Thorn Cycles Forum
Technical => Wheels, Tyres and Brakes => Topic started by: Matt2matt2002 on September 07, 2018, 08:10:12 pm
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Had new cables fitted to my Raven by LBS.
Did a good job on the gear cables. Very smooth now.
Re the brakes: I had a new set of pads so thought that since they were doing the cables they may as well fit the new pads.
It appears that the pins do not push down as far as the old ones did.
I had changed the pads a few years ago myself and recall the pins pushing down until the heads) loops were almost flush.
Now they sit a few mm proud.
After a short ride one on the front almost worked itself free.
I managed to save it and returned to the bike shop.
The guy had used the pins that came with the new pads.
He said this type didn't push down flat. I forget the type he called them.
He refitted a new one. And it was proud, like the other 3.
I rode to work just now and the refitted one has worked loose again.
Any thoughts folks.
Hope picture shows the issue.
Picture is of rear brake but all 4 are the same.
Matt
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Mm,
I suspect the groove in the pad which the retaining pin slides down needs to be opened up at the lower side.
That retaining pin should then slide down enough to go through the bottom edge of the brake shoe and stay in place.
Should be easy enough to take the loose pin out and slide the pad out of the shoe to work on it.
Just checked mine and they have a hole top and bottom of the brake shoe for the pin to slide right through.
I can see the pin sticking out of the bottom of the brake shoe and the top is almost flush.
Julian.
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Thanks Julian.
I'll work on that tomorrow.
Not impressed with the bike shop sending me out with brakes in that condition.
Matt
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I just found this from a a few years back...
######£
After playing for a while with the brake pads I realised about the pin and pull it out.
Puting new pads I found some of my new pins wouldn't find the hole in the other side, but the old ones did.
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Matt
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My own experience mirrors Julian's -- for my original pins. I save an astonishing amount of old bike stuff "in case it is useful someday" and find it often is! Salvaged things like old derailleur B-stop and limit screws, shoe cleat retainers and screws, brake pad holders and such go a long ways toward creating a useful bin of touring and shop spares.
I've occasionally come across pins that seemed intended to bottom out in the shoes themselves rather than travel through to the bottom hole of the pad holder. These I considered yoo dodgy to use and set aside, choosing instead to reuse the ones appropriate for my needs.
You really don't want to have a pad sliding out while parked on a hill.
I'm on my mobile while clearing brush at my little cabin on the coast and can't see your photo too well in the bright sunshine, at the moment so I'll ask a question I'd know if I could see better: Is the closed end of the pad holder facing forward? Not intending to impugn your mechanic, but that could account in part for things loosening so quickly under braking.
All the best,
Dan.
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Better picture to follow Dan. Near midnight now
Appreciate your input.
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The pin needs to be pushed in further, try it without the pad and it should go through both holes. A pair of long nose pliers may be needed.
You can see how the pins should look here: https://youtu.be/wFWBHVnJVSw?t=30s
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Thanks Mcspud. I'd searched on YouTube and hadn't managed to find anything but your clip is great.
Watching the whole thing I can spot 2 types of clip. I have the fatter one. I'm pretty sure that they came with the pads. Maybe I need thinner ones?
I can see how they should push further down but being ' fat' they don't want to go deeper. All 4 protrude. And 1 keeps wobbling out.
I'll spend more time today trying to get them to sink right in.
Should they ' clip' in? By that I mean, the end clip over the side of the pad?
Thanks for your time and help.
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Hi Matt,
Looking at replacement shimano cartridges on SJSC's website the picture shows both types of retaining pins: https://www.sjscycles.co.uk/brake-blocks/shimano-brr550-m70ct4-cartridge-brake-inserts-fixing-pins-y8a298060/
Have you tried inserting the pins in the holders without the pads in place?
There's a thread about it here: https://forum.cyclinguk.org/viewtopic.php?t=93665
As Brucey says there "if you don't want to alter the toe settings, and you do need better access, you can take the entire brake arm off the bike (one M6 bolt) instead of removing the brake shoe from the arm."
As for "Should they ' clip' in? By that I mean, the end clip over the side of the pad?", no not to my knowledge.
