I love my granny
Pretty sure Im going with a Rohloff for my new Turner DW Sultan build if can get the gearing I am used too.
On my 26er I really like the 20/34 (1.2 gain ratio) and would like a higher 32/34 (2.0 gain ratio).
On the Rohloff looks like the highest gear with a 32/13 is 1.4 gear ratio. I realize the 29er may negate this small difference but I really like the 1.2 for the terrain and style I am used too.
7.4 being my lowest gear, I probably could live with that, but I really enjoy the 1.2. Its seems most people run a single ring up front with a IGH, any advantage to 2 other than lower achievable gears? Suggestions?
current 26er setup
3.8 6.1 8.4
3.2 5.2 7.1
2.8 4.5 6.2
2.5 4.0 5.4
2.1 3.4 4.6
1.8 2.9 4.0
1.6 2.6 3.6
1.4 2.2 3.1
1.2 2.0 2.7
I'm a little confused by your question, and think you may have reversed what you're calling your lowest and highest gears, but I'll take a shot...
Minimum recommended ring:cog ratio is 2.4:1, ex. 38x16 or 36x15.
Your proposed 32x13 is actually a bit higher than this, at 2.46.
For starters, I'd recommend you avoid the 13T cog unless you're intent on using the 32T chainring. The 13T cog wears quickly, is less efficient than larger cogs, bumps the chainline out, and is not reversible for extended wear (the others can be flipped).
To get the low gearing you want, you can duck under Rohloff's minimum. 32x16 would get you the equivanent gearing you're looking for, and would partially address the larger wheel size. But you're going to need to be comfortable knowing you're exceeding their published limits, and damage could result.
The hub has 9 nylon shear pins that connect the internals to the hub shell. In theory, these pins would shear and disconnect the hub if torque limits were exceeded, preventing damage to the internals. Truth be told, anecdotally I know of lots of Speedhub riders taking liberties with their hub gearing, and I've yet to hear of damaged hubs as a result.
Chalk it up to the hub being overbuilt: the same recommended gearing limits that apply to you and me also apply to strong tandem teams, so it stands to reason that solo riders can get away with quite a bit lower gearing than published.
No problem running two chainrings and a front derailleur. There's no limit to how high you can gear the Speedhub.
Here's a list of Speedhub derailleur gearing equivalents, published by Rohloff:
· MTBR Hiatus UFN ·
I'm running a 35x15 on my Sultan with a Rohloff. I know it dips below their recommendation but I probably don't have the legs of one tandem racer much less two racing up a hill. So I'm not too worried about breaking it. And like SpeedhubNate said it seems like lots of us choose to go lower with no problems. I chose that gearing because the 15 came with the hub and the 35 gave me nearly exactly the same low ratio as the geared setup I removed. I don't remember what that was now, it's been a couple years. I love my granny gears too and use them a lot and didn't have to change my pedaling style at all when I made the switch. It's plenty low even with 29" wheels.
Definitely confused but I think Im on it now...I did so many calcs in SB I got the results mixed up. So Im thinking the 36x15 or 35x15 as dave9er mentioned may be my target. Daves config is just so ever slightly under the spec and Im no Goliath either.
So just for clarification Granny gear would be your lowest gear? ok, thinking back to my Jeep days, yes, granny, low, crawl...
Yes, granny is lowest.
Originally Posted by RipRoar
36x15 and 35x15 are both pretty close to 22x34 derailleur equivalent. It's not going to get you the 20x34 equivalent you're looking for.
The 10% larger wheel size of the 29er would make a 20x34 derailleur setup feel like 22x34, so you'd want 18x34 to counter that (which is creepy-crawly low). Personally, I think you may be selling yourself short aiming that low, but I don't know the particulars of your riding situation so I'll let you figure that out. However, this low a gear will definitely negatively impact your highest gears, in which case a front derailleur setup is justified. It's too bad, though, because the front derailleur is the best thing to get rid of when installing an internally geared hub.
· MTBR Hiatus UFN ·
I think I had 22x34 before and that's why it felt normal to me. I don't miss anything at the top end with 35x15, I tend to coast at those speeds on a MTB. I think you could go a tooth or two lower without any danger to the speedhub, but I like to crawl up some hills and my setup works for me. I had gotten used to the 29er wheels and the effective higher gearing before going to the Rohloff and I do remember feeling like I had less of a granny when I first got on the Sultan. So making all the changes at once may make you feel like you lost a gear. But you'll love it. Especially the first time you need your granny right now and you're in 6th or 8th or 10th and you just twist and go, no waiting for all the derailleuring to happen. I'm in VA, come ride mine if you want.
I definitely dont want to run a front derailleur, Im more concerned about the low gear and wherever the high ends up that will be fine. Im thinking the 35/36x15 will be close enough and dont want to over think this without just riding the thing.
The whole bike is going to be a huge change for me so if the gearing is just slightly off, the weight difference and efficiency should make up for it! In the end the saving on cranks, no derailleur and cog etc almost make the Rohloff the same price..
Thanks, if I was on the other coast I would do that! Hey post a pic of your setup if you can...
'm in VA, come ride mine if you want.
Last edited by TraxFactory; 01-09-2010 at 08:38 PM.
Here it is, it's even fairly clean.
That setup looks cleaner than I expected, nice color combo. Do you like that G Dropper? I went with a Kind Shock i-950r should be here any day..
Thanks, any color coordinating I do is purely coincidence but I do like the way it looks.
I like the gravity dropper, had it for a couple years. It will hit you hard coming up if you don't control it with your thighs but never releases until you want. The KS looks good, and better price too. What fork you going with?
Im pretty sure Im doing the WB Fluid-29 135, I wanted to slacken the bike just a bit. No lockout but Im more of a sit/spin guy than stand/grind. This is my build, ordering everything tommarrow:
Shimano XT FC-M770 180mm
Blackspire MonoVeloce Chainrings 104, 35T
Blackspire Lite God Bash Ring 104, 36T
Front - Hope Pro II 36H Disc 20mm axle (black)
Rear - Rohloff (black) Disc Brake Hub, Quick Release, External gear Mech, OEM2 plate,
speed bone, 4 bolt disc rotor 180mm, black spokes, chain tensioner, 15T ring
Skewer - Hope
Chain Tensioner - See Rohloff
Front - Stans Flow 29er 36H Black
Rear - Stans Flow 29er 32H Black
Tires - front Maxxis Ardent 2.4 or WTB Stout 2.3
rear - Maxxis Ardent 2.25 or Geax Saguaro 2.2 or WTB Prowler 2.1
Bars - Syncros (black - not sure which, wide)
Stem - Syncros AM Stem - HP Black - 80mm or 90mm
Headset - Cane Creek 110 or King (silver polished)
Forks - White Brothers Fluid-29 135mm
Brakes - Front / Rear Formula TheOne 203mm front (rear disc from Rohloff 180mm)
Saddle - Selle SMP Avant (black)
Seatpost - KS i950-R
Last edited by TraxFactory; 01-10-2010 at 05:02 PM.
[QUOTE=dave29er]Thanks, any color coordinating I do is purely coincidence but I do like the way it looks.
I like the gravity dropper, had it for a couple years. It will hit you hard coming up if you don't control it with your thighs but never releases until you want. The KS looks good, and better price too. What fork you going
If you don't mind, do you know what she weighs?
If you don't mind, do you know what she weighs?[/QUOTE]
Thanks. 28.8 pounds by my scale.