# 2010 Sturmey-Archer 8 speed



## Alana (Oct 17, 2007)

Hi guys, interested in getting an internal hub for offroad/on road touring. I know the SA hubs have not had the best reviews, but the model has been completely redesigned for 2010

http://www.sturmey-archer.com/products/hubs/cid/5

I was wondering if anyone has tried it, especially the disk model. There does not seem to be any restrictions on the gear ratios or anything so one could put a granny on it.

I was going to go with a used I-motion 9 but after reading a few threads here it may not be suitable for loaded offroad riding if there is a restriction on the gear ratios.


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## J_Westy (Jan 7, 2009)

Alana said:


> I was wondering if anyone has tried it, especially the disk model. There does not seem to be any restrictions on the gear ratios or anything so one could put a granny on it.


I put an XRD8(W) on my klunker with a 30T front chainring: (http://www.retrobike.co.uk/forum/viewtopic.php?t=81547&start=66)

No problems so far, but not many miles either.

I did call S/A beforehand, and they didn't necessarily recommend it for off road and he said I should only try to shift when I'm not pedaling for best durability. I think he also recommended a 32T minimum chainring, but I could be wrong... I'd call them to confirm. Also remember that this hub is direct drive in 1st gear and everything else is overdrive.

I bought mine from a store that was using the predecessor hub (no W on the end of the name) but was breaking them when used on their cargo bikes. S/A sent them these new model ones as replacements, but the shop decided to change to a different hub in the meantime, so they were selling these cheap. The tech at the shop said the cargo bikes were really heavy and the riders were probably shifting under load, so she thought these new model ones should be okay for a light rider... all anecdotal of course.

Good luck.


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## pursuiter (May 28, 2008)

SA 8 speed isn't very good for off-road. Beside the fact it has a bad history of breaking down, it's lowest gear is direct drive. You can't get a very low gear using it, the SA 8 was designed for small diameter wheels found on folding bikes. IMHO, for off-road touring there's two options, Rolhoff and Alfine 8.


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## Alana (Oct 17, 2007)

Ok thanks guys, looks like its going to be Alfine.


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## Alana (Oct 17, 2007)

Oh one more thing, what exactly is direct drive?


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## CaptainDecisive (Sep 4, 2007)

Alana said:


> Oh one more thing, what exactly is direct drive?


That's the gear with a 1:1 ratio. In other words no internal gears changing the output to the wheel, eg like a singlespeed. The Sturmey Archer 8 speed hub is unusual in that the 1:1 gear is the lowest gear and the next seven gears all have the drive output changed by the internal gearing. Other hubs tend to have the 1:1 gearing somewhere in the middle of the gear spread and use gearing to provide both higher and lower output to the wheel. One effect of this is that, as pursuiter mentioned, because wheel diameter is part of the gearing equation the S-A 8 provides a good gear spread with small wheels like those on a Brompton or Dahon folder while a 700c / 29er wheeled bike would either end up with very high gearing or require a very small chainring.


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## Alana (Oct 17, 2007)

CaptainDecisive said:


> That's the gear with a 1:1 ratio. In other words no internal gears changing the output to the wheel, eg like a singlespeed. The Sturmey Archer 8 speed hub is unusual in that the 1:1 gear is the lowest gear and the next seven gears all have the drive output changed by the internal gearing. Other hubs tend to have the 1:1 gearing somewhere in the middle of the gear spread and use gearing to provide both higher and lower output to the wheel. One effect of this is that, as pursuiter mentioned, because wheel diameter is part of the gearing equation the S-A 8 provides a good gear spread with small wheels like those on a Brompton or Dahon folder while a 700c / 29er wheeled bike would either end up with very high gearing or require a very small chainring.


Ah ok, thats kinda what I figured... in that case why are the Sram i-motions supposed to not have a good granny gear (if you run it according to specs) it still doesn't go low enough with a 34/20? :skep:


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## pursuiter (May 28, 2008)

Alana said:


> Ah ok, thats kinda what I figured... in that case why are the Sram i-motions supposed to not have a good granny gear (if you run it according to specs) it still doesn't go low enough with a 34/20? :skep:


One man's granny is another man's knee crusher. It just depends on the rider and the application. I had an im9 on a MTB, it couldn't handle 34/20 without klunking and slipping, it's just not up to MTB applications. Now I have it on a road bike with 38/20, works nice. Still need to baby it while shifting but it's no worse than every other IGH I've owned except Nexus/Alfine 8.


