Sturmey Archer indicator rod (control toggle) lengths
Posted: 3 Feb 2019, 8:43pm
many sturmey archer hubs, (including Pre NIG AW, NIG AW, S5, S5-1, S5-2, 5-star, SW, converted AM, converted FW etc) use the same indicator rods. However they are available in different lengths to suit different axles and between all the different hubs and axle lengths that have been available, it is difficult to know what is the correct one. This illustration shows the variations possible in just the S5-2 model of hub.
S5-2 indicator rod lengths
However in practice almost any length rod (that isn't too long) will work on the LHS of S5-2 hubs because the control is binary; almost tight cable or slack cable; there is no need for a shoulder or mark on the indicator rod.
control rods for older (pre NIG) hubs. Note that many of the axles vary in the left side length only, so that there are many fewer different indicator rod lengths required than there are axle lengths
For all RH rods there is meant to be a specific length that will be correct in the direct drive ratio (second gear in a 3s hub) such that the shoulder on the rod is flush with the end of the axle. In some older 3s indicator rods there is a (largely superfluous) second mark about 4.25mm away from the main shoulder; this indicates the low gear position or can indicate second gear position in the case of a rod substitution.
The actual rod lengths from shoulder to shoulder (L) are;
Rod length (L).…solid axle length (non-NIG),toggle key depth (non NIG),solid axle length (NIG),toggle key depth (NIG),..... Part Number
Mk1 48.25mm (1.900")…42.5mm...………………………….56mm...………………………L-9mm………………………………L+ 7mm ......HSA125
MkII 54.8mm (2.155")…49mm...…………………………62.5mm...……………………………L-9mm……………………………L+7mm.....HSA126
MkIII 58-58.4mm...………….L-5.7mm...………………………L+7.7mm...…………………………49.1mm…………………………65mm......HSA315
MkIV ~62mm* .………….L-5.7mm...………………………L+7.7mm...……………………L-9mm………………………………L+ 7mm......HSA316
MkV ~66mm*.......................................................................................................................................................HSA420
MkVI 40mm*……………….HSA615
MkVII ~72mm*.....................................................................................................................................................HSA421
MkVIII ~75mm*...................................................................................................................................................HSA716
MkIX 69mm*................................................................................................................................................HSA715
* estimated values and/or not verified by personal measurement
In the table above the 'solid axle length' is the length from the RH end of the slot to the RH end of the axle. Use this measurement if you have a bare axle (NB not CS-series hubs).
'Toggle key depth' (KD) is the depth of the toggle key (eg as measured using a vernier caliper as a depth measurer) from the axle end when the hub is set in top (3rd) gear; use this measurement when you have an assembled hub and don't know what length control rod to use (again not CS series hubs).
So for non-NIG hubs the correct control length L is given by
L = KD - 7.7mm
and for standard NIG 3s hubs (not CS series, not S3X)
L= KD - 7mm
Specific rod applications in current hubs include;
MkIX 69mm (HSA715) used with SRK-3 hub
MkVIII 75mm (HSA716) used with CS-RF3 and CS-RK3 hubs
MkIV 62mm (HSA316) used with X-RD3 with 177mm axle
MkIII 58.4mm (HSA315) used with X-RD3 with 162.7mm axle, AW (NIG), SRF-3 with 163mm axle
MkII 54.8mm (HSA126) used with SRF-3 with 148mm axle. Also Brompton BWR and BSR with 148mm axle
I don't know what the 40mm long MkVI rod is meant to fit, but it occurs to me that if you fit one into a hub that normally uses a MkI rod, the shoulder will come about flush with the axle end when first gear is selected. Given that non-NIG hubs use shorter control rods than NIG hubs and the shortest non-NIG axles are barely long enough (for anything) on the RHS, it seems unlikely that there is an axle that gives a conventional setting (shoulder flush with axle end in second gear) when a MkVI rod is installed.
There is plenty more information (including lengths of 'skinny' i.e. single toggle 5s, and S3X rods) here https://www.sheldonbrown.com/indicators.html You can use a skinny rod in a 3s hub which normally uses a Mk1-MkVIII rod provided the length is compatible; the screw threads are the same.
some available control rods herehttps://www.sjscycles.co.uk/search/?term=sturmey+indicator
If you have no marks to go on, shift slowly from 1-2 and add 1-2mm more cable slack once second gear starts to catch. On an NIG 3s, once you are 1mm out of 3rd gear when shifting 3-2 then the adjustment for second gear is OK. On a non-NIG 3s, shifting 3-2, you need 3mm more cable pull from when second gear starts to 'catch'. If these tests indicate a range of satisfactory adjustments, aim for the middle of that range.
