, or “jet” bike. These bikes were pioneered by SandS Machine and Ritchey, and until now were only available from Ritchey.com or from custom bike builders. These custom bikes are very high quality, but may be outside the budget of a number of traveling cyclists. If you have a vintage steel frame bike sitting in your garage, or if you purchase a quality used frame for a few hundred dollars, installation of GroupJ’s BFCs allows you to have the benefits of a high end travel bike, at a fraction of the cost previously available.
Please Contact Us if you have an aluminum, titanium, or carbon frame you would like to convert. Unlike other couplings, GroupJ BFCs are available to the bicycle repair shop or home/amateur bike builder, as well as professional builders. You can also send your frame to GroupJ for modification.
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Figure 1. Full Torque BFC with Alignment Ferrule and “P” lug pattern options
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Figure 2. Standard BFC shown with Ritchey clamp
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On these pages you will find all the information you need to order couplings for your frame conversion and step by step instructions on how to install the couplings. GroupJ offers one-stop-shopping for ordering all the supplies necessary for conversion.
The internal name for GroupJ BFCs is JBob. Check out our Blog to hear the story behind the name. JBobs are fabricated from 304 stainless steel with a yield strength of 125,000 psi, and are silver brazed onto the frame in the tradition of chromoly construction. JBobs and available in two styles: Full Torque (Figure 1.) and Standard (Figure 2.). Full Torque couplings exceed the torsional load capacity of the frame tube. Because the typical front half of a frame is a wide base triangle, there is little torsion load in the coupling, and Standard couplings will suffice for most applications. For racing applications, or for heavy riders, consider making the top tube coupling Full Torque. For mountain bikes we recommend that both couplings be Full Torque. JBobs are avialable in two standard sizes for common butted frame tubes, 1 inch and 1⅛ inch OD. An optional Alignment Ferrule, (Figure 3.), while not required, is recommended as it makes assembly of the frame much easier and prevents coupling misalignment. Alignment Ferrules add 6mm (0.25in.) to the length of tube when packing in your case. |
Figure 3. Standard BFC with optional Alignment Ferrule "Fork End" on left
JBobs come with a default straight cylinder cut on the ends (see Figure 2.). Each coupling half can be ordered with one of two options to help customize your couplings to integrate with your frame lug pattern. Option "D" drills a 22mm diameter hole through the coupling, centered 28mm from the part line, Figure 4. A Dremel tool, or similar, is then used to cut the finish lug pattern. Option "P" provides a hand cut and fully finished pattern that starts with the "D" option. This "Pointy" lug pattern, Figure 4., is found on many frames. Hand polished, JBobs are elegantly beautiful, light weight, and look great on any custom frame.
Ritchey coupling clamps are used. You will need two clamps for each coupling you install. One set of clamps is used during brazing of the couplings. These will be discoulored as a result of the the heat, but can be buffed out (see Figure 1.) and used as spare clamps. The second set are your "ride" clamps.
Ritchey coupling clamps are used. You will need two clamps for each coupling you install. One set of clamps is used during brazing of the couplings. These will be discoulored as a result of the the heat, but can be buffed out (see Figure 1.) and used as spare clamps. The second set are your "ride" clamps.
Figure 4. Left BFC with "D" lug option ; Right BFC with "P" lug option
Below are several videos to help you with your travel bike design. Coming soon is a video showing the construction of a woman's step through frame.
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How to Order Your JBobs
Order JBobs by the following part number key: NN-XX-FEY-OEY-Z
Where:
NN = OD of frame tube in ⅛'s of an inch (08 or 09)
XX= Style: ST for Standard or FT for Full Torque
FEY= Fork End of the coupling
OEY = Other End of the Coupling
Y= Lug End option: C for Cylinder, D for Drilled, P for Pointed
Z= Alignment Ferrule option: Y for yes, N for no
Important Ordering Notes:
1. A 08-FT-FEP-OEC-N coupling would be for a 1 in. OD tube, Full Torque, with Pointed lug on fork end and Cylinder lug on other end and no Alignment Ferrule. a 09 -ST-FED-OEC-Y is for a 1⅛ in. OD tube, Standard, with Drilled lug on fork end, Cylinder lug on other end, and Alignment Ferrule. If your tube size does not match one of these, please Contact Us
2. By convention the Alignment Ferrule is installed in the "Other End" of the BFC, (the "Fork End" receives the Alignment Ferrule male end). This is important only when you order two different lug end options. The BFC can be installed in any orientation you desire.
3. The amount of tubing to be removed for BFC installation is listed in the table below. See the JBob Design and Installation Guide for details on coupling locations and installation.
