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Help I can't stop!

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Old 05-07-18, 09:58 PM
  #26  
Leisesturm
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I've read just about every post in this thread. An amazing amount of talking past one another and a startling amount of outright mis-information. Some factual information too. But who can tell? At this point I think the o.p. needs to take their tandem to a decent LBS or Bike Co-op to be assured that the brakes are set to spec and safe. My suspicion is that they were just fine and stopping about as well as bicycle brakes can stop but to the uninitiated that is often not as confidence inspiring as it should be. Brifters work with Canti's just fine. My preference is for V-brakes. Not because they stop better, they do not. But the package is neater. Ironic, because back in the day, sidepulls (v-brakes) were considered very much inferior to centerpull (cantilever) brakes. It's all just perception! At the end of the day what stops the bike is the pad against the rim and the pad material, pad size and shape matter as much or more than the force of the pad against the rim. I would avoid the long pull caliper brakes because it sounds like that will be very much inferior to using the brake bosses that have been supplied. But don't take my (or anyone else's) word for it online. Get to a shop.
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Old 05-07-18, 10:06 PM
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Originally Posted by rm -rf View Post
If your brake levers don't bottom out against the bars, then the cable pull sounds okay.

You have cantilevers, not V-brakes, correct? V-brakes need more cable pull than newer shifter brake levers allow, so the levers bottom out. Mini-V brakes have the correct pull. The downside is mini-Vs have very little travel, so the pads need to be very close to the rims, and accurately aligned. It's fussy to set up correctly.

Are the pads pressing against the rims over their whole surface? Take off the front wheel and check the pad's wear patterns. EDIT -- you mentioned: " The pads are hitting squarely and pivots cleaned and lubed." I guess you could check anyway.

I don't think you need to roughen the rims. Factory roughened rims get completely smoothed out from pad wear, anyway.
Yes I have cantilever's NGR 982 Dia Compe. The shifters are Shimano ST3300 7 speed. I have adjusted the straddle wire every way I can, moved the shoes in and out, cleaned the rims, replaced the cables, replaced the pads with Cool Stop Salmon pads and its still about the same. So travel agents will make short pull levers work with long pull brakes? I thought the were the other way around or do they go both ways? Edit...I just read up on travel agents and see they work with short levers and long pull brakes.

Last edited by TXsailor; 05-07-18 at 11:13 PM. Reason: Did more reserch
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Old 05-07-18, 10:38 PM
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Originally Posted by Leisesturm View Post
I've read just about every post in this thread. An amazing amount of talking past one another and a startling amount of outright mis-information. Some factual information too. But who can tell? At this point I think the o.p. needs to take their tandem to a decent LBS or Bike Co-op to be assured that the brakes are set to spec and safe. My suspicion is that they were just fine and stopping about as well as bicycle brakes can stop but to the uninitiated that is often not as confidence inspiring as it should be. Brifters work with Canti's just fine. My preference is for V-brakes. Not because they stop better, they do not. But the package is neater. Ironic, because back in the day, sidepulls (v-brakes) were considered very much inferior to centerpull (cantilever) brakes. It's all just perception! At the end of the day what stops the bike is the pad against the rim and the pad material, pad size and shape matter as much or more than the force of the pad against the rim. I would avoid the long pull caliper brakes because it sounds like that will be very much inferior to using the brake bosses that have been supplied. But don't take my (or anyone else's) word for it online. Get to a shop.
I do know what good brakes feel like I have 3 other bikes that all stop great one even has carbon wheels. I don't know what to expect with a tandem but I do think it should stop pretty good when I am solo. I also think that without a stoker the back would be light enough that I could come close to locking up the back wheel I can't. The nearest bike shop is 50 miles away, the nearest good one is 75 and I don't have a pickup or tandem rack. If I can't figure it out I will find a way to get it there but I haven't gave up yet.I have set up cantilever's on inexpensive mountain bikes and got them to work fine.
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Old 05-09-18, 08:42 AM
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Originally Posted by Alcanbrad View Post


I would expect that the hole for the brake would have a counter bore on the side opposite the brake for the recessed nut. Take a look at any bike with side pull brakes and you should see this counter bore. If your bike has this geometry it probably will support side pulls.

My experience, though, tells me that a frame built to support cantilever brakes would not burden the frame with the cost to support side pulls.

