Different hardware standards?

[bikejunk]

Lol "if your strong enough you can make it fit " - What someone told me at a British motorcycle meet .......

 

[fshbydesign.com]

I’m disassembling my 1923-ish Iver J and I’ve noticed some of the nuts and bolts don’t take “normal” wrench sizes. Example - a 5/16 wrench is a bit too small for a bolt head but a 3/8 is way too big. I’ve worked around this using metric wrenches and/or a crescent wrench. I’m not a fan of crescent wrenches but it’s getting the job done. Also, modern screwdriver blades are too thick for the slots on screw heads. The hardware on my bike isn’t boogered up so that’s not the issue.

I did some internet scouring and apparently there was no universal standard for hardware in this era. True? Also, is the threading on old hardware more or less the same as current fine and coarse stuff?

Sorry if this has been discussed before but I did a search and didn’t find anything.

No standard is a true statement. Universal fit for screw threads based on major and minor diameter plus pitch diameter was not in the Machineries handbook till the end of the 40's. There was a push dude gd&t standards that arose as a result of the war effort. Also manufacturer-specific thread sizes were popular among many companies. Though most make sense, like the 3/8-20 threads on many Wald stems, some do not, like the oversized threads on the New Departure hubs. Hope this helps.

 

[Andrew Gorman]

There's some good information at:

Standard Numbers for Open-End Wrenches

A table of industry-standard model numbers for open-end wrenches.

alloy-artifacts.org

 

[fattyre]

Not sure if this video will have any info or an explanation, but if you wanna geek out this is a good one!

 

[RustyJames]

Not sure if this video will have any info or an explanation, but if you wanna geek out this is a good one!

Wow! That was informative and confusing at the same time. Now I’m wondering if my Whitworth wrenches might actually become useful. My pitch gauge will definitely be put to use. Also, the rear axle on my IJ is slightly bent so using something off a newer bike may not be an option.

Thanks to all for the input. I’ve dragged home bikes with stuck seatposts/stems, weird hodgepodge of parts, bent forks but this hardware thing is a new challenge. This makes old French bikes seem like a walk in the park!

 

[rustyjones]

A draw full of these old wrenches comes in handy. Most don't even say what size they are. I just keep trying different ones until one fits

 

[Barnegatbicycles]

Also some of their threads are special. Especially their fork threads. Just an FYI if you have chae threads. Definitely get a split die.

 

[chitown]

Feb 1917 Motorcycle Illustrated

 

[chitown]

End of the WWI and end of standardization regulation in bicycle & motorcycle industry.