Thursday, 17 November 2016

Are internal gear hub bikes the secret to low maintenance commuting?

Summary: In Australia, derailleur bikes with 20-27 external gears are so ubiquitous that most people don't even know there is a type of bike with internal gears hidden in the rear wheel and only 2-11 gears. Yet, in countries like the Netherlands, where everyone bikes for transport, internal gears are standard and it's mostly sports cyclists who use derailleurs.

One could conclude that derailleurs still dominate in Australia because cycling is still mostly a sport or recreation. Utility bikes are breaking through but, presently, the ones with internal gears tend to be heavy, slow Dutch bikes or too expensive to take the leap of faith.

But if hills, winds or a disinterest in unnecessary exertion put you off a single speed for getting around, I've long considered internal gear hub (IGH) bikes with 3 to 8 speeds to be - at least in theory - the next best alternative. Especially, if you want to minimise bike maintenance and service costs, leave your bike exposed to the elements all year round, and don't use most of the gear combinations on a 20+ speed bike.

A recent clearance price ($399) on a commuter bike with a 5 speed Sturmey-Archer IGH has led me to finally having the opportunity to use a common IGH bike and in this post I will provide guidance on suitability, finding the best option, saving money, and will also update the long-term results (maintenance required, mileage I get out of the IGH). Because of the wider steps between IGH gears, my Sturmey Archer 5 speed (wide range model) is delivering ~80% of the effective range of my 20 speed road bike.

XDS Adult Street with 5 speed Sturmey-Archer internal gear hub

Details:

1. What is the difference and pros vs cons between a bike with derailleur gears and an internal gear hub (IGH)?

For a brilliant explanation on the key differences see: BootieBike - Derailleurs, internal gear hubs and the transport cyclist
For all the proliferation of styles and designs currently available, in concept the typical new bike is closer to the 70s 10 speed ‘racing’ bike than the practical ‘transport’ bikes of yore. Not that there’s anything wrong with that – as long as that bike isn't intended for everyday, all-weather transport. This is a shame, as more and more folk are trying cycling for that very purpose; they walk into a bike shop looking for a transport bike but are instead foisted a machine designed for recreational use, whether that be road racing, tooling around the park or exploring bush trails.
BootieBike - Derailleurs, internal gear hubs and the transport cyclist
Read the whole post as it also has enlightening sections on:
- Derailleurs couldn't be too bad – could they?
- How can one possibly live with fewer than 27 gears?
- Efficiency: Internal gear hubs vs derailleurs

BootieBike also has some other relevant articles worth reading:
> So you want to ride to work...

For a great list of advantages versus disadvantages see: Hubstripping - Gear Hubs vs Derailleur

These include:

Advantages:
- Less maintenance efforts and costs than derailleurs
- Chain and sprockets last longer
- Less fragile to crashes or when bicycle falls to one side
- Easy to use with one shifter
- There are no ratio overlaps and ineffective “cross” combinations
- Less and simpler parts: Single chainwheel, single cog, shorter chain
- Shifting without pedaling

Disadvantages:
- A lower overall gear ratio
- Rear wheel removal usually more difficult (e.g. fixing punctures)
- Often more expensive than derailleurs
- Cheaper models require easing off pedalling to change gears (including the Sturmey Archer 5 speed I have)
- As low drive ratios get further below 1, there is proportionately more torque on the rear frame. The rear wheel nuts need to be very tight and checked regularly and you need to be careful not to put too much force through in low drive ratios (more chance of frame cracking). Use a larger rear sprocket instead of very low drive ratios.

A key tradeoff of IGH bikes is that there are less gears but they cover a wider range due to much greater steps between adjacent gears. While professional sports cyclists would see the loss of granular gear choice as a disadvantage, having fewer gears with greater steps is a definite advantage for most transport cyclists.

See also:
> Pure Cycles - Gears and Shifting 101: 3-Speed vs. 8-Speed
> StackExchange - Bicycles - What are the pros and cons of internal gears?


2. Which internal gear hub type is the best tradeoff of quality, price and practicality?

It's most helpful to narrow this down by elimination first.

- The most renowned IGH for design and quality is the Rohloff Speedhub (14 speeds, lasts 20,000km+ under suitable operating conditions) but it costs at least $1,600 alone and is thus overkill for almost everyone.

