MikewsMITH2 wrote:I have been looking at this as a solution to a tourer I will be building up this summer. I am not keen on triple chainsets. They never index properly and I end up fiddling with them to keep them quiet. This seemed a sensible option and gives wide ratios.
Ah ! So are you thinking along the lines of having a single chain wheel at the front and using derailleur/hub at the rear ? A gentleman has advised that S/A supply a 3sp free/hub assy, which can be fitted with an 8 or 9sp cassette . Wouldn't that remove Brucey's concerns over chain width ?
Yes that is what I am considering. 8 speed derailleur with 3 speed hub gear with a single chainset at the front.
Brucey. I have no doubt you can buy lighter components. I was just comparing the parts I would be otherwise using. I am not bothered too much about the weight, but its an old myth that people keep repeating that hub gears are a lot heavier. They are a bit, but not enough to bother about for a tourer. I am not buying the bike either. It is an old 531 Claud Butler that is coming for free
S.O.S - Save Our Steel! 1971 Raleigh Mercury 2010 Condor Fratello 1980 Peugeot Tandem 1989 MBK Aventure MTB 195? Viking Severn Valley 1951 Raleigh Lenton Sports See them here http://tinyurl.com/Mikewsmiths-Bikes
One problem I can foresee with using a 7/8/9 speed cassette or freewheel on an existing 3 speed SA Hub is the OLD width. You may need to cold set the rear of your frame. In addition, you will need to find a much longer SA axle bolt. I know it is possible as Sheldon Brown has done it before! In addition, a hub gear and 7/8/9 speed cassette would give a lot of overlap on the gear ratios.
My personal decisions were a bit different. When I got my Moulton F frame bike, it came with a 4 speed SA Hub. I found that these standard gears were OK for riding on flattish land but were not low enough to get up steep hills or high enough to go down the other side! The simple solution was to fit two standard Shimano cogs & a spacer from an old Casette. The cogs needed a bit of tweaking with a file, but they both fitted on a FW4 hub. I choose to use a 12 and 24 teeth cogs. This gave me a high and a low range on the two rear cogs with overlap between the 24 tooth/4th speed and the 12 tooth/1st speed. This also required the use of a standard 7speed chain, so I had to replace the front chainring to ensure compatibility. I happened to have a 48/52 double chainring, so I used this. In addition, this gave me a fine adjustment of 10%ish steps on the front chainring, compared to 20ish% steps on the Hub gear. I realise that this is all a bit backwards and I have to juggle with 3 shifters, but it works quite well. I have done two Devon coast to coast challenge rides of 70 odd miles across hilly routes and always had an appropriate gear. I think I surprised a few people riding so far & relativey fast on a 16" bike! The main advantage of the hub gear is the ability to change whilst stationary whereas the derailleur gave me the bir range. The further advantage of only using 2 front and rear cogs is that it simplifies the setting up of the derailleurs- I just need to adjust the min/max stops. Happy days Mark
Hi, I have just seen the thread and was prompted to write as I have almost 40 years experience of combining AW Sturmey hubs, derailleur gears, and double/triple chainsets and thought others might like to read about that experience. Firstly, for the person who wants one bike that does everything from tootling around town to cycle-camping, this is a great combination. Advantages are gear changes whilst stationery in traffic, and quick engagement of ‘over-drive’ and ‘low gear’ using the AW hub gear. The set up potentially provides a wide range of touring gears with robust, quick easy changing and good chain lines. Disadvantages are the extra weight ~1 kg in the back wheel due to the hub gear, one extra gear changer, and setting up the system in the first place. So, what are the options for achieving such a system with a Sturmey AW hub? As has been mentioned, a Cyclo 2 speed or 3 speed adaptor on a slotted AW driver works well and I have both of these set-ups on different bikes with triple chain sets. This gives a great range of gears from 52-42, 24 rings at the front, and either a 23, 19, 16 triple sprocket, or a 22, 19 double at the back combined with the 33% increase or the 25% decrease in each of the six or nine gears provided by the AW hub. A 1/8th chain is needed with this set up.
