Smooth Post Brake Pads

[Ted Durant]

Jumping off of Bill Lindsay's RoadeoRosa thread, where he commented on the varsity level work required to de-squeak his Rene Herse brakes....

I love Jan and his stuff, but I think keeping the smooth post brake pads for his brakes is being a slave to the past. I've never liked any of the brakes I've had that used them. Hard to set up, impossible to adjust after tightening (any aluminum bits immediately deform, preventing further adjustment), limited replacement options. 

I just replaced the pads on the Shimano CX-50 cantilever brakes on East Coast Sam. I wanted cartridge holders for easy pad swapping, prompted by a white-knuckle descent of Connor Pass in Ireland on a very wet day. I put on 105 holders with Kool Stop dual-compound pads, which I've loved on the Silver/Tektro long-reach side pulls I've had on various bikes. Setting them up took all of about 5 seconds on each side, and zero squeal out the gate. (Release the springs, do an initial install and slight tighten, then put a credit card between the trailing edge and the rim, squeeze the brake lever, loosen and re-tighten the pad, done. Don't forget to put the springs back on.)

All of which made me dream up an adapter that would allow for mounting a bolt-on pad on a brake that uses smooth post pads. I'm envisioning a bolt on one end, to attach to the brake arm, and a flat tab on the other, with a hole for the pad mounting bolt to pass through. The tab probably wants to be offset from the center axis of the bolt, to put the inner face closer to the inside edge of the brake arm. 

A bit of Googling came up with zilch. Anybody handy with machining stainless steel rod stock?

Ted Durant

Milwaukee WI USA

[Bill Lindsay]

Ted

I agree with you that contemporary cantilevers with their various concave/convex washers are easier to set up.  I think your product development idea to make some adapter object that converts smooth post cantilevers would find some buyers and may get some vintage brakes into the rotation, but I don't quite see how you'd get out of the initial setup challenge inherent to smooth post cantilevers.  In my view the Shimano CX70 and CX50 were uniquely good because they came with three completely different and separate bolt/washer combos so the user can accommodate for rim width.  I hope everybody using those brakes have retained those extra bits for future setup (or resale) 

I'm "almost" ALL-IN on smooth post cantilevers, for those same reasons.  I just did a survey of the bikes in my garage at the moment.  9 have cantilever brakes, and 6 of the 9 have smooth post cantilevers.  The three that don't are 2 bikes with V-brake style cantilevers, and my commuter.  "Easy to set up" brakes is great because it "raises the floor".  Instead of ~20 things you can do wrong, now there's only like 4, so a home-mechanic has a much better shot at getting to "good enough".  That's a very good thing.  I think they were adopted to make bike assembly easier and faster (thus cheaper), which helps everybody.

Smooth post cantilevers, in my view, raise the ceiling for a good mechanic.  I feel like the extra work required represents the mechanical "envelope" to get things perfect.  On these forums (RBW, IBOB, 650B) I've advised that the typical home-mechanic should probably not take on Rene Herse Cantilevers, it's too heavy a lift.  The second reason is that smooth post cantilevers give me more room to play with rim width.  In the hands of the right mechanic, I think smooth post cantilevers are preferable. 

I agree that there were models of cantilevers that would deform all to heck if you over tighten them at initial setup.  The first Ritchey Logics, and the Dia Compe 986 in the late 80s were the ones that 20-year-old bike-builder ME would squish all to heck.  I avoid those now.  Some non-smooth post cantilevers also succumb to ham-fisted over tightening.  Your CX50s are excellent in that respect.  The vintage brakes I seek out are late-development Shimano's.  The cantilevers Shimano made right before V-Brakes took over were absolutely sensational, IMO.  When I was stuck with my Rene Herse set up, I considering just throwing on a set of M737 Shimanos and be done with it.  Those 6 bikes above with smooth post cantilevers are one Rene Herse, and all the others late Shimano.  For what it's worth, all my Shimanos get Kool Stop "Cross Pads" that take the same inserts as your CX50s.  Swapping in an insert is the way to go, IMO.  Stock Shimano pads were too chunky.  

I think it's good that most brakes today are "easier to set up".  I think having a few "harder to set up" choices out there is good, but it takes a good mechanic (a "brake whisperer") to get the best out of them.  Rene Herse are historical re-enactments.  That's a fact.  "Celebrating the past" may be a more generous phrase than "slave to the past". They are objectively among the lightest brakes ever made, and subjectively have a different look than anything out there.  I think it's good they exist as a choice. 

Bill Lindsay

El Cerrito, CA

[Ted Durant]

On Sunday, March 10, 2024 at 9:11:20 AM UTC-5 Bill Lindsay wrote:

...Smooth post cantilevers, in my view, raise the ceiling for a good mechanic.  I feel like the extra work required represents the mechanical "envelope" to get things perfect.  On these forums (RBW, IBOB, 650B) I've advised that the typical home-mechanic should probably not take on Rene Herse Cantilevers, it's too heavy a lift.  The second reason is that smooth post cantilevers give me more room to play with rim width.  In the hands of the right mechanic, I think smooth post cantilevers are preferable. 

Such a great, thoughtful response, Bill. I encourage everyone to read it through, even though I've kept just a small part of it here.

