Saturday, 5 March 2011

Raleigh Twenty: Sturmey Archer Hub Gear Cable Adjustment - Indicator or Toggle Chain

People have asked me how to adjust the gear cable on a 3 speed Sturmey Archer hub. Indeed, some folks are a bit perplexed by the dangly chain bit, knurled parts, and the somewhat "mystical" operation of the whole affair. This sequence of photos attempts to explain cable adjustment in easy steps. So, assume you've picked up a Raleigh 20 or other bike with a 3 speed Sturmey Archer hub gear. This one is from 1980 (pictures in a previous blog). I'm also going to assume that the short chain part shown below, called the "indicator", is the right type for the particular hub. Why it's called an indicator will become apparent later.
First step is to loosen the knurled nut at left in the photo above (untwist it a few turns). Then undo the knurled tube connector (far left in the photo above). Once disconnected, carefully take the plastic cap off the axle nut, to leave what's shown below:
Now, the dangly chain part is the indicator. The part on the left still attached to the cable is what I'm calling the knurled tube connector - it's also called a "barrel nut". Grab the indicator by the chain, lift it gently (upwards in the photo) and untwist it carefully from the hub. Hopefully, it will be free to turn. Take it out and clean it up using, degreaser or whatever you like really.

It's worth looking at it carefully - see below. The tip (top right) is shaped into a cone - this is to assist when screwing it back in. Then there is a uniform rod, the chain, the threaded part on which runs the knurled nut and the knurled tube connector (not shown in the photo below):
Grease both threads. Oil the chain links. Put the gear thumb lever in 3rd (top gear) in order to slacken the cable. Then insert the tip back into the hub and tighten it very slowly and gently. When you feel it become just hand tight, then unscrew it by half a turn - no more. Put the plastic cap back on and tighten the knurled tube connector back on to the threaded rod of the indicator. A few turns is fine initially. Now put the thumbshift lever into 2nd gear. It looks like this:
Look through the viewing hole in the axle nut and you can see that part of the uniform rod is showing. Meaning that the rod is jutting out from the end of the axle tube. Now, the aim is to get that uniform rod end LEVEL with the end of the axle tube. Turn the knurled tube connector one way, and see what happens:
In this case, the rod has come out even more - see the yellow arrow above. Now you can see why it's called an indicator, and what the viewing hole in the axle nut is for. So, turn the knurled tube connector the other way...
In the photo above, the rod has gone inside the axle tube. Remember, you want it level with the end of the axle tube. Just to reiterate, the thumb shifter must be in 2nd gear while you do this adjustment - which is in essence cable length/tension. Keep twiddling the knurled tube on the threaded rod until it is level, like this:

Now spin the pedals a few times, change gear up and down and back to 2nd, and re-check that the indicator rod is level with the axle end. Then tighten the knurled nut against the knurled tube connector, to lock down the cable length and replace the plastic cap, thus:

Go ride! It should all be hunky dory now, and shifting should be fine. If not, it probably means that the indicator is not the right one for the hub. You can sort that out by getting the right one from a good supplier, like Oldbiketrader, or if not, then you have to adjust it by careful and gentle testing. If you end up having to go through the testing route, remember that the cable should not be too tight in first gear - you may feel too much tension at the thumbshift lever - and gears should change smoothly, with no free-spinning in second. You should be able to see the uniform rod on the indicator moving in and out as you change gears. That indicator is also known as a TOGGLE CHAIN, and here's a great site for cycle touring and hub gear afficianados:
The planetary hub gear was a wonderful invention!

Falcon Revenge Boy's Bike

Photos of my son's Falcon Revenge bike, now for sale on eBay here. Specs below.

Purchased new in 2008 this bike has served my son well. Details:

- 11" steel frame and steel forks
- Shimano Capreo Alloy brake levers (I upgraded the original plasticky ones)
- Original pedals have been replaced by better quality ones
- KAlloy long seat post (adjustable height of course)
- single speed
- Alloy wheels 18"
- Tyres 18 x 1.95" knobbly tread

This bike has been well looked after and has plenty more life left in it. He's just outgrown it. Original paperwork included.

eBay auction here.