Dan_1802

This is my first post but hopefully not my last!

On a ride recently, 2 nuts on my rear brakes became loose and the brake pads and a specific spacer fell off. On my walk of shame home i managed to find the pads but not the spacers.

Talking to a local bike shop, i was recommended to replace the whole brake set (being a legacy part, they couldn't supply it). I also had a look for exploded diagrams of the Shimano STX-RC brakes to no avail.

Here is the brake set that I think would work - but I would like someone more experience than me to double check because I am no expert. https://www.ebay.co.uk/itm/Shimano-Al...kAAOSwRYRelGGz

Here is a picture of the bike and the front brake: ibb.co/cTZgh04 ibb.co/XJsQbVg

Thank you for any help.

fietsbob

Your link ibb.co/cTZgh04 ibb.co/XJsQbVg "Does Not Exist"

Shimano CX 70 brakes are a little bit nicer,these can also use V brake pads , https://si.shimano.com/pdfs/ev/EV-BR-CX70-3223A.pdf
I like these pads .. it has V brake threaded posts ... https://www.koolstop.com/images/KS-CTSA.jpg


Economics of internationally sourced components parts with a long distance supply chain , just do not favor stocking individual parts at retail shops,

Like Campagnolo did in the 70's..







...

Happy Feet

Why did they say replace the whole set?
Not to be jaded but a lot of modern bike shops lack common problem solving skills and reflexively say "buy a new one" whether component or bike. A spacer is just a spacer, unless proprietary in some way.

veganbikes

Replacement while sometimes a good idea may not quite work in this situation. Older cantilever brakes hit the rim lower than modern stuff. What brakes are currently running? If they are 80s to now then you could replace things and if it were me I would do Paul brakes as they are fantastic.

However as people have said spacers aren't super difficult to get and if it is an older school bike you may check in with René Herse cycles and see what he might have as I know Jan is making MAFAC compatible stuff in really nice quality.

cyccommute 

Before you go unloading on the shop, you should research what the problem is. STX RC brakes use a smooth post pad and the “spacers” are part of the brake system. A threaded pad comes with the spacers and losing them isn’t much of a problem. The spacers, nuts, and other hardware in the STX aren’t easily replaceable.

Dan_1802: Here’s the exploded view of your brake. Did you only lose one pad and the spacers? I’ll see what I can find.

cyccommute 

I think you are incorrect in your assessment. I’ve changed lots of cantilevers and never had an issue with the height of the brake posts. This brake should even be that much of a problem considering the age of the brake. The STX RC is from the late 90’s.

Happy Feet

That's pretty rich.

Before you go unloading on me perhaps you should do some research. In the post you quoted, I clearly asked the OP for more clarification as to why the shop suggested a whole new brake set.
Modern shops trying to sell new product instead of trying to fix old is a thing to be aware of when considering advice, unless otherwise indicated - hence the request for more information..
Your attempt at disagreement as a rhetorical device is unfounded. Just help the OP if you choose to do so.

Ps. In the exploded view you linked, it's a common nut, lock washer and two beveled spacers. Pretty common parts. Most of the time one can get away without the bevel in the spacer and just use stacked washers. Look at your own diagram.

veganbikes

I was more thinking Claude Butler being potentially an older bike. I didn't notice the STX. However yes on most modern-ish bikes the cantilever position is standardized and cantilevers are standardized however back in old country that wasn't the case and things were a touch lower.

Most frames you come across probably will be able to use any more modern cantilever so yes you would be correct but I heard Claude Butler and thought much older.

cyccommute 

You asked for more information but I know exactly what Dan_1802 is missing based on lots of experience with this kind of brake. His problem isn’t going to be easy to solve at most any bike shop because of the age of the brake.

I am trying to help Dan_1802 by not getting into some “rhetorical device” blaming shops for being shady.

.

No, those parts are not “common”. The curve on the concave washer on the back has a steep curve to it that matches the back of the brake. A concave washer used to provide a flat place on a side pull brake on a fork doesn’t have enough curve to it and likely won’t match.

