Pads for Shimano CX50 Cantilever brakes

For discussions about bikes and equipment.
Grumpyoldbiker
Posts: 64
Joined: 14 Jun 2007, 6:54pm

Pads for Shimano CX50 Cantilever brakes

Postby Grumpyoldbiker » 21 Jan 2014, 6:35pm

I have Shimano CX50 cantilever brakes on my touring bike. They have replacement pads that are specific to these brakes only, they are a design with no slide out pads.
Using the specific replacement pads means no choice in pad type and being tied into a fairly pricey replacement option (£12.99 a pair, half the cost of the complete brake!)
I notice that the CX70 pads do have a slide out pad design, and they are compatible with the CX50 brakes, so presumably if I invested in a set of these complete pads I could simply change the slide out pads in future. However, this is still an expensive option, since the complete CX70 pads are even more expensive.
Does anyone have any ideas on how to get more flexibility/economic pads for these CX50 brakes?
Thanks
Peter

User avatar
531colin
Posts: 12633
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Pads for Shimano CX50 Cantilever brakes

Postby 531colin » 21 Jan 2014, 7:07pm

This put me off those brakes....... :(
don't know if you could use something like this, with a longer bolt.....the canti might require more angular adjustment than a dual pivot.

http://www.koolstop.com/english/road_pad.html

Grumpyoldbiker
Posts: 64
Joined: 14 Jun 2007, 6:54pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby Grumpyoldbiker » 21 Jan 2014, 7:58pm

Thanks Colin
Yes, I think a pad with a threaded bolt system would work.
If bolt length is an issue, presuming the bolt size matches, I could used the threaded bolts from the existing pads.
But before I go down this route and possibly waste money it would be good to hear from anyone who has tried it!
The other possibility could be to use a pad type with a threaded bolt fixed into it. The existing CX50 pads have a threaded bolt through a spacer, which engages in a "nut" embedded in the actual pad. I can't see why a pad fixed to a threaded bolt couldn't be held adequately by a nut and washer at the other end of the spacer?
Thanks
Peter

User avatar
CREPELLO
Posts: 5558
Joined: 29 Nov 2008, 12:55am

Re: Pads for Shimano CX50 Cantilever brakes

Postby CREPELLO » 21 Jan 2014, 8:01pm

I'm guessing that you'll have to adapt some existing pads like the ones Colin links to above. I'm not famillier with these brakes, although I was aware that they used different length spacers. It's a novel design, isn't it?

The problem you may encounter is that the Koolstops above use (outside) nuts to secure the pad holder to a screw retained within, whereas the CX50 pads are the reverse - using screws that secure into a nut retained by the pad. Now if you can find cartridges that also use this design, it would mean that you could re-use the existing screws.

Is it all worth it? Heck, you can buy new canti's for about the same price as a pair of Shimano pads...

User avatar
CREPELLO
Posts: 5558
Joined: 29 Nov 2008, 12:55am

Re: Pads for Shimano CX50 Cantilever brakes

Postby CREPELLO » 21 Jan 2014, 8:06pm

Regarding the nuts with those Koolstop shoes, the slot width may differ on your canti's from a regular road brake. If it doesn't, I wonder if it's possible to insert a longer screw (as I think Colin was alluding to) from the shoe side. This would need the head filing down to fit inside the shoe. Whether this compromises strength of the remaining head may be an issue. Sorry, not much help.

Brucey
Posts: 37358
Joined: 4 Jan 2012, 6:25pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby Brucey » 21 Jan 2014, 8:24pm

I think that koolstop eagle 2 (threaded) pads probably have a long enough thread on them to allow fitment (with suitable spacers) in place of the short pattern CX50 block/spacer. Provided the nut can still be accessed OK I don't see why you couldn't do that.

As mentioned in the above posts there are other threaded shoes which you might be able to adapt in various ways.

The pads you need may have a similar slide-in profile to another style of pad; it may be worth checking to see if there isn't a compatible insert that you can use with the old holders.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Grumpyoldbiker
Posts: 64
Joined: 14 Jun 2007, 6:54pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby Grumpyoldbiker » 21 Jan 2014, 8:41pm

Thanks guys for the ideas.
Just photographed the pads in place and taken off the bike. Not sure how to load them on to a post.
Anyway bolt is about 28mm long, I think it is 4mm.
Regards
Peter

Grumpyoldbiker
Posts: 64
Joined: 14 Jun 2007, 6:54pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby Grumpyoldbiker » 21 Jan 2014, 9:06pm

This is the pad on the bike:
IMG_0644b.jpg

and here is the pad, the threaded insert can move to give correct alignment:
IMG_0648b.jpg

and here are the bolt, washers and spacer:
IMG_0647b.jpg

Brucey
Posts: 37358
Joined: 4 Jan 2012, 6:25pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby Brucey » 21 Jan 2014, 9:35pm

well that looks like an M5x0.8 threaded screw, but that the caliper arm would accept an M6 bolt if necessary.

Interestingly the pad swivels about a centre that is within the pad itself; this is very unusual and quite sensible; most other pads swivel near the bolt where it goes through the caliper arm, which creates higher loads I think.

