Hub axle too skinny for drop-out...? (image)

[drissa]

My fumbling self-build saga continues... I've just received my Nexus 8 Hub and it sits rather awkwardly in the drop-outs of my frame, especially the filed-down section, which I assume is supposed to slot in snugly. I don't yet have the Nexus installation kit and I know this contains various non-turn washers which are supposed to fit into the drop-outs. Will these help?

Is it time to give up on my folly and just buy a new bike?!

 

[John the Canuck]

surely the axle will deform/warp under load

have just read the 'Sheldon'' page...live and learn

 

[Tim Hall]

I think (but can't be sure) that the axle goes at 90 degrees from the way it is in the photo. Get the anti-turn washers and see what's what.

Link to an article about anti-turn washers by The Late Great Sheldon is here

 

[Smurfy]

Is it time to give up on my folly and just buy a new bike?!

There's plenty of help available here. You just need to be patient, and then when it's finally built, you'll know it inside out and will never need to pay anyone else to fix it.

Here's a few vernier measurements from my Alfine 8:

Spindle diameter: 9.5mm
Spindle across flats: 8.0mm
Width of track dropout opening: 10.0mm
Width of anti-turn tab on anti-turn washer which locates in my track dropout: 9.7mm

 

[drissa]

Thanks all, especially for measurements YT.

Yes, I just measured the non flat part as 9.4mm and my dropout opening as 9.8mm. Sounds like this will add up after all. I'm learning slowly, but still in the dark for some of this.

"you'll know it inside out and will never need to pay anyone else to fix it." Here here. That's certainly my aim. Thanks for the encouragement.

YT, unless it was all stock on a new bike, can I ask how you chose a BB/chain-set to match the Alfine chain line? Trial and error?

 

[Smurfy]

I think (but can't be sure) that the axle goes at 90 degrees from the way it is in the photo. Get the anti-turn washers and see what's what.

The different anti-turn washers do two things:
1. They control the orientation of the flats on spindle
2. They control the orientation of the gear cable exit.

The Shimano instructions that come with the hub have some guidance regarding which anti-turn washers to use with different dropout designs.

Checkout the middle-right table here.

 

[drissa]

Thanks, yes I was checking out these details today. Does 'standard' mean 'horizontal' (i.e. the ones in my frame)?

 

[Smurfy]

YT, unless it was all stock on a new bike, can I ask how you chose a BB/chain-set to match the Alfine chain line? Trial and error?

I bought it as a fixed-wheel and single-speed bike, but I built an Alfine 8 wheel for occasional use.

I had to measure very carefully to make sure that the chainline would be right for fixed-wheel, single-speed and Alfine 8, without doing anything to the bottom bracket or chainset when I swap wheels.

The chainline for Nexus 8 is stated very clearly here, but that will probably be with a standard Shimano sprocket. However, note that Sturmey Archer are the same spline pattern as Shimano, and I found that a deep dish sprocket would match up with my existing fixed/ss chainline.

Best thing to do is measure the chainline with a known BB length, and then see if you can make it work by varying BB length. If not then look into alternative sprockets. However, be aware that if you run deep dish 17T, the cassette joint will run a hairs breadth from the sprocket on an Alfine 8, and probably the same on a Nexus 8!

 

[drissa]

Thanks. I was planning to use the stock sprocket. The 'family' Alfine chain set/BB matches perfectly (42.7mm), but I'd like to feel I can consider other options.

 

[Smurfy]

Thanks, yes I was checking out these details today. Does 'standard' mean 'horizontal' (i.e. the ones in my frame)?

I don't know, I can only see a tiny portion of your chainstay in the pic. You need to assess the angle marked 'theta' in the diagram.

I am using silver on drive-side, and white on non-drive-side, with horizontal track dropouts, and that makes my gear cable exit point forwards, which is where I want it.

I'm going to bed soon, I'll be back tomorrow, or someone else will be along first.