Which IGH?

[mattsccm]

I fancy re building my commuter bike with a hub gear. The commute is 21 miles round trip, 15 on gravel , some of it muddy. I don't half get through chains, cassettes and jockey wheels. Maybe a IGH would be better. Whats worth having. Pleae don't use the R word as my budget isn't that big. Ideally disc brake but could do rim as the frame can cope with both.

[PH]

Alfine 8. You can get one complete in a wheel, shifter & fitting kit for £200 inc postage from Germany. I have one in my work bike, 200+ miles a week, cheap enough to abuse, but with a little care it's hard to see why you wouldn't get the value out of it.
I also have two of the R's, yes the spacing and range of gears is better and the legendary longevity, but as long as the gear range suits the riding, the Alfine is just as nice to ride.

[Brucey]

A SA 3s hub is pretty reliable and pretty easy to keep in good condition/repair if necessary. A 5s SA hub has more gears but it both more likely to give trouble as well as be more difficult to repair. SA 8s hub only gears up so best suits small wheelers. SA 2s hub gears up for second gear but there are no cables to worry about; it used a kickback shift. If three gears is enough I've vote for a 3s hub.

Nexus 7 is a basically reliable hub but it isn't super efficient. Nexus 5 is based on Nexus 7 but there is simply less of it. Nexus 8 is a lot like a less well sealed Alfine 8; both have a direct drive gear 5 but both use (slightly squashy) roller clutches which means that they are inefficient by an unknown amount. Nexus 3 is a reasonable hub but only comes with a steel shell and the three gears are slightly further apart than a SA 3s hub.

In SRAM hubs they are out of production now so spare parts are a problem.

SA hubs come with options for coaster brakes or (even better) drum brakes.

I'm not mentioning the 'R' word but I will mention the 'P' word; if you can pick up one of those (complete bike) used it might be just the job for you.

FWIW I used to have a similar muddy commute and I used to get about 2000 miles out of a 8s chain/cassette; it got muddy every day but I did also clean it every single day.

If you are converting an extant bike to IGH you need to worry about OLN, chainline , and dropout issues. If you end up having to run a tensioner then it could be almost as prone to trouble as a derailleur.

cheers

[mikeymo]

SA hubs come with options for coaster brakes or (even better) drum brakes.

Shimano Nexus 8 (and maybe others) also will take Shimano roller brakes. Which I found a lot better than some people said they would be. Certainly at least as good as the cantis on another bike.

Remember that if you're going to have roller/drum brakes on the front fork, there <may> be issues with fork strength:

http://smutpedaller.blogspot.com/2014/01/braking-bad.html

[mikeymo]

If you are converting an extant bike to IGH you need to worry about OLN, chainline , and dropout issues. If you end up having to run a tensioner then it could be almost as prone to trouble as a derailleur.

+1

I already had 3 IGH bikes. But I wanted something with a steel frame and drop bars to convert to IGH. It's surprisingly rare to find a frame that works. You'll probably need a 135 OLN, you'll need horizontal dropouts unless you're going to run a tensioner (which for me defeats the point, a bit). I looked a lot for a suitable frame/bike, and that combo was a lot less common than I thought it would be. For instance the Dawes Galaxies seemed to change from horizontal to vertical drop-outs at the same time as they went to 135 OLN. I think there might be a suitable Claude Butler. In the end I snagged a Ridgeback World Journey:

https://www.thebikelist.co.uk/2012/ridgeback/journey

But only after a lot of looking (and it's actually a bit too long for me).

There's this going on ebay ATM:

https://www.ebay.co.uk/itm/Ridgeback-World-Journey-Touring-Road-Bike-56cm-Green-c-w-Stand-Lock-Mudguards/133339705933?hash=item1f0baa724d:g:CZsAAOSwBrReTrah

It's the same frame as mine, but somebody's already converted it to flat bars. That price is a steal, actually, I would say. If that frame is a good size for you I'd buy that.

[robc02]

It's surprisingly rare to find a frame that works. You'll probably need a 135 OLN, you'll need horizontal dropouts unless you're going to run a tensioner (which for me defeats the point, a bit).

I dealt with this by buying an old (probably '80s) frame with horizontal dropouts. They were spaced at 126mm or thereabouts so I cold set the rear triangle to go with my old Sturmey Archer hubs. I currently use an AW (plain old wide ratio three speed) hub for my undulating rural commute and it is fine.