Again, I am not familiar with your frame. If in doubt, take it to your LBS.
Just curious, and sorry if you posted and I didn't catch it, but were you able to determine if your frame would support side pull brakes or not?
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Old 05-09-18, 11:14 AM
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Originally Posted by Alcanbrad View Post
Just curious, and sorry if you posted and I didn't catch it, but were you able to determine if your frame would support side pull brakes or not?
I am sure the front would support them the top of the fork is a solid cast piece. The rear I am not too sure about. It has a little bridge between the seat stays with a hole in the center is positioned just like my "83 Centurion. What I don't know about is the Centurion has a sleeve through the hole to keep it from crushing and the Kuahara doesn't. I also don't know if its the right wall thickness that would be needed to transfer the energy required to stop such a heavy load. If I decide to try that route I will get a bike shop to look at it. I am toying with the travel agent v-brake option but haven't made much progress since my wife had a double knee replacement last Friday/Monday and I am working full time.
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Old 05-14-18, 02:58 PM
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Originally Posted by Leisesturm View Post
I've read just about every post in this thread. An amazing amount of talking past one another and a startling amount of outright mis-information. Some factual information too. But who can tell? At this point I think the o.p. needs to take their tandem to a decent LBS or Bike Co-op to be assured that the brakes are set to spec and safe. My suspicion is that they were just fine and stopping about as well as bicycle brakes can stop but to the uninitiated that is often not as confidence inspiring as it should be. Brifters work with Canti's just fine. My preference is for V-brakes. Not because they stop better, they do not. But the package is neater. Ironic, because back in the day, sidepulls (v-brakes) were considered very much inferior to centerpull (cantilever) brakes. It's all just perception! At the end of the day what stops the bike is the pad against the rim and the pad material, pad size and shape matter as much or more than the force of the pad against the rim. I would avoid the long pull caliper brakes because it sounds like that will be very much inferior to using the brake bosses that have been supplied. But don't take my (or anyone else's) word for it online. Get to a shop.
Hmmm, not to be a jerk here, but starting your post with accusations of "mis-information" and finishing it with calling v-brakes "sidepulls" and cantilevers "centerpull" furthers the misinformation. And saying "v-brakes were considered very much inferior to cantilever brakes" misses the mark too.

Sidepull brakes are NOT v-brakes. Sidepull brakes are caliper brakes on road bikes where the cable action occurs on the side of the caliper:


Centerpull brakes are NOT cantilevers! Centerpull brakes are also caliper brakes on road bikes. But these brakes are similar to cantilevers in the way there's a straddle cable that attaches to each caliper arm, to which the main cable attaches.


Both of these brakes attach to the frame/fork with one center bolt, whereas cantilever and v-brakes mount to cantilever posts. (Hey, what about u-brakes? Let's not go there!!!)

And v-brakes were designed to apply much higher forces at the rim for given forces applied at the brake lever. The result was a much more powerful brake, which is why they quickly replaced cantilevers in the industry. On average, they were far superior to cantilever brakes on mountain bikes, which is why they were quickly adopted. (Set up was also easier, another reason the industry embraced them.) Once I tried v-brakes, I immediately switched to them on all my mountain bikes. I was thrilled with one-finger braking that gave me all the power I could ever want with excellent modulation.

There, that should reduce any additional misinformation!
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Old 05-20-18, 08:15 PM
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Originally Posted by Paul J View Post
I would think about converting the "V" brakes (Shimano's branded name but what most people call them) and use the above Travel Agents to get the correct cable pull ratio with your integrated shift/brake lever set-up. It is what most manufactures were using before the disc option became the standard. We have the "V" brakes along with the drag brake and never feel at risk in our very hilly area.
I am over cantilevers - after using them on touring bikes, MTBs and tandems for more than 20 years. V brakes are so much easier to live with.

And I am not a fan of brifters on tandems - too fiddly. Some people really like them because the gear lever is 'just there', but you very quickly get used to bar-ends (or even downtube levers). The ability to do safe emergency stops is much more important.

My recommendations are:
  • bar-end shifters
  • Tektro RL520 brake levers
  • Shimano XT brake levers.
Everything plays nice. Braking performance is very good. The standard XT pads are fine but Swisstop may be marginally better.

No need for travel agents. They are fine but also fiddly. The brake levers have a QR button which means you can run the brake pad very close to the rim if you want and still remove the wheel easily.

