Apologies if this has been done to death, or is a silly question, but I’m new here

I’ve been reading this article:
http://www.justridingalong.com/news/2011/01/alfine-11-speed-review

So I gather that using an Alfine Hub with a double chainring is possible, but is it common ? Doesn’t it negate at least some of the advantages of the hub. What set-ups do people recommend ?

The reason I’m considering an internal hub is for a hardtail on which I do fairly technical but long distance rides – e.g. Pennine BW, Kielder 100. And chain suck is the bain of my life at times. I had thought that using a hub would resolve this, but now I’m not so sure.

Why do you want multiple chainrings? It’s a lot of faff for little gain, especially if you’re using an 11-speed hub, the overlap between the two chainrings means you’d be better off using it as designed (IMHO)

Edit: The moment you introduce a deraileur/chain tensioner you’re leaving yourself open to chainsuck – even if you get the chainline right, the swing required between chainrings means the line will always be a compromise.

I think the range of gears you get from an alfine hub is plenty good enough for most applications.

Buy once, buy right – if you want a real off road hub get the Rohloff. Katie’s Alfine 11 is quickly losing all it’s oil again and shifting sounding distinctly ropey.

Buy once, buy right – if you want a real off road hub get the Rohloff. Katie’s Alfine 11 is quickly losing all it’s oil again and shifting sounding distinctly ropey

For balance, my 11-spd is going in for it’s second/6000km oil change at the end of the month and has been rock solid.

Agree with B-O-A-S…… just don;t drop the drive ratio too low (2:1 is it?) and over torque it.

Or man up and get an 8 speed. Far more reliable than the 11 speed

Running a double up front won’t really reduce your chance of chain suck, you’ll still have chain flapping around

The moment you introduce a deraileur/chain tensioner you’re leaving yourself open to chainsuck

That’s what I thought, but given that the bike in question has vertical dropouts (it’s a Trek x-cal), I think I’m going to need a chain tensioner anyway. It’s not a component I’m familiar with, so I wasn’t sure how differant they are to derailleurs

just don;t drop the drive ratio too low (2:1 is it?) and over torque it.

Would that rule out a 26T chaingring with a 20T rear sprocket ?

Have to say I like the really low gears for technical climbs

I bought one of the Alfine tensioners that allow 2 chainrings to be used but I never got round to trying it. I was going to give it a go on my commuter/tourer.

Even if you have vertical dropout & need a tensioner you’re unlikely to get chain suck. The difference between a tensioner with just enough chain & enough chain for two chainrings will be fairly big

Aactually I guess it depends on the difference between the two chainrings.

You’re more likely to get chainsuck with two up front but you might get away with it.

Would that rule out a 26T chaingring with a 20T rear sprocket ?

I believe so, yes – in the sense that the 2:1 drive ratio is the Shimano recommended minimum.

christhetall – Member

just don;t drop the drive ratio too low (2:1 is it?) and over torque it.

Would that rule out a 26T chaingring with a 20T rear sprocket ?

I ran mine (8sp) for snow riding with 22 front 18 rear and it survived – but I was spinning away not mashing the pedals so fairly low torque – do this and you end up with the equivalent of just a granny ring on a triple – I was spinning out at 12 ish mph 🙂

No p[oint in using multiple cainrings – you will find it hard to get a tensioer that can cope with enough difference in length I think and negates some of the advantages of an alfine

I did it on a Long Haul Trucker with a 44 and 32t ie on and off road gearing, worked fine with a Sora road derailleur out back.

I ran an alfine 8 with 26/36 chain rings up front on a prince albert frame, never had chain suck or any hub issues in around 2500 miles before I sold the whole lot.

simons_nicolai-uk – Member
Buy once, buy right – if you want a real off road hub get the Rohloff. Katie’s Alfine 11 is quickly losing all it’s oil again and shifting sounding distinctly ropey.

Rohloffs leak oil like a 50 year old British motorbike. Or a brand new Harley.

Thanks for all the replies – very informative

There seems to be various mentions that the minimum ratio is 1:1.9, which given that it comes with a 20T sprocket means a 38T chainring.

That would mean mean (by my calculations) I’d lose my bottom 4 granny gears from my current setup, and the bottom gear on middle ring.