It looks to me that if you had a male threaded pad it would have to have ~25mm length plus enough to put the nut on the outside of the arm, so about 30mm in total. I don't know if the Koolstops are long enough for that; most V pads are not.

There are plenty of road pads that will accept the M5 screw, but IIRC they don't generally have the same swivel adjuster in the pad holder; if you use those with your bolt and spacer you will have a basically fixed alignment I guess.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

User avatar
CREPELLO
Posts: 5558
Joined: 29 Nov 2008, 12:55am

Re: Pads for Shimano CX50 Cantilever brakes

Postby CREPELLO » 21 Jan 2014, 9:39pm

There are these... http://www.spacycles.co.uk/products.php ... 0s104p1625 ...which may allow you to insert the floating nutsert, if you can liberate them from your old pads. Or much cheaper, these clarks cross shoes... http://www.chainreactioncycles.com/clar ... -prod55807

delap
Posts: 38
Joined: 26 Nov 2012, 4:40pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby delap » 22 Jan 2014, 2:11pm

I feel your pain. It never occurred to me that these brakes would use such a proprietary pad...

If you shop around you can get R50t2 pads for around eight pounds (still nearly half the best online price for the brakes themselves). Getting shoes for the CX70 is, as you say, expensive but allows you to use standard road inserts thereafter.

From here (http://techdocs.shimano.com/media/techdocs/content/cycle/EV/service/EV-BR_SHOE-Road-1326N_v1_m56577569830698525.pdf), it looks as if R55C2s might have the profile to fit into the concave spacer ends and give you the same toe-in adjustment you get from the R50T2s but I am not certain. SJSC (one of the few online suppliers carrying the pads/shoes for the CX70) seem to say that these take R55C+1 pads/shoes but looking at the shimano doc (link above) these seem to have a flat shoulder rather than the convex shape for the R50T2s which suggests that someone is wrong or that the spacers for the BR-CX70s have a different profile and adjust toe-in differently to those for the BR-CX50s.

I did try offering up some generic dura style shoes from a dead road bike. These shoes have the same flat shoulder around the threaded insert (where R50T2s are convex) so I added a toe-in adjusting washer from an old v-brake pad. This had a different profile to the convex housing on the R50T2s but was close enough to give you toe-in adjustment. I am torn between trying this out on the back brakes to see how it works in practice versus buying CX-70 pads/spacers unless anyone is in a position to identify if there is a shimano, or third-party, shoe that has the same shoulder profile as a R50T2 (so will seat into the end of the BR-CX50 spacer) and takes standard pad inserts.

Grumpyoldbiker
Posts: 64
Joined: 14 Jun 2007, 6:54pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby Grumpyoldbiker » 22 Jan 2014, 8:36pm

Thanks Delap
Do you know which pads are the actual replacement for these brakes? There seem to be different packs of R50T2 pads with different length spacers, and while I know my spacers are approximately 18mm, I have no idea whether these are the short, medium or long ones?
Thanks again.
Peter

delap
Posts: 38
Joined: 26 Nov 2012, 4:40pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby delap » 22 Jan 2014, 9:59pm

They are the same as mine. I assume if you buy a set of BR-CX50s you get all three spacers but mine came attached to a Galaxy. Judging by the pictures on SJSC (who describe the CX50 and 70 pads as interchangable), I reckon they are mediums. This is consistent with the proportions shown in the shimano tech docs - I judge the shorts as being about the same lenght as diameter, mediums as 1.5 x diameter and longs as nearly 2 x diameter (12,18 and 24mm).
small (cx50)
http://www.sjscycles.co.uk/shimano-br-cx50-brake-shoe-set-r50t2-small-spacer-8k5-9804-prod30132/
medium (CX70)
http://www.sjscycles.co.uk/shimano-br-cx70-cartridge-brake-shoe-set-r55c+1-medium-spacer-8k4-9804-prod30128/
and large (cx70)
http://www.sjscycles.co.uk/shimano-br-cx70-cartridge-brake-shoe-set-r55c+1-large-spacer-8k4-9803-prod30127/

This is just my judgment based on comparing the pictures with my blocks in real life.

Below are pictures of what i described above. My back brake blocks have pretty much worn out in around 900km (mostly winter, up and down the Mendips) so I am keen for a more generic (cheap) block solution.

These are some cheap v-brake blocks from a kids bike:
Image

Counting from the brake block end, washer two or three is placed against the back of these generic dura style shoes.

Image

The nut in the shoes is the same as the one in the R50T2s although without as much space to slop around. Using the spacer, washer and bolt from the R50T2 gives you some toe-in adjustment although not as much as with the R50T2

Steveo2020
Posts: 215
Joined: 26 Apr 2012, 8:57pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby Steveo2020 » 22 Jan 2014, 11:27pm

Hi

I had the same problem with these and solved it but I can't remember how! Aztec cartridge style blocks with the original bolts I think? Will try to check tomorrow.

Cheers

delap
Posts: 38
Joined: 26 Nov 2012, 4:40pm

Re: Pads for Shimano CX50 Cantilever brakes

Postby delap » 23 Jan 2014, 12:48am