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walter
Joined: 11 Jan 2004
Posts: 4391
Location: metro-motown-area5/24/18 1:38 PM |
these pancake 1x cogsets boggle the mind!!!
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Sparky
Joined: 08 Dec 2003
Posts: 19092
Location: PDX5/24/18 1:47 PM |
Does it boggle the scale? ;) Not that I can count that high, is that like 60 teeth?
Between the clutch in the DR and the cassette. Have to do some googling to see total weights/system.
But I guess setup is really all about the narrow/wide tall tooth chain ring with no guide and control of slap?
SunRace CSMZ90 11-50 cassette is just shy of 600 grams
I bet you gotta get way group level high and coin high on a RD with clutch that does not add notable weight.
FYI: Ultegra RX rear derailleur for road seems to be the first road clutch RD.
Gravel use target market? Chain slap issues on road bikes a thing?
Worth a mention, SRAM 1x12 speed Eagle, that out yet?
EDIT: Yep.
SRAM XG-1299 XX1 Eagle 12-Speed Cassette Gold, 10-50t $449.00
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dddd
Joined: 11 Jan 2004
Posts: 3345
Location: NorCal5/24/18 11:24 PM |
I'm still waiting for the independent study to tell us how many watts go into such a sharp chainline at the extremes of a one-by's cassette.
While today's preference for wider tires makes the one-by's frame design easier, I predict a trend reversal at some point with possibly some large # of chainrings controlled by a futuristic smart derailer system.
Those clutches cost watts and grams, so need to be able to be switched off when the road turns smooth.
With my go-to freewheel for vintage bikes often being a 13-26 or 13-28t 6-speeder these days, I can imagine a mere 9-speed, 11-34t cassette eliminating my actual need for two or more chainrings on the road.
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Sparky
Joined: 08 Dec 2003
Posts: 19092
Location: PDX5/25/18 1:03 AM |
I have a SRAM 1x with a 10 speed rear. When in the low gears I can sure hear the NarrowWideTall chainring get real noisy. And that is with the offset XX1 Ring to make it better. Pretty sure the noise does not mean less resistance.
"controlled by a futuristic smart derailer system"
di2 synchro shift already exists I guess. ;)
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Brian Nystrom
Joined: 26 Jan 2004
Posts: 5101
Location: Nashua, NH5/25/18 6:22 AM |
I just don't buy into the 1x concept, after having tried it. I'll gladly take the extra complexity of a 2x in order to get a wide range with reasonable gaps between gears. These mega-wide cassettes make no sense to me at all.
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KerryIrons
Joined: 12 Jan 2004
Posts: 3236
Location: Midland, MI5/25/18 7:03 AM |
Agreed
On a recent vacation I rented a bike w/1X drivetrain and superwide cassette (only bike available). On the road there was way too wide gaps between gears, not great shifting, and not enough top end gear for downhill grades.
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dan emery
Joined: 11 Jan 2004
Posts: 6894
Location: Maine5/25/18 7:49 AM |
Yikes
What is the low gear on that bike? The chainring is tiny, in addition to the pie plate.
I don't have any particular problems with a front derailleur, so I'm not motivated to lose it.
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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC5/25/18 8:55 AM |
quote:
I don't have any particular problems with a front derailleur, so I'm not motivated to lose it.
Can you mate the big cogs with regular 2x front derailleur to produce extra low climbing gear without losing the tight spacing and high end hear? (assuming there's a need for such, such as some of us who had small power output)
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dan emery
Joined: 11 Jan 2004
Posts: 6894
Location: Maine5/25/18 9:08 AM |
Not sure how big you need with a double
I don't know if those pieplates will work with a double or not, but how low do you need? For D2R2 I used 46/30 with 12-32, felt that was right for me, and elsewhere I don't expect to climb steeper than 27% (Achambo Rd). Of course loaded touring is a different kettle of fish.
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Sparky
Joined: 08 Dec 2003
Posts: 19092
Location: PDX5/25/18 9:16 AM |
"Can you mate the big cogs with regular 2x front derailleur"
Shimano spec seems to limit above 46T to 1x. Apparently the XTR 50T 1x is the latest and won't trickle to XT just yet.