- Indeed because the aim of this blog is to provide advice on transport cycling - which includes being able to park your bike at any destination without fear of theft - I generally exclude consideration of all IGH costing more than $300. This essentially excludes all IGH over 8 speeds. This price threshold would also exclude the NuVinci Hub (a continuous shifting IGH with a 330% range) but if you are going to spend $1,000 on a bike then the NuVinci hub is worth test riding to see if it's worth it - just be sure to always secure your rear wheel with a U lock or chain lock with a Sold Secure Gold rating.

- I consider automatic shifting and 2 speed IGH to be a waste of money and just lead to annoyance. It delivers little value but plenty of frustration, and you'd be better off just putting a larger rear sprocket on a single speed or getting at least a 3 speed. See: RideOn - Comparative test: Sturmey Archer S2 Duomatic versus SRAM Automatix

- That leaves us with IGH of 3 to 8 speeds from the most common manufacturers: Shimano, Sturmey Archer, SRAM.

- A 3 speed IGH can be ideal for short or mostly flat commutes. And 3 speeds can cover even more challenging trips if you change the rear sprocket freewheel to make it slightly larger and shift the whole 3 speed range to a little easier (better for hills). The gear range is around 175%.

- If you're using an IGH over a single speed because you want a wider gear ratio, then 175% may not be enough. The next common step up is to 5 speeds and around 250% gear range. After that it is 7 or 8 speeds and around 300% gear range.

- Take into account how often you may need to take off the rear wheel (to fix punctures, change tyres or other reasons). At this cheaper end, Sturmey Archer hubs tend to be easy enough to get off. But many of the Shimano and SRAM hubs take more expertise.

- Ultimately, once you know approximately what will suit (e.g. 5 speed up to a 7/8 speed) your value-for-money decision may be guided by a sale price on an IGH bike. In my case, I wanted a 3-5 speed but would have considered a 7 or 8 speed if there was a massively-discounted sale price. It turned out the $399 clearance sale of the XDS Adult Street 2016 came with a Sturmey Archer 5 speed (wide range), and I was happy with that. If I could buy a NuVinci hub bike for less than $700, I would probably consider that too.


3. What gear range do I need and how do you work it out and compare?

Standard 20-27 speed derailleur bikes have a gear range of around 400% - 500% depending on whether there are two or three chainrings at the front. This percentage is the ratio difference between the highest (hardest) gear combination and the lowest (easiest) gear combination.

For an IGH you simply need to specify the size of your chainring and rear sprocket and the type of IGH to find out the gear range. Both can be calculated using: Sheldon Brown's Derailer and Internal-Gear Calculator

If you are coming to an IGH bike from a derailleur bike with 20+ speeds then doing this comparison may be worthwhile. For example, I can compare my Otway 2.0 road bike with 20 speeds to my XDS Adult Street with 5 speeds.

The Otway 2.0 has two chainrings of 50 teeth and 34 teeth. And 8 rear sprockets between 11 and 30 teeth. The XDS Street has a 46 tooth chainring and a 16 tooth rear sprocket with an SRF5(W) 5 speed hub.

Sheldon Brown's Derailer and Internal-Gear Calculator - Otway 2.0


Gear inches for Cell Otway 2.0 road bike with 20 speeds

Sheldon Brown's Derailer and Internal-Gear Calculator - XDS Street 5 speed

Gear inches for XDS Street with 5 speeds

Gear inches and their corresponding "metres of development" are nicely explained in the diagram and article below. "The resulting value, gear inches, is the equivalent diameter for a direct-drive wheel (like the front wheel of a Penny-farthing)." In the diagram below, one pedal revolution with a 53-12 setup on a standard 27 inch wheel bike has 119 gear inches and produces 9.3m of travel (metres of development). By using smaller front chainrings or larger rear sprockets you reduce the gear inches and metres of development but make turning the pedals easier.

Beyond the big ring: understanding gear ratios and why they matter

So my 20 speed Otway 2.0 road bike has a gear inch range of: 30.6 (easiest) to 122.7 (hardest).
= 401% gear range

And my 5 speed XDS Street IGH bike has a gear inch range of: 48.5 (easiest) to 124.2 (hardest).
= 256% gear range

Consequently, the Sturmey Archer 5 speed (wide range) is delivering 64% of the range of my 20 speed road bike.

