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I have a long wheelbase recumbent built by Sun Bicycles. There are some complications with finding out what kinds of components went into the interior of the bike. Brakes and shifters have their brands labelled proudly, but the rest, not so much. And the manual that came with the bike doesn't mention anything about advanced maintenance.

This is my first major bike maintenance project, going beyond my normal stuff of cleaning and oiling the chain or replacing the brake pads. The entire drivetrain has about 5000 miles on it and needs an overhaul. I can feel a lot of drag in both the front and rear axles. Not grinding drag, but just sluggishness in turning about the axle. So, I was taking them apart to figure out what components need replacing, and in both cases I ran into basically the same problem.

The front looks like this:

Front axle, starting disassembly

I've started to take off the lock ring here on the front hub. That entire conical shape actually appears to be the front lock ring. I can take it completely off, but once done, I have a lock ring on the opposite side, the axle sticking through the entire bike, and no indication that any part of it wants to come out. So, problem the first... how do I get the rest of the axle to slide out?

The back looks like this:

Rear freehub

On the opposite side, I just have an axle sticking out. On this side, I have a freehub and an axle with a lock ring, and no clue how to get the lock ring loose so that I can pull the axle out.

What am I missing? This should be relatively easy, but I've been banging my head against it for a couple of hours and making no headway at all. My bike shop was closed today and is closed tomorrow, so I'll call them on Thursday if I'm still having trouble. But, I wanted to ask here, first.

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  • 1) Note that a little "sluggishness" when you twist an axle by hand is normal and good -- it indicates that the bearings are appropriately "preloaded". 2) There is a modest possibility that your axles contain cartridge bearings vs loose balls (though usually the diameter of the hub is a little larger if this is the case). If this is the case there's no conventional cone.
    – Daniel R Hicks
    Oct 17, 2012 at 12:15
  • I found that to be the case after I got stuff to pop out. What I'm not sure of now (and I haven't pulled off the freehub yet) is how to diagnose where all of the drag in the system is coming from. If it's spread around a lot of components, I could be in trouble, but I'm going to hope that examining and replacing worn components will solve all of it.
    – Savanni D'Gerinel
    Oct 17, 2012 at 16:01
  • Describe "drag". The axle should be stiff enough that it doesn't spin if you twist it rapidly with your fingers, but it should not require any real effort to turn.
    – Daniel R Hicks
    Oct 17, 2012 at 19:46
  • That seems about right. I notice the drag most when the whole system is put together. Spinning the front pedals when not under load should be trivial. In fact, they should actually continue spinning for a moment after they let go. Instead, it takes noticeable force, and they stop the instant I release them. Could be an issue in the bottom bracket, which I've not taken apart yet.
    – Savanni D'Gerinel
    Oct 19, 2012 at 2:15
  • Note that one common complaint about cartridge bearings is that they have slightly more drag than loose bearings when not operating under load. In a wheel hub the axle will not seem to spin quite as freely. This all equalizes, though, once you apply weight to the bearing.
    – Daniel R Hicks
    Oct 19, 2012 at 2:27

2 Answers 2

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They both look pretty standard to me. Normally you remove the lock nut and cones from one side. The bearings should be visible and fall out (careful to catch them all.). The axle should then just push through to the other side. If you can see the bearings (or they fell out), a gentle tap, with a light hammer may be needed (although i cannot imagine why) to dislodge the axle.

With the rear wheel, remove the lock ring and cone from the left side (non-drive) and push the axle through (again, watch the bearings).

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  • I went back to try it. It took more than a gentle tap... I actually applied a bit of force with the palm of my hand. It appears that the bearings are in semi-sealed cartridges and those cartridges are in a very, VERY tight fit.
    – Savanni D'Gerinel
    Oct 17, 2012 at 16:03
  • Generally, sealed cartridges would be a force-fit to the hub and would require a specialized puller to remove. The axles should come out without much effort, though, if they are similar to the cartridge units I've worked with.
    – Daniel R Hicks
    Oct 17, 2012 at 19:43
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First things first, make sure you have the specific 'cone' spanners for the locknuts (these are just thin, 2-3mm thick, spanners). They're probably 14/16mm on the front and 15/17mm on the rear. This is one of many jobs that you'll need specific high quality tools for :)

Secondly, from the look of it the front cones have rubber dust seals over them, these can just pull off to reveal the locknut/cone. You only have to undo one side to reveal the bearings on both sides as the axel will slide out. For the rear bearings, just undo the locknut/cone from the non-casette side. I expect there will be another dust seal on that side.

There's many tutorials online about how to properly tighten the cones/locknuts back up. But let me warn you: it's a skill and will probably take you more than 10 attempts to get right (just persevere!) You want a little drag and very minimal play (the quick release will remove a tiny bit of play when tightened).

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    +1 : Even though it does not answer the question (or does it answer an as yet unasked question?), the last paragraph deserves recognition.
    – mattnz
    Oct 18, 2012 at 0:59

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