Wednesday, 11 September 2019

stitch in time saves nine (and maybe some skin and bone too)

I'm a big fan of preventive maintenance, its how I've kept so many things I own lasting for so long (like my 1989 Pajero which is still going nicely thank you).

I decided that I thought I could feel some movement in the steering head bracket where it joins the board and pulled the base plate off to have a look if any bolts were loose.

Turned out one was, but not how I expected:


So this bolt has had the head shear off, but I am not sure this is what's causing the small amount of play, as the others were tight.

None the less I'll be now taking extra care in riding on bumps until I can get back up home on the weekend where it will be:

  • easy out that bolt shaft
  • go to the bolt shop to get a replacement (maybe more)
  • remove and inspect the other bolts
  • replace those washers with something better (perhaps even a stack)
Interestingly the bolt is FKE 12.9 which as it happens is a very high standard of bolt strength. I got this information (from this site)

Property Class 12.9 

PC 12.9 parts have a minimum tensile strength of 1220 MPa for all sizes. These parts are very high strength. In fact, they are the strongest of all the parts that we have covered in this series of blogs. 1220 MPa are roughly equivalent to 175 Ksi.
So that's encouraging ... especially how my scoot always gets used on "smooth roads" ... a compilation of one of my favorite tracks around a wetland area



My advice to you is if you haven't pulled the belly pan off your scoot I recommend you do so because you don't want that other bolt to go and risk a situation of having no front wheel (at speed). Like this one I observed on a website:



which goes to show that bolts need to not only be high tensile but also screwed into something which will take the forces (which are magnified by speed). As it happens that bike was doomed from the start because the maker did not put the full compliment of bolts that were needed in on assembly:


pretty fucked for a scooter which costs nearly double mine...

So if you value your physical health, take safety inspections (like brakes) seriously.

Happy Scooting

PS: The Solution

 my solution to my problem is here (well, its the next post above this too, but if you didn't come in through the front page you may miss it)

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