how does Campagnolo automatically detect the teeth on the bicycle sprocket? - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: August 25, 2022, 09:45:03 am
content: 50 minutes ago I was shocked at what I saw!On my street corner I was all busy replacing the inner tube because some hipsters must have been drunk enough to leave thumbtacks lying around, when I saw a road bicycle parked near me, and its Campagnolo computer able to auto detect the teeth on the sprocket and show it on the LCD.A serious rider shifts and picks gears by feel and intuition, and there is no real need to have indicators, what matters in the end is the cycling cadence, the number revolutions per minute that bike crankset / pedals spins. The actual selected gear is secondary.Even because the gearing is continually adjusted up or down to maintain the optimal efficient cadence for the cyclist in question for the current terrain, pace and desired level of effort.So, for this reasons, road bikes do not include unnecessary features, for the most part, but ...... technically WOW, is it science fiction? How can it be?Unfortunately, I don't speak French .. I couldn't make any interview to that lucky owner.

author: dave j
author_rank: Regular Contributor
timestamp: August 25, 2022, 11:32:12 am
content: I suspect it doesn't automatically detect the number of teeth on sprockets. The Campagnolo bike computer has wireless connection and there is aMyCampy appthat lets you specify the exact bits you're using on your bike.

author: DiTBho
author_rank: Super Contributor
timestamp: August 25, 2022, 11:50:30 am
content: Ahhhh so it's a trick

author: wn1fju
author_rank: Frequent Contributor
timestamp: August 25, 2022, 11:57:03 am
content: Typically there are wireless transmitters in the two shifters on the handlebars that send data to the bicycle computer. Once you tell the computer your rear gear cluster range and the front chainring sizes, the computer can display what you have selected from the internal positions of the shifter mechanisms. This kind of stuff has been around for several years...But I agree with you. I can usually tell pretty accurately from my workload what gear I am in and don't really need a cycle computer to tell me. Besides, you can always simply tilt your head down and look at the gears!

author: thm_w
author_rank: Super Contributor
timestamp: August 25, 2022, 09:39:04 pm
content: There is some new obsession with head units recording: what gear you are in, what ratio, how many shifts you made, when you made them.Most of it is just to say "hey we have a new feature, you'll have to buy the 2022 head unit to get it".Maybe some fraction of people have use for it when training, should shift earlier here? who knows.The more interesting aspect to me is:- Shimano/SRAM/campag all fix their electronic shifters based on the number of gears.This is pure marketing decision, because what you have inside the shifter is a small geared motor that is being told to move a certain distance when a shift signal is received (essentially).On a 10 speed cassette it might be 3.95mm on 11 speed 3.7mm. Its a variable in the code somewhere.A Chinese company decided on their model instead to let you enter that information yourself. So you can set 7 speed, 8 speed, 12 speed, whatever.https://www.youtube.com/watch?v=eISsqEf3r7kNow, the reliability of it is probably crap currently, but, at least they are fighting back against this idea of "must buy all the latest parts" to be compatible.

author: timenutgoblin
author_rank: Regular Contributor
timestamp: August 25, 2022, 10:23:23 pm
content: Quote from: DiTBho on August 25, 2022, 09:45:03 amMore than 10 years ago,Shimanoreleased a bicycle computer called the Flight Deck SC-7900 with a gear display. I don't know exactly how it worked, though.https://youtu.be/YIFP1ZMRUdU

author: thm_w
author_rank: Super Contributor
timestamp: August 25, 2022, 11:10:56 pm
content: Flightdeck has wires going off to the left and right shifters, they have to be compatible:https://www.amazon.ca/Shimano-SM-SC70-Flight-Wireless-Bracket/dp/B000F5HXPUSo it could be like the swipe contacts in a multimeter, because it has to know the absolute position of the shifter (angle of the toothed cog inside). Can't quite tell from the photos.Probably a reliability nightmare.https://www.bikeforums.net/road-cycling/540563-what-shimano-flight-deck-what-flight-deck-compatible.htmlhttps://www.bikeforums.net/general-cycling-discussion/1068371-what-flight-deck.html

