Khamsin bearings

mididoctors
mididoctors Posts: 18,144
edited October 2011 in Workshop
anybody with experience of popping out the fixed bearings in Khamsin hubs?

TIA
"If I was a 38 year old man, I definitely wouldn't be riding a bright yellow bike with Hello Kitty disc wheels, put it that way. What we're witnessing here is the world's most high profile mid-life crisis" Afx237vi Mon Jul 20, 2009 2:43 pm

Comments

  • Yes, I've just done this job last week on a ~3 year old rear wheel.

    How can I help?
  • mididoctors
    mididoctors Posts: 18,144
    Yes, I've just done this job last week on a ~3 year old rear wheel.

    How can I help?

    got one...cheers

    ok front bearings

    you have to tap out the bearings on one side by knocking though the axle from the other?

    because the bearings are fitted from the outside?


    rear hub how? especially the orange sealed units in the hub as opposed to the free body?
    "If I was a 38 year old man, I definitely wouldn't be riding a bright yellow bike with Hello Kitty disc wheels, put it that way. What we're witnessing here is the world's most high profile mid-life crisis" Afx237vi Mon Jul 20, 2009 2:43 pm
  • I did the rear bearings, haven't looked at the fronts because they didn't need it. I assume the process is similar.

    So, here's what I did:

    Remove nuts from either side of the hub, plus the covers and what not. This should expose the bearing on the non-drive side.

    Remove freehub and the axle spacers. This should expose the bearing on the drive side.

    Remove axle.

    You now have a hub shell with two old bearings to remove. Next job is to get them out of the hub shell. I don't know if this is the officially sanctioned method, but basically I located a suitable drift, slipped it in, supported the hub shell, then banged the bearing out from the other side.

    The hard bit is that by default, there is very little of the interior of the bearing for your drift to push against, so it tends to slip rather than transfer the blow.

    Now, the bearings are firmly pressed into the hub shell with with a little cylindrical collar thing in-between that the axle runs through. It's maybe an inch or so long. This bit isn't firmly fixed in, so you can wiggle it, to get a better grip for your drift.

    I had to hit it quite hard. Harder than, say, removing a headset cup. It surprised me how hard I had to hit it.

    At this point, people may be wincing. There are probably better ways to achieve this with superior tools. I couldn't find any bearing pullers or whatnot online, so I improvised in typical have-a-go-hero style.

    Now you just need to resassemble it. I cleaned everything up, greased up the hub shell and put the new bearings and collar thing in place. I pressed them into place with a homebrew bearing press made from threaded rods, nuts, washers and whatnot from Wickes. Once your bearings are in, I then greased up the axle and installed that, then greased the freehub and reinstalled that plus spacers. Be very careful re-installing the freehub! It's easy to maul the spring that holds the pawls in place and makes them compress and return. It's only a £1 or so to get a replacement spring, though.

    Once the freehub is in place, then you add the other spacers, covers, axle nuts and whatnot. Then it should "just work". The only problem I had was first time round when I mauled the pawl spring and turned the freehub into some sort of strange semi-fixed semi-free device. Replacing the spring fixed that, and I now have a smooth running wheel!

    Hope that helps! :)
  • mididoctors
    mididoctors Posts: 18,144

    The hard bit is that by default, there is very little of the interior of the bearing for your drift to push against, so it tends to slip rather than transfer the blow.


    Hope that helps! :)

    good post

    this was my concern

    I can see NO exposed lip to put a drift against..... i can just see a thin line where the bearings meet the hub body (I think)

    what "suitable drift" did you find
    "If I was a 38 year old man, I definitely wouldn't be riding a bright yellow bike with Hello Kitty disc wheels, put it that way. What we're witnessing here is the world's most high profile mid-life crisis" Afx237vi Mon Jul 20, 2009 2:43 pm
  • I managed to find a few metal rods in the garage, about 12 inches long, half an inch in diameter. It worked really well, as I could bend it a little to brace it the opposite side of the bearing lip I was pressing against.

    Obviously, that's a totally random item in my garage, so not sure how much that helps.

    It looks like you coud probably fashion something out of the right sort of rawl plug and screw. One of those ones that opens outwards as you wind the screw in.

    HTH!
  • mididoctors
    mididoctors Posts: 18,144

    HTH!

    yeah it did cheers

    at least I know its possible :lol:
    "If I was a 38 year old man, I definitely wouldn't be riding a bright yellow bike with Hello Kitty disc wheels, put it that way. What we're witnessing here is the world's most high profile mid-life crisis" Afx237vi Mon Jul 20, 2009 2:43 pm
  • So how did you get the bearings out in the end?

    The whole process was way too clumsy for my liking. If you've found a better trick I'd be very interested to know, as all this has really put me off cartridge bearings. Would be interesting to know if there are better solutions (outside of difficult-to-obtain specialist tools).

    I'm seriously thinking of going 100% cup-and-cone in the future.
  • mididoctors
    mididoctors Posts: 18,144
    So how did you get the bearings out in the end?

    The whole process was way too clumsy for my liking. If you've found a better trick I'd be very interested to know, as all this has really put me off cartridge bearings. Would be interesting to know if there are better solutions (outside of difficult-to-obtain specialist tools).

    I'm seriously thinking of going 100% cup-and-cone in the future.

    struggling... going for a puller from sealey one of the inner diameter tools or a race insert type which I think means you destroy the old bearing. Thou this is not really a problem

    ... will let you know

    thinking of getting zonda's or neutrons and not being a cheapskate on my wheels in future
    "If I was a 38 year old man, I definitely wouldn't be riding a bright yellow bike with Hello Kitty disc wheels, put it that way. What we're witnessing here is the world's most high profile mid-life crisis" Afx237vi Mon Jul 20, 2009 2:43 pm