I had a thought that I don’t know whether has a definitive answer. Maybe it’s been answered here but with 2500+ comments, it’s a behemoth to find anything here…
That thought is, “What is the highest known mileage a single Schlumpf hub has accumulated?”
This can include repairs and maintenance, of course.
(if you’re in a rush there’s a question in para 3 )
Realised I had got lazy with my Schlumpf checking yesterday when I suddenly found myself flat on my back having been pedalling along happily in low gear a moment earlier. Turns out the crank on the knurled bearing side was working loose and had got to the point of pushing its button outwards so that it changed me out of low but not yet into high, so I was suddenly riding a both-ways-freewheel uni!
Tonight I have undone and cleaned everything and reminded myself of the wonderful process of cranking up to 50 NM with the special tightening crank bolt then switching to the fragile bolt and hand tightening it hard. With that and some ‘guessed’ torquing of the bearing cups I’ve got that wonderful ‘I wonder if the gear will change and if the knurled bearing will hold’ test ride to do tomorrow. Enough of that… I had a question too:
When checking all was back together properly I did the ‘press each button in turn and help the cranks move slowly round’ test. For me there was significantly less free rotation when going from low to high, and significantly more going from high to low. Is this normal?
If so it would help explain why I’ve not yet mastered shifting down on the move - not only do I have to prepare for suddenly pedalling much faster, but also the initial free spinning stage is for longer / further shifting down than when shifting up
The free rotation should be between 0° and 1/6 (I believe) of a rotation. Basically, it depends on the alignement of the clutches inside the hub (which move relative to each other. Have you tried it only one time (or going back and forth) or several times with several different hub rotations ?
I went round a full forward rotation of the cranks without moving the wheel, so pressing back and forth a lot of times. You mentioned going ‘back’ which I hadn’t thought of, so I tried that, pushing the cranks round in the back-pedal direction as I pressed alternate buttons in. The result in that case was that there was significantly more free rotation after changing up to high gear, and less rotation changing down to low gear.
Assuming it’s not an issue that there is consistently more slop going one way than the other, then for me it might help to flip the hub so I change gear up or down with the opposite button from what I’m used to. That way I would get the ‘big slop’ when changing up, when it’s easier to compensate, and the ‘small slop’ when changing down, making it less likely I’ll lose control before taking up the slack at a much faster cadence