#avr Logs

Mar 25 2019

12:45 AM day_ is now known as day
09:31 AM day: i've got a cool project idea, but it's too expensive to get started on it q.q
09:32 AM nohit: yeah ?
09:32 AM nohit: what is it
09:32 AM day: it would even easily sell, but then again i probably would get sued :P
09:32 AM day: a rohloff di2 compatible shift mechanism
09:33 AM day: di2 being shimanos electric shifter system. rohloff being a very popular gear hub
09:40 AM cehteh: i tihnk some people build that and shimano has its own Di2 for the alfine11
09:41 AM cehteh: i wont really go for di2 when selfbuilding, maybe repurpose the shifters/switches
09:42 AM cehteh: but doing the electronic by myself
09:42 AM cehteh: while there isnt that much need for rohloff, what would be the benefits?
09:43 AM cehteh: adds more weight and wont improve shifting
09:45 AM day: cehteh: some people like dropbars, and there was no drop bar shifter for them. now there is, but compared to a nice shimano shifter they look rather cluncky
09:46 AM cehteh: https://velotraum.de/news/cinq-shifter-r-road-fuer-rohloff-im-speedster-sp3
09:46 AM day: yes thta one
09:47 AM day: saying people dont want an electric rohloff is like saying people dont want di2. which they clearly do
09:47 AM day: at least they buy it ^.^
09:47 AM cehteh: i see the afvantage for brifters .. but i dont see the advantage for going electric (well no much disadvantage either, so maybe just do)
09:48 AM cehteh: while then it would be nice not to break patents and just use the switches (you can be compatible with sram etap then too)
09:49 AM day: in theory yes. but sram is wireless, so it would take more than just a "firmware flash"
09:49 AM cehteh: someone told me the di2 software is horrible . .also everything is closed source popietary protocol stuff
09:49 AM cehteh: isnt the electronics in the 'junction box'?
09:49 AM day: surprisingly i didnt very little about the protocol.
09:49 AM day: apparently there are two "junction boxes" most of them appear to be just "splitters"
09:50 AM day: and you can have as many as you want. but you can only have one "junction A" iirc
09:50 AM cehteh: i dont know it too well, but i'd just do custom firmware on standard avr, and repurpose the switches
09:50 AM day: yeah. i would simply see how the shift down/ up signals look like and trigger on those
09:50 AM cehteh: way easier than unlocking and reflasing their expensive controller
09:51 AM cehteh: you need some 'driver' on the rohloff side anyway, stepper or servo
09:51 AM day: yeah thats where it gets nasty
09:51 AM cehteh: so you can just leave all tat crap from shimano out
09:52 AM day: yes. all i need is the sti + mandatory di2 parts. then simply hook that up to my custom avr/arm board
09:52 AM cehteh: make a clutch to connect a servo (spring loaded and with safety switches in case the rohloff is under load) .. done
09:53 AM cehteh: and when you do, make that pinion compatible as well :D i might be interested
09:53 AM day: i doubt the servo can do it without additional gearing
09:53 AM cehteh: biger servos can be insanely strong, and there are some speced for more torque over speed
09:54 AM day: yes but you dont want a giant motor attached to your bike :p
09:54 AM cehteh: you rather need some clutch so that it wont break the rohloff or strip the servo gears
09:54 AM cehteh: not *that* giant
09:55 AM day: the shimano motor is tiny. they just use an additional reduction gear
09:55 AM cehteh: there are less than palm sized servos which are prolly strong enough to break the rohloff (can turn much harder than you could on a grip shift)
09:55 AM day: im more thinking thumbsize here
09:56 AM cehteh: real engineering starts when you find out what size would be the minimum to make it reliable, maybe even a standard servo is good enough
09:56 AM cehteh: di2 is bigger than thumb as well