The modern equivalent is the SRF3. As well as the hub brake versions (X-RD3) there is a disk version that comes with a long axle, thereby eliminating the need to cold set the rear triangle on most frames meant for derailleur gearing.

http://practicalcycles.com/products/245773--sturmey-archer-srk-3-hub-gear-disk-brake.aspx

[PH]

If you end up having to run a tensioner then it could be almost as prone to trouble as a derailleur.
cheers

I'm torn between sticking my fingers in my ears and wanting to know what trouble!
I run two of my IGH with tensioners, a Rohloff with a Rohloff and an Alfine with an Alfine, they seem such simple devices with such a basic function I'm not sure what the issues could be. Yes, it's something dangling down to get knocked, and it's just as likely to be a muck magnet, and the jockey wheels need to be kept turning freely, but none of those things have been trouble so far, is there something I'm missing?

[mikeymo]

If you end up having to run a tensioner then it could be almost as prone to trouble as a derailleur.
cheers

I'm torn between sticking my fingers in my ears and wanting to know what trouble!
I run two of my IGH with tensioners, a Rohloff with a Rohloff and an Alfine with an Alfine, they seem such simple devices with such a basic function I'm not sure what the issues could be. Yes, it's something dangling down to get knocked, and it's just as likely to be a muck magnet, and the jockey wheels need to be kept turning freely, but none of those things have been trouble so far, is there something I'm missing?

Yes, I'd like to know what the potential trouble is. My objection to tensioners is more aesthetic than anything. Which I know is a bit silly, considering the bike I'm riding now is a 3x9 derailleur, which is completely devoid of engineering elegance!

[Brucey]

you could say much the same things about a derailleur as a tensioner, it is just a question of extent I suppose. In offroad use there is a similar propensity for gathering muck, wearing out etc. For whatever reason it seems much more common that springs break in tensioners than in derailleurs; cheap tensioners seem especially prone to this but even Rohloff ones are not immune.

Spring loaded tensioners are easy to live with until they start to give trouble. However if you try and run a spring loaded tensioner with a new chain and an older sprocket then you can get skipping problems just like with a derailleur.

If you get a twig in a tensioner then it can be pretty bad, much the same as with a derailleur.

If you run a fixed tensioner then it will need to be adjusted. However if you run the chain to the bitter end, you can't take all the slack out of it, not without rough running. However if you leave too much slack the chain can unship in various (bad for the tensioner etc) ways.

Oddly enough one of my mad ideas is to convert a modern twin-sprung RD into a single-pulley RD/tensioner for use with an IGH. You can fit several sprockets to some IGHs and half (or even one-third) -step the IGH gears with 2T, 3T or 4T (total) intervals. In which case you only need a small capacity to the RD, and it will tolerate crud better because it only has the simplest movement to do. It is also possible to configure this setup using 1/8" chain rather than 3/32" chain in some cases. But for offroad use it might turn out to be a 'worst of both worlds' type setup.

I have worked out some 'near perfect' setups (with uniform gear spacing and a gear range that is sufficient for many commutes) using realistic sprocket sizes and based round a SA AW gear etc and some examples are given here

http://ritzelrechner.de/?GR=SAAW&KB=48&RZ=19,22&UF=2170&TF=90&SL=2.6&UN=MPH&DV=gearInches&GR2=SAAW&KB2=48&RZ2=21,19,23&UF2=2170

These setups are based round using 48/19 as a favoured 'tapping along' gear using the direct drive ratio in the hub. It happens (not by accident, it has all been carefully worked out) that (1 + 3/20.5)^2 ~ = 4/3 and (1 + 2/21)^3 ~= 4/3 too, hence the uniform spacing of the gear ratios in both cases. Obviously you can use a smaller chainring to get more lower gears than higher ones, but it would mean running in gear 3 of the IGH most of the time.

BTW I think 19-21-23 is used as a 'cluster' (i.e. three sprockets on a carrier) in some cassettes. This might open a fairly easy route to adapting IGHs which will only accept one sprocket normally so that they can use multiple sprockets. It would mean using narrow chain though. You would have to be pretty fussy to want your gears closer than 10% intervals...?

cheers

[Des49]

I have run a Rohloff on my vertical dropout old MTB for a very long time (certainly over 20 years plus).