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## theomdude (Jan 30, 2009)

I'm jumping in here because I haven't figured out how to post, can't find an answer anywhere else, and this is the closest question to the one I have. I have a friend I've known since high school (I'm 66) who because of a birth defect doesn't have the hand strength to use handbrakes. He can manage a single-speed cruiser with a coaster brake, but he lives in the Colorado Rockies, and even if he couldn't do offroad, he'd need lower gears. An old fashioned Sturmey Archer 3-speed is a start, but do any of the new multiple-speed hubs have coaster brakes?


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## finch2 (Nov 13, 2009)

theomdude said:


> I'm jumping in here because I haven't figured out how to post, can't find an answer anywhere else, and this is the closest question to the one I have. I have a friend I've known since high school (I'm 66) who because of a birth defect doesn't have the hand strength to use handbrakes. He can manage a single-speed cruiser with a coaster brake, but he lives in the Colorado Rockies, and even if he couldn't do offroad, he'd need lower gears. An old fashioned Sturmey Archer 3-speed is a start, but do any of the new multiple-speed hubs have coaster brakes?


I don't think so....he can't use a high end hydro brake either? They have heaps of power for little effort. It's a tricky situation as I can see that it could be dangerous with only a coaster brake off road.


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## Surly29 (Jun 8, 2009)

theomdude said:


> do any of the new multiple-speed hubs have coaster brakes?


There's a Shimano Nexus 8-spd with coaster brakes (SG-8C31).

http://bike.shimano.com/publish/con...cts/0/nexus/product.-code-SG-8C31.-type-.html

Don't know anything about it, though, or if it would have enough braking power for your freind's application.


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## theomdude (Jan 30, 2009)

Thanks for the thought, finch2. 
It's not just strength, but the way his hands are "constructed." This guy has never let his "handicap" hold him back before and I'm looking for a way that he can at least get out and do some single-track. He's not going to be doing technical rides.
I did some more research (Thank you, Sheldon Brown!), and Sturmey Archer's S-RC5(W) 5-speed has a coaster brake. With a 22 tooth sprocket and a 32 tooth chainring (White Industries makes one) that gives him a low gear of about 34 gear-inches with a 26" wheel. That's not exactly a "granny" but it's the equivalent of a 24/19 chainring/cog, and beats a 3-speed that starts with a direct gear and just gets higher.
Shimano's Nexus 7-speed has a coaster brake, and the spread is similar, but with smaller jumps (of course). It's lowest ratio yields a 31 inch gear, equivalent to a 24/21 derailleur setup. Not bad.
Of course you can't race downhill on-road with an 88 or 76 inch gear, but with just a coaster brake, you'd be courting disaster to do that anyway.


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## Surly29 (Jun 8, 2009)

theomdude said:


> Shimano's Nexus 7-speed has a coaster brake.


It's my understanding that the Nexus-7 has a Roller Brake, which is cable actuated and uses a hand brake lever. I think he'd want a true coaster brake that is foot/pedal operated.


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## theomdude (Jan 30, 2009)

Shimano's own Tech Specs say it has a coaster brake and is "roller brake compatible," whatever that means.
In any case my spreadsheet says the SG-8C31 8-speed yields a much lower gear, even though its biggest sprocket is a 23-tooth. If my math is correct, it gives a 19 inch gear with a 32-tooth chainring, which is lower than my old Raleigh Super Course II that I'd converted to an Avocet triple with a 24/32 front/rear combination. I could climb walls with that bike without breaking a sweat.
Once again, he'd only have a 58" top gear, but high speed decents are not part of the picture with a coaster brake. Besides, we all need to learn to spin more! ;-)
This guy is light, so I don't think durability would be too big an issue.


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## theomdude (Jan 30, 2009)

Great suggestion. With a 32/23 front/rear combination, that gives him a real granny gear at about 19 gear inches. Thanks!


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## Surly29 (Jun 8, 2009)

Cool. I know nothing about the roller brake. Funny thing is the Nexus-8 shows 2 models, one roller brake compatible and one coaster brake. And I can't bring up any specs for the Nexus-7, but it only shows 1 model.

I'm pretty sure the current Nexus-8 uses the same internals (and roller clutch) as the Alfine, which means you can run even smaller than a 32T chainring. I've used a 26 x 22 setup on my Alfine-8 for about 2 years now.