I totally see going 28/40 or 28/42 chainset with a a 42-6T for mountain use. 2x has the range and the ability for a much better chain line. And with Di2 syncro shift for eample shifting the front is automatic, auto trimming, and seemless [di2 front shifting road experience granted]
28-42T is 18 GI, 36T is 16GI [or so depending 26er/29er etc] 32 chainring with 50T is 17GI.
Also, is the long cage really needed for 1x? I can see it already, a bar mounted thumb lever to engage and turn off the clutch. ;)
FYI, there are quite a few Sunrace kits out there for 10 and 11s that include a 11-46 and a rear DR bit to drop the DR. Not sure lengthening the lever of a flexy hanger is going to be a good idea for performance.
Some bikes come with steel RD hangers, in fact Carl recommended I put a steel DR hanger on my Green Machine when/if I do Di2. Another example, the Pro level Domane Classics have a steel RD hanger. Not sure about the SL10/RSL Domane, but the Koppenberg has a non replaceable stainless steel RD hanger also.
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Nick Payne
Joined: 10 Jan 2004
Posts: 2626
Location: Canberra, Australia5/25/18 3:23 PM |
quote:
Worth a mention, SRAM 1x12 speed Eagle, that out yet?
Yes, I bought a GX Eagle 1x12 kit to install on a bike I'm building up for my wife. The kit comprised 10-50 cassette, derailleur, chain, and thumbshifter from r2-bike in Germany - only €216. An additional €60 or so for a DT Swiss XD freehub to fit the DT Swiss wheels I already have.
https://r2-bike.com/SRAM-GX-Eagle-Upgrade-Kit-1x12_1
Edit: The reason I decided to set her up with a 1x is that in spite of having been a keen cyclist for almost 40 years, she's basically uses a 2x as though it was a 1x. If she's on the big chainring, she doesn't change off it until she's in big-big and wants a smaller gear, and if she's on the small chainring, she doesn't change off it until she's on small-small and wants a larger gear. And as she's already running an 11s 11-40 cassette with 2x, she can have the same range and pretty much the same percentage change between gears with 1x and 10-50 cassette.
I have a couple of friends who ride cyclocross and think that 1x is the best thing since sliced bread. After using it on CX bikes, they've started to equip all their non-racing road bikes with the same setup.
Last edited by Nick Payne on 5/26/18 7:47 PM; edited 1 time in total
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Jesus Saves
Joined: 16 Jun 2005
Posts: 1150
Location: South of Heaven5/25/18 3:33 PM |
Roholoff hub, plus rear derailleur (and chain tensioner) has been an option for many years if you reallly need tightly spaced or a wide range gearing. One could take that one step further theoretically with a flip flop hub with two different sets of cassettes on each side of the rear wheel. ....or we could just wait for Shimano or SRAM or Honda to design a CVT for road bikes... ;-)
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dan emery
Joined: 11 Jan 2004
Posts: 6894
Location: Maine5/25/18 4:29 PM |
Rohloff with a rear derailleur
Do you mean with a front derailleur? I ride a Rohloff all the time (including today) and I fail to see how a rear cassette would work, and a google search yields nothing. People do try to use them with front derailleurs. Of course the 14 internal gears are adequate for just about anything you'd use that type of bike for.
I love the Rohloff for commuting.
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Jesus Saves
Joined: 16 Jun 2005
Posts: 1150
Location: South of Heaven5/25/18 5:50 PM |
I may be mistaken about Rohloff. Sorry. There's no reason one could not be made, in theory - with non standard drop out spacing, etc. and assuming there is enough market demand for it.
I do recall SRAM internal hub- rear cassette combos being common many years ago - especially for single front ring, folder/compact commuter bicycles - like a 3 x 9 x 1 setup, IIRC. The demand for such may have dried up, along with foldable bikes, with the advent of urban bike sharing schemes. I have not kept close tabs on such.
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Sparky
Joined: 08 Dec 2003
Posts: 19092
Location: PDX5/25/18 7:21 PM |
I recall the 3 speed internal with a SRAM/Shimano freehub/body also. The internal 3x emulates the triple chainrings. Have seen a triple speed fixed hub too. Used a 3 speed thumb shifter on the bar ala old euro commuter stuff.
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walter
Joined: 11 Jan 2004
Posts: 4391
Location: metro-motown-area5/26/18 5:49 AM |
in the interest of technical accuracy...
