Centerpulls Revived! Paul Components!

[dbrk]

I'm always raving about centerpulls not merely because I like old French things (though the best old ones were made by DiaCompe in that way the Japanese do it better). I know also that the redoubtable and wise BigMac has no liking for them and I truly respect his opinions. But when centerpulls are used with the proper braze-on pivots and decent brake pads, the former being rare and nowadays nearly extinct, and the latter being a feature of modernity (yes, brake pads are waaaaaay better now than in daysofyore), then the physics and feel of a centerpull is simply superior. Then you get to all the clearances, superior braking, and -none- of the hassle that cantilevers involve. Plus you get an aesthetic worthy of a great bike.

I've known about this project from Paul's Components for awhile but they have at last put their photo on their website and announced their intentions. Praise Jah. Like their cantilevers which take us back to the Mafac Racers except work better, these too have the look of Mafacs. The Even Better News is that these fit to cantilever studs rather than the smaller special pivot braze-ons that a proper centerpull brake requires. That makes them useable and mountable and do-able for "normal" builders. As you can tell, I am excited about something but it is a victory here not for fashion or nostalgia but for a better idea. Centerpull physics are far superior and there are some wonderful advantages, not the least of which are clearances for wider tires but a look that lets you also use a thinner tire and still get the brake.

I would wager that you will see these used on new bikes built by smart, innovative builders. (N.B., Don't take that wager...since unlike in Deadwood, I'm showin' a hand here...) My only hope is that Paul knows he's in for it and that there will some who see the wisdom, not just the coolness factor. These have both but wisdom wins every time. We can only hope that there are moer wise ideas that were once old ideas and are still better ideas ahead.

So here's the picture I pulled off the website.

dbrk

[saab2000]

.... I will.

They look sort of cool. What makes 'em better? Not saying I don't like them, because I like stuff which is a bit different, but why are these superior to normal cantis? I guess the rider can mount panniers or not hit his/her heel on the brake. That might be one advantage.

[BigMac]

Congratulations Douglas, you must be a very happy man to see such a fine product. I will say these offer several VERY important distinctions from the former Weinmann, DiaCompe versions:
1. The pivots are sealed and adjustable making centering very easy and action very smooth/free of road gunk -- just like Paul's Cantis
2. The KoolStop pads are oh so easy to align, toe-in etc. and when opting for the Salmon version, they are extremely powerful and reliable in all-weather conditions.
3. They use same defacto standard canti braze-on mounts which eliminates need for some proprietary braze-on fitting no builder in their right mind would want to hassle with.

Ok, so now you have your modern centerpulls, where's Jerk with my assymetric drilled Bontrager sewup rims he's promised me? :help:

Ride on! :banana: :banana: :banana:

[dbrk]

BigMac,
I too was happy to see the sealed pivots. On the Paul's cantis the springs being exposed can lead to rust. I'd have preferred that they either seal them like this or place them behind, as the old Mafacs are made. And oh so correct as well that if you use the salmon KoolStops these badboys will stop on a dime.

To SAAB I would say that centerpulls are about 1000times easier to adjust than cantilevers. I, for one, have never enjoyed the tweaking required to get a cantilever to center up, plus the cantilever cables are more to knock about. Centerpulls are much more like caliper brakes in terms of ease of adjustment.

I think if Paul is successful with these (and I know more than a few builders who are going to use them) then perhaps the S will get back in the game. After all I think we owe "normal reach" calipers to Mr Petersen's influence for the most part. These centerpulls are idea for fendered bikes but will look fine on nearly any other that uses cantilevers. I plan on replacing the cantilevers on my Moots PsychloYBB with these as soon as possible.

dbrk
pleased as punch...

[terry]

dbrk: i agree with you on the vast majority of issues here (sizing up is definately not one of them-& if i didn't have 2 tuition bills i'd be building up your peg as we speak) but i don't have the same affinity for the old stuff (NR/SR excluded) that you do. i have no need nor desire for centerpulls-i find their look inelegant and any 'advantage' is lost on me. i do like to see niche players in the market i just don't know how many would want to revert to a decades old concept/design. that said, Paul does make nice stuff.

[csb]

[DWF]

I plan on replacing the cantilevers on my Moots PsychloYBB with these as soon as possible.

dbrk
pleased as punch...
You realize that it's not a direct replacement right? The studs for centerpull's are located above the rim/pad, not below it as on modern canti's so you'll need to send your YBB to Moots for a retrofit.