Run all the cables under the bar tape (yes, even the gear cables) - you will need slightly longer gear cable outers. Looks neat and no performance costs.

Not too expensive either, especially if you pick up the shifters 2nd hand.

Good luck.

And always love to see pictures of tandems on this forum.


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Old 05-23-18, 01:58 AM
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I have considered switching it back to downtube shifters and may yet. That's what it came with and the bosses are still there but I do like brifters since that is what my road bike has and I am used to them. I did get it to stop a little better by taking all the toe in out of the pads but the squeal was quite loud and pretty annoying. We rode it a little last weekend and had a flat. The tires are pretty old and seem to be flat prone so I ordered some new Continental SuperSport plus tires and a Zefal 3 pump so we can fix flats on the road.

My granddaughter and me with our tandem
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Old 05-25-18, 08:04 PM
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Originally Posted by TXsailor View Post
I have considered switching it back to downtube shifters and may yet. That's what it came with and the bosses are still there but I do like brifters since that is what my road bike has and I am used to them. I did get it to stop a little better by taking all the toe in out of the pads but the squeal was quite loud and pretty annoying. We rode it a little last weekend and had a flat. The tires are pretty old and seem to be flat prone so I ordered some new Continental SuperSport plus tires and a Zefal 3 pump so we can fix flats on the road.

My granddaughter and me with our tandem
Originally Posted by TXsailor View Post
My granddaughter and me with our tandem
Thanks for posting the photo; it really helps with diagnosis. Your bike looks to be set up much like our our Santana and based our experience, I offer the following:

First, I wonder if the cable stop bracket that mounts in the headset is too flexible, and bends when you apply the brake hard. In our bike, this contributed to sponginess and wasted braking force. We replaced ours with one scrounged from a bike-shop parts drawer that is a solid flat slab of aluminum about 5 mm thick. (It actually has "Kuwahara" stamped on it.) The cable tension barrel adjuster fits into a keyhole slot in the bracket that allows you to pop the cable stop out of the bracket for easier maintenance. If you can find something like this you'd probably see some improvement. I'd let you have ours except that it is currently part of the cantilever installation in one of my wife's single bikes. Because of the short cable run to the front brake, the cable stop bracket is about the only place where sponginess can creep in, especially with the beefy fork blades typical of tandems. I would doubt that compressionless housing would help much. In a front disc brake where the housing goes all the way to the brake calipers, yes, but for a cantilever, the housing is short, ending at the stop. It also has to make a bend from where it emerges from under the bar tape to the stop instead of making the smooth sweeping curves that compressionless housing likes. I'd try to stiffen up your housing anchor point first. And while you have the brake cable loose from the brake to do this, make sure that it slides easily in the housing when you grab the free end and work the lever with your other hand. (Common things are common. Don't dress the wrong wound and miss the worse one like Yossarian did in Catch-22.)

Your brakes appear to be the same Shimanos we had. We thought we got good, single-bike-level performance from the front, especially with the improved housing stop I've described. (The rear was another story which I'll get to.) Since you've read Sheldon Brown's page on adjusting cantilevers, I know you know that the vertical position of the yoke for the straddle cable dials in the mechanical advantage of the brake, matching it to the cable pull of the lever you are using. It also sets, broadly, the resting position of the brake shoes because the straddle cable is a fixed length (or has just two choices of length. On some old centre-pull calipers you could adjust the length of the straddle cable and thereby set mech. advantage and resting position independently.) There will be an up-and-down sweet spot where the lever pulls the brake shoes toward the rim just the right amount, without bottoming against the handlebars and without requiring the brake shoes to be set so close to the rim that they rub. The design of cantilevers allows them, theoretically, to be set up to deliver enormous braking force, IF you had like a foot of lever pull before hitting the bars. Since you don't, you have to decrease the mech. advantage by raising the yoke until your 4" of pull gets the shoes to the rim. At that point, the braking force will be about the same as any other rim-type brake. The real genius in cantis is that you can use forks with lots of clearance for large tires and mudguards without having to accept the much weaker braking force offered by long-reach calipers, which have to reach over the tire from above. Yes, after the mech. advantage has been set, you will then have to do much fiddling with the orientation of the brake shoes on the arms, in and out, up and down, rotation, and toe-in so as to get the shoes to strike the rim properly and in the right portion of their arc as they are drawn in by the cable pull. Remember that the pivot point for the brake arm is below the rim, making the contact with the rim harder to orient than with side-pull calipers. And don't forget that as the pads wear -- and a hard-ridden tandem should absolutely wear out front brake pads! -- the arms will want to make the pads contact the rim lower and lower until eventually they dive under the rim -- the opposite to the situation with the old centre-pull brakes and with one arm of modern dual-pivots where the wearing pad eventually contacts the tire sidewall. You can also adjust the return force by selecting into which of the three holes on the tabs of the mounting bosses the brake-arm return springs are inserted. Consider using a different hole for right vs. left arm.

