STX-RC 8s wheelbuild

[AshtanoJoe]

I want to build a rear wheel with an Araya RM-20 rim (ERD 547mm) and Shimano STX-RC 8 speed hub (model # MC38a), however I can't find any info online for the hub's left and right flange to centre spacing. All that's available is for the 7 speed MC33 hub.

I need to order spokes fairly soon and don't have access to digital calipers atm. Would the 8s hub likely have the same flange spacing as the 7s, just with a longer FH body, or would it be a different size hubshell?

Would really appreciate any advice on how to work out spoke length from here.

 

[foz]

the flanges on the 8 speed hub are possibly a little closer to the non-drive side.

Most shimano hubs that have the same shape have the same dimensions though, so look for another shimano model that has the same shape as yours and take the dimensions from that, bear in mind that small differences in flange to centre spacing will not affect the overall spoke length very much at all - in my experience it's flange diameter and rim ERD, along with number of spokes and lacing pattern that have a much greater effect on spoke length.

just put the numbers into a spoke length calculator and change things like flange-centre to see what effect it has on spoke length

 

[AshtanoJoe]

Re:

Thanks for the suggestion....From images on the web it looks similar to some other 8s parallax models which all have varying flange-centre dimensions, but doing as you suggested and running them through the calculator, the resulting spoke lengths all come out to within about half a mm on either side. So, it seems it will be 264 for the nds and 262 for the ds.

This will be my first wheelbuild, the hub is NOS but the rim has had a bit of use. I was planning to use some brand of butted 2 - 1.8 - 2mm spoke, anything else I should watch out for?

 

[FluffyChicken]

Re:

So it's 36hole hub and rim then given its 264/262 araya?

But yes same as pretty much the other 8sp Shimano hubs. It may just be listed as stx-rc.

 

[AshtanoJoe]

Re:

So it's 36hole hub and rim then given its 264/262 araya?

Yes, 36h and 3 cross. I noticed the rim has offset spoke holes, but it won't affect the spoke length i've read.

But yes same as pretty much the other 8sp Shimano hubs. It may just be listed as stx-rc.

The only 8s STX hub I could find numbers for was the silent clutch model which looks like a different shaped hub shell.

All this to replace a split Mavic X517 which seems to happen a lot.

 

[FluffyChicken]

Re:

They're all 45mm hubs.

Ignore the offset it's negligable*, it is however a good gothca when you don't notice when you build, oh how we chuckled at my mate when he laced the rim back to front (who was so proud of his first build)

*think of it as a help to ease the bending on the nipple end, rather than a true offset.

 

[kalex]

Re:

If you don't mind me asking, where are you getting your spokes from