The theory certainly states that the ends of a coil spring will rotate relative to each other as the spring compresses and extends. It's not hard to imagine that being the case, without torturing your brain with the mathematics of it. Thing is, as already mentioned, you never seem to notice evidence of this - wear at the end of the spring/bearing surface - on the bike, despite the gazillions of times they compress.
Otoh, some air rifle guys add bearings to the spring seats so's the springs are free to rotate, and they swear this makes the rifle smoother.
Can anyone think of any other applications where you find bearings incorporated into spring seats, cos' I just,,,dunno?

Bearings of a sort, the leaf spring has them at the leading mount point. Climb under a leafspring car and have someone heavy jump up and down on the towball, then watch the spring rotate ever so slightly around the mounting shackle. i know it's a rubber mount but still. You'll notice the car hitting you in the chest more I'd expect.

oil pumps

Wouldn't the piston of the air rifle be free to rotate anyway. Wouldn't the bearing reduce the travel of the spring. Would the reduced travel make the spring more stiff?

Suzi Q wrote:Can anyone think of any other applications where you find bearings incorporated into spring seats, cos' I just,,,dunno?

I solemnly declare that I did not think of these.

Laitch wrote:I solemnly declare that I did not think of these.

Ah. A direct line to the leprechaun King then?

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Problems, problems....

Am currently devising a Schrodinger's cat scenario where the cat, now found to be healthy and liberated from the box, is asked to press a plunger that passes through to the inside of the box. The plunger acts on a spring, which cannot be seen from outside the closed box. The cat is asked (this is theory remember) "So, does that spring feel stiffer than the one you pressed a minute ago?" The spring could be either; A - the previous spring cut in half, or B - a completely new spring, which is twice the rate of the previous one.
The cat agrees that the new spring feels 'stiffer' but feels unsure as to whether he/she can actually use that word, since two realities co-exist......

I first need to find a talking cat. That might put the brakes on the whole project.

To throw another cat in the mix. Some car wishbones have a seat for the springs.
Regards Martin.

Talking about Schrodinger's Cat, there was a lady on the toy train down from Shimla wearing a T-shirt with a joke about said cat. It seems that only she and I understood it. Unfortunately the picture I have of the lady with T-shirt makes the T-shirt unreadable, but it was something similar to this:

https://www.amazon.co.uk/Wanted-Dead-Alive-Schrodingers-Cat/dp/B08HGWMVLW/ref=sr_1_2?keywords=schrodingers+cat+t-shirt&qid=1690238536&sr=8-2

Now, who's going to pull the thread back on-topic?

You took a picture of a woman's T-shirt....!

the second push would be harder as the cat would be tired from the first push

So it’s true - cutting a spring doesn’t make it stiffer - it’s just the cat getting tired!
This all makes sense now. A few weeks ago I had cause to visit the doctor over a personal problem. I explained that, when I was younger I couldn’t bend my manhood in half even using both hands. Now that I am older, I can bend it with one hand. I was worried, but it turns out I am getting stronger!

*

tried the cat and box (neighbours cat and mg midget spring) this morning the cats not moving but does appear to be going stiff , what does this tell me ?

Nah she's sweet, she's just pining for the fjords.

firstle wrote:tried the cat and box (neighbours cat and mg midget spring) this morning the cats not moving but does appear to be going stiff , what does this tell me ?

....that you're taking this thing far too seriously.