This is because derailleurs bikes with 2 or 3 front chainrings have significant overlapping redundancy as can be seen below:

Beyond the big ring: understanding gear ratios and why they matter

It's worth noting that the stock setup of the chainring and rear sprocket sizing for my XDS Street IGH bike is deficient. My 5 speed should not have a hardest gear higher than anything on my 20 speed road bike. It would be better if a larger rear sprocket was used - a 20 or 18 tooth rather than 16.

While the 256% range of the Sturmey Archer remains the same, using an 18 tooth rear sprocket would shift it toward climbing steeper hills by dropping the easiest gear inch value from 48 to 43. The reduction at the high end from 124 to 110 is no loss for such a city bike.


As I was paying $399 for a clearance bike, I didn't bother asking for any changes to the stock setup. I have made this modification myself. However, if paying significantly more or standard retail price, then you would be best off refining the rear sprocket to the best size - usually a step up in size (thus easier) but with an even number of teeth.

Effective Gear Range and Useable Combinations
As I noted above, my Sturmey Archer 5 speed (wide range) is delivering 64% of the range of my 20 speed road bike. This potential range coverage from fewer gears is promising. But it is the effective gear range that really matters:

- Most cyclists with 3 chainrings at the front have to avoid cross chaining - creating too much of an angle between the chainring and the rear sprocket as this rubs on the derailleur and leads to much faster wear on the drivetrain.

- Many cyclists also never use some part of the extremes of their gear ratios. At the highest end it is simply too hard to push round. At the lowest end, they almost never ride hills so steep they require them.

Consequently, if you adjust the rear sprocket size on your IGH bike you can ensure that all of your 5-8 speeds are within your useable (effective) gear range. 20-27 speed derailleur gears are rarely adjusted to suit the rider or their circumstances, or are just overkill, and so typically have an ineffective (unused) portion. So, with savvy rear sprocket size selection, my 5 speed IGH bike could deliver an effective gear range of ~80% of my 20 speed derailleur bike.

The below table and page provides a useful ballpark guide on the gear inch range that suits different types of riding and terrain. This reconfirms that having a top gear inch much over 100 is usually pointless for urban cycling and it is adviseable to err on creating more room at the bottom end.

Hubgear.net - Selecting a hub gear

Hence, for my XDS Sturmey Archer 5 speed bike, I have switched the 16 tooth rear sprocket to a 20 tooth rear sprocket. With the stock 16 tooth setup, speeds 4 and 5 had gear inches in excess of 100 - too high for most of my trips involving carrying my child or cargo. So I had only 3 effective gears. With the 20 tooth sprocket all 5 gears are now within a useful gear inch range given my circumstances (see below diagram). The lowest speed (gear 1) is now only 38.8 gear inches and is only used for the most challenging hills. Cruising speed is in gear 3 or 4 as it should be with a 5 speed IGH bike.

Sheldon Brown's Derailer and Internal-Gear Calculator - XDS IGH 5 speed with 16 tooth rear sprocket replaced by 20 tooth


4. Should you get an internal gear hub on a Dutch bike, City bike or Fixie-style bike?

An IGH typically comes on three main types of bikes in Australia:

(a) A Dutch-style (aka Classic, Vintage) bike which is usually steel with a step-through frame, very upright cycling, swept-back handlebars, typically comes with fenders, a rack, chain guard, wide tyres (32-35mm) and a kickstand.
E.g. The Nixeycles Classic (~$310 on sale)
Nixeycles Classic with Sturmey Archer 3 speed

If you can avoid hills, have mostly short trips, don't need to lift your bike often, and desire a very upright position, this is a good value option. Otherwise, look further.

There are also lighter, less upright Dutch-style commuter bikes with IGH that are more expensive but also more useful. E.g. See Lekker Bikes 3 speed and 7 speed options.

And if you have at least $1000 to spend there are Vanmoof bikes which are the ultimate in modern Dutch bikes - lighter, more functional, superior in-built lights, optimally designed for utility. If you can get one second hand for 50% or less of the new price they would be very worthwhile.

