How to bend a steel frame

[RodT]

Last Wednesday, late afternoon, the Cornish moors darkening as the sun sinks over the Atlantic, and I'm going like stink up the hill out of Gwithian towards the North Cliffs. I want to get home before nightfall. Suddenly I hear the sound of doom from the back wheel and everything grinds to a halt. I dismount, check the back wheel, and it doesn't look good. The rear mech is jammed in the spokes and won't be budged.
Two young men on road bikes power past. The first has a good look. The second asks if I'm ok. I tell him, no, but I've got two mates coming up behind.
Enter Dave and Steve. We're riding from Penzance via Hayle back to Truro, but right now we're going nowhere. I carry the bike off the road into a nearby lane and flip it. It takes two of us to extricate the rear mech, three of us to remove the rear wheel. The hanger is bent almost at right-angles and the whole drop-out is out of true.
15 minutes later, Steve has discovered a method of straightening the hanger. He inserts it into a crack in a nearby block of granite and uses the whole frame as a lever. Now we can replace the wheel, though not all that securely- the QR won't fully tighten. Dave breaks the chain, shortens it and links it up so I can ride home in one gear.
'Which gear would you like?' he asks considerately.
Optimum speed on the way home is 9.6 mph. The chain comes off four times, the rear wheel three. Escorted by Dave and Steve, I don't make it before nightfall, but I do make it, so when I told those two riders that I had mates coming up behind, I could not have spoken a truer word.
What I find surprising is the fact that the impact of the mech tangling with the rear wheel was enough to bend a steel frame without even bending, let alone breaking, the spokes.
The bike is a Cinelli Hobo, and is now at Argos framebuilders in Bristol.

[Cyril Haearn]

Maybe the spokes were too strong, stronger than the frame so the latter gave

Which single gear did you choose?

[RodT]

On the front, I chose the middle of a triple (36t) and third cog on the rear, which ranges from 13-34t. Can't remember exactly. Before the incident, I was climbing steadily in 26t on the front and 34 at the back. The jump into the spokes wasn't caused by a gear change.

[hemo]

Nice to know who your true riding mates as they stayed with you until home, lesser mates would have cleared off. Though a good mate could have still cleared off then come back with the car to pick you and bike up.

[fossala]

On the front, I chose the middle of a triple (36t) and third cog on the rear, which ranges from 13-34t. Can't remember exactly. Before the incident, I was climbing steadily in 26t on the front and 34 at the back. The jump into the spokes wasn't caused by a gear change.

Where you in the lowest gear while honking? Maybe the limit screws where incorrectly set and the flex of the back end while out of the saddle pushed the chain into your spokes.

[RodT]

I was in the lowest gear, but not out of the saddle. Just pedalling steadily. You might be onto something, though- not about the screws, but the barrel adjuster on the cable. I had given it a tweak while riding because the indexing seemed slightly out.

[fossala]

I was in the lowest gear, but not out of the saddle. Just pedalling steadily. You might be onto something, though- not about the screws, but the barrel adjuster on the cable. I had given it a tweak while riding because the indexing seemed slightly out.

If the limit screws where properly adjusted it wouldn't of mattered if you touched the barrel adjuster. Either that or they where set OK, then mech or hanger took a knock. Maybe that was reason you had to tweak the indexing.

[661-Pete]

It's not unknown for this to happen.

Many years ago (my student days) I was cycling with a fellow student, when he suddenly ground to a halt. A piece of paper (I kid ye not - a piece of paper!) blown up by the wind had got caught in his chain and somehow wrapped around the rear mech, jamming it. His continued force on the pedals, until he realised, had twisted the rear mech right round through 180º, and also bent the right drop-out completely out of shape (old Campag steel type with integral derailleur bush).

After fiddling around a bit we decided there was nothing we could do by the roadside. Luckily he was only about 3-4 miles from home, so he decided to walk it. I thought at first he'd need an expensive frame repair and re-spray, but he told me afterwards that in the workshop he managed to straighten the end out. To his satisfaction I hope - well it was his bike.....

[661-Pete]

Incidentally, doesn't this incident make a strong case for spoke protectors - ugly and 'un-cool' though they may be.....

[Antan1]

Blimey, I Can't wait for the second chapter