I've been talking to Paul about these for some time and he's deadset against making a "booster" plate for them that will allow them to be installed on bikes with canti studs in the normal location. That said, I've got a pair in black coming which I'm going to intall on my '59 "Biatchi" with the lugged internal headset. Everything old is new again.

[dbrk]

Ah, yes, I spoke too soon. These are not a one to one replacement...and I knew that! See what happens when you lose your mind?

But in reply to a decades old technology I would say that the physics of centerpulls and the _idea_ of centerpulls has _always_ been superior. This isn't some retro piece or nostalgic foray into what was, this is a revived notion that was superior to begin with. Why then did it go away for so long? The bike industry moves to its own motives and for nearly two decades it has sold us its own versions of "better" and what we need, etc. So to see this come back, well, that's a matter of developing further an idea that was a good idea to begin with but suffered neglect. Surely decent calipers are better than bad centerpulls but really good centerpulls would be quite the feat.

dbrk

[pale scotsman]

These aren't going to be as easy to adjust as the centerpull of yor. The brake arm tension adjustment looks to be just like U brakes and my all time favorite Suntour Rollercam brakes. Which means each arm is going to have to be tensioned with a 14mm or so wrench and a 5mm allen wrench.

The old mafac 2000s just had a spring behind the brake stud that you could bend to add more or less tension.

I'm not nit picking since these are a step in the right direction but they aren't classic centerpulls.

[kenyee]

In a classic old vs. new, why would you use centerpull brakes rather than asking a custom bike designer to add disc brake mounts instead and mount Avid road disc brakes? Inquiring minds want to know ;-)

[bfd]

Contrary to dbrk's belief, some would disagree about centerpull's effectiveness:

From the Bicycle FAQ:

Centerpull

The centerpull brake of the 1950's, was popular for nearly a decade,
in spite of being entirely without merit, being worse in all respects
than the side pull brake with which it competed. It had the same hand
levers and its caliper the same 1:1 mechanical advantage, but had
large position error, moving its pads upward into the tire with wear.
Its symmetry may have been its main appeal, an aesthetic that people
often admire without functional reason. Its acceptance might also
have been from dissatisfaction with flimsy sidepull calipers of the
time. It used a straddle cable on which the main cable pulled from a
flimsy cable anchor attached to the tab washer under the head bearing
locknut. Besides its two levers, it had a connecting bridge that
flexed in bending and torsion, making it spongy. Although Mafac was
one of the greatest proponents of this design it began to vanish on
sport bicycles with the introduction of the Campagnolo sidepull brake.

[dbrk]

That Bicycle FAQ is cobswobble. It is as if this person never used a centerpull. Sorry, this made me crabby. Shall I refute it point by point? Want reasoned argument?

*Pads did not move up into the tire with wear but rather if the brake was mounted on braze-ons pulled consistently to the rim.
*Straddle wires and guides almost never broke. Go to just about any curbside wreck of a bike that used the worst centerpulls and you will find the wires and guides intact on most. Use a good brake properly mounted and this doesn't happen.
*Centerpulls were "replaced" not necessarily by a superior sidepull but by the advancing notion of whole groups. People started buying whole boxes of bits, a real revolution in that era. Of course I still prefer using mix and match parts so that I can happily bang my head against the walls of conformity and genericism that plague the bike industry (and most everything else nowadays in America, I mean, look at food: the most prosperous civilization in history buys mass produced crap when it actually has the choice not to...ahhh, I rant, apologies.)

I'd wager this same Bicycle FAQ tells us all to ride bikes using the Lemond or Hinault sizing formula too, or some such nonsense. Does Singer still use centerpulls because they are inferior and because they are hopelessly lost in the past? Uhh, no.

BicycleFAQ author is entitled to his opinion no less than I but what is a shame is that this design did not see the same advances that sidepulls did. Rather, it just sort of died and now is largely treated as retro and hopelessly out of fashion. What is at stake is whether it works well (it does) and solves problems that calipers do not (it does).

dbrk

[vaxn8r]

It used a straddle cable on which the main cable pulled from a
flimsy cable anchor attached to the tab washer under the head bearing
locknut.


