I recently bought an old Eastman ten-speed. It's got 700x23 tires on steel rims.

The walls of both rims bend out slightly, maybe 10 degrees each. I'm not sure if they were built that way, or if they've bent slowly over time.

I want to know if this bike is safe to ride with the tires at 80-100 psi. I don't want the (front) rim to explode at 40mph.

Does the fact that they are steel (instead of aluminum) remove the risk of a blowout?

Here's a picture:

steel rim

  • 2
    They would have been built that way, as I recall. Take a tire off and check if they are hook rims. As @uxp100 implies, braking is nowhere near as good as alloy rims, and they are much worse when wet.
    – andy256
    May 23, 2015 at 23:55
  • 1
    I think you should uploads some pictures of your rims so that we can conform that if they are safe or not.
    – robert20
    May 27, 2015 at 11:06
  • 1
    If you're going 40mph on old bike rims, you should get a better bike (with better brakes too).
    – RoboKaren
    May 28, 2015 at 16:16

2 Answers 2


Steel has an advantage over aluminium in that it bends rather than cracking. So as long as your rim is true and not overly buckled its rideable.

Doing 40 mph or 60 km/h suggests you're going downhill or you've got legs like steam pistons. Steel rims are not as good at braking, and stopping from those speeds will take a while.

The discolouration on the rims suggest they are well used, and/or have been rubbing on the brake blocks.

Don't worry about the slope on the sides - that's normal and to help caliper brakes close up flat onto the braking surface.


Some old wheels do not have a hook to hold the tire bead, which limits you to around 70 PSI. Straight wall or a slight flare, doesn't matter, 100 PSI is not doable without the hook, afaik. (Wikipedia says the hooks were invented in the 70s)

In my experience, the tire will come off within an hour or two, and the tire will pop off with a bang as the tube explodes. With straight walled rims, I think 700x23 tires are unusable. There may be some uncommon rim design that I'm not familiar with, but if your rim wall looks more or less flat, it's not going to work.

And the fact that they are steel makes blowout more likely if anything, because they are more likely the old design.

If they have a hook on the rim, I would ride them after I let it stand for a day, but steel wheels really do suck for braking.

  • I'm not concerned about the tire coming off (btw, they are hooked rims). I want to know if my rim has been structurally compromised to the point where one of the walls might blow out.
    – BSO rider
    May 25, 2015 at 0:13
  • Hmm, better post a picture of the rim. I'm typically more worried about wear on older rims, since I've never heard of bending, but I can imagine certain mistreatment could make it happen.
    – uxp100
    May 25, 2015 at 0:58
  • 1
    Darn. They aren't hooked rims. I thought I could tell without taking the tire off :) Sorry.
    – BSO rider
    May 28, 2015 at 14:46

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