super slim
Zen MBB Master
Yes, as you are keeping a LOT of people waiting!!!
I suppose you have some reasons for the delay!!!
SRAM service is very good AND fast!!!
I sense a disturbance in the 3rd Law
- Thread starter ratz
- Start date
Yes, as you are keeping a LOT of people waiting!!!
I suppose you have some reasons for the delay!!!
SRAM service is very good AND fast!!!
ratz
Wielder of the Rubber Mallet
Yeah work; I had multi days with 5pm-11pm projects. I haven't been getting off the trainer until 1-2am this week.
But today is a rest day.
SamP
Guru
50 Hz does not strike me as a high sampling rate. However, as long as your cadence isn't near 50 or 100 rpm (in which case aliasing might produce some interesting measurement artifacts) it'll probably average out ok over a few seconds.
ratz
Wielder of the Rubber Mallet
Hmm never thought it through; but
100 rpm = 1.666667 revolutions per second. 50 Hz = 50 measurements per second right?
So that's 50/1.6666 = 30 measurements per revolution.
360/30= 12
So at 100 rpm power2max is taking a reading every 12 degree of rotation.
Meanwhile P1
40/1.6666 = 24
360/24 = 15 degrees
That's not too bad for a Q-ring's shape which is splayed equally over 4 quadrants of 90 degrees ; probably some conflation but as long as it's consistently shifted the data will be workable i think. The ring going in and out of phase this cadence should randomize the positional samples.
Let me know if my math is baulky it's 2:45am
The troublesome ridable cadences would be 60 rpm and 120 rpm which would result in always reading the ring at the same spot if the timing were Hz triggered. 90 rpm might be the most common trouble spot at 1.5 phasing, might get pulsed (Hi/low) if you could nail that cadence perfectly. P1 doesn't really tell us if the are using 40Hz or some way to detect 40 positions in the rotation. I'll assume it's Hz as it would have been the simple way to trigger it.
ratz
Wielder of the Rubber Mallet
Well at least you thought to think about it; I just took it on blind faith.
RojoRacing
Donut Powered Wise-guy
I was ready to pull the trigger on Etap and was just waiting for availability, but then I learned you can't go bigger then a 28t cog in the rear. I know that doesn't matter to most of you who aren't riding in the mountainous regions of the West coast but it's a deal breaker for me. I could go Etap on my DF and just stick with a 25t in the rear because I can stand up out of the saddle for hours but the current sram red 10speed stuff from 8 years ago still works perfectly, it's the Vendetta that could use an upgrade. I don't think sram will release a longer mid cage rear anytime soon for etap so it can go up to the 32t, a mtb etap group set would likely come along before that. Sucks because if I was just focusing on racing the V in events I could go Etap but if I want to take the V where recumbents have yet to venture and expose the CruzBike brand to more people I'll need those larger cogs. Now that Etap is out, maybe I'll just grab a smoking deal on Red22 stuff and be happy with shaving off a good chunk of weight over my rival components.
ratz
Wielder of the Rubber Mallet
Rumor is that WiFli will be next year.
However, just as an experiment......
Right now with the RD if you crank out the B screw you could run a 32T; you just couldn't cross chain beyond 28T because you won't have enough chain to get into Big/Big. The derailleur only has a 31T capacity so there obviously not enough uptake to contain the extra chain. I did check that as a mockup; once the builds are done and I clean up the gigantic mess in the shop I can throw a 32T wheel on there and verify it's functional from a clearance stand point. Doing the final build outs today with luck I can start posting the results this weekend.
RAR
Well-Known Member
I have a Rival short cage with a 28T capacity that I screwed in the B screw all the way and now I can use my 32T cassette. I can't say if others will work this way but it doesn't take much effort to find out.
RojoRacing
Donut Powered Wise-guy
I wonder if the med cage off the most recent red22 mechanical could be fitted to the etap? It looks like you could order a med cage to retrofit etap for 32t if that was the case. https://sram-cdn-pull-zone-gsdesign...default/files/techdocs/2016_sram_spc_reva.pdf
ratz
Wielder of the Rubber Mallet
SRAM Red eTap goes Hydro Finally. Next Up let's hope for Wilfli medium cage derailleur and you have the ultimate V20 Groupo
https://www.sram.com/sram/road/products/sram-red-etap-hrd-shift-brake-control
https://www.sram.com/sram/road/products/sram-red-etap-hrd-shift-brake-control
RojoRacing
Donut Powered Wise-guy
Or I could just stop being so weak and climb with a 28t
ratz
Wielder of the Rubber Mallet
Or I could just stop being so weak and climb with a 28t
FWIW I fitted an 30T and with some B-screw abuse they chain wasn't sloppy loose and it worked.
super slim
Zen MBB Master
Ratz, when are you buying a system?
What do you think of the FSA system, with the four change switches?
http://www.bikeradar.com/us/road/news/article/fsa-electronic-groupset-first-look-43625/
ratz
Wielder of the Rubber Mallet
I think FSA and anything they do pushes the big three to innovate.
I'm of the mind that the SRAM system with Batteries on the derailleurs is the simplest system and most suited to CB design. We've had zero issues with the RED eTap system since installing them. Once the longer cage versions; and less expensive force versions come in out; these are going to be that purchase the leaves you with total buyers remorse due to the price; until your first 10 minute ride at which point you will think you stole them.
snilard
Guru of hot glue gun
What about Wolftooth RoadLink http://www.wolftoothcomponents.com/collections/derailleur-optimization/products/roadlink ?
ratz
Wielder of the Rubber Mallet
Might work;
When you the cassette range gets over 11-30T you have alot of chain slack to take up. If you go little ring and shift into the lower half of the cassette the length of the derailleur arm isn't long enough to wrap up all the slack. So either you have to not use little/little and some of the near by gears; or you have to make the delta on the front less; so instead of a 50/36 combo you'd have to run a 50/38 or 50/39.
It's a good idea and putting the numbers into a gear calculator should tell the effect of picking up a 36 on the back and surrounding a 34 or 36 on the nose.
certainly cheap enough to test this winter. That'll get added to the RAAM idea list. Thanks
bazzawill
Guru
If only the firmware was open source and could be reprogrammed to be shimano 10 speed compatible, then it might almost be affordable for me.
super slim
Zen MBB Master
The Sram would have also taken a LOT less time to set up, compared to Shimano with all the different cable lengths required, and junction boxes