Having said all that, my suspicion is that, like a lot of medicine, an in-person physical examination beats a long "sounds like it could be...." discussion. Your front cantilever should be able to be got working well enough to protect you and crew with stock parts (except possibly a stiffer mounting bracket for the cable housing stop.) But without actually seeing it, I confess I can't say how.

The rear brake is another problem, very possibly un-fixable. Like yours, our frame was sized for an "under-tall" stoker -- shorter than yours I think. Consequently, the brazed-on stop for the rear housing was much lower, and closer to the wheel, than the front, limiting the vertical range over which we could move the cable yoke to optimize mechanical advantage. We could never find a sweet spot: because of the low-riding stop, we could not raise the yoke high enough, given the fixed length of straddle cable, to bring the shoes to a suitable resting position and still clamp the rims with the available rear-lever pull. Too high and the yoke struck the stop before the brake was braking, too low and the shoes rested so far from the rim that the lever bottomed before the brake came on. (And this defect was compounded by the large mechanical advantage conferred by a low-riding cable yoke -- very little pad movement per centimetre of cable pull. Messing with the position of the shoes on the brake arms didn't produce a solution. The only fix would have been a bigger frame, allowing the yoke to be set higher, or a shorter straddle cable, allowing the shoes to rest closer to the rim. We never considered travel agents -- I don't see where there'd be room to put them in a cantilever setup.

If you think this applies to your situation, I'd suggest installing a rear caliper brake with adequate reach. That's what we did. A dual-pivot brake develops lots of force even in the long-reach versions and would be better than an obstinate cantilever. Your front brake is still the main brake, even with a tandem. From what I can see from your photo, (and thinking back to our own bike), the hole in rear brake bridge is likely not compatible with modern brakes with short mounting bolts which take a recessed nut. You likely need a old-fashioned brake with a mounting bolt that comes all the way out through the hole and is secured with an ordinary M6 nut. You also need the two aluminum mounting bits (flat on one side, deeply concave to match the brake bridge) on the other to keep the nut from crushing the thin bridge tube. If you can't find a modern dual-pivot brake with an old-fashioned long bolt, you can maybe disassemble the bolt from the front brake of a modern set and use it in the rear. But you would still need to source the little pillow blocks. Orrrr, have a frame builder replace the brake bridge with a modern one that takes short bolts. Have him/her place the bridge as close to the tire as you think you can get away with.

I'm glad your grand-daughter likes riding with you. Mine (first and so-far only) is only two months old, so she'll be a while yet. Best to your wife in surgical recovery & rehab.

