Servicing Silver hubs?

[Eric Myers]

Has any one serviced one of Rivendell's Silver free hubs?  I want to grease the pawls to quiet things down back there (I have Phil Tenacious Oil for this), but the only free hub I've worked on is a VO, which doesn't need any tools.  I've figured out that the Silver hubs were made by KT, but they seem to make different designs.  Do I need any special tools, other than to remove the cassette?  Or is there something I should be watching out for so I don't muck things up?

Thanks for any help or advice,

Eric

[Jeremy Till]

I have one of the prototype Silver hubs and I'm pretty sure the production ones have the same internals. I've had mine open a few times and it's pretty straightforward. You don't even necessarily have to remove the cassette.

-The freehub body is held in place by the drive side axle end cap, which threads onto the axle.
-You can remove either end cap by inserting 5mm allen wrenches into both ends of the axle and holding one steady while turning the other counter clockwise. However, it's kind of a crapshoot which end cap loosens first. If the non drive starts turning, unscrew that one and remove it. The axle itself then has a fitting for a 10mm allen which can be used to hold the axle while you unscrew the other end cap.
-Once you have removed the end cap, you can slide the freehub body straight off the axle. Make sure you have the wheel on its side with the drive side up so you don't lose any parts. The axle is captured between the bearings in the main hub shell and will stay in place.
-This will expose the pawl mechanism. The hubs are somewhat unique in that the drive ring is on the freehub body and the pawls are contained in the hub shell -usually it's the other way round. Take a minute or two to grok how the pawls and springs go together, and then you can slide each pawl and spring out to clean and lube them. If you want to quiet things down you might put a little lube on the drive ring where the pawls run over it (see my commentary below).
-Reassemble everything just as it came apart. IIRC there's a spacer that goes on the axle between the freehub body and hub shell, make sure that's there. If the freehub body doesn't drop right into place when you slide it onto the axle, slowly rotate counter clockwise until it drops down into the pawls.
-thread the axle ends back on and tighten them against each other. The bearings aren't adjustable so it's just a matter of threading them on until they stop and then torquing them appropriately. If the axle isn't turning smoothly after the end caps go on then something is assembled wrong.

Commentary: my silver hub had occasional skipping issues under high pedaling loads (think steep single track climbs). The first time I opened it i discovered that it was missing one of the pawls springs. I've been unable to source replacements, but was able to fabricate my own pawl spring that's been working well. However, in my various attempts at addressing the skipping issue it was my experience that lubricating the pawl/drive ring interface exacerbated the issue, even with all 6 pawls and springs in place. My best results have been lightly lubing each pawl so that it rotates freely in its seat in the hub shell but leaving its interface with the drive ring dry. Yes, the hub is on the loud side but its engagement works well. YMMV.

- Jeremy Till
Sacramento, CA

[Jeremy Till]

One follow up (sorry, working from memory): there may also be a small seal between the freehub body and the pawls. It can be gently pried up to access the pawls and pressed back into place before reassembly.

-Jeremy Till
Sacramento, CA

[Eric Myers]

Thank you Jeremy, for all that detail!  

Based on my experience with the VO hub, just lubricating the pawls themselves and not the interface was enough to make a huge difference in noise level.  I'll make sure the interface stays clean.

Best regards,

Eric

[David Carner]

I have a production Silver hub.  My memory is not as detailed as Jeremy's, but I took the hub apart to add grease to the pawls when I first received it. It required no special tools and Jeremy's description fits what I do recall. I have had no problems with the hub over approximately 3000 miles.

David

[Eric Myers]

There was still some grease in the mechanism, but I added some more and gave it a short test ride; it's a lot quieter now :-)  The noise level oscillates a bit with each tire rotation though, so I guess I wasn't very even with my application :-(