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  1. #1
    Rohloff
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    Alfine - How low can I go?

    I'm currently running a Rohloff with 34/16. That give me plenty of low end gearing for sitting and climbing the steep loose terrain I ride a lot and still leaves me too much top end that I rarely use.

    I just set up another bike with Alfine 32/22. That gives me similar gearing to my Rohloff's 3rd-12th gears. That's OK but when I try to crank out my bottom gear, I tend to slip and lose traction. I've tried sitting and standing. It just not good for the trails I ride. On hard pack, it's no problem, but I don't ride a lot of hard pack.

    It is my understanding that Shimano hasn't set any firm limits on gear ratios but that my 32/22 is pushing it. I calculated that a 26/22 would give me similar gearing to my Rohloff's 1st-10th gears. That sounds nice, but I'm wondering how the Alfine will hold up.

    Any thoughts or experience?

  2. #2
    Frt Range, CO
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    Quote Originally Posted by bsdc
    ...It is my understanding that Shimano hasn't set any firm limits on gear ratios but that my 32/22 is pushing it. I calculated that a 26/22 would give me similar gearing to my Rohloff's 1st-10th gears. That sounds nice, but I'm wondering how the Alfine will hold up.

    Any thoughts or experience?
    I'm running 32x23, weigh over 250lbs fully loaded and I don't feel like I'm "pushing it". Quite the opposite, I feel like there's more left in the Alfine, esp after running it for 12 months.

    26x22 hasn't been reported yet, why not be the first?

  3. #3
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    I just switched to 26:22 on my Alfine this weekend. Only two rides on it so far, but it seems ok.

    The gearing is sweet, 1st being approx. equivalent to a 22:34, and 8th being approx. 34:18. I found myself riding 5-7 most of the ride, 3 and 4 were great for most climbing, then I had teh big jumps up to 2nd and 1st gear for the steeps.

  4. #4
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    Spoke to soon......

    Just blew up my hub this weekend. Running a 26x22 combo on my Alfine seems to have done it in. I was doing alot of standing and cranking on the pedals and I think I stripped the clutch. Now it feels like the clutch will barely catch but then it just spins out, giving me no forward motion. Its also very hard to move the shifter now. It does still select gears, just doesn't hold them. Like the clutch is slipping...

    I'm going to pull it apart, but I don't think I'm mech. inclined enough to diagnose the problem. If I can fix the clutch, I'll go back to a 34x18. Not low enough gears for the mountains, but good enough for the desert.

    For the record, Shimano's website lists the cogs available with and Alfine hub as 18T, 20T. They also list chainrings for an Alfine group as 33-38T. Seems like these hubs were designed to be run with at least 33x20 gearing.

  5. #5
    dru
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    Bah, that sucks! Let us all know what you find wrong with it.

    Drew
    occasional cyclist

  6. #6
    Rohloff
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    Yig! That's my worry. We may be trying to push the Alfine a little too far. FWIW, I haven't changed my gearing yet.

    I put the Alfine on a HT with a Thudbuster. While the HT/Thudbuster is good for some of the smoother and flatter trails in my area, but it's not cutting it for me on some of rougher and steeper trails. I think I'll just keep the Alfine as it is on the HT for relatively tame trails and have the extra gearing and suspension of my FS/Rohloff for the rough stuff.

    I'm liking the Alfine. It's certainly smooth and I think the gearing is adequite for many applications but I like the rock solid shifting, quick multiple gear shifts and extra range of the Rohloff for the hilly, rough terrain I ride. That said, I think Rohloff better watch their back. If Shimano comes out with a little bit more solid mountain bike approved IGH with just a little more gear range, the current Speedhub might be surpassed.

  7. #7
    Frt Range, CO
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    Quote Originally Posted by Surly29
    ...Seems like these hubs were designed to be run with at least 33x20 gearing.
    I'll stick with my 32x23, many others are running this gear for months with no problems.

  8. #8
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    Finally got a chance to look at my hub and I just spun the cog. The c-clip that holds it was half out and the cog actually spun inside the grooves. I can't seem to locate the three alignment tabs anymore, so the cog is stuck in there for now.