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Old 05-25-18, 10:08 PM
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Wow thanks for the long post that was full of info. I am going to have to read it several times to let it all soak in! I actually tried to post a picture a while back and it would fail to upload every time. I finally did something right and it posted it. I have 7 granddaughters and it would't be right to say I have a favorite but this is the oldest one (21) and is a very special young lady. Our frame is pretty big in fact its nearly too big so the rear cable probably isn't as short as yours. Those are Dia Compe brakes and they have a straddle cable that is just that a cable with a lug on the end that runs over a little pulley (yoke) and back to a pinch bolt so its has a lot of adjustment. I looked at the cable stop bracket and its very short and looks pretty robust but when I put the brakes on hard I could see some flex in it. Now I am coveting your thick bracket! I am going to see if I can find something like it. I got the new tires in and put them on today. I would not want these on my road bike! They are thick and heavy but maybe they will stop the flats on the tandem. We have had 3 flats in about 5 rides and they all have been punctures on the tire side. I also put a thick tube on the rear which is where we have had all the flats on. I appreciate all the help and info the people have posted on this thread and will keep my progress updated. My granddaughter & I are off to do a group ride on our road bikes in the morning but maybe we can get a tandem ride in over the holiday weekend. Our goal is to do some group rides on it and she wants to do at least part of Ragbri on it in 2019 if we can figure out a way to get it and our road bikes to Iowa.
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Old 05-26-18, 01:17 PM
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I sent you a PM.
I tried to draw you a sketch using normal keyboard keys. But the typeface used for typing the message is different from the one that is actually sent, so the thing looks all scrambled and likely not helpful. Sorry.
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Old 05-27-18, 07:37 PM
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Originally Posted by TXsailor View Post
Wow thanks for the long post that was full of info. I am going to have to read it several times to let it all soak in! I actually tried to post a picture a while back and it would fail to upload every time. I finally did something right and it posted it. I have 7 granddaughters and it would't be right to say I have a favorite but this is the oldest one (21) and is a very special young lady. Our frame is pretty big in fact its nearly too big so the rear cable probably isn't as short as yours. Those are Dia Compe brakes and they have a straddle cable that is just that a cable with a lug on the end that runs over a little pulley (yoke) and back to a pinch bolt so its has a lot of adjustment. I looked at the cable stop bracket and its very short and looks pretty robust but when I put the brakes on hard I could see some flex in it. Now I am coveting your thick bracket! I am going to see if I can find something like it. I got the new tires in and put them on today. I would not want these on my road bike! They are thick and heavy but maybe they will stop the flats on the tandem. We have had 3 flats in about 5 rides and they all have been punctures on the tire side. I also put a thick tube on the rear which is where we have had all the flats on. I appreciate all the help and info the people have posted on this thread and will keep my progress updated. My granddaughter & I are off to do a group ride on our road bikes in the morning but maybe we can get a tandem ride in over the holiday weekend. Our goal is to do some group rides on it and she wants to do at least part of Ragbri on it in 2019 if we can figure out a way to get it and our road bikes to Iowa.
I bought a new front cable-hanger from St John St Cycles online (I also bought a Thorn Club Tour from them 18 years ago!). Your headset is 1 inch, and you should be able to get a Tektro cable-hanger easily online (eg E-Bay). Not more than $10-15.

Big changes in tires in the last 5 years. Basically the manufacturers have put race tire technology into bigger volume tires. At the same time new materials have greatly improved puncture resistance. We have had tremendous success with the Clement/Donelly Strada 28 and 32c rubber on our tandems. Light, fast, very grippy and no punctures. And not hideously expensive.

We enjoy our tandem in the group. Very comfortable with our improved braking. Just tell people to give you room on the downhills, you will probably roll away from the half bikes.

Great bike, there are a few of these in Australia I think. I would love one.

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Old 05-28-18, 01:42 PM
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Originally Posted by LV2TNDM View Post
Hmmm, not to be a jerk here, but starting your post with accusations of "mis-information" and finishing it with calling v-brakes "sidepulls" and cantilevers "centerpull" furthers the misinformation. And saying "v-brakes were considered very much inferior to cantilever brakes" misses the mark too.