That is exactly what I recall about centerpulls. The flimsy cable hanger which was a big washer in the headset or a flimsy piece of metal hanging from the seat bolt clamp. Hard braking severely distorted the little hanger pieces. I suppose in the back there could be a way to braze something into the frame for added braking strength and stability but how about in front?

[bfd]

I believe the article on Centerpull brake, actually a discussion on all types of brakes, was written by Jobst Brandt. In fact, here's his recent's thought about centerpull brakes, from rec.bicycles.tech:

Gary Young writes:

> Though I've been critical of Grant Peterson's effort to revive
> centerpull brakes, I have to admit that the latest Rivendell Reader
> (#30) gave me reasons to pause.

I think two things should be noted about all brakes before the dual
pivot era, and that is they all had a 1:1 ratio in the "caliper" and a
4:1 ratio in the hand lever, all brakes being interchangeable under
any hand lever. This includes sidepull, centerpull and cantilever.

The second feature is that sidepull brakes have the pad pivot above
and only slightly (rim half width) offset from the braking surface so
that there is essentially no position change as the pad sweeps through
its wear life (cosine error). Centerpull and cantilever brakes
approach the rim at nearly a 45 degree angle and have large vertical
change throughout pad wear life, so much so that cantilever brakes
have dived under the rim leaving the bicycle with no brake at all.

The cantilever dives under but had the advantage of endless mud or
radial tire clearance, the centerpull goes into the tire as it wears
and offers no advantages whatsoever. I believe that is why it died so
quickly as it should have. It was sold on the premise that it had a
higher mechanical advantage, something that at first inspection it
appears to have through its long levers. They are twice as long as
the pad arms... but there are two of them, each receiving half the
force.

> First of all, in the letters section, a reader (Thomas Papetti)
> points out that dual-pivot sidepulls won't track an out-of-true rim
> the way all other brake types will. I'm not sure how much that
> counts in favor of centerpulls (Papetti doesn't discuss them at
> all). Even though most riders would probably use long-reach dual
> pivots in lieu of centerpulls, long-reach single-pivot sidepulls and
> cantilevers are still available if tracking is a significant worry.
> Then in an article, Jan Heine makes several claims for the
> superiority of sidepulls.
> He says, "The long lever on the cable side [above the pivot, if I
> understand him correctly] and the short lever on the pad side [below
> the pivot] gives centerpulls a huge mechanical advantage over
> sidepulls. Just like a bolt-cutter, where long arms and short jaws
> allow you to cut through thick steel bolts." Later on, he adds that
> only with the advent of dual-pivot brakes did sidepulls catch up to
> centerpulls in this respect.
> That doesn't seem to jibe with Jobst's discussion in the FAQ, which
> seems to suggest that single-pivot sidepulls and centerpulls had the
> same mechanical advantage.

They had to have the same ME or you couldn't operate them with the
same pad clearance. The purpose of the dual pivot is to allow half
the pad clearance of former brakes and this required accurate
centering. This is necessary to offer the higher mechanical
advantage today's avocational riders need to stop their bicycles.

Just recall the story bicycle shops had to come up with to explain why
riders could not stop their Campagnolo Record equipped bicycles...
"These are racing brakes. Racers only need to modulate speed, not
stop." and the like. If you believe that you deserve to be led around
by the nose. The faster you go the harder you must brake. Descending
a mountain pass with straights and hairpin turns requires standing the
bicycle on its front wheel into every turn. This is done with two
fingers by racers using 4:1 brakes.

> He argues that only the part of the arm below the pivot needs to be
> beefy, because that's the only place where flex matters. "As a
> result, the arms above the pivots can be incredibly skinny, as they
> don't need to resist flex. That is where the weight savings of a
> centerpull originate." He doesn't say what the weight savings is.

Flex in any part of the system eats up hand lever stroke. Who invents
this cock and bull stuff anyway? The lower arm must be stronger
because it is loaded in torsion from brake pad drag.

> He writes, "And since the pivot on centerpull brakes is on the fork
> leg, adding reach does not increase the flex or change the
> mechanical advantage. So there is not incentive to go to
> short-reach brakes." I think he means that since the distance
> between the pad and the pivot point always remains the same, adding
> lever length above the pivot doesn't effect the mechanical
> advantage. That sounds dubious to me -- doesn't changing the length
> of a cantilever brake's straddle cable effect mechanical advantage
> even if all else remains the same? Furthermore, from the photos of
> old centerpulls in the Reader, it doesn't seem as if the distance
> from pivot to pad was always kept constant (some long-reach brakes
> seem to achieve that reach in part by increasing the lever below the
> pivot).

