Question on yesterday’s blugh

[Ray Varella]

 

In Will’s email yesterday there was a link to a new blugh but there is nothing there. 

I had a question about the 7 speed cassette that was alluded to, did anyone read about it?

It looks like a great option,

Can anyone offer a brief synopsis. 

Thank you 

Ray

[Joe Bernard]

13-42 which will mount on a 8/9/10 hub with a spacer Riv will provide (you would use it with the included spacer most 11-speed hubs offer, too). Intended for friction shifting and will use Riv's own 7-speed chain but an 8 (and probably 9) will work, too. No idexing compatibility was mentioned but I would imagine/hope this would work with Shimano 8-speed shifters with one click locked out. 

The post will probably be back, it was short and sometimes Grant pulls them back for edits. 

Joe Bernard

[Ray Varella]

Thanks Joe,

….so which derailer will we use with these? I say “we” because you may be just as likely to run one as I will. 

Cheers 

Ray

[Joe Bernard]

It's intended to work with the new RapidRise (low-normal) derailer Grant is working on. But if we have something in a drawer that'll work with the 42t cog I say give it a whirl! 

[Joe Bernard]

The Blahg is back up. Casette uses 7-speed spacing (Grant's words) which should (my words) nominally index with a Shimano 8 shifter and normal matching derailer. But I don't know if the teeth will be indexy twisty, I don't presume Riv is pushing hard to make this thing work with anything other than friction shifters. 

Joe "wildly guessing" Bernard

[Ray Varella]

I don’t have anything that will work with a 42 tooth rear but a 2x configuration definitely has my attention. 

Ray

[Garth]

Ray, What isn't included in the story is the use of a rear derailleur hanger extender. It's been mentioned in bits and pieces within their various media. There's many brands but what they all do is essentially lower the rear derailleur hanger which allows the RD to clear much larger cogs than otherwise, and without maxing out the B screw.. Note though that while it allows for cog clearance, it doesn't change the total teeth capacity of the given RD. Most of the mfr's of the extenders say it's for 10sp. 1x setups, but it will lwork for 2x 9sp or less as long as you work with the given capacity of the RD.  Riv appears to offer the Sunrace version, but it uses an aluminum bolt. I'd prefer the stainless steel bolt the Wolf Roadlink and Wheels Mfr. offer. Here's just one type .... https://wheelsmfg.com/extended-hanger.html  

[Ray Varella]

Thank you Garth,

So if my rear derailer wraps 40 teeth, I could run this cassette and a 10 (maybe12) tooth difference in my front chainrings. 

I’ll definitely stay tuned for its appearance. 

Ray

[dougP]

When you think about a 2x, something like a 34-46 double with that 13-42 cassette has a pretty decent range & the front should shift just fine.  Hmmmm.....

dougP

[Ray Varella]

I think there are a number of useful possibilities as a 2x and it has me looking at some chainrings I already have but would not otherwise use. 

Ray

[MP]

It’s intriguing to me, I have an '88 Panasonic PT-3500 I’m building up as a poor-man’s AHH and there’s nothing with gearing like this that’ll fit into a 126mm rear-spaced frame (without doing some surgery on MTB 9 speed cassettes).  

Matt

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[Bill Lindsay]

It will indeed be interesting to see.  Several thoughts:

13-42 is 323% gearing, which is approximately a 21% jump if you do equal percentage jumps at all six jumps.  Assuming equal percentage jumps my guess at the cogs would be:

13-16-19-23-28-34-42

If that's the cogs, then the biggest percentage jumps would be 23% at the 13-->16 and 23% at the 34-->42.  The smallest jump would be the 19% from the 16-->19.  

It would be sweet if there was a rear hub with a short freehub body that this cogset could fit on, for very low dish rear wheel or to enable a 126mm OLD.  I've ordered the 120mm OLD model from Cycles Grand Bois in Japan, and they offer a 126mm variant, but they intend that very-short freehub body for 5-speed or 6-speed spacing.  People sometimes run 7 cogs from a 10 speed cassette on that hub, and I've personally run 8 from 11 on that hub.  If the Rivendell 7sp cassette is disassemble-able, then maybe one could run narrow inter-cog spacers and get it to work on that hub.  

Bill Lindsay

El Cerrito, CA

[lconley]

Remember that the newish Shimano mountain standard 11 speed cassette width is essentially the same as a 9 speed cassette width. The three inner cogs are joined and overhang the hub flange. This was done to allow less wheel dish for a stronger wheel on a mountain bike. It is possible because the inner cogs are so large now that they CAN overhang the flange and spokes. Might be able to get a lot of cogs on narrow cassette running the inner three from a mountain standard cassette.

My Bombadil (3x7) and Kevin's Cargo Bike (1x7) both run 7 speed FREEWHEELS on 135mm hubs - very little dish. One is a 40H Phil Wood hub and the other is an NOS Sansin Tandem 48H hub. I think that I can put a freewheel on both side of the tandem hub because the drum brake threading is the same as freewheel threading. Haven't checked what is possible here - 6 on one side and 7 on the other? Could I call it a 1x13 freewheel?

Laing

who spends way too much time swapping parts between bikes.

[dougP]

Bill's analysis makes me think using a 2x with 10% difference would get back to the old half step gearing.  It'll be the newest development in gearing!

dougP

[J Schwartz]

Hello, I couldn't find the info about the 7 speed cassette ...Does anyone know if it's an imminent release or many months off?

thanks