Left ergo to operate SA AW hub?

[Brucey]

if you image search for 'dura-ace gear indicator' you will find images of the things and this will lead you on to part numbers and for sale pages etc.

I just found this picture



which is of a RSX gear indicator; the marks might even be spaced correctly for an SA hub, too.

cheers

[fausto99]

Found lots of images but none led to any place with stock. Seems like the in line indicators have been discontinued probably due to the demise of Shimano washing lines. Plenty of shift trigger indicators. I may have to refresh my Blue Peter training and get to work with an old ballpoint pen, some ferrules and a mini O-ring.

[Brucey]

darn. I am pretty sure that a year ago you could still buy them new.....

cheers

[fausto99]

OK, so, I've done it. I measured the cable pull per click on the existing S-A 3 speed trigger by taping a ruler to the frame and putting a masking tape pointer on the bare cable. Setting zero at the slack cable/high gear point (H), I got 8.5mm to the direct drive position (N) and 12.8mm to the low gear position (L).

I then swapped out the handlebar and stem for an new one with (old) 9 speed Ergo levers and new cables all fitted nicely under some original Grab-On covers - very neat.

Testing: The Right hand indexing was spot on, as old Campag 9s pulls 3.2 mm per click, exactly the same as Shimano 6s. The left hand ergo pulls 2mm per click, as far as I could measure, allowing for cable hysteresis and my ruler viewing parallax error. So, using 5 clicks from High to direct (N) and 2 clicks to get from direct to Low it all works swimmingly on the workstand . Haven't had time to try it on the road yet. Will report back when I have given it a fair trial.

[rjb]

From an old thread the Sturmey 3 speed trigger shifter pulls 5mm of cable when changing from 1 to 2 and 7mm when shifting from 2 to 3.
viewtopic.php?f=5&t=113613&p=1116804&hilit=Sturmey+Pull#p1116804

[Mick F]

Super!
Fingers crossed for you, but I'm sue you'll be fine.

The linked thread has it all.

[Brucey]

the required cable pull varies a little bit depending on the age of the hub. But if you have

gear 3 = slack cable
gear 2 = indicator rod correctly positioned
gear 1 = no slack

then you should be fine

cheers

[Mick F]

From page one.

If a friction shifter is adjusted so the 2nd gear is at the mid position, tight would be 1st and as loose as you like would be 3rd.
Therefore, a LH Ergo would do it IMO.

the required cable pull varies a little bit depending on the age of the hub. But if you have

gear 3 = slack cable
gear 2 = indicator rod correctly positioned
gear 1 = no slack

then you should be fine

[fausto99]

the required cable pull varies a little bit depending on the age of the hub. But if you have

gear 3 = slack cable
gear 2 = indicator rod correctly positioned
gear 1 = no slack

then you should be fine

Gears H/3 and L/1 will be fine: it's N/2/direct drive that concerns me. I can't use the indicator rod position as a guide because I had to fit the long axle and dish the wheel to get my makeshift 6 speed freewheel in, while having enough threads on the drive side to hold the wheel in the dropouts.

How much leeway is there in the middle direct drive position? +/- 1mm?

[Brucey]

depends on the hub. But on most if you shift gradually from 1-2 (as you might with a set of friction levers) the correct setting is about +1 to +2 mm from when second gear starts to 'catch' for the first time. The consequences of being wrongly adjusted in 2 vary with the AW version you have.

Gear 2 is not 'in the mid position' between 1 and 2 in most 3s hubs; the 3-2 pull is longer than the 1-2 pull.


cheers

[Mick F]

How much leeway is there in the middle direct drive position? +/- 1mm?

Going bak to the linked thread above, you'll see from my experiments that there's quite a bit of leeway.
Mine is a different SA3sp to your SA3sp of course, but the numbers must be similar.
I use a bar end shifter with clicks moving up to tight, and friction moving down to slack.

I gave it thought, and I experimented whilst riding yesterday ........... and took notes.

Clicks

Shifter has 18 clicks lever down to lever up …………..but silent friction up to down. 3rd-2nd-1st was straightforward using the clicks.
Unable to measure 1st-2nd-3rd due to lack of clicking.

There is too much lever movement for the hub requirements, so the cable is very slack when the lever is fully down.

There are 10 clicks from fully down to inline with the handlebar drop and is where the yellow mark on the toggle chain is correct for 2nd gear as per the hub instructions.

Moving the lever up from fully down, from first time the cable is starting to tighten without any toggle movement yet ……. call this Base ……….. a further 3 clicks makes 2nd gear engaged.

Yellow mark aligns at 10th click.

At the 9th click from Base, 1st gear engages positively.

0 = Lever fully down. Cable very slack and floppy.
1
2
3
4 = Base
5
6
7 = 2nd Gear Engages
8
9
10 = Yellow Mark
11
12
13 = 1st Gear Engages
14
15
16
17 = Cable Taut
18 = Lever fully up (but won’t go due to cable already being taut)

Total cable pull down to up = 25mm for full 18 clicks. Measured this morning with cable disconnected.
Therefore 1.389mm per click.

Hopefully that means something interesting.

[Brucey]

Mick has a CS- series hub which uses a longer cable pull than normal, in order that a LH MTB style pod/twistgrip (normally meant for a MTB front mech) can be used to work the hub. Some of the cable pull is redundant (so that the hub will work with the shifters, serving no useful function inside the hub) and in addition the clutches in this hub are different to others, so the minimum cable pull to work Mick's hub isn't quite clear either.

cheers

[Mick F]

Yes, I'm sure you're right about that.

The point I make though, is that a non-SA shifter will work very well indeed.
I have no doubt whatsoever that my system would work a SA AW just as well. Yes, the clicks would be different, but it would work nonetheless.

[fausto99]

Still haven't been on maiden voyage. Apologies. Too much other stuff to do. However I thought I might post some pics for anyone interested in hybrid gearing and/or 60s Moultons.




p.s. Brucey might spot that I did take a dremel to the freewheel teeth to try to stop the chain riding on the toothtops. We'll see...

[Greystoke]

Brilliant, British back street engineering at its best