These are not people to be believed. They have no idea what they are
talking about and do it profusely. It reminds me of the kooks I see at
InterBike every year with a new crank mechanism that will make you go
faster, not to mention how much mechanism and weight it adds to the
bicycle.

> He notes that centerpulls don't stick out to the side like
> sidepulls. It seems to me that that problem can be cured by using
> v-brakes, though that introduces problems of its own (e.g., mating
> them to road levers).

How far??? What is the issue here anyway. Is it perhaps streamlining
or just someone who suffers from the "loose ends" syndrome (things
that protrude, as in toilet paper rolls that pay off the front instead
of the back [hidden ends])?

> He says that even the standard-reach (what would be called
> long-reach by most) dual-pivot brakes offered by Shimano don't leave
> much room for fenders. Is that true?

NO.

> Just how big a tire would you have to run before you would crowd out
> the dual pivots? (Elsewhere in the Reader, Grant says that
> centerpulls will clear a 40mm tire or a 38mm tire with fenders;
> what's the limit with the current long-reach dual pivots?)
> Furthermore, why not long-reach single-pivots, which are still
> available?
> Probably his most controversial claim is that single-pivot sidepulls
> "offered inferior performance" and became widespread mostly because
> of Campagnolo's advertising and gruppo packaging. Contrast that
> with Jobst's claim in the FAQ that, "The centerpull brake of the
> 1950's, was popular for nearly a decade, in spite of being entirely
> without merit, being worse in all respects than the side pull brake
> with which it competed."

A conspiracy! The sidepull brake is the obvious mechanism for road
bicycles to all who understand mechanical design. All this other
stuff is amateur thinking guided by misunderstanding of the concept.
Even places like Campagnolo are not immune. After Tullio died the
place was run by incompetents who made the Delta brake, a non linear
response brake with huge cosine error. It was an Ide? fixe of someone
with "loose end" syndrome, externally clean but a mess inside.

http://draco.acs.uci.edu/rbfaq/FAQ/8f.15.html

> In the past, I've been pretty fed up with Grant's talk of reviving
> centerpulls, because it so often appeared side-by-side with complaints
> about Rivendell's financial straits and lack of popularity. I do
> notice a more refreshing tone in this issue: he mentions a bike
> planned for next year that will have braze-on pivots for centerpulls
> and adds, "But we don't expect anybody to follow that lead., and we
> fully expect to sell fewer bikes because of it. Centerpulls, for as
> much sense as they make, will still scare off most customers."

... and they should. Now let's hear it again concisely. What are the
advantages?

Jobst Brandt
jobst.brandt@stanfordalumni.org

[hypnos]

Too bad that I was unaware of these new Paul centerpulls back when I was planning my new bike. I really wanted brakes that would work well with fenders, so the bike was built for cantilevers. These brakes would have been much better. Oh well.... maybe on the next bike.

[jl123]

DBRK,

DO you think you would ever put newer but improved parts like the Pauls on any of your French steel? Have you ever thought of putting together an old classic with simply the best parts of both old/new? Thanks, JL

[dbrk]

DBRK,

DO you think you would ever put newer but improved parts like the Pauls on any of your French steel? Have you ever thought of putting together an old classic with simply the best parts of both old/new? Thanks, JL

This is an interesting question. I think that certain bikes like those made by Singer and Herse should be kept as close to period correct as possible without compromising performance. These bikes really operate beautifully. I wish some who doubt that would spend an afternoon on one of my Singers with 30 year old parts. I mean, the ride is wonderful and the parts are flawless. Yes, they do not work like the invisible modern indexing bits but that's hardly the point. When you ride these bikes your riding gains a certain quality, even personality. It's not at all frustrating or "retro". Rather, it's simply a different experience and one that puts you very close to the bike, attuned to its nuances and aware that the ride is more cooperative, more of an exchange between rider and bike. On many modern parts the "ride" is essentially not there! I mean, the parts are so snappy and invisible that _that_ is understood to be the point. Okay, I like to ride that way but riding great parts on older styles of bicycles is wonderful.

