“Pink Flamingo” gearing with Sora-Ace 9 speed cassette

[lconley]

Last year I was riding a single speed Mystery Bike on the levees here in south Florida, this year it will be a 2x9 Rosco Bubbe V1. Analog calls their wide ratio gearing "Turkey Vulture"; in keeping with the two word, four syllable avian theme, I will call this "Pink Flamingo” gearing. Here in South Florida, gearing is used to compensate for wind direction, not terrain, so close ratio is the name of the game.

I combined the 1^st 6 corncob cogs of a 14-25 Sora 9 speed CS-HG50-9 cassette (14-15-16-17-18-19) with the last 3 cog section of a Dura-Ace 9 speed CS-7700 cassette (21-24-27 titanium cogs on aluminum carrier) to get my Sora-Ace 14-27 cassette. I used all Dura-Ace aluminum spacers instead of the plastic Sora spacers. Probably would be just fine with the stock Sora 14-25, but now I can call it “Sora-Ace” and it saved 40 grams while adding a lower low.

Crankset is a VO Drillium 34-48 (110 BCD). The result is 34 to 93 inch gearing – most important to me is the 51, 54 , 57, 61, 66 on the small front chainring for riding against the wind, and the 62, 68, 72, 76, 81 on the large chainring for riding with the wind. I don’t ride very fast. The 34 x 27 (34 inch gear) is handy for the short but quite steep slope to get from the parking lot onto the levee.

Rear derailleur is a 9 speed Dura-Ace RD-7700 (beautiful used condition from eBay for a very reasonable price) and front derailleur is an NOS 7 speed Shimano RX-100. I did have to file a small notch in the front derailleur to clear the water bottle boss to allow the front derailleur to mount low enough for best shifting. Dura-Ace 9 speed bar-end shifters on Paul Thumbies handle the index shifting.

The chain, like on most of my bikes, is an ultrasonically cleaned and Molten Speed Waxed stainless steel Wippermann 9 speed.

Laing

Delray Beach FL

[Bill Eberle in Portland OR]

Well done. I'll be saving this for future reference. "Pink Flamingo" is icing on the cake.

[Patrick Moore]

Now that's an intelligent cog combination that I entirely approve of -- since it matches my own biases. I built the cassette for my only derailleur bike out of Miche Shimano-type cogs shipped via slow trireme from COVID Britain in 2020, but I was able to get just the sizes and series I need for a 13-25 10 speed, the first 8 corncobbed, then 22 and 25. My rings are 42 and 28, and I should probably swap the 28 for a 26. I get 95" to 50" on the 42 and down to 33" on the granny -- plenty for my riding.

My DA rd is a 7402, I think (I have 7400, 7401, and 7402, and I get them confused); come to think of it, fd is much the same. Crank Ritchy Logic, Suntour barcons.

I used to use Molten Speed Wax but James at Analog convinced me of the ProLink/wipe method. Oh! And I use the trick of a chain one gen later than the cassette: 11 sp chain for 10 sp cassette. Said to promote crisp shifting and avoid rattling.

On Sun, Mar 12, 2023 at 10:45 AM lconley <lco...@brph.com> wrote:

... I combined the 1^st 6 corncob cogs of a 14-25 Sora 9 speed CS-HG50-9 cassette (14-15-16-17-18-19) with the last 3 cog section of a Dura-Ace 9 speed CS-7700 cassette (21-24-27 titanium cogs on aluminum carrier) to get my Sora-Ace 14-27 cassette. I used all Dura-Ace aluminum spacers instead of the plastic Sora spacers. Probably would be just fine with the stock Sora 14-25, but now I can call it “Sora-Ace” and it saved 40 grams while adding a lower low.