Alternatively, as others have mentioned it is possible to fit two dished Sturmey/Sachs sprockets (either 1/8th or 3/32ths) onto the driver, with either the 5 ¾ or the 6 ¼ inch axle. If one wants more gears a relatively easy way to do this is to replace the HSA 123 slotted driver, with one of the older pre-1951 K507 threaded drivers. A conventional 5 speed freewheel will then screw onto the driver and there will just be enough clearance for the chain to run on the smallest sprocket with an frame OLD of 126mm. There will also be just enough axle thread available to tighten and secure the wheel within the frame with a conventional Sturmey axle lock nut. To fit a 5 speed freewheel, it is important to make two simple modifications. Firstly the 6 ¼ axle is necessary, and secondly the right cone lock washer HSA 147, needs to be filed down, because this washer must be able to pass through the centre of your freewheel body. This is crucial. Otherwise, once the right hand cone and lock washer are in place and the freewheel is screwed onto the driver, if the lock washer will not pass through the freewheel body, it will be impossible to remove the driver (or the freewheel) from the hub.
I have used a variety of freewheels over the years and those using a Shimano freewheel extractor are just wide enough in diameter, to be able to remove the filed down cone lock washer through the freewheel body aperture. When the freewheel body is in situ i.e. screwed onto the threaded driver; to remove the freewheel and driver from the axle, I use a hooked needle to remove the filed cone lock washer through the freewheel body aperture first, and then it is possible to get sufficient purchase on the flats of the cone through the freewheel body with two screwdrivers, to screw the cone off the axle. When the cone is free from the axle, the freewheel and driver can be removed from the hub. The freewheel can then be removed from the driver by fixing the splines, and using the freewheel extractor in the conventional manner. To avoid the need to do this on the road, if I have to fix a drive side spoke, I use Sachs freewheels, where one can remove the sprockets from the freewheel body to gain easy access to the drive-side spokes, rather than having to remove freewheel and driver to gain access to the drive-side spokes.
So, my favourite set-up for touring is a freewheel of 16, 18, 21, 24, 28 or 30 coupled to either a double 52/34 or a triple chainset with the Sturmey AW three speed hub. The chain lines are good for all sprocket/chain ring combinations. A standard 5,6, 7 speed chain can be used and an inexpensive 7 speed long cage derailleur (that fits directly to a frame hanger) in order to save axle width so that there are enough axle threads available for the drive side lock nut to secure the wheel. I would advise against trying to recreate Sheldon’s 7 speed freewheel set up on the AW hub, because the axle is really not long enough to accommodate the extra width of two more sprockets. Also, as others have said before, when building wheels for touring with steel AW hubs, I always use 3mm washers to try and improve the fit of the spoke heads in the hub. I also use 2.3mm butted spokes on the drive side to reduce breakages.
Re: the torque loading on the AW hub with such a set up, I have never had hub failures even cycle camping. However, I weigh 75kg, carry only 15 kg max and get off an walk when the gradient is >20%............Food for thought I hope! Ps – this works well on my Claud Butler 531 and 1980s Peugeot
I have a cut down (no front double) version of Mick F's conversion on my Raleigh Chopper and it was relatively straight forward to achieve www.purplechopper.co.uk - scroll down until 3 speed is now 6 speed. Regards
If you've used a standard chain, be aware that it doesn't do it much good over time. Better to use a 3/32 derailleur chain as it's more flexible. You'll need thinner cog teeth though.
Thanks for that bit of advice Mick. I'm not intending doing big mileages on the bike (it would hurt too much) apart from my coast to coast effort and I guess I could always carry a spare chain.
Actually I tried to buy some 'proper' 1/8" chain recently and failed. They are seemingly all -or at least mostly- of the bushingless design, and are consequently more flexible than 1/8" chains of yore, if not quite as flexible as a 3/32" chain.
Mick F wrote:Brilliant post! Excellent nuggets of information. Thank you.
Hear Hear! I'm doing lots of thinking ( and not much doing, yet...) on this subject, and this solution appeals - have donor S-A 3-speed as well as suitable freewheel already available - and a quick dip into the vaults of old bicycle trader reveals he has a k507! (Fancy cdtp taking the trouble to quote the part number!) Well Done, mate!
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