09:56 AM day: i dont think so
09:56 AM day: its pretty tiny
09:56 AM cehteh: and it most likely doesnt need to be bigger, rohloff needs less torque than derailer i bet
09:57 AM day: possible. and it even offers a proper cog so one could install the motor 90° rotated to make the profil slimmer
09:57 AM cehteh: https://bike.shimano.com/en-EU/product/component/alfine-s7050s705-di2/MU-S705.html
09:58 AM day: cehteh: ah i was thinking of the ultegra rear derailleur di2, for which i saw a teardown
09:58 AM day: of which*
09:59 AM cehteh: yea i know, i just watned to show you that there is one for the shimano hub as well
09:59 AM day: yeah i know the alfine 11 di2 one
10:00 AM day: but anyhow. it's 1k for the hub, and another 200 for the di2 equipment. a bit much for a hobby attempt for my taste~
10:00 AM cehteh: depends :D
10:00 AM cehteh: i tought you already have a rohloff
10:00 AM day: nah
10:00 AM day: my dad had one D:
10:00 AM day: sold it q.q
10:02 AM cehteh: i have a pinion bike and a new roadbike ... sometimes i think 'hey how about dropbar on the pinion' ... but not with gripshift
10:02 AM cehteh: and that shift*r is rather expensive too
10:02 AM day: i dream of a randonneur with a rohloff :p
10:02 AM day: cehteh: exactly my usecase :D
10:03 AM cehteh: i have flatbar, but rather low :)
10:03 AM cehteh: https://public.pipapo.org/lumix/P1000346.JPG
10:03 AM day: i have a road bike as well. but seeing that i dont race, i would rather have a randonneur that takes mudguards that i can use for commuting and roadbiking
10:05 AM cehteh: i just use the pinion for 'traveling' and the roadbike for fun, dont race either but doing longer tours with it sometimes
10:31 AM day: yeah we are currently planning a 150km trip to the north sea
10:31 AM day: longest ive dont so far was 95ish though
10:32 AM day: im not toooo keen on the pinion drive though. It may be good but i dont like how the frames look :|
10:33 AM cehteh: on a roadbike it would look a bit ugly, bit on mtb its nice
10:33 AM day: looks like an emotor :p
10:33 AM cehteh: who cares ... and my wife has a hub motor :)
10:34 AM day: but true, on a bulky carbonframe it wouldnt be tooo visible i guess
10:34 AM cehteh: well i got one of the first C.12 and managed to bereak it 2 times, i hope now its good after repairs
10:35 AM cehteh: at least their service is excellent
10:35 AM day: is it a german product as well?
10:37 AM day: looks like it. what is it with germans and geared hubs...
10:37 AM cehteh: yes
10:38 AM cehteh: i brought my bike at a bike manufacturer right around the corner from pinion HQ :S
10:38 AM cehteh: when i was there for repairs they just walked over for spare parts
10:39 AM day: that explains the splendid service :p
10:39 AM day: we have some clients in our town too, obviously they have godly service. someone can just walk over lol
10:39 AM cehteh: and 150km to north sea will be easy, as long there is no wind :D
10:39 AM cehteh: headwind
10:39 AM cehteh: everything flat there
10:40 AM day: you would think
10:40 AM cehteh: where are you?
10:40 AM day: but its not THAT flat
10:40 AM day: near münster
10:40 AM cehteh: slight hills ok
10:40 AM day: there are a few rolling hills to the north
10:41 AM day: nothing higher than 200m though but it adds up
10:41 AM cehteh: karlsruhe here ... Schwarzwald and Vogesen :)
10:41 AM day: yeah, no comparision ^^
10:41 AM cehteh: i 've done some 17km rides with 1500-2000m elevation
10:41 AM cehteh: 170kkm
10:42 AM cehteh: but wind can be nasty at the coast, no shelter from it
10:42 AM day: i would die on my roadbike
10:42 AM day: yeah wind is the worst
10:42 AM day: with hills you at least gain height
10:44 AM day: 170km on my roadbike would murder me. the setup is wayyy to racy lol
01:27 PM paulo_ is now known as Guest43513
09:19 PM davor_ is now known as davor