SunTour XC 9000 hubs

These are the hubs I got with Old Bike aka the Alves in 1990. They are SunTour XC 9000 with a threaded freewheel and solid threaded axles, and cartridge bearings. With this combination, and at their high quality, they must be a bit of a historical curiosity. At the time, the same family of hubs were offered in a cassette freehub version and with solid or QR axles, as though SunTour were keeping their mind open about what people would want. The history nerds say these hubs were manufactured by Sanshin, and there are some nearly-identical relatives branded Specialized.

At the time, I just wanted the most solid, good-quality hubs I could get. The choice of the threaded freewheel version was probably down to thinking freewheels would be more available than cassettes in odd parts of the world. The solid axles resulted from Charles asking whether I needed quick releases and we agreed nah, I’m not in a race, the extra seconds it takes to use a wrench don’t matter and it makes it less easy for some passing opportunist to steal the wheels. I also had the experience of QR hubs on my old Peugeot, and I’d had to hammer the rear axle straight a couple of times, so I was inclined to get the most massive axle available. I still would be, tbh, though I know that strength-wise, the material in the middle of an axle isn’t really contributing.

The hubs worked without complaint until recent years, and if I hadn’t taken an interest in them, they probably would still be running alright on their original bearings. But as it happens I did take an interest in them and thought I could detect a little play in the rear wheel, so I decided to replace the bearings in 2019, just before they turned 30. To do this I bought a Wheels Mfg. bearing press and a bearing puller. I don’t have any pictures of that episode, partly because the front wheel was easy and done in seconds and partly because on the rear wheel it was a battle getting the bearings out. (When I’m in the throes of a mechanical panic, I feel taking pictures is sure to jinx things.) In the course of this I broke the conical-headed screw whose job it was to spread the split end of the bearing puller in order to grip the inner ring of the bearing. I did a bodge using a length of M5 stud and grinding a somewhat conical end onto a long nut, but I wouldn’t recommend this.

So I have a few tips for anyone doing this:

• For reference, the bearings in these hubs are 6001 2RS, ID 12 mm, OD 28 mm and thickness 8 mm. I got the Enduro ABEC-3 with LLM seals as replacements. A guy from Enduro seems to suggest LLU seals might help the bearings last longer, here.
• When replacing the bearings, remove and replace one side first, before removing the old bearing on the other side. This is so there’s always a bearing in the opposite side from where you’re pressing a new one in; the other end of the press needs to locate into it.
• Use a bearing puller with a lip. Mine was smooth and I had a huge fight to make it grip the bearings firmly enough in the back wheel. This is confirmed by seeing the original SunTour tool for the job and, on getting into the hub, by noticing that there is space behind the inner ring of the bearing for a tool to hook in there – rather than relying on friction alone to grip the bearing.
• Be very careful setting up the axle. Just recently I noticed that the rear bearings seemed rough, and (after having the fight with the bearing puller again – I am really gonna get a proper one for next time) I found that the drive-side one had failed – meaning it still turned, but one of the balls isn’t a ball any more. I doubt this was a random failure; I think it was probably because I screwed the nuts down too tight on the bearings. The setup is like this: on the axle, there are two nuts that have a right-angled profile that gives them a press fit in the inner ring of the bearings. These need to be set at the exact position where they hold the bearings without any play, but before they make the bearing run any less freely. You can test this by twiddling them. On one end, the nut will already be fixed in position by its locknut. On the second end, you then have to add the locknut without letting the bearing nut move at all. FYI the bearing nuts have flats for thin 13 mm cone wrenches and the locknuts are 17 mm. TIL: these bearings are not made to work under a persistent lateral load (lateral for the bike, axial for the bearing, that is).

I debate the future of these hubs with myself on a slightly obsessive basis. It would be logical for me to switch to 8-speed freehubs; for example, with an 11-34 cassette I could probably have all the gears I need with a double crank instead of a triple. And the freewheel availability problem would be solved.

OTOH, for 8-speed I would have to “cold set” the rear end of my bikes out to 130/132 mm and I don’t really fancy doing this. Just to get around the freeweheel issue, 7-speed freehubs with 126 mm OLD are also a thing, and quite easily available.

And again, I tend to think that these hubs have served me well for 30 years and what if I had 2 or 3 pairs of wheels based on this type of hub? In all probability I’d be set up for the foreseeable future – if I have good freewheels. (Another 30 years would get me to my late 80s … must try to wear stuff out faster …) And there are some NOS pairs of these hubs around. A curious detail is that there are plenty of the freehub versions (SunTour made two different types of freehub in those years; incompatible with each other and with everything else), but they are effectively obsolete because cassettes in usable condition are disappearing. Whereas my threaded-freewheel version, in principle, is still viable. The availability of decent freewheels into the future is the question-mark here.

This is the one part of the bike where I am tempted to stay retro just for the sake of it. For what it’s worth, there’s a big ol’ thread on Bike Forums debating the virtues of these and other historical hubs, and if you have the patience to wade through an entirely male (as far as I can tell) forum, there are some quite interesting facts in there.

I think the consensus is that the most bombproof, as well the most serviceable hubs, and the first to use cartridge bearings, are the Phil Woods. But they’re out of my price range. Hubs like mine, in contrast, are definitely not serviceable “out there”; they are a bet on never needing it.

And then for the vintage lovers there are the Maxi-Car hubs. These have a special place in history as almost a hybrid between how cup-and-cone and cartridge bearings work, if I understand them correctly, and apparently they can last forever. No wonder they stopped making them …