Although 6 speed (on a 7 speed freehub body HG20 hub), the wheel actually came from a
130mm spaced frame (all noted above) and is already 130mm spaced.... Axle length is the correct 141mm (but regardless I have lots of spares in different lengths). It had some gratuitous spacing on the drive side, there is a distinct possibility that I may only need to adjust the spacers on this side (due to new bearing location) and not have to re-dish much at all, if I do it will be 2 to 3 mm move for this specific wheel (see points below).
The only problem for me is finding a dirt, dirt, dirt cheap Shimano 8/9/10 speed freehub body (or even a cheap 36 hole hub and I will just rebuild the wheel around that hub....). It is an anti theft beater, the goal is min spending in the end so I am looking for very cheap parts... For personal reasons (they came from my brother's 80s Japanese Bianchi) I would like to re-purpose these rims on this build but finding the freehub or hub seems to be a PITA (at my price point...). I would also like low profile rims to make it look older (in line with the period of the frame below) and crappy... I may end up using the Aksiums for now but that sort of defeats the purpose IMO.
It is going into a different frame (really nasty looking old gaspipe CCM) that will need to be cold set to reach 130mm ( I also need to add braze-ons as it has none, I have them and the brazing gear...) but I am keeping an eye out for a different better ugly old steel frame (maybe 80s instead of 60/70s).
Regardless, for academic purposes....
- A 126 mm seven speed wheel (not exactly mine above as it started as 130 mm) original centre is 63 mm....
- The new spacing after the change is of course the standard (8/9/10....) road 130mm, new centre will be 65 mm.
- The 8/9/10 speed cassette plus cassette spacers where required is roughly 5 mm wider than the seven speed (~32 mm to ~37 mm), so assuming the same brand like to like freehub is roughly the same amount wider (5 mm). Forget 11 speed+
- We need to add 5 mm "spacing" (not spacers but distance) to the drive side (ds) for the new wider freehub (but that results in 131 mm width) so we will also need to remove 1 mm from the non drive side/nds to get back to 130 mm total.
- The centre of the rim (hoop) is now sitting at 62 mm on the nds and 68 mm on the ds.
- The centre needs to be moved 3 mm towards the ds to get to 65/65 mm.
Total change in dish is 3 mm.
Other option is to increase the spacing to MTB 135 mm (or as it is your steel bike whatever fits your non-standard fancy). As an example adding a 5 mm spacer to the nds results in 67/68, we only need to change the dish 1/2 mm (or just go for a beer and forget about a half mm between friends...). Requires a longer axle and the correct frame spacing if possible (depends on starting point)....
Spacing out to a non-standard 136 mm (by adding 6 mm to the nds) requires no change in dish at all...
Some references from the late Sheldon Brown:
Useful dimensions and conversions for the cyblist/mechanic: hub and sprocket cluster spacing
www.sheldonbrown.com