UKH

Hi

Suffered the dreaded stripped head on the bs rs505 105 hydraulic caliper on my commute bike. Disk pads down to metal. And can't get the buggers out. 

Tiagra is £50, grx800 is £76.

Any advice on difference? . Direct replacement/105 seems impossible to find... And want to  replace ASAP so I can get to work. 

Many thanks ...

Can't comment about Tiagra vs. GRX, but when I did the same last year, I just drilled out the stripped Shimano bolt - freehand, managed not to damage the threads in the caliper - and just used the allen head bolt that came with the new pads (SwissStop). Plan B (if threads get damaged) was to a split pin in place of the bolt. Seemed like a nightmare, proved to be simple.

Thanks mate. Its certainly a plan I'll try. Cheese masquerading as metal! 

...BUt harder than my drill bits... Still stuck. seems to be absolutely welded in. I don;t have enough time to faff, so I've ordered a new caliper... NOw they joys of fitting it... and then bleeding the system...

in case anyone is interested, the tiagra may have resin pistons, whereas 105 & grx 600+ have ceramic pistons. 

Hmm that weird. The bolts are pretty soft - hence the easily stripped heads. I just used an ordinary 2mm (I think) HSS drill and the remains of the threaded part of bolt (little more than swarf) just spun out. Academic now I guess. I think the trick is not to think of the bolt as a 'bolt' but as a 'threaded pin', i.e., only screw it in far enough to fit the clip at the back. Don't tighten it at all. And make sure the thread is greased.

I agree. If only the bike builder had done that. I retorqued almost every other bolt on the bike when I got it, but sadly failed to do those ones...

Must remember to do the seat post again 

New drill bits may in order. Or a drill bit sharpener. 

I did get some needle nose vice grips on the bolt after breaking the spring. Even they would nt turn the bolt. Think it's welded itself. 

You could try sawing across the bolt head with a junior hacksaw and inserting a flat head screwdriver. I previously rounded out a brake rotor bolt and ordered a "Screw Extractor Set" online. It consists of hardened drill bits and reverse threaded extractors, that extract screws from 2 to 12mm.

Use an electric drill on its lowest torque setting and set it in reverse and the extractor bites into the bolt head hole and tries to remove the whole bolt. Too much drill torque can snap the extractors so once the extractor bites into the head the low torque setting will kick in. Then I just unscrew the bolt without power.
I have used the set multiple times now.

I tried an extractor. No joy.

I think my only hope it to pay it to someone with a bench drill to sort it. I'll try to do that at some point, so I have a spare front.

Replacement arrived today. Also ordered me hex bolt head retaining bolts. Copper slip will be applied! 

The resin pads have lasted 2 years. I'll do sintered front at some point.. If I can cope with the noise. 

Certainly made me think that my choice of summer bike with rim brakes is OK... I'm not looking  at carbon rims atm.

I am however looking at a gravel bike for Mrs b (at some point) ... Which would be hydraulic discs... 

Thanks all.