Chris King hub conversion (10sp to 11sp)

General Pub
1

So I have a lovely set of Chris King Classic to Open Pro wheels, that cannot be converted to 11sp.

Lucky I have 2 freehub shells (Al and Steel), and keen to ‘give it a crack’.

Success would mean that I have to find 1.8mm of ‘space’ to allow for the increase in width from a 10sp to 11sp cassette.

Step 1.

Sadly, and the reason that I can’t find many conversions of the old CK hubs, is that the freehub has only (exactly) 1.8mm of ‘meat’ available. So I’ve milled down 0.9mm (see arrow), leaving between 0.7-0.8mm left for the cassette to be locked against, I think (explain later) that I will have to mill down another 0.4mm for this to actually work, the whole thing just might be a disaster…its going to be TIGHT.

You can see how much I milled off already (Thanks for GONZ for doing this, a true problem solver).

Step Two

The issue is that a 10sp freebody doesn’t have enough room to allow the 11sp cog to rest on the freehub body, and in turn, not allow the 11th cog to lock onto the freehub to give it bite…and then move forward. The amount I’ve milled off just allows this (when the lockring is installed) to bite down…but must be holding on by 0.6mm (as SRAM cassette is 1 piece, there is NO compression of width…which sucks). Its this reason that I want to mill down another 0.4mm off the freehub, I know its not alot, but it will give me another 1/8th turn of the lockring.

STEP Three.

Finally, an overview of the 11sp cassette, actually on the 10sp freehub body…so the theory works. Lockring is installed, and the 11th cog is biting on the freehub.

HOWEVER…

Chris King hubs are a nightmare to pull apart without the tools, and I DON’T have the tools to do this. So its not a easy process to replace this freehub body into the wheels, and see if there is enough ‘overall’ clearance in the frame to make it all work.

My calculation is I still need to find 0.8mm ‘somewhere’ for the system to work.

ISSUES;

1). I need the 11th cog to have more bite on the freehub, or the first time I ride in the 11th, it will tear the freehub and spin around doing nothing.

2). Space for the actual chain on the 11th cog and the frame. This could all work, or as the spacing isn’t enough, and the chain will rub against the frame. How little room could I have, if it was 1.5mm I would be happy…

3). Potential issue with the rear mech and the spokes, however as I plan on running SRAM Force1, and a 11 -36, I think the space will be fine as a 36th is further from the spokes than a 26th (in a vertical plane).

Summary

So that’s that…if anyone has a CK freehub tool in Melb, and keen to play around, please let me know.

All other ideas also welcome, like how could I add a 1mm spacer to the Chris King hub on the drive-side, thus giving me a 131mm overall hub width.

Or have I just wasted my time…

2

Potential issue, the bits you have milled become so weak that they crack and shear off when you torque the lockring down.

3

Totally correct, and that is the fear. However I choose the AL freehub first to see if it would work, and if it does tear (but the system works) then mill down the steel freebody.

My thoughts are the sheer resistance would be higher on the steel…not by much, maybe a extra 0.1UTS.

4

Just loctite the lockring and not Ape it on? Looks meaty enough to snug the cassette against to me. The 11t is part of the one piece cassette? If so, and its biting onto the splines at all, it should get support from connection to the neighboring cogs, as well as a little from the tiny bit of bit on the splines. I bloody love that you just gone for it, and if I was a betting man I’d say the chain grinding the inside of the dropot will be the stopper, but that depends on the frame. And frames can be filed, of course :slight_smile:

5

Sadly, the smallest (11th) is the only separate cog in the cassette, however if I can find a 1-piece 11sp cassette then your idea is BRILLIANT.

Thanks JP for a idea BOOM…

6

I wouldn’t have the confidence in riding something like this in anger. Not enough meat.

I had the same hubs, bought from xbbx, built to Belgiums, and sold them because they can’t be converted. Saddest day of my life, really. That rear hub with the stainless driveshell is so good it’s worth staying 10 speed for. You could probably get super cheap 10sp di2 and just leave it.

7

Totally agree, I guess the only reason for doing this is to see if it works. I’m lucky enough to have the spare freebody shell to play with. I’m going to mill it down a bit more, to ensure it has some more bite. Amazing wheels, hence I wanted to try and future-proof them.

8

Hate it when smuggy is right but he is right here. Buy an eleven speed wheel set, get new frame to blaze it on the ten speed set.

That said: watching with interest.

9

Or just accept that 10sp is OK…

10

Or what about use a standard 11 speed cassette, and remove one sprocket making 10-speed and use appropirate small spacer?
So 10 speed but using your 11 speed shifters.
Your ideas are v cool, but sounds risky!

11

cost of time expended exceeds cost of new hub