The front convex washer has a much larger hole and is oval in shape. There aren’t any other spacers on bikes that would have the same size hole nor the right shape. Convex washers are also not all that common on any bicycle part . Neither spacer is something you can run down to the hardware and find. And, finally, the eye bolt that the pad fits into is not something that you’ll find outside of this kind of brake. Most modern brakes don’t use that kind of eyebolt. I also suspect that the eyebolt is totally missing.

The eyebolt, nut, flat washer, concave and convex spacer are a unit and may not fit from another model of Shimano brakes, especially from another year. Shimano has used this kind of arrangement for many brakes but they made changes from model to model that would make the chance of the hardware being interchangeable iffy at best. The only thing you might find that is “common” is the nut and flat washer.

A stack of flat washers likely isn’t going to help either. The convex spacer is used to tilt the pad for toe-in.

cyccommute 

Dan_1802: Get your post count up to 10 so that you can PM me. I have 1.5 sets of these brakes I can send you for parts.

Happy Feet

I did not accuse anyone of being shady. Don't invent words that posters did not say in order to create drama where there need not be any.
The OP is missing a spacer. He said a shop told him to buy a whole new brake set instead. I asked for clarification as to why that was because, if the part was generic, it should be easy to find or replace. Unless you find a mom and pop shop, it is common for modern shops shops to try to sell, rather than fix, so I sought clarification as to why they suggested that. That's not calling shops shady which conveys a sinister or dishonest intent.

Otherwise, it's great you have the parts the OP needs. Hopefully that will resolve the issue for him.
Try to have a nice day.

cyccommute 

The type of brake that Dan_1802 has doesn’t just “lose a nut and a spacer”. The pads on a STX RC aren’t threaded on they are studded. If you lose a nut on the back of the Bremsschuch-Befestigungsschraube (from the exploded illustration) or “brake pad mounting screw” in English, you lose everything...the nut (red screw),



All of these parts (3 red arrows) the concave and convex washers, and the brake screw itself will be lost as well. These parts aren’t readily available. They probably weren’t all that available when the brake was new.




We see them a lot in my bike co-op. Bike shops probably won’t have them.

Papa Tom

Dan: I recently replaced my original cantilevers with those CT-91's and hated them. They did not sit properly on the bracket and no matter how much time I spent adjusting them, I could not get them to stop the bike. They are now back in their original package waiting for someone to make me an offer on them.

If you want a good set of cantilever brakes, check out the Tektro Oryx model, about $24, maybe less if you buy them online. The CT-91's are dirt cheap for good reason. Given that your safety is at stake, I'd recommend that you invest an extra thirty bucks or so and get something that will actually grab your wheel when you are speeding downhill and a car suddenly appears out of a side street.

JaccoW

I have a 1995 bike that used a pair of Shimano STX RC cantilevers. When I replaced them (worn out springs) with Tektro CR710s I still needed KoolStop Thinlines for the front because regular pad holders were too long and wide and would hit the fork, causing drag.

When properly set up the Shimano CT91 cantilevers will work just as well as any other canti but at the very least they could provide OP with the spare parts for the STX cantis.

cyccommute 

While the CT91 is similar to the STX, I'm not sure that the parts are interchangeable. Shimano has a nasty habit of changing things slightly on a regular basis. The rear concave washer of the CT91 is different from the STX. It might work, it might just need some file work, or it might not work at all. It's hard to tell with Shimano parts.

Germany_chris

To be fair if parts are getting hard to find for a reasonably inexpensive part it might just be time for some new ones. I have Avid Sorty Ultimates they're great with Salmon koolstops but I don't think they really provide any better stopping power that *pick a cantilever. Tektro Oryx are what $22 a wheel and will have spares and replacement part for more than a few years to come.

JaccoW

Fair enough, I only have had a limited amount of them in my hands and practically always replaced them with nicer modern Tektro or Dia-Compe alternatives.
My STX's were the plated pink chrome color which was getting spotty in most places.