(b) A city/commuter bike which is usually aluminium alloy (lighter), has flat handlebars allowing a less upright position, often has fenders and rack (or can easily add), stock tyres around 28mm, no kickstand but this can be added.
E.g. Apollo Exceed 25 (~$660 on sale)
Apollo Exceed 25 with Shimano Nexus 8 speed

Similar alternative bikes include:
- Urban Mover Urban Commuter with a Nexus 8 speed IGH, rack, fenders. ($500 on sale)
- Giant Seek 1 which has a Shimano Alfine 8 speed, disc brakes and 50mm Schwalbe Big Apple tyres (older models can be had on sale for ~$800). (However, an Alfine 8 speed IGH is overkill and the hydraulic disc brakes detract from the low complexity/maintenance)

At the value-for-money end these are unsexy, utilitarian bikes but they can be very reliable workhorses that require little maintenance and can be used for a wide range of trips.

(c) A single speed/fixie style bike which is CrMo steel, has flat or bullhorn handlebars for a more speedy flatter position, is minimalist, doesn't come with fenders and often has less clearance for them, generally doesn't come with a rack (but can be added), stock tyres are often ~25mm. Most fixie frames won't allow tyres wider than 28mm so if you want wider tyres check the tyre clearance (the XDS Street can take 32mm wide tyres)
E.g. SE Bikes Tripel (~$400 on sale). Step-through frame version

E.g. XDS Adult Street 5 speed Sturmey Archer (~$400 on sale)

E.g. Samson Cycles 3 Speed Internal Road Bikes ($370)

E.g. Chapelli NuVinci hub bikes - 330% continuous shift. ($1,000)


Personally, I find Dutch-style bikes too heavy and slow for a bike you want to use multiple times a week for a range of trip distances that may involve hills, winds, lane filtering (narrow handlebars better).

A 3-5 speed fixie-style bike is perfect for those who are best suited to a single speed bike in every way except for only having 1 gear.
See: > When is a Single Speed bike most suitable and how to make the most of one

Ultimately, I was looking for an IGH bike to be the family bike - with either WeeRide child seat attached or the bike trailer. I bought the XDS Adult Street as 5 speeds are enough for me, I prefer the single speed style, and I have two other bikes so $400 was as much as I wanted to spend.

However, if you are looking for just one IGH bike for commuting and getting around, the Apollo Exceed 25 (or similar) is one of the most practical and value-for-money IGH I've seen in Australia. It would make an exceptionally reliable bike with minimal maintenance costs.


5. Tracking and comparison of maintenance costs of an IGH bike with a derailleur bike

The main attraction for me of buying an IGH bike is to find out if you really can have a geared bike that has negligible maintenance costs and is super reliable.

I will track any reliability issues and all maintenance costs for my XDS Adult Street in this section.

I expect the Sturmey Archer 5 speed IGH to last for at least 15,000km (several years) with no issues.

As usual, I have replaced the stock tyres with Schwalbe Durano Plus puncture resistant tyres. This is even more worthwhile for IGH bikes as taking the rear tyre off is a bit more complicated.
See:
How to remove a Sturmey Archer Rear Bike Wheel

A derailleur bike used all year round to do 2000-4000km will often require two ~$90 services mostly to clean and adjust the gears and cables and replace worn parts like brake pads. Plus every 4,000-6,000km the chain and rear cassette will need replacing. Every 8,000-12,000km the chain rings will need replacing.

So if you have bought all of the tools you need and do your own servicing of all derailleur adjustments and drivetrain replacemnts, you will spend at least $80 a year on drivetrain parts and servicing.

If you outsource all of your servicing the annual saving is likely to be at least $200 a year.

See:
> Abbotsford Cycles - Regular service


6. Maintenance guides specific to IGH bikes

IGH bikes will still require typical maintenance of non-drivetrain components like brakes, keeping wheels true and checking tyres. However, if you choose your bike with low maintenance in mind, you can minimise even non-drivetrain work:

- IGH bikes have no cassettes thus the rear wheel is not dished and is stronger. In addition, bikes based on fixies - like my XDS Adult Street - have deep rims which also add strength. So trueing wheels should be rare. However, true a new bike after the first few decent rides as all spokes settle into tension only after actual use

- IGH bikes don't have derailleurs and so have thicker 1/8 inch gears and chains. These are stronger and as they don't need to shift they wear much less quickly and are less likely to skip. Horizontal dropouts also mean the rear wheel can be moved back gradually as the chain elongates with wear to eliminate the possibility of skipping.

