(my) Campy 12-speed ( Campagnolo Shimano)

The 12-speed project started in early sumer 2008 after the first rumors circulated in the Pro Team that Campagnolo is going to launch a 11 speed groupo. 

A bit energized to be always one gear in advanced I started the development of the 12-speed system. The adjustment of the transmission ration of the cable retraction to revolving angle was made by proportional reducing the drum radius of the index ring. Prior calculation figured out to choose a center-2-center dimension of 0.5*1.60mm + 2.00mm + 0.5*1.60mm = 3.60mm. this leads to a total cassette width of 41.2mm. this width requires an integrated lock ring into the 11 teeth sprocket and a further shift of the cluster towards the spokes. On the Ergopower shifter I accoutered three problems :

• where to locate the addition slot on the index ring                                                                                                                                                                                                                                       on the 11-speed system I add to the innermost gear the 11th, and it was impossible to add another one, due to the limited rotation angle in this direction. So I decided to add it on the side of the smallest sprocket. This required significant changes of the plastic housing to allow the additional rotation angle.  The space for the additional 12th slot was now identified.                                                                                                                                               
• How to maintain the additional rotation of the index ring                                                                                                                                                                                                                          The bigger total rotation angle needs to be considered and required two additional changes. The ratchet mechanism of the thumb lever couldn't be engaged because there were no teeth to rotat the index ring further than the original outermost position. I decided to cut out sufcient teeth out of an standard index ring and braze it onto my 12-speed I-ring.                           The second major change needed to be done on the ratchet teethed ring operated by the lever behind the brake lever. At least one or better two additional teeth need to be added in order to increase the operational revolving angle.                                                                            
• Campagnolo has no equidistant angle increments between each shifting step. To make it worse is the shifting angle increment biggest between generic 9th and 10th gear (second to outermost and outermost). So this force me to find a solution to live with the non-linearity by making the cable retraction to parallelogram inwards swing ration non-linear too. A old solution is know by changing (shifting) the cable fixing point further to the spokes. 

The cassette needed to be change significantly on the aluminum spider. It was required to disassemble the sprockets from the carrier and to machine it to achieve the 2.00mm spacer dimension. The assembly was easy by simply riveting the carrier and sprocket with stainless steel rivets together.   An integrated look ring into the 11 teeth sprocket leads to a clean lock and sufficient clearance to the drop outs.

•  
• shimaNo 10-speed  c-2-c dimension   3.95mm 
• Campy   10-speed                                  4.20mm       
• (my) Campy  11-speed                          3.95mm                                                                                                             
• The cassette can be made either out of Campy 1.75mm wide sprockets with 2.20mm spacer or with shimNo 1.60mm sprockets and generic 2.35mm spacers. For a cleaner look I prefer to integrate the lock ring into the 11 teeth sprocket.                                                                                                                                                                                                                           
• (my) shimaNo 11-speed ST-78XX      3.95mm    
• Campagnolo 11-speed                         3.95mm                    
• (my) Campy 12-speed                           3.60mm requires Campy 11 speed chain                                                                                                                                                                  
• 11 speed cassettes can be assembled to all Campy/Fulcrum rear wheels and Lightweight wheels with Campy or HG rotors.   12-speed cassettes can only be assembled to Campy/Fulcrum rear wheels with a modified HG rotor .

shimaNo 11-speed

After the campy project came to an end I focused myself on the 11-speed upgrade for shimaNo. I do have some pro bikes (Rolf Aldag giant prototype 2005 and an Giant 2008 Team Columbia) and a couple of bike buddies with shimNo equipment. 

Due to the fact that (my) 11-speed campy (2005-2008) is based on the shimaNo shifting increment of 3.95mm  and that I have compatible rear wheels I started to investigate the shimaNo STI 78XX shifter. To my surprise I found out, that a 3 minute machining operation adds to the innermost position (biggest sprocket) an 11th gear. 

After marking the 11-speed is ready for the first ride.