I NEVER said that v-brakes ARE sidepulls. Why can't Americans handle a little metaphor now and then?! I said that the cable entry on a v-brake is from the side (like a sidepull caliper brake) vs. from above, and it is so. I never said v-brakes were considered very much inferior to cantilever brakes, rather, I said it is the opposite. V-brakes are widely reputed to be superior to cantilevers. Most v-brakes can't deal with fenders capable of covering 2.125" tire sections, however, a cantilever will take such a fender in its stride. What I actually did say (and stand by) is that in the days before v-brakes or cantilevers were dominant, of the two main brake types in wide use then: sidepull caliper brakes and centerpull caliper brakes, the centerpull variant was considered superior. You misread my entire post and fired away in righteous indignation and have added your own layer of misinformation because, in fact, v-brakes are not superior to cantilevers as you suppose. Fine examples of each can be found. Both v-brakes and cantilever brakes were developed because there was a need for a brake that could remain powerful regardless of tire size! When a tire approaches 2" in section and beyond, and needs clearance for a fender besides, the reach of the caliper arm can exceed 60mm. Nothing can be done about that. The pivot bolt has to be in the fork crown and the work has to be at the rim. What if you moved the pivot from the fork crown to a specific point on the fork where you had a consistent relationship with the rim diameter, one which was not going to change no matter what size of tire was mounted to the rim? Thus was born the Cantilever. The v-brake tidys up the cabling but the assymetric nature of the sidepull (deal with the terminology) arrangement means more attention has to be paid to the centering. The length of the arms requires strong alloys and careful design. The rest of your post tracks very closely with mine because we were saying the same thing all along. It's almost not worth the replying to except that I have my legacy to think about. If you read from that that I need more of a life outside of bike forums you may well be correct.
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Old 05-28-18, 11:02 PM
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Originally Posted by conspiratemus1 View Post
If you think this applies to your situation, I'd suggest installing a rear caliper brake with adequate reach. That's what we did. A dual-pivot brake develops lots of force even in the long-reach versions and would be better than an obstinate cantilever. Your front brake is still the main brake, even with a tandem. From what I can see from your photo, (and thinking back to our own bike), the hole in rear brake bridge is likely not compatible with modern brakes with short mounting bolts which take a recessed nut. You likely need a old-fashioned brake with a mounting bolt that comes all the way out through the hole and is secured with an ordinary M6 nut. You also need the two aluminum mounting bits (flat on one side, deeply concave to match the brake bridge) on the other to keep the nut from crushing the thin bridge tube. If you can't find a modern dual-pivot brake with an old-fashioned long bolt, you can maybe disassemble the bolt from the front brake of a modern set and use it in the rear. But you would still need to source the little pillow blocks. Orrrr, have a frame builder replace the brake bridge with a modern one that takes short bolts. Have him/her place the bridge as close to the tire as you think you can get away with.
I like most of what you have to say in your post, but at this point I have to disagree. Ignoring for a minute the fact that after 'looking' (as you rightly say, that's only worth so much) at the o.p.'s setup, I see nothing untoward, and even if the cable hangar isn't the stiffest piece of kit in the world, it should work just fine! In fact, even compressionless housing setups include a few inches to a foot of standard cable, because a totally unyielding brake setup, while nice in theory, feels awful in actual use. You need a little compliance in the system. A 'little' give is a good thing. But about that rear brake thing ... why a caliper? Why not use the studs that are already there and put v-brakes on the rear and then the short distance to the straddle cable becomes a non-issue. Truth to tell, if it was my bike I'd slap some Shimano LXV's (mid-level v-brakes) front AND rear and call it very good. I did exactly that to the Burley Samba we bought off Craigslist but, sadly, never got to ride it that way because it was stolen. Brand new v-brakes and more. Those brifters would not play nice with v-brakes but a pair of Travel Agents would set things right. I rode around for months on a tandem with only one working v-brake (front). A cheapo v-brake without any branding. That brake easily stopped over 550lbs. of team, tandem and (loaded) trailer screaming towards a timed out traffic light on a downhill bomb. FWIW.
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Old 05-30-18, 01:41 AM
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I may eventually go to V-brakes but for now I am going to play with the cantilevers a little more. I already bought good pads for them and am kind of stubborn when something mechanical is giving me a hard time. Conspiratemus1 is kindly sending me a stiffer cable hanger and I want to see what effect it has on the front. He also seems to be somewhat of a cantilever guru and has some other ideas for me to try. I got the new tires on it and we rode it around town a little yesterday evening. They feel good and the granddaughter said she thought they ride was smoother on our rough streets. We also DIDN'T have a flat which is encouraging since out of 5 previous rides we have had 3 flats plus one in the garage at home.
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Old 06-04-18, 12:07 PM
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You definitely do not want rough braking tracks on your rims. They should be smooth.
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Old 06-11-18, 11:45 AM
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Originally Posted by noglider View Post
You definitely do not want rough braking tracks on your rims. They should be smooth.
I realize that a very rough surface would eat up pads very quickly but these seem as slick as the old chrome steel wheels cheap bikes had when we were kids. My new Giant and other bikes with aluminum wheels are not this slick. My carbon fiber wheels are probably close but they don't stop like my other aluminum wheels do either. I am going to do some more tinkering soon but haven't had a chance the last week or so.
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Old 06-11-18, 02:57 PM
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Originally Posted by noglider View Post
You definitely do not want rough braking tracks on your rims. They should be smooth.
Depends on how you quantify "rough"

Mavic used to offer a rim with a relatively rough ceramic coating on the braking track for improved performance, especially in wet conditions.
Unfortunately the coating was relatively brittle and easily damaged, and therefore fell out of use.

Other manufacturer's have offered surface profiles on carbon rims (and perhaps on aluminum rims) for improved braking performance.
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