Now that said I would very much like to build a modern bike with these improved "old" style technologies. I think Mariposa or Vanilla is a good candidate for taking up these ideas: building in French style with the best of the best modern parts. I also think, without letting too much out, that the Hampstens have a notion to build bikes just like the ones we are thinking about. To wit, bikes that utilize the new improved technologies, so bits like Paul's centerpulls, Ergo or STI shifters with 27 or 29 rear doubles, 110bcd cranksets like TA Zephyrs or the like, Honjo fenders and Schmidt dynohubs if that's your fancy, and then build the frame more like a French fit (fist full of post, threaded stems like Nitto Pearls, classic lines and clean proportions). We might also see 650B or 26" wheels as well as 700c wheelers with clearances. I think we can expect to see such bikes from Hampsten soon and perhaps others like Rivendell's impending Saluki (650B with Paul's being the current notion...) that will be whole bikes but not in the constructeur tradition (more in the versatile, all-arounder tradition where parts are swapped in and out). Of course it would be neat if old bits were also offered as options on such bikes, such as friction shifting of the highest order, like NOS Campagnolo retrofriction dt shifters or Mavic/Simplex rear derailleurs. All of this would be possible if minds were put to the task. As fun as it would be outfit frames with the best of the classic parts it would be even better to see them built with the best of the "old" designs, both 700c and 650B, much the way Herse and Singer were built (and still are, in the latter case). I think Rivendell's interest in 650B, the revival of centerpulls which are _clearly_ the best choice for fendered bikes by a long shot, and the need to have fast, fun, and _comfortable_ bikes portends wonderful things ahead. I think, as I said, that Hampsten Cycles already has such notions, if I am not too bold in saying. One can only hope that there are more interesting things ahead than even more generic race bikes built for folks who largely don't race. I don't mean fuddyduddy bikes. I mean really, really fun and fast and comfortable inside great traditions and with great innovations. We are mostly being sold images of young racers. Sooner or later bicycle riders who are real enthusiasts will understand look harder at how they ride and how many different ways they can have fun riding bicycles. I find cycling culture to be pretty narrow right now, immature you might say, and driven by marketing rather than practical imagination and more expansive ideas of having fun.

dbrk

[jl123]

DBRK, Interesting response as well.

Along the track of your newer frame with parts mixed with old school french geometry idea; if one was to indeed utilize sti/ergo, would you agree with some others on this board that maybe 9/10 speed cassettes are often overkill and possibly time consuming to shift, especially for all day riding. I know Jan Heine often speaks about using far fewer gears for most of his long rides (using double chainrings and six speed cassettes) and never complaining about a lack of ratios- of course he is a very strong rider. I suppose my question is, is what sort of index shifting system (maybe an older one) would you most see yourself using for non-loaded single day touring? Thanks, JL

[saab2000]

I am one of the all-time retro-grouch world champs in some ways. I have never believed that having modern stuff necessarily makes bikes "better". I love bikes from the '80s with C-Record and Super Record with toe clips and exposed brake cables, etc. I dig 'em.

But I also have a couple of bikes with "modern" stuff like 10-speed Record Ergo, Time Impacts, etc. If I have to choose for a group ride there is little doubt about which one I will choose. Give me the new stuff any day.

But for a solo ride on a summer evening I like the old one.

I have a Surly Crosscheck which I have outfitted with one speed and in some bizarre way it is the most enjoyable bike I have. I just got it and it fits pretty well when I am riding it and it is rock solid and comfy and I am sure it will get some midnight miles this summer with a small taillight and a headlight, but for the faster groups, give me the 2004 stuff.

I like the old stuff for sure. It took me a long, long time to go clipless, but now that I have been converted I really like to have my modern bikes.

But I like that others keep the "Classics" on the road!

:beer:

[PaulE]

to me for some reason. But back in the day, my Mafac and Weinmann centerpull brakes did not have pivot bosses brazed on to the frame, they had a single center bolt and the bosses were part of the brake itself. So what was so familar about centerpull brakes with frame-mounted bosses? Fixing the third flat this year on my son's Haro freestyle bike, it hit me. BMX and freestyle bikes use a similar brake, with the pivots welded to the frame, although the portion of the arm above the pivot is much shorter. :D