Turkey Vulture Gearing 101: We (the nerds at Gravel & Grind) came up with Turkey Vulture gearing in the fall of 2016 response to a few needs and a few concerns. Issues: climbing with a loaded touring bike on rough steep fire roads, single track, 15% + dirt roads, etc was often not doable without climbing out of the saddle with all of it’s related issues. We live near short steep punchy climbs and have many miles of fire roads and single track around us. Walking a loaded touring bike up a slippery chunky gravel fire road is harder than riding it. How to ride it became a concern. Turkey Vulture gearing is our ultra super wide range gearing solution that uses normal rear hubs, normal rear derailleurs, normal friction shifters. Read on to learn more, there are guidelines and rough rules to follow, but as always, when going outside the norm with gearing or whatever, expect to have to mess around a bit.
Lower gears are the obvious answer to not walking up hills, but how to get those without loosing the top end go fast gears? Traditional touring gear was not low enough. We did not want to go to a 1×10 or 1×11 or 1×12 system. The reasons why include but are not limited to lower chain, cassette and chainring life, higher expense for a given cassette, derailleur, shifter, etc, and less room for mechanical slop, ie less room for imperfect adjustment. Imperfect adjustment is never talked about, but field servicing something often requires imperfection or improvisation. Using a multi tool to realign a derailleur hanger, for instance, which the bike below has had done. Turkey Vulture gearing worked fine for the remainder of the tour. 1x systems also limit your gearing either on the higher or lower end. We did not really want that, either. In short, we wanted a relatively affordable, highly versatile, field serviceable gearing beyond what any one is currently offering. After some tinkering, we landed on Turkey Vulture, so called to poke fun at the highly proprietary and expensive SRAM eagle 1×12 system.
Here’s the basics:
Go lower in the back. A 11-40 or 12-40 works well here. We have a few 9 and 8 speed cassettes in that range (the 8 is 13-40) that work well. The best derailleurs for this application are relatively new Shimano 9 speed mountain derailleurs. Skip plastic if you want to fix it by bending it. Our favorite is the Shimano Deore 9 speed derailleur, with the loaded b spring, not that Shadow 9 speed one. It works better, wraps chain better, costs less. Add a Wolf Tooth Road Link to the top, which drops the derailleur down a bit, which helps with having the pulley not hang up on the bigger cassette cogs. Makes it shift better. It’s tough, I’ve bashed it up, it can hand nasty hits.
Go low in the front. You can use a Sugino crankset, or a White Industries, or a Shimano MTN crankset, but make sure the low gear is either a 22, 24, or 26. We like 24 best. Add a maximium of 20 teeth to the granny gear tooth count you have. Thats how big your big ring can be. IE I run a 44/24. Bigger tooth difference than that, the derailleur can’t wrap it up. You can run it as a double or triple. You can obviously go with a smaller big ring (IE a 18t difference) but the idea here is max gear range for max versatility.
Use a flat cage front derailleur. Not something with lots of bumps and whatever. We like the Shimano CX 70 or old 1990’s road or mountain triple mechs. That’ll make running extreme gearing combos (44/40) easier to do without rubbing.
Your system should be friction, to fit in with the idea of field serviceability. Will Turkey Vulture work with Brifters? Some, but not all. Don’t message me about it, you are on your own there. Each brifter issue is a bit of a nightmare, and I’ll only look at them in person, not try to guess as to why its not working via email. Your friction shifters should have barrel adjusters to make cable tension adjustments easy. Either on the downtube, on the derailleur or inline. Front derailleurs without barrel adjusters are silly.
Use a longer chain, probably. Some setups with short chainstays won’t need a longer chain, but most will. Here’s what we do: set up a full length chain with a quick link. Connex makes our favorite, because the quick link is easy to open by hand, they are really tough, and they are nickel plated for good silvery looks. If you are rad and get this stuff from us because we told you about it, we sell the other things you need: a few extra chain links, and an additional quick link. Add a few links, and use the chain sizing technique below to get the right length. It’s not hard, but it might take a few tries. It works though, if you do it to his spec’s.
You can use any friction shifter for this, more or less, but we like IRD’s brake levers with Shimano Bar cons mounted to the front. You can position the Bar Cons pointing up or down to personal preference. I like em up. This is a good solution for Brifter fans who have been feeling the pull of friction shifting.
I love Riv, but I would recommend against using Silver shifters (Update, the new Silver2 shifters are much better!) or anything with a weak ratchet. Old Suntour shifters work, Shimano, full friction shifters like Campy downtube shifters… but weak ratchets slip.
Here’s the deal: we stock all of this stuff, or try to. The cassettes, the chains, the levers, the shifters, the derailleurs… We’re a small shop that happens to be a Riv dealer, a fact we’re proud of. If you want to go full Turkey, call us or better yet email us, and throw us some support. We’ll help make your bike more versatile, and make touring and steep roads more fun. We’ve set it up on a bunch of bikes now, and pretty much know what will work and how. Go low, don’t walk, fix your stuff in the field. That’s it.
I’m James, the mechanic and co owner here. You can reach me at james (at) gravelandgrind (dot) com (Editor's note: don't try that email address now, use our contact form to hit us up!)
Thanks for reading!
Round about 2018, we updated the Turkey Vulture system with a rear derailleur swap and a cable pull modifier. By replacing the Shimano 9 speed rear mech with a SRAM 10 speed GX unit, we were able to gain a quieter drivetrain. The GX derailleur has a clutch mechanism that keeps the derailleur cage from flopping all around on rough terrain. By using a J-tek shiftmate cable pull modifier, we were able to use friction or 9 speed indexed bar cons with this 10 speed derailleur. The kit is still available on our site, and we occasionally have reason to spec it still!
2019 saw the final development of Turkey Vulture gearing: Turkey Vulture Loco Supreme. This was a semi failed experiment, in that the gearing was too wide to be useful. We paired a 46t chainring with a 20t granny. No middle ring. With an 11-36 out back, the system boasted an incredibly wide range of gears. Wider than anyone would need. Although the shifting worked fine, the gear jump between the 46t and the 20t was rather abrupt. We spec'd Loco Supreme on a few bikes, but have shelved the idea as far as further development goes.
Nowadays, Candice rides Turkey Vulture Supreme on her 1993 Bridgestone XO-1, and I ride it on my MB-1 from the same year. But for most of our bikes, we stick with the simple 1x drivetrains that have come down in cost, work great, and have a very wide, useful range. Older tech isn't always better, and we've come to know, trust and love 1x gearing. We're happy to build a friction Turkey Vulture bike for you, but the next time I go to build up a bike, I know it will have a 1x11 set up. I've been using a 9-46 range on my road bike for a few years, and a 10-50 on my Moonshiner. I never run out of range on either end, and to me, that means I'm in a good stop, gearing wise. It's quieter, lighter, and shifts really really well, even under load. Hard to complain about that.