I have a “new” bike with an Alfine 8 hub. It’s been unbidden for quite a while, I did 50 miles on it today but 8th gear constantly slipped, so spent most of the ride in 7th. The yellow dots line up, could the cable be too tight? I’m new to gears so any pointers gratefully recieved…
Ta

If you stand beside the rear wheel(drive side) and change between 7 and 8, you should see the assembly that the cable attaches to move backwards and forwards in time with your shift. If it doesn’t, then you can take your pick from sticky cable( lube it up), crap and clag set solid in or around cassette(i think its called) or as in my case, poor cable alignment into the cassette by the chainstay. I had problems changing from 2 to 1 though.
This is from experience with a nexus 8, which I think is much the same, but not 100% sure.
hth

Alfine + gear slip/issue = cable… in 99% of cases

The other 1% are normally ‘internal shenanigans’ but they really are rare and normally come on gradually or as a result of damage.

If the bike has been sitting for some time my money is on gunk and/or something drying up. It only needs a bit of friction to cause issues, they’re more sensitive to it than derailleurs and you can’t compensate for cable issues at the shifter end with a bit more thumb/finger like you can normally. If you have the rubber boot on the cable exit point at the CJ then make sure that’s not sticking or contacting the barrel of the CJ preventing full movement of the cable, this can cause issues at each one end of the range.

Also worth noting that the adjustment between ‘perfect’ and ‘not perfect’ can often be less than the width of the yellow marks, so just because they line up doesn’t necessarily mean it’s perfect, and there is also the possibility of some slop and tolerances in the CJ unit so they can sometimes need a fraction of a turn to either side of lining up, and which side and how much can vary between hubs and CJs.

So, having said all that first point of call is to check, clean and relube the cable, if you’re lucky that’ll sort it. Any kinks, corrosion or excessive drag and just change it (outer too to be safe).

On a side note, if you’re spending most of your time in 8th (or 7th) then do you not have the gearing set up a bit low? I’d expect to spend most of my time in 4/5/6, leaving a couple either side for fast bits or slow bits, otherwise you’re not only not making good use of the hub but you’re spending most of your time in less efficient gears. If you’ve come from SS riding then remember 5th is the 1:1 ratios so better to gear yourself for using that as your ‘main’ gear.

It’s currently 34 X 23, which as you say is low. I’ll be using it mainly for tow path type rides and rode up a comedy hill in 4th on the way back, where’s a good place to start with a 34t chainring???

I’ll take the cable off and lube for starters….thanks for the advice all…..

For gear ratios you might do well with a gear calculator to get it right.

FWIW my commuter uses 42 front and 19 on the back. I spin out on a good road downhill but I can tow the trailer up a slight slope without having to honk.

Would I be right in thinking the ratio that the fitted 34 chainring 23t sprocket is 5th gear?

Iirc 5th is 1:1 ratio, yep.

Isn’t the sprocket supposed to be at least had the teeth of the chainring? Iirc, my Pylon8 was 38T chainring, 18T sprocket.