[l008com]

Don't you just hate derailer hangers?

So Shimano just came out with a new internally geared hub. It's an 11 speed hub (Alfine-11). Even though it has the same name as their previous hub, it has a totally different design. Very similar to the Rholoff 14 speed hub.

So this Shimano hub *might* change the face of mountain biking. It's specs are very... interesting.

409% shifting range (most riders use 1x9 or 2x9 these days anyway)
32 or 36 spoke hubs... great for those bigger stronger wheels
Trigger style shifters - with a Rholoff, you're stuck with 90's style gripshifts
Disk brakes
Low Normal shifting - other shimano internal hubs use reverse shifting
Oil bath - super easy maintenance.
Priced about 1/3 the cost of a Rholoff hub.

I said that most rider use 1x9 or 2x9, but I'm actually one of the few that still uses 3x9 off road. But I did all the math, and going from a 3x9 to this hub, works out to loosing your two lowest gears, and your top gear. I use all three of those gears, but that's really all I have to give up. And in exchange for it, no more broken derailer hangers, no more shitty shifting, no more extreme chain bounce when you're going down fast hills, the benefits of a good internally geared hub go on and on.

http://www.fellsbiker.com/docs/alfine_11_ratios.pdf
Here's the spreadsheet i whipped up, showing a 3x9 XT setup, and a range of Alfine-11 ratios with different sized chainrings and cogs. I highlighted 32/20 because I think that is the best ratio for mountain biking. I think any biker could get by with those gears. I use my 4.0 gear a lot, and I do super steep climbs in my lowest gear too. But I'll gladly give those up.

The greyd out blocks in the 27 speed chart represent approximately the only gears you have to give up.

So to install this hub, all you need is a small chain tensioner (the kind you use to turn your bike into a single speed, because that's what you're doing) and just enough chain that the chain doesn't hold back your wheel travel. This hub even comes in black. Drivetrain problems can be a thing of the past.

So aside from adapting to fewer total gears, the second biggest question about this hub is probably weight. I expect to gain no weight by making this switch. The hub is a lot bigger than a normal hub. But I'm losing one whole shifter, one whole shifter cable, a front derailer, front derailer mount, a granny gear, a big ring, and I can trade in my bash guard for a much smaller one, since it only has to protect a 32t ring instead of a 44t. Oh and I get extra BB clearance with this setup too!

So there are only two things that might hold this hub back from dominating the mountain bike worlds...

1) Durability - not only do the gears have to hold up, but the bearings have to hold up too. I've been known to get a foot or two or ten of air, and I need to be able to land these drops without destroying the hubs. And besides that, the hub has to handle the torque from pedaling up step step hills in the lowest gear.

2) Range - Gear range I mean. The numbers in my spreadsheet all add up fine. However one shimano document "implied" that the lowest input this hub can take is 1.9:1. That would be about a 38/20 combo, which would make the lowest gear ratio about a 1:1. That is way too high a gear for technical riding. That .843 gear that you'd lose is key. When you compare to the 27 speed, using a 38/20 would be like losing your 4 lowest gears. That would mean no more tough climbing period.

So if 1.9:1 is the lowest gear ratio this hub can handle, it's pretty much off the table for serious riders. But if you can run it with a 1.6:1 ratio, and the gears and bearings are durable enough to handle some serious mountain biking... then this hub is going to be a revolution in mountain biking.

[l008com]

Yeah my first post is not very coherent, just do your best to keep up

I'm not just looking forward to this hub on the local rocky technical trails... I'm also looking forward to it for downhilling. When you're flying down mountains, your chain is ALL over the place. I have to shift into my big ring and big cog (44t/34t) just to tension the chain enough to keep it under control. Problem with doing that is that its such a low gear, you can't pedal. You get nothing but air. But if you downshift, all that slack you get in the chain just throws the chain all over the place. It bounces out of gears front and rear, its just a mess. So I can't wait to shell out the dough for this hub!

Oh and that was one other point I forgot to touch on. A Rholoff costs about $2000 and lasts forever. So for me, it would take 5 years to break even, figuring a new cassette, 3 new chainrings, and a new rear derailer every year, plus a front derailer, and new cables and shifters every other year or so. The Alfine hub should only cost $700-$800. Now you're looking at only 3 years use before it pays for itself. If my math seems a little fuzzy, that's because I can't remember the details... I didn't make a spreadsheet for that . . .
The point is if you ride hard and go through parts regularly, both of these hubs will pay for themselves in a few years. But the Alfine only has to last 3 years or so to pay for itself. And the initial-cost-hump is so much lower. For $800, you could sell ANY biker on this hub, just mention it on the next day their derailer gets torn off, or the next day they simply cannot get their rear derailer to stop skipping, no matter what they try.

This hub's potential is very exciting! I'm thrilled with the idea that I MAY have already purchased my LAST derailer ever!

[d4nth3m4n]

Had trouble with that wall of text there.

Internal hubs can be shifted while coasting right? If so, that's already awesome. How much adjustment is there with the size of the cog on the hub?

And you're talking about running this with a normal chainring up front, right? no front deraileur? because if you had the front deraileur you'd still have to run a chain tensioner much like a rear deraileur which gets all hung up on trailside detritus.

either way, this could prove to be pretty sweet if it can actually stand up to the rigors of mountain biking.

Edit: now that I'm looking at your bike, you'd still need some sort of chain tensioner as the pivot for the suspension is between the rear axle and the bottom bracket.

quick release and horizontal dropouts is a pain in the ass, but there are always tradeoffs.

[l008com]

The smallest cog on this hub is 18t. Theres no real upper limit, except that if it's huge, you'll have to run a mega huge chainring to keep the input great ratio sane. And that cancels out one of the big benefits of this hub, which is (for example with my ideal gears) a 32/20, you get tons more ground clearance.

Yes they can shift while coasting, and the shift is very fast. Think riding up a 4 foot boulders, to a 6 foot flat area, then another 5 foot boulder. Now you can shift at the flat spot between climbing. You don't have to get a full wheel revolution in to get the chain to shift fully first.

You will still have to run a chain tensioner with this "single speed" setup. Unless you are using it on a hardtail with horizontal dropouts (unlikely). Other wise on a normal hardtail or full suspension frame, you will need a few extra links and a tensioner. But just a tiny bit, nothing like a full derailer. For example, here's the same setup on my park bike, which is a frame made for a rear derailer, but converted to singlespeed:



Thats an extremely tight chain. Plus it's a single speed chain so it's more durable and thicker, and has no side to side flex. And single speed gears have taller teeth because the chain doesn't have to jump over them. All that adds up to a rock solid chainline. (my chainring in this picture is actually not singlespeed, it's a normal XT middle ring).