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Lunchtime job: Replace pads in Spyre mechanical calipers. Estimated 10 mins.
Front one done and adjusted in a few minutes.
Rear one, oh the retaining pin seems tighter, just a little more forc... GRARGHAARGHHARGH!
I've never changed these before and it was an ex-demo bike, which leads me to believe there was some existing wear. I used a nice new hex key at the outset, but no joy. Bolt head is totally rounded out.
Tried cutting a slot with hack blade but the sweep of the caliper body means can only cut a slot on one side of the bolt head.
What would STW do? It's been a Rottenday™, am about to kill self with fire*. Please don't say it 🤐 🤣
Main body of pin is approx 3mm wide.
*notreally.
Can you get a set of Molegrips on there?
Use the 'rod' bit where it goes through the pads between the two halves of the caliper - hold that with needle nosed pliers/mole grips and turn from there.
easier with caliper off the frame I suspect.
Drill it out. Replace with shimano split pin as a temporary measure.
if you can get to it, tighten a drill chuck around the head.
or last chance, running an oversized metal drill bit in reverse can sometimes catch and shock it out. might trash the bit though.
Should be able to get some pliers on there.
Or just save a lot of hassle and buy a new caliper....
Molegrips highly unlikely/impossible, there is so little room, and have already nicked the caliper with hacksaw blade.
The pin is prob fairly rusted in there going by the first one. Not sure needlenose will do it.
Say if was to drill - what type of bit? I only have a Dremel/rotary type tool available, the drill is elsewhere.
I have split pins on hand for temp fix.
well dremel a slot in the head then.
dremel a slot? I doubt you'd get much force with pliers, or that molegrips would fit.
It can be tough to drill steel out of aluminium IME, but the socket should give you a good centre to start, you'll need to re-tap.
Dremel a slot
Por supuesto!
*update - slot cut. (Shame the angle of attack was different from the prior hacksaw hence the double slot on one side).
For this to work I need to penetrate that rust. What product for max penetration with minimum pollution of pistons? The bolt head is more or less sealed from the outside, something may trickle in/ingress from the pad side. Don't really want to dismantle, soak in some product, and then degrease/reassemble if avoidable.
Smash a torx bit into the bolt head? Has worked for me in the past.
Never had to myself, but folk do recommend bashing in a torx and trying to drive that.
Obviously do as much as you can to at the same time - soak in penetrating oil, or WD40, add heat and then try to make it budge.
Hammer in next size torx bit?
Get hold of a set of these, left-hand drill bits:
https://www.amazon.co.uk/Sealey-AK8189-Left-Spiral-Drill/dp/B01N2NLHMY
and use the smallest on the head, at low speed (with the drill in reverse, obvs). It's likely to start biting in and _may_ catch and unscrew it.
If you've got Torx keys, you may find one that's the right size to push into the hole where the hex head should go and get that to bite.
If the worst comes to the worst, it's only a retaining pin - if you have to drill the whole thing out of the caliper and / or you enlarge the threaded hole slightly, you can just use a split pin through the holes and the pads, like some other manufacturers do from new. 😉
Seems I need to type quicker
Argh, just read the torx key solution. I only have one torx which is too big, would have bought a set tho. Too late. Now the cocking slot has malformed/split because impatience with screwdriver. I have about 2mm of material left to slot out and try once more. Only have GT85 or 3 in 1 AFAIK
*EDIT oh my dear gods, the utter ARSE OF IT ALL.
Translation - stupid bagofshite Lidl/Parkside proprietary 3 pin softashit power-connector has broken off when I disconnected after round 1. It didnt have a hard life - cut 4 guard stays and four brake cables in four years. Unfixable. Worthless. Not economical. I want to smash it all with heavy things/my skull.
Thanks all, BTW. Your good and generous advice deserved more careful translation into considered action.
did you see my suggestion? work from the middle of the pin where there's more access?
For future ref - bash in a torx...every....single....time!
I bought a couple of cheap torx bit sets for exactly this purpose.
Also....when I tried to type ‘bash in a torx’ it autocorrected to ‘bash in a Tory’....how very STW!? 😄
Do you have access to the reverse side or do the chainstays get in the way? Tried getting a drill on to the blind side?
Dont waste time with penetrating oil. Tap the bolt very sharply at each end with a punch, that will shock the threads and break the corrosion.
Irwin bolt extractor over the top If there is space to get in and you can get one the right size?
