etrogge

Being a bit older than the average Cat 3 rider, I have little use for 11 and 12 tooth cogs except maybe as punk dog collars for chihuahuas. Also, I live on the san francisco peninsula, so 39/27 gears don't cut it for me on 15% grades. I decided to build my own old-guy-climbing cassette using a CS-6500 9 speed 12-25 cassette as a starting point. I took out the 12 and 13 tooth cogs, leaving the 25-23-21 cluster and the 19-17 cluster. To the two cog clusters I added 27t and 29t Miche cogs and an 8-speed 14t primary cog. So, the cog sequence is 14, 15, 17, 19, 21, 23, 25, 27, 29. Of note, at 90 rpm, a 53/14 gear puts me at 26.7mph. Solo, that's screamin' fast for me. Today I took the new Frankenstein cassette out for a try. The bike has a Dura Ace rear derailleur in mostly new condition. Conclusion: works great. Shifting is just fine, maybe just a tiny tad slower, but maybe that's just my expectation. The 14 is just a bit more usable than a 13 and way more useful than a 12 or 11. It'll last longer too. I did have to adjust the B-tension screw so that the jockey pulley didn't rub on the largest sprocket. During the shift from 27 to 29, there is a bit of rub, but once the chain is on the 29 cog, its fine.

I have another bike where I use an M900 MTB cassette (12-32, but with a 13t primary cog) with a Shimano 600 short cage derailleur. That works great too.

So, why do this? Well, these two bikes have 130bcd chainrings (53/39). I didn't want to buy compact cranks for two reasons: 1) $ and 2) with compact cranks, an upshift from the small to larger chain ring usually requires two shifter pushes to downshift 3-4 cogs to get the next taller gear. Bad design, in my opinion. With these more widely spaced cassettes, upshifts from small to large chain rings only require a two cog (one shifter push) downshift to get the next taller gear.

Could I have just bought a Harris Cyclery Century cassette? Sure, but I had the CS-6500 already, and the additional gears were only $40.

Hopefully, someone will find this useful...