With a 5-bolt compact crank, you can use a granny ring down to 20t. Thanks, shitmano, for changing the standard and screwing everybody that needs a super low gear.jaco said:Anybody know if theres any special chainrings out there that provide ultra low gearing, even more than a 22 tooth and a 34 sprocket cassette combo? Some of the steep parts up the mountain kick my ass and id like to get up the whole thing all the way through.
OMG do you know cycling trivia.bulC said:With a 5-bolt compact crank, you can use a granny ring down to 20t. Thanks, shitmano, for changing the standard and screwing everybody that needs a super low gear.
Going further back, with a standard crank (74mm granny bolt circle) there used to be made a variety of adaptors to fit smaller rings than the 24t that's the normal lowest for that diameter. Avid made one that fit 20t and 22t compact grannies. White Industries made one that fit freewheel, as in thread-on freewheel, cogs down to I believe it was 16t. So did the guy who first raced the train from Durango to Silvertown in like '72 or so, starting the Iron Horse Classic. His bro was the engineer. Tom Mayer's his name, out of Albuquerque, I forget the original name of his little company, then he changed it to GIOS Team, God is our Savior, or God is on our Side, something like that to let the cycling world he found religion in a major way. Anyway, he had several adaptors, including one that added a fourth teeny tiny freewheel "chainring" behind a normal granny. On yer own making the front derailleur handle it, but it could be done if you were clever and ingenious enough.
Pretty sure all those adaptors died when compact cranks got popular.
And I think Bullseye cranks had, maybe still have, a configuration to take a ring down to 16t, if I recall.
Maybe the above adaptors are available on ebay, I never looked.
Another option is tracking down an old SunTour 14-38t, yes 38t, freewheel. I actually have one here, and took it apart -- it was a 5-sp. -- and fitted the larger cogs to a 6 sp. freewheel body. SunTour had a special derailleur for it, but I made mine work fine with a long cage shitmano deore. Not that I need it, just because I had it and it was a shop project.
So, to sum up, theoretically, using available technology from the recent past, you could have a 16t granny ring and a 38t large cog. Let's see, that, oh my, a 10.9 inch gear with a 26" wheel. Somebody tell Frank Berto (ask google if you never heard of him).
Good to see Tom's still selling his wares. I didn't see anything for 4-bolt cranks listed on his site, however. All the product described there is just like he was selling more than a decade ago, so I suspect he's just running off of existing stock. But there ya go, if you got a standard bolt circle crank, you can still set it up as a quad to amaze and astound your friends. He used to always go to the Moab Halloween fest and hang out on the slickrock, spinning up the steepest slopes while everybody else was climbing at like 20 rpm.jaco said:Right on! Seems like Mountain Tamer might have an option for my shimano 4 bolt crank. Appropriate name too.
5 characters added to appease idiot softwareDuckman said:5 bolt compact. Thats the only way your gonna be able to do it. Very common(both my NRS rides run it). You could run a 20t granny and a 11-32xt(250gms with an alum lockring)and still be measurably lower then a 22t x 34t and save weight and/or $ from a 300gm 11-34xt or a 11-34xtr cog.
Does the weight weenie board know you escaped?
20/32=16.25" with 26" wheels. 22/34=16.8".
Plus, as you get stronger, you can go to an 12-27 Duraace cassette at 178gms. About the same as 22t x 30t.
Also...you can run as small as a 29t middle ring.
Yup, I got 42/29/20t with 12-34t on my backcountry bike. I'd run a 38t or 40t big ring if I had one. Good luck finding the 29t, I know I bought the last 3 that Ritchey had.
Typical 5 bolt compact setup with a 42-31-20t up front and a modified 11-27t Duraace cassette. Plenty gearing for anything in Pisgah if one is fit. But this oldtimer still needs that 20/34t at altitude in the San Juans.