Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Bicycle Mechanics (https://www.bikeforums.net/bicycle-mechanics/)
-   -   Want to replace side pull brakes (https://www.bikeforums.net/bicycle-mechanics/850490-want-replace-side-pull-brakes.html)

jrickards 10-04-12 09:05 AM

Want to replace side pull brakes
 
I just picked up a late-80's Bianchi that is is pretty good condition but because it was stored in a garage, some parts have a bit of rust on them so I'm planning on replacing them before taking the bike out, the first on the list are the brakes.

Of course the pads are shot, they are the original, but I would like to replace the brakes alltogether. The originals are listed as "Polygon AF500 with QR and hooded levers", they look like standard side pulls. Could I simply replace them with any other side pull like Sora or Tiagra or other?

Any considerations I need to take into account?

Bianchigirll 10-04-12 09:17 AM

It depends on the bike. Are the current brakes long or short reach and nutted or recesed mount? What model Bianchi and where di you source the brake info? Some online catalogs are listed incorrectly.

In general the answer to your question is Yes provided the mounting style and reach of the brake is compatible.

FBinNY 10-04-12 09:23 AM

There are two issues.

First of all, you need to match the reach to what you need. Brakes come in ranges, ie 39-49mm (often stamped on the back of the arm), corresponding to the vertical distance from the center of the brake hole to the center of the rim's brake surface. This is critical, though not to the last mm unless you're at the extreme end of the range.

Second, side pull brakes come in 2 basic designs, single pivot (both arms pivot on the center bolt) or dual pivot where the arms are linked to each other, but each is on it's own pivot. This matters because there's a difference if leverage and cable response. Replacing a single pivot brake with a dual pivot may create a situation where your lever lacks sufficient throw.

Seco

jrickards 10-04-12 09:27 AM


Originally Posted by Bianchigirll (Post 14805857)
It depends on the bike. Are the current brakes long or short reach and nutted or recesed mount? What model Bianchi and where di you source the brake info? Some online catalogs are listed incorrectly.

I viewed the 1987 Bianchi catalog from Velobase for the info provided above on the brakes.

It looks like a nutted mount (see photo of what appears to be an identical model, http://cdn.velospace.org/files/t_bs2.JPG).

jrickards 10-04-12 10:08 AM


Originally Posted by FBinNY (Post 14805876)
Replacing a single pivot brake with a dual pivot may create a situation where your lever lacks sufficient throw.

It would seem that the current brakes are single pivot so either I look for replacement single pivot brakes or switch out the levers as well.

FBinNY 10-04-12 11:15 AM


Originally Posted by jrickards (Post 14806051)
It would seem that the current brakes are single pivot so either I look for replacement single pivot brakes or switch out the levers as well.

The leverage mismatch may or may not be a problem, so if you see nice double pivots you like, by them, but allow for new levers in the budget just in case.

bradtx 10-04-12 11:22 AM

jrickards, I'm using dual pivot brakes without a lever made for them and there is only a slightly increased amount of hand force needed, you may or may not experiance the same result. They're still much better in braking performance than a single pivot.

AFIK only Tektro makes DP calipers with external nuts, R539 and R556 models (differences are in the reach). You might want to perform a search to verify this. You can also drill out the rear of the fork and the front of the rear brake bridge to accept an internal nutting mount.

Brad

Bianchigirll 10-04-12 11:27 AM

Does your Strada still have the Safety or "Turkey" levers on it? Are you using them to stop? Despite the name they are better for slowing you down, for stopping you need to get in the habit of using the actualy brake levers.

Since you need nutted brakes you best bet to easily get a quality brake is to go witht he DP Tektro w/ nutted mounting. But as FB points out you may need to upgrade your levers too.

I still might try cleaning everything up and going with a new Slamon or daul compound pad like the KoolStop 'cross. These will also let you adjust the toe of the pads a bit to aid in braking and reduce noise.

FBinNY 10-04-12 11:32 AM


Originally Posted by bradtx (Post 14806367)
jrickards, I'm using dual pivot brakes without a lever made for them and there is only a slightly increased amount of hand force needed, you may or may not experience the same result.

Yes, which is why I said, may, not will. But the brakes you want and try them, jut be ready to deal with the leverage if you need to.


Originally Posted by bradtx (Post 14806367)
AFIK only Tektro makes DP calipers with external nuts, R539 and R556 models (differences are in the reach). You might want to perform a search to verify this. You can also drill out the rear of the fork and the front of the rear brake bridge to accept an internal nutting mount.

Brad

A lot of nice Brakes today only come with short bolts. There's a way to make a coupler to extend the bolt for a std fork without drilling the back, if the bottom of the crown is an open tube. I do this fairly routinely for friends who are mounting new brakes on older forks.

cycle_maven 10-04-12 11:39 AM

First off, I'd just replace the pads and cables. A little bit of rust on the brake nut or a little corrosion on the arms is no big deal- safety is the most important thing and the original brakes will stop just fine. Lube the pivot with a tiny dab of tri-flo and you're good to go. Borrow a buffing wheel and some Zam if you want the metal parts to shine, but classic parts on a classic bike are just better looking, IMO.