    Good news is the hub seems to be spinning normally again. Hopefully with a new cog and clip, new dust caps and shifter linkage, it'll be good as new. I pretty much tore up everything outside the hub.

    Do you think this was caused by my horrible chainline?

  9. #9
    Frt Range, CO
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    Quote Originally Posted by Surly29
    ...Do you think this was caused by my horrible chainline?
    LOL, ya think? Sheesh, I was worried we had found the limit, looks like there's more experimenting to do. I bought 1mm washers for the BB so I could align mine within a mm. Just for an FYI, how much do you weigh?

  10. #10
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    I probably weight 190 lbs., 6'2", haven't weighed myself in years.

    Sorry if I hi-jacked this thread, but how do I get a 26T ring close to the 42mm chainline? I've got a karate monkey with raceface Evolve ext. BB and 104-bcd cranks. The middle ring seems to be too far out (around 47mm if I remember right) and the granny ring is way too far in. Can I move the cranks over 5mm out?

  11. #11
    dru
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    If you've got a 47mm chainline just flip your new sprocket over. That will give you 47mm on the back. Lots of people (me included) have done this. Get a sprocket without the plastic guard.

    Drew
    occasional cyclist

  12. #12
    Frt Range, CO
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    Dished cog gives 43mm and 47mm chainlines on an Alfine hub. Undished is 45mm.

    50mm chainline cranks is 50mm for outside chainring.

    Each ring is in ~5mm, so the middle chainring's chainline is 45mm and the inside chainring's is 40mm chainline.

    I'd leave the crankset at 50mm chainline, then use a dished cog and set the Alfine for 42mm chainline (dished cog inside). This would allow both chainlines (inner chainring and middle chainring) to be off by 2mm, shouldn't be a problem. Then you could get a bashguard to replace the outer chainring.

  13. #13
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    Thanks guys.

    My crank is 49mm chianline and I did flip my cog between the middle and inner chainrings, but I guess I'm still 3mm off. My BB has a spacer on the non-drive side, so I guess I'll find some 1mm spacers and try to get this a little better.

  14. #14
    Frt Range, CO
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    49mm on the outer chainring? If so, you should be good on the middle and inner.

  15. #15
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    Quote Originally Posted by pursuiter
    49mm on the outer chainring? If so, you should be good on the middle and inner.

    Race Face states the crank is between 48.5 and 49.5 mm, but I didn't know that referred to the outer chainring before you told me. I was thinking that was the middle ring, as this is supposed to be a "singlespeed" crank. Its really just the same triple crank with a bash guard. Not that there's anything wrong with that....

    Amazingly, I was able to put it back together with all the original parts. I put the axle in a vise and was able to remove teh cog with a chainwhip. Everything went back on nicely, even the plastic shifter, which is a little dirty and scratched but functioning like new. The clip to hold the cog is "stretched" to where I tap in one side and the other pushes out, but I found those for $1.60 each at beyond bikes/air bomb, so I'll pick up a few when I order some tires.

    Final thought: A freakin' clip to hold on the cog? Shimano never claimed this as more than "comfort bike" quality, but I'd sure like to see something threaded.

  16. #16
    President, CEO of Earth
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    I am quite certain the chainline is measured to the middle ring...

    http://www.sheldonbrown.com/gloss_ch.html#chainline
    (check the notes in the chart called "Chainline Measurement")
    "Newfoundland dogs are good to save children from drowning, but you must have a pond of water handy" - Josh Billings

  17. #17
    1*14*29*2.1 & 1*1*29*2.4
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    OK, from being directed from the other post, I just wanted to ask Surly29 or any other for an update on the small chainring issue (hence resurrecting this old thread). Any further problems, or does it look like the hub is holding up? thanks.

  18. #18
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    Yeah, sorry if I confused people with those posts. The problem was not with the clutch, I spun the cog within where it sits. When I took it apart, the cassette joint was holding things in place allowing me to shift the hub, but the cog was spinning in place.

    Internals were fine and I've been running 26x22 ever since.