The above comments apply to all toggle chain 3s hubs (bar CS-series ones and S3X) and apply to the RH adjustment of twin toggle 5s hubs. (NB the only NIG type 5s twin toggle is the 5-star hub.)
hth
cheers
S5-2 indicator rod lengths
However in practice almost any length rod (that isn't too long) will work on the LHS of S5-2 hubs because the control is binary; almost tight cable or slack cable; there is no need for a shoulder or mark on the indicator rod.
control rods for older (pre NIG) hubs. Note that many of the axles vary in the left side length only, so that there are many fewer different indicator rod lengths required than there are axle lengths
For all RH rods there is meant to be a specific length that will be correct in the direct drive ratio (second gear in a 3s hub) such that the shoulder on the rod is flush with the end of the axle. In some older 3s indicator rods there is a (largely superfluous) second mark about 4.25mm away from the main shoulder; this indicates the low gear position or can indicate second gear position in the case of a rod substitution.
The actual rod lengths from shoulder to shoulder (L) are;
Rod length (L).…solid axle length (non-NIG),toggle key depth (non NIG),solid axle length (NIG),toggle key depth (NIG),..... Part Number
Mk1 48.25mm (1.900")…42.5mm...………………………….56mm...………………………L-9mm………………………………L+ 7mm ......HSA125
MkII 54.8mm (2.155")…49mm...…………………………62.5mm...……………………………L-9mm……………………………L+7mm.....HSA126
MkIII 58-58.4mm...………….L-5.7mm...………………………L+7.7mm...…………………………49.1mm…………………………65mm......HSA315
MkIV ~62mm* .………….L-5.7mm...………………………L+7.7mm...……………………L-9mm………………………………L+ 7mm......HSA316
MkV ~66mm*.......................................................................................................................................................HSA420
MkVI 40mm*……………….HSA615
MkVII ~72mm*.....................................................................................................................................................HSA421
MkVIII ~75mm*...................................................................................................................................................HSA716
MkIX 69mm*................................................................................................................................................HSA715
* estimated values and/or not verified by personal measurement
In the table above the 'solid axle length' is the length from the RH end of the slot to the RH end of the axle. Use this measurement if you have a bare axle (NB not CS-series hubs).
'Toggle key depth' (KD) is the depth of the toggle key (eg as measured using a vernier caliper as a depth measurer) from the axle end when the hub is set in top (3rd) gear; use this measurement when you have an assembled hub and don't know what length control rod to use (again not CS series hubs).
So for non-NIG hubs the correct control length L is given by
L = KD - 7.7mm
and for standard NIG 3s hubs (not CS series, not S3X)
L= KD - 7mm
Specific rod applications in current hubs include;
MkIX 69mm (HSA715) used with SRK-3 hub
MkVIII 75mm (HSA716) used with CS-RF3 and CS-RK3 hubs
MkIV 62mm (HSA316) used with X-RD3 with 177mm axle
MkIII 58.4mm (HSA315) used with X-RD3 with 162.7mm axle, AW (NIG), SRF-3 with 163mm axle
MkII 54.8mm (HSA126) used with SRF-3 with 148mm axle. Also Brompton BWR and BSR with 148mm axle
I don't know what the 40mm long MkVI rod is meant to fit, but it occurs to me that if you fit one into a hub that normally uses a MkI rod, the shoulder will come about flush with the axle end when first gear is selected. Given that non-NIG hubs use shorter control rods than NIG hubs and the shortest non-NIG axles are barely long enough (for anything) on the RHS, it seems unlikely that there is an axle that gives a conventional setting (shoulder flush with axle end in second gear) when a MkVI rod is installed.
There is plenty more information (including lengths of 'skinny' i.e. single toggle 5s, and S3X rods) here https://www.sheldonbrown.com/indicators.html You can use a skinny rod in a 3s hub which normally uses a Mk1-MkVIII rod provided the length is compatible; the screw threads are the same.
some available control rods herehttps://www.sjscycles.co.uk/search/?term=sturmey+indicator
If you have no marks to go on, shift slowly from 1-2 and add 1-2mm more cable slack once second gear starts to catch. On an NIG 3s, once you are 1mm out of 3rd gear when shifting 3-2 then the adjustment for second gear is OK. On a non-NIG 3s, shifting 3-2, you need 3mm more cable pull from when second gear starts to 'catch'. If these tests indicate a range of satisfactory adjustments, aim for the middle of that range.
The above comments apply to all toggle chain 3s hubs (bar CS-series ones and S3X) and apply to the RH adjustment of twin toggle 5s hubs. (NB the only NIG type 5s twin toggle is the 5-star hub.)
hth
cheers