NN = OD of frame tube in ⅛'s of an inch (08 or 09)
XX= Style: ST for Standard or FT for Full Torque
FEY= Fork End of the coupling
OEY = Other End of the Coupling
Y= Lug End option: C for Cylinder, D for Drilled, P for Pointed
Z= Alignment Ferrule option: Y for yes, N for no
Important Ordering Notes:
1. A 08-FT-FEP-OEC-N coupling would be for a 1 in. OD tube, Full Torque, with Pointed lug on fork end and Cylinder lug on other end and no Alignment Ferrule. a 09 -ST-FED-OEC-Y is for a 1⅛ in. OD tube, Standard, with Drilled lug on fork end, Cylinder lug on other end, and Alignment Ferrule. If your tube size does not match one of these, please Contact Us
2. By convention the Alignment Ferrule is installed in the "Other End" of the BFC, (the "Fork End" receives the Alignment Ferrule male end). This is important only when you order two different lug end options. The BFC can be installed in any orientation you desire.
3. The amount of tubing to be removed for BFC installation is listed in the table below. See the JBob Design and Installation Guide for details on coupling locations and installation.
JBob Introductry Prices (subject to change)
Part Number Parameter |
Description |
Value |
Size |
NN |
Tube Outside Diameter |
08 |
09 |
ST |
Standard |
$125 |
$175 |
FEC |
Cylinder Fork End |
N/C |
N/C |
OEC |
Cylinder Other End |
N/C |
N/C |
ST/FT |
Length of tube to be removed |
15mm |
15mm |
Introductory Option Prices
Part Number Parameter |
Description |
Size 08 |
Size 09 |
FT |
Add Full Torque |
$100 |
$105 |
FED |
Add Fork End Drilled |
$10 |
$10 |
FEP |
Add Fork End Pointed |
$50 |
$50 |
OED |
Add Other End Drilled |
$10 |
$10 |
OEP |
Add Other End Pointed |
$50 |
$50 |
Z |
Add Alignment Ferrule |
$15 |
$30 |
In addition to couplings and clamps you will need the following parts to complete your frame conversion: 1) Two (2) Ritchey shifter cable connectors; 2) One (1) silver braze rod (one rod is enough to braze two BFCs); 3) One (1) Silver braze flux ( 1 order is enough for 2 BFCs); 4) The 4 mm Ritchey hex wrench is a nice tool as it applies the correct torque to the clamp bolt; 5) 3M Scotch Brite pads and tool holder are used to clean up brazed joints. As a service to our customers we supply the clamps and above parts at our cost.
Part Number |
Description |
Price |
C89 |
Ritchey size 08/09 (31.8mm) clamp |
$18.50 |
SCC |
Ritchey shift cable coupling |
$14.50/pair |
SBR |
Silver Solder rod |
$30.00 |
Flux |
solder flux |
$5.00 |
HW |
Ritchey 4mm Hex Wrench |
$18.50 |
3M |
3M Scotch Brite Pad |
$1.50 |
3MT |
3M Scotch Brite Holder Tool - 1/4" shank |
$6.00 |
Shipping in the 50 United States is a flat $12 for the first 6 pieces + $0.50 for each additional piece. Each part number unit counts as one piece.
To make it easy to order everything you need to convert a single frame having a typical 08 top tube and 09 down tube, we have put together the following introductory kits consisting of the following: (1) 08 JBob, (1) 09 JBob, (4) clamps, (2) shift cable couplings, (1) silver braze rod, (1) silver braze flux, (1) hex wrench, (2) 3M pads, (1) pad holder, and inclusive shipping in USA. Alignment Ferrules are included in all kits except "Basic". Order these kits by the part number listed.
Part Number |
Description |
Price |
Basic Kit |
Everything you need - STD Lugs no ferrules |
$466 |
STD Kit |
Everything you need - STD Lugs w/Ferrules |
$511 |
Drilled Kit |
Everything you need - Drilled Lugs w/Ferrules |
$551 |
Pointed Kit |
Everything you need - Pointed Lugs w/Ferrules |
$671 |
Placing your order
You can order your parts directly via Paypal. Enter your email address below and click the "Buy Now " button. That will take you to the [email protected] Paypal account. Enter the total value of your purchase, including taxes and shipping. Log into your Paypal account. An Order Summary page will appear with the purchase amount. Under your Shipping Address you will see "List Part Numbers and Qty". Click the "Add" button and list your part numbers and (Qty). Please provide a phone number with the list so we can sort out any communication glitiches, and be sure your "Contact Information" email address, at the bottom of the form, is correct before closing the trasaction. We will send you an order confirmation.
Alternatively you can send us an email at [email protected] listing the parts and quantity you want to order, and we will send you an an order confirmation and Paypal invoice. If you don't have a Paypal account you can also find out products listed on eBay. Search for Bicycle Frame Couplings.
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Please download and read the JBob Design and Installation Guide which walks you through the steps of selecting your couplings and converting your frame.