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Problem solved
Many thanks for links and advice
I pushed all 4 pins right down until the day end hooked over the brake pad holder.
There wasn't always a clear run through due to a slight burr on the inside of the blue pad. Once smoothed out the pin went right down with its end hooking over.
They sure won't be coming out now.
Not impressed with the LBS!
Pictures not good but show pin going right through.
Once again appreciate all comments and links.
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Glad you got it sorted, Matt.
Some more threads on the subject: https://forum.cyclinguk.org/viewtopic.php?t=120317 and https://forum.cyclinguk.org/viewtopic.php?t=103503 and https://forum.cyclinguk.org/viewtopic.php?t=109140&start=15 and https://forum.cyclinguk.org/viewtopic.php?t=103503
The only retaining pins I could find are the same as yours https://www.ebay.co.uk/itm/232049215081
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Matt,
great work - that looks a lot safer.
Julian.
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yeah this is surely the trouble I had that caused me to lose one pad and then have another pad fall out a couple times. I found the original pins that came with the bike. I'll have to compare these to the new pins I got with the new pads. For sure I have not managed to get the new pins all the way through that bottom hole.
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I can confirm Matt2matt2002 that you have now fitted them correctly, they should always be fitted right down.
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I can confirm Matt2matt2002 that you have now fitted them correctly, they should always be fitted right down.
Many thanks. Always good to hear from the expert!
I'm just wondering if I should enlighten my LBS.....
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I think that I have always re-used the pins. Not for any particular reason, but the pins were right there from when I removed them and the new pins were still in the package that the pads were in.
Interesting, it never occurred to me that pins could vary.
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I can confirm Matt2matt2002 that you have now fitted them correctly, they should always be fitted right down.
Many thanks. Always good to hear from the expert!
I'm just wondering if I should enlighten my LBS.....
I think you should indeed enlighten your LBS, you may need to print out some evidence so that they believe you, but it could save someone else from a potentially very serious accident, so well worth while.
I think it is a fairly common mistake.
I just noticed the same thing on the Sherpa advertised here http://thorncyclesforum.co.uk/index.php?topic=13093.0 though it is the older version of the pin.
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Thanks. That picture shows exactly how the pins were.
Yes. I'll call.in for a chat with the LBS.
New cables and wires set me back £80+.
I had supplied the new pads.
Came away with the pins about to fall.out and a loud squealing from the front brake.
" Don't worry, it will bed in soon!"
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I finally got a pin properly inserted to secure the last brake pad - the other three pins went in pretty easy, but for some reason the fourth pad gave me some fight. What seemed to be the problem - there's a mold seam that runs right through the the middle of the pad, down the long way. At the nose of the pad, the part that gets inserted first into the holder, that seam prevented the nose from running all the way up into the closed end of the holder. It was probably just 0.2 mm or so short of being fully inserted, but that was enough to prevent the pin from being able to fit through that bottom hole. I scraped that mold seam clear up at the nose of the pad and reinserted it... now the pad went in just that little bit more, and the pin could find its way out the bottom hole.
details, details!
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Yes yes. I had that same problem. I thought I had mentioned it.
All 4 pads had that ridge. A production problem I guess.
Once removed, problem disappeared.
Good to know for the future or other folks tips.
Nice feeling, new pads. Stops on a sixpence or whatever the equivalent is now!
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There wasn't always a clear run through due to a slight burr on the inside of the blue pad. Once smoothed out the pin went right down with its end hooking over.
My pad also had the pin channel rather obstructed from the mold seam. I scraped this clear but it wasn't enough to allow the pin to seat properly. Then I smoothed out the seam up at the nose of the pad so the pad would insert more fully. That was the final step that got the pin fitted. Oh and I tried cleaning out the front of the pad holder, in case there was a little pebble or something stuck in there that was blocking the pad from inserting fully. There might have been some cursing along the way too. But I think it was cleaning up the mold seam that had actual positive effect!
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There might have been some cursing along the way too. But I think it was cleaning up the mold seam that had actual positive effect!
Don't underestimate the importance of your creative language, Jim. It's often the intangibles that make the difference ;)