The drivetrain on IGH bikes requires much less maintenance but there are also some important IGH-specific tips to note:

- When dissembling the rear wheel - for example, to put puncture-resistant tyres on - make sure you take careful note (and photos) of the correct assembled setup. For example, IGH rear hub axles have flat sides and a special anti-rotation washer is fitted on one side to prevent the axles being rotated in the dropouts by forces from the hub. It is important to place this washer correctly.

- Make sure the axle nuts are very tight or the anti-rotation washers will strip metal from the dropouts, or the axle thread will get stripped, or the hub could be damaged. You also need to check rear wheel nut tightness regularly on IGH bikes as the action of the hub loosens the nuts.

- IGH bikes have more torque through the rear frame when using low gears. Avoid putting too much force through the pedals, such as by standing.on the pedals and grinding. Use a larger rear sprocket or smaller front chainring to avoid having to put too much force through the pedals.

- It is also important to note/photograph the correct setup of the gear-switching mechanism. Whether it's a pullchain, rotary or other type, photos will provide a useful reference point when re-assembling or trying to adjust the gear changing to make it smoother.

- With the Sturmey Archer S-RF5, switch to 2nd gear (spin pedals to make sure engaged), then tighten the pullchain, then switch to 5th gear and the pullchain should be loose but hanging on to the roller (not falling off). Keep switching back and forth between 2nd and 5th gears to refine.

See:
> Loch Side Cycles - Internal gear hub
Sturmey Archer - Instructions for 5-speed Internal Gear Hubs (pdf)
Ride Your Bike - Internally Geared Hubs (IGH)


Further Info:

RideOn Magazine
> Hub of the matter

Hubstripping
Gear Hubs vs Derailleur
> Internal Gear Hub Review

Sheldon Brown
> Internal Gear Hubs
> Servicing Sturmey-Archer 4- 5- and 7- Speed Hubs
Parts for Sturmey-Archer Hubs
> Sturmey-Archer Bicycle Hubs Cribsheet
Sturmey-Archer Internal-Gear Hubs, Tech Tips
Chainline and Overlocknut Distance on Bicycles with Internal-Gear Hubs

SJS Cycles
Hubs Internal Hub Gear / Brake
Sturmey Archer S-RF5(W) 5Spd Hub
Sprockets - Hub Gear
Sturmey Archer 20T Sprocket - 1/8" for RX Hub - HSL200

Chapelli Cycles
> NuVinci Hub Bicycles
> Buy Sturmey Archer Sprocket (15 to 22 tooth)

Abbotsford Cycles
> Sturmey Archer parts

Brommie Plus
> Sturmey Archer S-RF5 Parts list (part numbers for 14-22T sprockets. e.g. 20T = HSL834)

Sturmey Archer
> Rear hubs

BikeCalc

Bike Roar
> XDS Adult Street Mens 2016

Loch Side Cycles
> Internal gear hub

Cycling Tips
Beyond the big ring: understanding gear ratios and why they matter

Sydney Cyclist
Seriously what is the point of a 3 speed hub?

Hubgear.net
Sprockets for hub gears

Lovely Bicycle
Just Three for Me! In Praise of the Humble 3-Speed

Sturmey Archer
> Rear Hub Sprockets
> RX-RF5 Parts List (pdf)

YouTube
How to remove/install a fixie cog without a chainwhip (rotafix)
Overhauling 60 Year Old Sturmey Archer 3 Speed Hub

YouTube - Dan Burkhart
Bicycle repair 3 spline cog removal and installation

Ride Your Bike
> Internally Geared Hubs (IGH)

A View From The Cycle Path
Anatomy of a reliable, everyday bicycle

Lochside Cycles
> Sturmey Archer and Shimano IGH model adjustment

Bike Forums
Help adjusting Sturmey Archer S-RF5

Urban Bicycles
Instructions for 5-speed Internal Gear Hubs (pdf)

Terminal City Riders
Troubleshooting Sturmey Archer 3-Speed Hubs

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