...i believe we should no longer call them "cogs" in the back. we have front and rear chainrings. :-P
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dan emery
Joined: 11 Jan 2004
Posts: 6894
Location: Maine5/26/18 9:32 AM |
No reason Rohloff with rear derailleur couldn't be made
Go for it, JS. I'll be interested to see what you come up with, starting with this:
https://www.rohloff.de/en/
And I expect you can find a market for 140 gears:)
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Sparky
Joined: 08 Dec 2003
Posts: 19092
Location: PDX5/26/18 11:24 AM |
I think Walter is on to something. FCR and RCR.
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Jesus Saves
Joined: 16 Jun 2005
Posts: 1150
Location: South of Heaven5/26/18 2:41 PM |
You must be mistaking me for the late Sheldon Brown. I'm not that eccentric or crafty with bicycles. Yes, I do agree, if it was unclear before, that there is not a market for such, however if I owned Roholff, the company, I would develop such much like auto companies do with concept cars. If nothing more it would create some buzz and attract a few for its novelty, much like those who purchase a Rolhoff in the first place. (I only went so far to own a measly 7 speed only Shimano Nexus i-geared hub). When you get to 12, its a slippery slope to 140 or even 280 with a 1930s circa TdF flip flop hub....
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Andrew Lee
Joined: 10 Jan 2004
Posts: 85
Location: Anchorage5/27/18 9:44 AM |
quote:
I don't know if those pieplates will work with a double or not, but how low do you need? For D2R2 I used 46/30 with 12-32, felt that was right for me, and elsewhere I don't expect to climb steeper than 27% (Achambo Rd). Of course loaded touring is a different kettle of fish.
Mountain biking can take you much steeper grades. I bought an all-new drivetrain for my new/used mountain bike last year, because the previous owner set it up with too-high gearing: 32x11-34 9-speed.
I installed a 32 front SRAM XX1 crank (to get the narrower 156 Q, and shorter 170 arms that I prefer), and 11-46 Shimano XT 11-speed cassette. With that, I can climb 40% grades. But with good traction, I'm gear limited on higher grades. I'm happy enough with my gearing but would definitely make use of a 32/51 low if I had it. I definitely like the 1x system for mountain biking. I think the gaps between gears are good. In fact, I'd probably be happy with larger gaps, such as a 9 speed 1x with the same range. I'm more likely to double or triple shift than single shift.
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Sparky
Joined: 08 Dec 2003
Posts: 19092
Location: PDX5/27/18 11:06 AM |
"I don't know if those pieplates will work with a double or not"
That is all about capacity. But pretty much, almost maybe? ;)
Example:
Cassette 11/40, 40-11=29. Chainset 28/42, 42-28=14.
14+29='43T' Ultegra R8000 GS has 39T capacity. It may just make it, but the push past spec only has a little wiggle room.
Example: [my ex Domane]
11/34, 34-11=23 34/52, 52-34=18 23+18='41T' The Di2 GS RD capacity is 37. My 41 capacity worked with a little extra chain so you are safe from damage if a 52-34 x chaining gets used accidentally.
If small small cross chained, the chain was close to the top pulley, DR cage past horizontal tail pointing up a bit. I never even did that even accidentally.
Note: With Di2 Syncroshift you can program out cross chain completely. Syncroshift would have popped you to the big chain ring before you got there.
Some RD with good capacity. Pre 11s Shimano Road triples RD typically 37T capacity. RD-6703 39T.
Shimano RD with SGS [long cage] capacity typically in the 42-44T range . [SGS on road bike, MEH?]
Thus:
11/46, 46-11=35 28/40, 40-28=12 35+11='46T'
That is 3 over with SGS and a 46 low cog, so a 50 will be to far over. Even if you used a DR drop extender, the capacity still applies. You can expect poor performance approaching cross chaining, not to mention chain slap. For road use chain slap probably less of an issue unless you hop and go through big shit speed bumps and pot holes aggressively I'd suggest.
So is make sense to see the CX 36-46 and 26/36 MTN chainsets out there. a 10 tooth chain ring difference make the last example 43T, so in that case the 50 Tooth cassette would be 3-4T over spec.
You could always trim out the 11T to gain 2 teeth in capacity. When would you use the 11 in the small ring on a double? Compromise there being loosing 10+ gear inches on top.
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