It is a nusiance to have to use the tensioner, it makes wheel removal more difficult and the bike would look cleaner without it.

But my main objection is that the jockey wheels do wear out pretty easily. Especially with any off road use they wear out in weeks potentially. I raced the bike in some MTB events with the Rohloff, the jockey wheels could just wear out in a couple of mucky events, the seals aren't great and they would develop a lot of play. Several times I would find the pulleys seized up.

Nowadays I do not use the bike off road much and the tensioner wheels last much better, but still not as good as they should be, and like anything Rohloff they aren't cheap to replace.

[Cyril Haearn]

Best to use a hub with a back-pedal brake, no need for a tensioner, much less trouble with brakes

[Tiberius]

My 'winter bike' is a Genesis Flyer single speeder with a SA 3 in the rear and a Shimano dynohub up front.

Steel frame, drop bars, sliding drop outs (120 OLN). The SA 3 works very well with a bar end shifter and drags this 62 year old, around hilly North Yorkshire, through over 2,000 winter miles every year.

I wanted the bike to be as reliable as possible (many of the original bike's components were rubbish) and the bike has become a bit of a 'Trigger's brush'. The BB, saddle, pedals, headset, chainring plus the entire braking set up have been changed and obviously the wheels - leaving just the frame, seatpost, stem, 'bars and full mudguards from the original bike. The parts were changed bit by bit over the years so owe me nothing now. The original paint was very good, there is hardly a mark on the bike despite the hard use and it's still a good looking bike with (vital to me) full mudguards and dynamo lights.

I keep my eye on the chain through winter and then it gets a full strip/lube/brake shoes whatever one afternoon in summer and that's it.

I have an expensive derailleur bike and a 'R' bike which are both very good but I enjoy the utter simplicity of the Genesis. It's a cheapish simple thing but I would think nothing of riding off anywhere on it.

[Brucey]

Best to use a hub with a back-pedal brake, no need for a tensioner....

well you can't run one unless it is a special one; the brake won't work. This is the thing that stops you from running a coaster brake in many frames (even if you are mad enough to want to). You only need a tensioner if you have multiple chainrings or sprockets, and/or have a frame with vertical dropouts; 'No need for a tensioner' is not dependant on the hub. [edit; except if it is a coaster; then you can't have a standard tensioner]

…..much less trouble with brakes

up to a point yes, but when there is trouble, it is often terminal. I've very rarely seen a coaster brake I actually liked the look of; the best I'd say about them is that they can be 'adequate' in some (mostly not very demanding, not high mileage) uses. There is always an additional parasitic drag in such hubs; if there isn't, the brake won't come on. In geared hubs with coaster brakes there are always additional parts which actuate the brake, and these can usually wear or break in exciting ways that you never thought of.

A fairly fundamental problem is that there is nearly always a ring bearing in a coaster brake mechanism, using a clip with not many balls in it. This bearing is subject to wear and a very large load whenever the brake is used. It is a wheel bearing so it turns (under whatever load is on the wheel) whenever the wheel turns, is not really sealed in any meaningful way (it probably can't be, because it has to be cheaply made and it gets hot in service) and is lubricated by a small amount of grease which quickly becomes loaded up with hard metal wear debris from the brake. I have seen many such bearings in many such hubs fail catastrophically, and when the bearing fails , it often takes out the whole hub (including the hubshell itself) and therefore the whole wheel.

Given that IGHs are all sensitive to their state of lubrication, deliberately including a mechanism which only works at all by virtue of strewing hard metal fragments throughout the hub is surely some special form of madness.

The only glimmer of light in this darkness is that in shimano coaster brakes there is a usually a small hole in the ring bearing/brake cover. This hole allows clean grease to be added to the bearing (if not the brake per se) and you can sometimes see through it if the ring bearing is starting to break up or not.

cheers

[Cyril Haearn]

I have done thousands of kilometres on back-pedal braked bikes, must have been 12 000 km on one alone, never thought about them, no problems at all
I think I am a gentle rider, easy on equipment

[gregoryoftours]

I'd agree with Alfine 8, quite a lot better than the Nexus, nicer gear shift (especially with trigger shifter), more forgiving of bad shifting technique. I think 8 is the most reliable, I've heard several bad reports on the 11 speed Alfine.