Bianchigirll 10-04-12 12:20 PM


Originally Posted by cycle_maven (Post 14806406)
First off, I'd just replace the pads and cables. A little bit of rust on the brake nut or a little corrosion on the arms is no big deal- safety is the most important thing and the original brakes will stop just fine. Lube the pivot with a tiny dab of tri-flo and you're good to go. Borrow a buffing wheel and some Zam if you want the metal parts to shine, but classic parts on a classic bike are just better looking, IMO.

Well said. it is funny we used single pivot sidepulls for a few decades, and although some worked better than others, we never heard many horror stories about riders falling off mountains, or getting run over by cars because their brakes did not stop them. DPs have been around about 20yrs and in the last 5 or so years it seems everyone thinks it is suicide to ride without them.

My only bike that had DPs mounted had them removed in favor of CampI Monoplanor style brakes. I am very happy with the stopping action of these brakes and they look much better than a DP brake.

Edit Actually I made an error here. I do have one bike that mounts DP brakes but that is more a act of fashion not function. I wanted a black brakeset and got tired of being outbid on black Dura Ace brakes.

jrickards 10-04-12 01:18 PM


Originally Posted by Bianchigirll (Post 14806381)
Does your Strada still have the Safety or "Turkey" levers on it? Are you using them to stop? Despite the name they are better for slowing you down, for stopping you need to get in the habit of using the actualy brake levers.

When I was a teenager, my bike had those levers but I removed them because right away, I recognized their "safety". No, this bike does not have them so no worries.


Originally Posted by Bianchigirll (Post 14806381)
Since you need nutted brakes you best bet to easily get a quality brake is to go witht he DP Tektro w/ nutted mounting. But as FB points out you may need to upgrade your levers too.

That sounds like a good solution, especially since I am 4hrs drive north of Toronto and cycling season is coming to a close so if I need levers, I won't need them for long and can set myself up over the winter.


Originally Posted by Bianchigirll (Post 14806381)
I still might try cleaning everything up and going with a new Slamon or daul compound pad like the KoolStop 'cross. These will also let you adjust the toe of the pads a bit to aid in braking and reduce noise.

Sound advice for pads, I may just get them first so I can use the current brakes.

FBinNY 10-04-12 01:21 PM

I too prefer single pivot brakes, but the OP didn't ask whether he should replace his brakes. He said he wanted to replace them, and wanted to know about potential complications.

Ours is not to reason why.....

jrickards 10-04-12 01:32 PM


Originally Posted by FBinNY (Post 14806833)
I too prefer single pivot brakes, but the OP didn't ask whether he should replace his brakes. He said he wanted to replace them, and wanted to know about potential complications.

I must replace the pads, wait, pads implies some degree of resilience, these ones could scratch diamonds. Replacing the brakes is primarily to get rid of unsightly (and, for the purpose of removal, awkwardly located) rust as well as a desire to improve the brakes over their original quality.

fietsbob 10-04-12 01:44 PM

New brake shoes , and just replacing the odd rusty looking nut , too economical?

FBinNY 10-04-12 02:24 PM


Originally Posted by jrickards (Post 14806860)
I must replace the pads, wait, pads implies some degree of resilience, these ones could scratch diamonds. Replacing the brakes is primarily to get rid of unsightly (and, for the purpose of removal, awkwardly located) rust as well as a desire to improve the brakes over their original quality.

You don't have to explain your reasons to me. That was the point of my post, you asked a question, and I felt it was appropriate to answer your question, without offering unsolicited advice, or questioning your decision.

If you asked whether it was necessary, or recommended that would have been different, but the post implied that you'd decided, so I simply gave you the info about the implications w/o the extra baggage.

Bianchigirll 10-04-12 05:37 PM


Originally Posted by fietsbob (Post 14806895)
New brake shoes , and just replacing the odd rusty looking nut , too economical?

They are not quite the same but I sometiumes get stainless steel acorn nuts for brakes with rusty nuts.

jrickards 10-05-12 06:09 AM

Thank you everyone for your comments and criticisms, all were welcome because it made me think about my priorities. It also educated me a lot about brakes.

I'm going to clean up the rust on the brakes, replace the pads, ensure that the brakes are mechanically sound, lubricate the cables and replace the nuts with stainless steel ones (good idea!). It sounds like this will provide me with decent braking.

I will take this approach with the rest of the bike: clean, lubricate, adjust and only if necessary, replace.

Thanks again!

JohnDThompson 10-05-12 07:02 PM


Originally Posted by Bianchigirll (Post 14806591)
Well said. it is funny we used single pivot sidepulls for a few decades, and although some worked better than others, we never heard many horror stories about riders falling off mountains, or getting run over by cars because their brakes did not stop them.

Indeed. Although dual pivot calipers in principle can have better mechanical advantage than single pivot calipers, once the caliper has stopped the wheel from moving (either skidding the rear or face-planting with the front) that additional mechanical advantage doesn't really matter. It would be much more cost effective for the OP to simply replace the pads with e.g. Kool Stop pads.


DPs have been around about 20yrs and in the last 5 or so years it seems everyone thinks it is suicide to ride without them.
They've actually been around much longer than that, but until about 20 years ago they were never found on professional-level racing bikes. E.g. here's a Gerry Burgess "Synchron" dual pivot caliper from the early 1960s:

http://www.os2.dhs.org/~john/gb_dual-pivot.jpg


All times are GMT -6. The time now is 03:16 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.