fossyant
Ride It Like You Stole It!
- Location
- South Manchester
100% failureproof does not exist in the universe...
You need an unobtanium UN91. Or UN71. I have both.
100% failureproof does not exist in the universe...
I returned home today and, in an idle moment, examined the bike. I found a little play in the bottom bracket (square taper 'cartridge'). There is about 1mm of movement at the end of the cranks. I'll give the bike a good clean (lots of mud still on our Norfolk rural roads, and remove the cranks and examine the BB. It's not making any odd noise or feeling 'rumbly', but may not feel great when I turn it by hand once i've removed the cranks. My calculations suggest it has done about 11 million revolutions, so I guess that's pretty good.
In other news, I decided to replace the headset. A bit 'fussy' really, because it had no mechanical problem but was going rusty externally. I had a cheap (but hopefully good) alloy headset with cartridge bearings, which I'd bought a few years ago. I could have done with a hammer and chisel to remove the cups from the head tube, but used a handy piece of 1/2 inch rod and a hammer instead.
. The presses from Temu look ok, but may be a bit short? I really ought to get a couple of suitable-sized washers which just fit inside the 1 1/8 cups and weld them onto the larger washers so it all centres correctly when used.Did you read the word "max"?That approach for alternating loads - like on spindles - inevitably leads to failures.
E.
Of Course Shimano's Hollow Technology Can ALSO be Considered NOT a Calamity.Another forum I'm on has a "classic threads" archive @Moderators
Perhaps you could chisel a space for that on here?
Just saying.
The dealer of my previous 2 bikes can help you - he grinds washers to a smaller outer diameter in order to make them fit between chainring bolts and spiders centering ring, to correct a chainline.I really should get the correct tools, but I have always resisted the urge because the occasion to use them is so infrequent. I use my piece of studding with large washers and nuts to insert the headset cups. Today, as previously happened many years ago, I found it wandered off centre, resulting in the cup going a bit wonky, so I used a piece of wood with the hammer to straighten it before continuing. The presses from Temu look ok, but may be a bit short? I really ought to get a couple of suitable-sized washers which just fit inside the 1 1/8 cups and weld them onto the larger washers so it all centres correctly when used.
Yes it exists, gravity never fails, and collapses any Hollow, those of Shimano first.A well-made square taper cartridge axle can last years of heavy use and abuse without much care...at least for the vast majority of utility bikers.
That's why I still use these things om my winterbike.
100% failureproof does not exist in the universe...

Since your post my rear cog with all its teeth broken off serviced me another 300 km, with Not Any Animal Harmed (too cold for flies).Do you own a car/vehicle ? Only asking, because I hope you'd pay more attention to something like that. If not, then we can breath easy !
If you're interested: https://www.machinerylubrication.com/Read/28517/grease-dry-out-causesI removed the cranks, and the BB spindle felt as though it was very dry. It took quite some torque to unscrew the BB cups - I remember putting Silkolene RG 2 water resistant grease on the threads years ago, and I suspect (as it's very viscous) it dried out a bit and acted like threadlock. The spindle did indeed feel a bit rumbly, and when I knocked the bearings apart there was some rust inside. I found a new BB cartridge in my 'new spares' drawer, only 3mm wider than the original, so fine for the task, especially as the difference was on the NDS. I partially dismantled the cartridge, removed the inner seals from the bearings and added more general purpose grease so it's likely the bearings will last as long as I do. The general purpose grease was also used on the BB cups instead of RG2. When the BB was all installed and tightened, it felt perfect.
I still haven't used my other idea of fitting a 73mm cartridge with a traditional lockring into a 68mm BB shell - to avoid any risk of bearing preload!
As reported: the dealer that replaced my HollowTech Thing found a chisel handy to get out the driveside part of the Hollow Failure, and it did the job.In other news, I decided to replace the headset. A bit 'fussy' really, because it had no mechanical problem but was going rusty externally. I had a cheap (but hopefully good) alloy headset with cartridge bearings, which I'd bought a few years ago. I could have done with a hammer and chisel to remove the cups from the head tube, but used a handy piece of 1/2 inch rod and a hammer instead.
So, at the Very End, you Finally Admit you DO hammer your bicycle.I've only used that tool a handful of times, literally. No use on modern bikes, but I have 3 vintage bikes and the old MTB get's hammered commuting, so the tool has been used, especially when I refurbed the MTB and one of the old road bikes.

Yes. I know it's meaning for roughly 35 years already.Did you read the word "max"?
That changes nothing at all that the approach to "know the amplitude, add a safety margin, done" leads to failures for mechanical parts.The "max" of an alternating cycle is named "amplitude".