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## theomdude (Jan 30, 2009)

I didn't know they made single chainrings smaller than 32T. The whole single chainring thing is new to me. I haven't seen these things since the old Raleigh "lightweights" of the fifties and sixties, which compared to the Schwinn boat anchors of the day (we didn't know about such things as Paramounts) seemed featherweight. LOL!


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## Alana (Oct 17, 2007)

Just an update, I'm going 33/23 with the Alfine. JensonUSA has Alfines for $199 (the black 501 model even). Bikeman has the premium Nexus complete kit for $189.. lowest price I found online. http://www.bikeman.com/JB-SG8R36.html


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## pursuiter (May 28, 2008)

Another option for the road is the SRAM i-Motion 9. The gear steps are more uniform and I find it's better for the road than a Nexus/Alfine. There's a coaster brake version available. If you go with a Nexus 8 hub, be sure to get the 8C31, it's the newest version with Alfine 501 clutches.


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## theomdude (Jan 30, 2009)

I looked up the SRAM "i-Motion 9 with Backpedal Brake" and it looks like a good candidate. Trouble is, there's no way to figure mechanical advantage for comparison, because none of the literature I found gives a gear ratio. If I at least knew which gear was direct drive I could figure it out by the steps, but I don't.


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## theomdude (Jan 30, 2009)

I finally found a clue, and it doesn't look good. The bottom gear is over 1:1, giving a "development" of 2.3 meters. A 700c wheel goes about that far in a revolution, which is the equivalent of 42 gear inches. That's the same as a 27T sprocket with the inner ring (42T) of an old Campy Nouvo Record double crank (i.e., not very low). Acceptable for a strong rider on a road bike but nowhere near low enough for a mountain bike. I'm assuming that's with the 22T sprocket. If the spec is for a smaller sprocket then it's slightly better, but still a non-starter.


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## theomdude (Jan 30, 2009)

I gotta go back and recalc. A 24/24 chainring/cog should give a 2.30 meter development, because that's a 1:1 ratio. My math must be way off.


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## theomdude (Jan 30, 2009)

Okay. Got it. With the setup they use for their example, low gear is 29 gear inches, the equivalent of a 24/22 chainring/cog combination. That's acceptable for single-track and fire roads. High is 101.4, which is 'way higher than he'll need. Looks like a good choice.


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## pursuiter (May 28, 2008)

You did mention single track and fireroad, I wouldn't run an im9 off-road, for that I'd use a Nexus 8C31.

In any case, I'm running a 38x20 on a 700c wheel:

94.6r
82.6
70.5
60.1
51.3
43.8
37.3
31.9
27.8

you could run a 38x22 and be inside the im9 spec:

86.0
75.1
64.1
54.7
46.6
39.8
33.9
29.0
25.3


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## theomdude (Jan 30, 2009)

I was thinking 32X23.

60.7
53.3
45.9
37.6
32.0
28.1
24.2
19.8


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## BrianMc (Jan 5, 2010)

J_Westy said:


> I put an XRD8(W) on my klunker with a 30T front chainring: (http://www.retrobike.co.uk/forum/viewtopic.php?t=81547&start=66) ....No problems so far, but not many miles either. Good luck.


Some miles now? Still happy with it? Running 25T rear cog?


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## theomdude (Jan 30, 2009)

Thanks. What's your lowest gear in gear inches?


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## itsdoable (Jan 6, 2004)

I don't have a Sturmey 8-speed, but I do have the Alfine, Nexus, i-9, NuVinci and Rohloff.

The Nexus, i-9 and NuVinci are available with coaster brakes.

The Nexus 8-speed premium (red-band) is the same hub as the Alfine (different packaging), but with a coaster brake option. The Alfine/Nexus twist shifters have a very light feel, so that may help. It's probably the best bet for off road use. Shimano does not specify a minimum drive ratio, but the lower you go, the more leverage you have on the coaster brake.

The i-9 has only been used off road, and works fine as long as you shift carefully. The main failure mode of IGHs, inluding the Alfine, is the shifting mechanism, which gets mangled under load. Alfine's (and Nexus) have a mechanism to minimize this, i-9 does not. Rohloff's prevent this my placing the index mechanism in the hub and preventing shifts from happening until the load on the hub is low enough. I'm also running the i-9 below the minimum specified drive ratio.

The NuVinci is pretty indestructible, but it should be considering it weighs more than twice the other hubs (!).


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