I had a laugh because Dia Compe 986 are exactly what I had in mind about impossible to readjust brakes. 20 year old me had them on both a Marukin Northstar and a Santana Elan. The Santana was especially challenging because Santana placed the mounts way too close together. They might have worked on a 5mm wide rim. The tandem was my wife's and my wedding gift to each other, and around our 30th anniversary I had Waterford do a full repaint and I replaced all the components with updated parts. Shimano CX-70 brakes were a revelation and for the first time I had fully confident braking on the bike. Wished I had them on our honeymoon, camping in Vermont!

I hadn't thought much about rim width in writing my initial post, probably because I'd forgotten about the initial installation and choosing the right bolt/spacer combo on the CX-50s. But I don't think my mind is changed about the extent to which the Shimano CX system improves on smooth posts. On the contrary, the fact that I didn't have to think about that part of the setup when changing pads illustrates one of its advantages for me. Different length bolts and spacers would be compatible with the adapter I have in mind. Fortunately, having put 4 sets of CX brakes on bikes, I have a pretty good supply of spacers and bolts :-). I don't think the weight gain, if there is any, would be enough to change my mind.  

One thing that the CX and Rene Herse brakes have in common, that makes them such a pleasure (and so much easier) to work on, is the quality of the hardware. 

Ted Durant

Milwaukee, WI USA

[Greg J]

Bill and Ted,  can you explain what you mean by the Dia Compe 986 deforming or squishing when overtightened?  These are my favorite cantis.  What should I be careful about over tightening, and what part is prone to deforming?

Thanks, 

Greg / Oakland

[Ted Durant]

On Monday, March 11, 2024 at 12:46:15 PM UTC-5 Greg J wrote:

Bill and Ted,  can you explain what you mean by the Dia Compe 986 deforming or squishing when overtightened?  

I just did a bit of googling and realize the brakes I'm thinking of were 980, not 986. Wish I still had them to take photos. On mine, working from memory, the washers that have the channels for holding the brake pad post and the brake pad posts themselves deformed, making fine adjustment impossible. The eyebolt openings may also have deformed.

[Bill Lindsay]

Dia Compe 986 and the Ritchey Logic variant of them would bend/squish/deform four different ways in my ham-handed hands.  

Facing the brake, the stack of parts was:

1. Allen Nut.  It takes a 6mm allen wrench.  It's threaded internally M6x1.0mm and threads onto the eye bolt

2. flat steel washer
3. Aluminum concave spacer wraps around a convex surface on brake arm

4. Brake arm.  Presents a convex surface up front and a concave surface in back

5. Aluminum convex spacer nestles into the concave backside of the brake arm

6. Eye bolt that grabs the brake pad post.  Has 10mm flats built into it so you can hold it in place with a 10mm wrench

Because of 1 and 6, you'd use a 6mm allen key and a 10mm wrench, which practically begs you to over tighten it.  Everything that takes a 6mm allen normally ought to be good and tight.  On almost all other brakes, the eyebolt has no flats, so you hold the brake pad steady with your fingers as you tighten the bolt.  It's harder to overtighten something with that technique.  

When you over tighten a 986 (or Logic), the four ways to cause damage are:

A. The "smooth post" pads weren't smooth.  They were serrated.  Those serrations bite deep into part #5, making future rotation adjustments hard. 

B. Part #5 itself would squish, ovalize, imprint itself into the height adjustment slot

C. Part #3 would squish, ovalize, imprint itself into the height adjustment slot

D. The post itself would bend

Bill Lindsay

El Cerrito, CA

[Greg J]

Thanks, both, for the very clear explanations!  I will have to go see how badly mine have gotten --- but that said, my 2 bikes brake great with 986 and 987 brakes with Kool-Stop salmon shoes.

Greg / Oakland

[Bill Lindsay]

Squishing the various parts does nothing for braking, only for subsequent adjustment.  If they ain't broke, don't fix em.  It's more something to be aware of when buying more of them on the secondhand market

BL/EC

[Garth]

 I have 3 sets of Shimano BR-MC70, a M734, Suntour XP Pro and most recently the Dia Compe 988, which looks very much like the XC Pro and is still made today. There's no deformation happening on any of these. I think Ted simply could try another brake, like the mentioned 988, it very much looks like the XC Pro. I got them from Porkchop BMX, and they even have multiple colors, plus part for them.

https://www.porkchopbmx.com/search/988/

You never know, maybe all or some of the 988 mounting hardware is usable for the 980.

https://www.porkchopbmx.com/dia-compe-bicycle-cantilever-brake-pad-mounting-ha.html

Kool Stop smooth post Cross Pads are also sold that you can change just the road sized pad if that works for you better.

[Bill Lindsay]

"Kool Stop smooth post Cross Pads are also sold"

I hope that remains true.  I'm finding them at fewer and fewer places.  

BL in EC

[Garth]

https://www.ebay.com/sch/i.html?_from=R40&_nkw=Kool-Stop+Cross+pads+smooth&_sacat=177806

As well as some other retailers in using various search engines. 

[Bill Lindsay]

Garth

I did the same search as you and I do that search reasonably often.  On that eBay search there are exactly two sellers with the part we're talking about.  One seller has exactly two pairs and the other seller has exactly one pair.

None of the online sellers that I've found are sellers I've ever bought from before, and none of them have more than two.  

These are the observations I made before saying "I'm finding them at fewer and fewer places".  When all the "normal" online retailers list them as out of stock, it seems they may be going away.  

Anyway on that chance I bought two pairs on eBay (one bike's worth).  Maybe that means one fewer place to buy them.

Bill Lindsay

El Cerrito, CA