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Whats the correct sidestand?

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Oddjob:
I bow to your superior knowledge on the metal of tow bars Sye, never really interested me enough to check one.

K2-K6:

--- Quote from: sye on August 09, 2022, 01:45:17 PM ---Tow balls are cast iron I believe. Very strong but brittle and shouldn't be straightened or otherwise heated.

--- End quote ---

I can see the thought process as it certainly looks similar to cast iron, but usually it'll be cast steel, or forged and very likely something of a match to these Honda footpeg/sidestand materials and construction.  A fully loaded tow ball hitch would likely run go something like 30 ton localised tensile loading (that's peak load reversal) and probably could sustain something like 60 before yielding. Cast iron wouldn't get anywhere near this in tensile loading with that cross section, also illustrates just how strong steel is.

The particular problem with a repair or modification as asked previously is that if an item was damaged (maybe in an accident) what on earth happened to it to take it past the yeald point! The tester responsible to the owner for inspection would never want to entertain that level of uncontrolled liability, hence the probable advice to replace with another that's been supplied to confirmed standard by giving a fail notice from that inspection.

K2-K6:

--- Quote from: deltarider on August 09, 2022, 07:37:34 AM ---I'm no expert. Here a few questions.
Why is it when a frame needs to be corrected after an accident, this is done cold?
Why is it that both in Germany as well in Holland when cars at the yearly APK (Holland) IÃœV (in Germany also for bikes) will be rejected when the inspector detects parts like trailer hooks have been heat treated?
A friend's bike's handlebars were slightly bent after a drop. The mechanic at his dealer refused to bend it back to its original form, arguing it wasn't safe.
I'm not suggesting I know the answers. I would like to learn more on the subject.
Can you suggest what caused the metal fatigue of my main stand?

--- End quote ---

There's many detail running concentrically here.

To give initial split it would be design/structure & metallurgy/heat treatment.

Handlebar and frame tubes are usually bent cold but using a mandrel (inner and outer tube support) to keep their cylindrical shape as far as possible in finished item. Bending through damage that compromised the bore geometry significantly is ordinarily not recoverable by straightening as the tube is normally left partly crushed, which affects it's load performance.

Liability again, nobody in a legal sense where they are asked to judge and assure you "it'll be fine" will want to take that on realistically.  If anyone is involved with cycles that use carbon construction on bars, frames etc the structures can be caused to fail just with things like brake lever clamps, paranoia prevails with any suspect item too risky to use critically.

Side stand and foot peg mount are generally solid cast steel and will accept realignment without much problem at all. There's practical limitations on anything though, with bent double as example likely to give problems.

K2-K6:
For the metallurgy aspect,  the steel types can initially be split into two groups (it's a very large topic, this is just scratching the surface) those that respond to heat treatment and change their structural properties in proscribed way, then those that remain stable when heated and cooled, the properties not changing.

It's principally carbon content that promotes how this happens,  above a threshold in steel the reaction is to harden and be more brittle when heated and quenched, seen in cutting tools for example. Heated/quenched/ tempered for springs, in which the tempering process (heated to lower level than quench routine) has a very long slow cooling period to refine the grain structure, and hence the material hardness to flexibility aspect. With the alloying mix and process type it can be optimised for the type of components it's used to produce.
A metal hacksaw blade as a example of mixed properties is interesting, it can be made of all heat treatable steel but with just the teeth hardened and quenched but back side of blade not heated to leave that section flexible and supporting intended use without snapping.

The route to research this if of any interest is by looking at "martensite" or martensitic microstructure as it describes how the grain structure forms differently in response to heat treatment methods.

The other side of this split is low carbon steel that doesn't respond to heat treatment, often referred to as "weldable" in workshop.  Frames etc are mostly going to be this as it's not easily possible to control the temperature around the weld site, leading to potential fractures at the boundary of temperature because of different localized heat range. That's if it were made of the wrong alloy.
Generally something that's heated through welding or other means it's wise not to quench the workpiece unless you have very particular reason and knowledge as to why that's needed.  All of these components are safe to bend, weld etc if there's no obvious damage to compromise the way it works.

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