General aspects of 11- and 12 speed configurations

Starting the consideration from the cassette which I used for many years the 10 speed 12-23. I preferred this configuration over the 11-23 taking the disadvantage on our long descents into account not be able to go into the lead in a Belgium circle, but having the 18 reducing the gear ratio increment between the 17 and 19. This is always important to me in headwind  in the big chainring or for the climbing.   All my discussions with pro riders and technical directors of pro teams came to the same conclusion that the 18 teether is highly appreciated if the race course is hilly. 

START  12-23   12 13 14 15 16 17 18 19 21 23

Subsequently I decided to add now to the ideal 12-23 the 11 teeth sprocket. 

11 speed 11-23   11 12 13 14 15 16 17 18 19 21 23 

The second alternative if a lower gear ratio is of advantage to skip the 18 and add a 25 or 26 and/or scarifying the 11 and add a 27 or 29 

11 speed 11-25(26)   11 12 13 14 15 16 17 19 21 23 25(26)

11 speed 11-27(29)        12 13 14 15 16 17 19 21 23 25(26)  27(29)

With this 3 configurations a wide range of needs can be covered. For special purposes like flat TT and up-hill TT  other configurations like 

11 speed 11-21         11 12 13 14 15 16 17 18 19 20 21  or

smaller increments on bigger sprockets for up-hill TT are more ideal to adjust riders cadence to the given output power and combined resistance (drag and potential energy) by skipping the11, 12 or even the 13.

Now what's ideal for 12 speed ? Again starting with the ideal 11 speed 11-23 it makes only sense to add a 25.

12 speed 11-25   11 12 13 14 15 16 17 18 19 21 23 25

or again if lower gear ratios are required skip the 18 and add a 27 .

12 speed 11- 27(28)   11 12 13 14 15 16 17 19 21 23 25 27(28)

Depending on riders preference if the 11 is really required or of any advantage the 

12 speed 12- 27(28)   12 13 14 15 16 17 18 19 21 23 25 27(28)

evolves and the 18 is back. 

Bottom line is the 11 speed covers a wide range of needs. The 12 speed configuration is ideal if a lot of climbing has to be done e.g. alpine stages with steep grades and long descents.

12-speed Campy 11-27 cassette 

 

Campy Campa Campagnolo 2005 - 2008 11 - speed

In 2004 an idea crossed my mind to add an 11th sprocket to the 10 speed Campy cluster. The motivation was not to replace the 18 teeth sprocket of the 12-23 10 speed cluster  by an 11 teeth and switch to the 11-23 cluster used in the pro peloton. 

A quick measurement of the distance between the look nut and the spokes of the rear drive side revealed that Campagnolo rear wheels have the clearance needed to add another sprocket.  

Before I started the lath I decided to use the same center-2-center dimension as the shimaNo 10-speed, 0.5*1.60mm +2.35mm+0.5*1.60mm =3.95mm in order to be somehow compatible at least as the shifter increment from sprocket to sprocket is concerned. In practice it's after the Campy 11 speed  rear wheel is replaced after an defect by an generic shimaNo 10-speed no problem to remember that there is the possibility to through the chain between the last sprocket and the spokes. 

The small campy sprockets with the integrated spacer as well the spacer were machined to my new 11-speed spec 0.5*1.75mm+2.20mm.0.5*1.75mm=3.95mm and the entire cluster moved 0.90mm+0.10mm closer to the spokes. This is done by machining the Aluminum carrier on the internal side. The only bit of difficulty is to disassemble the riveted sprockets on the carrier, machine it to reduce the clearance to the spokes, to obtain the 2.20mm spacer and to assemble it afterwards.

Now after the sprocket turned out to be functional I started to focus myself on the Ergopower shifter. Space for the 11th groove for indexing was found quickly and the transmission ratio has been reduced by adjusting the radius of the drum which winds up the cable proportionally.

After the Ergopower has been assembled I mark the housing and the job is done.