Bolt extractor
Just drill through the entire head of the bolt. Once the heads gone there's no longer any tension on the shaft, no tension means no friction and the remainder should just screw out by hand.
Works every time with stuck cleat bolts, just stick a sharp 6mm* bit in the drill and go through the head of the bolt till the cleat falls off and the "stuck" shaft in the sole turns out to not be stuck at all.
*needs to be one size bigger than the shaft so it drills through the head and breaks it off the shaft rather than trying to drill down the center of a steel shaft in an aluminium body.
Bit late now but torx bit, penetrating oil and hot water from a kettle. Don't worry about the pistons getting contaminated, just wash them off with IPA after and keep the new pads oil free.
As it is, do the above but with screwdriver, possibly also something to grab the central section of the pin - you could dremel it to put a flat on one side to help out a bit with this?
+1 for the extractor set
Dont waste time with penetrating oil. Tap the bolt very sharply at each end with a punch, that will shock the threads and break the corrosion.
Yes. This shock thing works quite good.
Plusgas penetrating fluid and let it do it's stuff for a while. I'd try to cut the pad spring with your dermal type tool and get hold of the pin in between the pads.
Changing pads?
Parkside Dremel, that connector is repairable. Cut it off, open the case of the charger and hard wire.
Use the Dremel to cut the eye off the 2 pads in such a way that they can be removed completely.
This will then give you access to the plain diameter of the pin.
Can you then get a thin nosed pair of molegrips on the pin. eg. https://www.screwfix.com/p/stanley-long-nose-locking-pliers-170mm/6711j
Whilst you are out shopping for this, leave the caliper soaking with gt85, wd40, plus gas, diesel etc.
Good Luck.
have you got a manual impact driver? cut a new slot and then use one of them to get it turning. make sure you support the caliper properly on some wood.
I was just going to add what drnosh said as another option. Cut the pads out as they are going anyway and get some good grips on the pin.
You could also try putting something in the pin hole and turning that but I suspect it will just break across the hole.
Em...isn't this a 2-piece caliper? Split it up then remove the retaining pin with molegrips.
Don’t listen to folk poo pooing penetrating oil. Try ZX54 - solved every siezed fastener, bearing, cassette etc I have ever had. It’s military spec, used for sorting stuck tank tracks!
You will need a sacrificial torx bit too though.
Can you cut a slot on the other end ? Plusgas is your friend, let it soak to do it’s stuff.
Feel your pain. These days I use a mixture of acetone and ATF for loosening fasteners.
I also tapered the end of some cheap Allen keys. Bash the short end in, put pressure on the long end and tap with hammer. Usually works for small bolts
For larger ones the impact wrench plus a set if sacrificiak torx ends, the wrench jams them in tighter as it tries to turn
Also sometimes filing a couple/several flats on the outside and jamming a slighlty too small impact socket on the outside and then using the impact gun, which again jams it on tighter
I also have a manual impact wrench. You hit one end with the hammer and the other end turns a quarter turn down and around.
Between those things I've only ever had to drill out a couple of bolts.
OP.
Any updates?
Had this happen and the efforts to get it off ending snapping the head off. In Glyncorrwg car park at Afan, and I needed to change the pad!
Bike shop there fiddled about and got a drill with fine enough bit to drill it out. Not sure which way they did it but I'd guess drill the end that has the thread.
After that... split pins, always.
If you must use those bolts, don't do them up too tight. It's tempting to tighten them fully but doesn't make a difference to the pads, they're only a retaining bolt and usually have a clip other side to stop falling out. But then, split pin. What used to be used. Ain't broke, don't fix it.
Drill the hole out where the split pin goes through to a larger diameter
insert a tiny bar and use that to twist whilst you try to turn the head with a flat hhead screw driver
Wont make it any worse but may add more torques
Plus gas it to deathe ,
Try heat as well, but maybe not a blow torch
You may get a result from hammering a 6-7mm socket over the head , the cuts may allow the head to collapse in giving the socket something to grip on
Two weeks already? Just an update and to say thanks to all for suggestions. As stated, the dremel thingie was knacked, and having no solderer or skillz there was no way to fix that. Turned out a friend knew a local MX engineering bloke who kindly took a look and very lickily managed to extract the pin with an EZout set. Took a couple a goes and 15 mins of his time which I was more than happy to pay for.
Stuck a split pin in with new pads, it will stay that way, followed by the front one. Much better!
Onwards...
Stainless steel or brass split pin?