Call me a wimp, but that wouldn’t suit me on anything vaguely interesting.

Can someone explain (in vague terms – I’m not an engineer) why a 20/26 setup would cause problems ? Any tales of woe from running a low ratio ?

I didn’t think there was a minimum ratio of 1:1.9, so I’ve been running mine with a 32t ring and 20t sprocket. Fine so far, but I’d be interested in any link to this minimum ratio if possible please.
Started with 36-20 but, like the OP, wanted some lower gearing so changed the ring to 32. It’s a lot more user-friendly for me now, didn’t really use the very top gear except on the road.

32:22 here for the last year. will i die?

No minimum stated for the 8 sp so far as I am aware – one is tor the 11 sp

My IOID came as standard with 32 / 18

I’m running 32:18 as well.

I have been told that is the minimum ratio but I forget who it was and where the info came from

TobyMC

How does the 32:22 feel generally? I am about to fit a new 23t rear for Mayhem (making it a 32 : 23)

Again looking for advice – will I kill the hub?

The minimum gearing figure is in the Shimano tech doc

For the 8 spd Druidh? I was unable to find one at all despite searching a lot

I can see in the 11sp tech doc that you should aim for 1.9.
It doesn’t state what the consequences could be though… mis-shifting, death ???

I’m hoping to make it more bearable for muddy mayhem misery – I dont want to introduce a different technical problem. Any experiences?

You could break the hub if you really mash the pedals – its the torque thru the hub that is the limiting factor. If you are a spinner then going lower should be no issue as there will be a safety margin – to allow for a 18 stone man stamping on the pedals to climb hills

The topic of minimum gearing for the Alfine seems to come up quite a lot, however no one has ever found any shimano docs that state ‘minimum ratio’ that i have come across. The 1.9 appears to be only what they suggest, this figure may only be given for the sole reason that it gives you a good range of gearing from going down hill to going up.

If you search on line there appear to be quite a few people who have used lower gear ratios with out problem.

You could always e-mail shimano and ask, yet to read of anyone trying that yet!

considering a 18 tooth gives you roughly the same spread as a standard 9 speed set up, isnt running a 23 going to be super low?

I’d be off and walking long before that.

11-speed techdoc http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Alfine/SI_37R0A/SI-37R0A-002-ENG_v1_m56577569830728103.pdf

It is recommended that the gear ratio of the front chain ring be set to approx. 1.9
Example: F34T – R18T, F39T – R20T, F45T – R23T

As has been pointed out above, it doesn’t say what the consequences of running a lower ratio is. However, there must surely be a reason and it’s odds on that running a lower ratio would harm your chances of any warranty repairs.

The only similar recommendation for the 8 speed is that the rear sprocket should be between 16T and 23T.

grtd – i do like a nice low gear, but i’m a spinner… been running like (8 spd) that since last summer with no discernable ill effects.
It’ll probably explode in flames and shrapnel now.

reading from the review of the corratec ’29erone’ from cycling plus (aug/ 09), by using an alfine8 combined with a 34/50 chainset the bike has an effective gear range (inches) of 35 to 71 on the smaller chainring and 52 to 104 on the larger one.

the bike as tested was using a 20t rear sprocket and the tyres were 622×54.

so, yes the double and alfine works but how this translates to your particular bike, esp if you are on a 26er, i cant guess.

maybe 35inches (gear ratio) is as low as you can go?

hope this helps in some way!?

Yeah I would not normally go this low (32:23) but for this weekend only, if the conditions are miserable at Eastnor I wanted to be able to just keep going (solo). I will be sitting and spinning rather than powering anywhere.

I’ll fit it now and test ride tomorrow night. If it’s too spinney ( or sounds like it’s going to self destruct) I’ll go back to 32:20

Is there any reference to wheel size in relation to ratios recommended? 1:1.9 ratio on a 20″ wheel would be significantly lower gear ratio than with a 26″ wheel.

It would be the same ratio.

I think you mean different development?

Indeed I do.

Don’t for Christ’s sake buy an 11, mine went back to madison more times than I care to remember, they never fixed it and eventually gave me a complete new hub and shifter/cables et al, which I quickly sold. I run an 8 speed Alfine while saving up for a Rohloff, buy right 1st time( unlike me)After all, all you will lose is a little extra money.