    This weekend I loaded 15-lbs of camping equipment on the bike with no problems. I've also been pulling a trailer with it. Internals looked spotless on the only "oil-change" I've done.

  19. #19
    1*14*29*2.1 & 1*1*29*2.4
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    that is good news...after further chats to shimano the rep pretty much specifically said they have no problems with running a 28t ring...their concern was that there be a 16t max difference in a two ring set up. Alfine 11 looking promising!

  20. #20
    aka DummyDiva
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    Quote Originally Posted by Surly29
    Just blew up my hub this weekend. Running a 26x22 combo on my Alfine seems to have done it in. I was doing alot of standing and cranking on the pedals and I think I stripped the clutch. Now it feels like the clutch will barely catch but then it just spins out, giving me no forward motion. Its also very hard to move the shifter now. It does still select gears, just doesn't hold them. Like the clutch is slipping...

    I'm going to pull it apart, but I don't think I'm mech. inclined enough to diagnose the problem. If I can fix the clutch, I'll go back to a 34x18. Not low enough gears for the mountains, but good enough for the desert.

    For the record, Shimano's website lists the cogs available with and Alfine hub as 18T, 20T. They also list chainrings for an Alfine group as 33-38T. Seems like these hubs were designed to be run with at least 33x20 gearing.
    The recommended ratio is 1.9. Cogs 18-23T.

  21. #21
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    Quote Originally Posted by Surly29
    Yeah, sorry if I confused people with those posts. The problem was not with the clutch, I spun the cog within where it sits. When I took it apart, the cassette joint was holding things in place allowing me to shift the hub, but the cog was spinning in place.

    Internals were fine and I've been running 26x22 ever since.

    This weekend I loaded 15-lbs of camping equipment on the bike with no problems. I've also been pulling a trailer with it. Internals looked spotless on the only "oil-change" I've done.
    I was wondering about this when I setting mine up. The cogs only have 3 rounded nubs for engagement, and the snap ring to hold it in place. It sure seems like this is the week link in the system and would blow out before the internals ever do.

  22. #22
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    Quote Originally Posted by cowboygrrl
    The recommended ratio is 1.9. Cogs 18-23T.
    Back in 2009 when this thread started, there was no recommended minimum ratio for Shimano Alfine or Nexus hubs, and I'm still not aware of any today (but I may have missed something). The 1.9 ratio is the recommended minimum for the i-9 hub.



    Quote Originally Posted by TBMD9er
    I was wondering about this when I setting mine up. The cogs only have 3 rounded nubs for engagement, and the snap ring to hold it in place. It sure seems like this is the week link in the system and would blow out before the internals ever do.
    The 3-spline interface c-snap ring interface has been around for almost a century on geared hubs and track cogs. It was designed when all the parts were steel, and has worked fine. If the snap ring is properly seated and you try to pry off the cog with crowbar, you will most likely bend the cog. An earlier red-band Nexus hub of mine failed at the interface because the hub side cracked in-line with the cog (it was a porous casting), allowing the cog to spin. Subsequent hubs (in the Alfine/Nexus red-band range) have used a machined steel part.

    Shimano, SRAM and Sturmy IGHs typically fail in the clutches due to shifting under power. (Almost all hubs fail by the ratchet) So far the Shimano Alfine lines seem to be the most robust in that department.

  23. #23
    Frt Range, CO
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    Quote Originally Posted by cowboygrrl
    The recommended ratio is 1.9. Cogs 18-23T.
    She could not have read this thread except for the first post....

  24. #24
    aka DummyDiva
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    Quote Originally Posted by pursuiter
    She could not have read this thread except for the first post....
    Sorry to disappoint you regarding your ASSumption. This info is on the Alfine 11 instruction sheet. I can give you the link if you'd like. That's no to say other ratios won't be successful.

  25. #25
    Master of None
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    http://techdocs.shimano.com/media/te...9830728103.pdf

    It is recommended that the gear ratio of the front chain ring be set to approx. 1.9.
    I am running 1.45:1 and I'm loving it so far.

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