author: Someone
author_rank: Super Contributor
timestamp: August 25, 2022, 11:18:34 pm
content: Quote from: timenutgoblin on August 25, 2022, 10:23:23 pmAt least 23 years:Quote from:https://www.sheldonbrown.com/dura-ace.htmlHow did it work?https://forum.cyclinguk.org/viewtopic.php?t=124594Binary coded switch in the mechanical lever which reported the selected gear (not the gear currently engaged) just as the mechanical indicators did/do:https://bike.shimano.com/en-AU/technologies/component/details/optical-gear-display.htmlFlight deck's main feature was to report cadence from wheel sensor data rather than needing another sensor for the crank. The buttons on the hoods were convenient if you were "playing" with the computer on the go.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 25, 2022, 11:35:02 pm
content: I never got good enough to automatically select gears. Easy enough to change up and down through the sprocket range, but since the ratios from the chain rings overlap so much any time I changed the ring there was a period of hunting for the right sprocket gear. A single lever system that picked equally spaced overall ratios would have really appealed to me. Even better two levers, one to bump up/down one gear and another to bump up or down say five ratios fort those rapid changes needed at the tops and bottoms of hills. Never saw anything that seemed both light and reliable.

author: thm_w
author_rank: Super Contributor
timestamp: August 26, 2022, 12:00:01 am
content: Quote from: CatalinaWOW on August 25, 2022, 11:35:02 pmYeah, thats becoming more common now. You have a single lever and 10-12 somewhat evenly spaced gears. Makes it way more intuitive.Levers depend on flat or drop style bars, with some drop bars you can downshift (easier gear) one or two gears at a time.With some flat bar shifters you can go down four gears at a time, and up two at a time. To shift two you push the lever further on those. Depends on the model and brand though...https://youtu.be/bRvRL4ZkD-Y?t=85

author: Someone
author_rank: Super Contributor
timestamp: August 26, 2022, 02:18:56 am
content: Quote from: CatalinaWOW on August 25, 2022, 11:35:02 pmPart of this is that the gear ratios aren't designed for convenience or ease of use but for racing, the overlap was intentional for 2 reasons:racers want to always have spare up/down gear or two at a moments notice without the slow change of the frontsome chains cant bend enough to use the full width of the rear gearsSo the shift between the front gears had to be matched with 3-6 "shifts" in the rear which would vary depending on both the specific ratios assembled/setup and the to-from gear ratios in use. As mentioned above, its only the newest electronic shifting sets (also eyewateringly expensive) that now enable it to be seamless (fast) enough that a single up/down control is possible....Which reached the market at almost the same time as wide range 1x (only single gear at the front) specific rear gear clusters, so for the "normal" around town rider there are two good options:gear hub (the price puts some people off)1x11/1x12 with a 1:4 range or higher

author: DiTBho
author_rank: Super Contributor
timestamp: August 26, 2022, 10:24:53 am
content: Quote from: CatalinaWOW on August 25, 2022, 11:35:02 pmI don't do any climbs because I have a back problem, long journeys but all in the plains, I noticed I am using the same setup 52 { 13, 15, 17}Only and always the same gears- tours within the city, 52-17- urban stretches, 52-15, 52-17- extra-urban stretches, 52-13- stretches along the sea or lakes, 52-15speed between 27 and 35Km/h, low rpm, old steel-frame bicycle, Campagnolo Mirage 1992I cannot do the same with anyPinarello Prince, Paris, Razha(worse still with my Monza Wr) with Shimano Ultegra bloody thing, they have a completely different gears-setup, and I have to continuously shift up and down like a deranged dog on speed because I never find the optimal ratio.

author: DiTBho
author_rank: Super Contributor
timestamp: August 26, 2022, 10:36:12 am
content: Quote from: Someone on August 26, 2022, 02:18:56 amSingle gear at the front looks like what nowadays they callGravel-profile, optimized for long travels (>200Km) and comfortI am more forEndurance-profile, optimized for short travels (<150Km) on 32Km/h average speed with a bit of comfortDecathlonhas some interesting bicycles, but no gear-hub.Quote from: Someone on August 26, 2022, 02:18:56 amCan you convert a vintage bicycle into gear-hub? 3 speeds would be OK for me.1x3

author: thm_w
author_rank: Super Contributor
timestamp: August 26, 2022, 09:35:38 pm
content: The point of having easy gear ranges is that you can put the same low effort into climbing as riding on the flathttps://www.youtube.com/watch?v=ipENw5mjjSgBut I might know what you mean, it seems to engage the back muscles more than flat riding.You can convert any bike with a standard quick release dropout spacing of 127-135mm to a nexus gear hub. Don't really know if its worth it though.https://www.sheldonbrown.com/nexus-mech.html