|This edition of Tim Laflin's Tech
Talk examines the "go slow"
part of your "go fast" bike: Brakes
. . .
I don't get too excited about brakes. Brakes had not evolved much in the last 20 years and seemed to work just fine. For a while the brakes went from side pull to center pull and back to side pull. Everybody was pretty much happy.
The big boys at Campy and Shimano were looking for some improvement in this area and Campy was first to strike with the Delta brake system. While this brake system had much more leverage over a standard brake it had some serious flaws. The Delta brakes required a 22mm rim width because of the geometry of the brake calipers.
A narrower rim caused the brakes to increase leverage and made locking up the brakes a real problem. They also tended to wear down the pads too much. A wider rim would not fit very well in the system and decreased leverage and the pads could not be angled to correct for it. All this, coupled by the fact that the they were extremely heavy made for a poor solution. Shimano was still using the monoplanar style side pull during this time.
The big two next came out with what I call the V-brake for the road. The dual pivot caliper was introduced. It increased leverage by offsetting the caliper pivots for each arm of the caliper. The older monoplanar had a central pivot that also doubled as the brake stud to hold the caliper to the frame. The dual pivot increased the lever arm of the caliper to increase braking power. I have had no problem locking up the brakes with the old monoplanar style so the dual pivot was overkill in my view. The dual pivots do have several new features the old monoplanars did not. The Shimano Dura-Ace has a spring force adjustment to tune the return force of the caliper, as well as a micro adjustment for the centering of the caliper. The 600 version is very similar to the Dura-Ace except that it only has two settings for brake return force (high and low) but keeps the centering adjustment. The 105 caliper is almost identical to the 600 except is gets a plastic quick release lever.
The Campy line up matches Shimano very closely. The Record uses the same features of micro-centering adjustment and adjustment for return spring force. The Chorus has the same features as the Record. The Athena model loses the spring return force adjustment that the Record and Chorus have. All the Campy and Shimano units now use ball bearings on the dual pivot locations and very similar construction.
The Campy units are easier to disassemble and service, but the average user will probably never do this. The biggest feature that Campy and Shimano differ on is the quick release. You are probably thinking big deal. Well it is to a racer.
The Campy quick releases to the brakes are on the hoods near your hands. They can be released without taking your hands from the bars. That is not much of a feature in and of itself. The Shimano brakes have the quick release located at the calipers. Big deal. I can reach the front and rear brake quick releases while riding. The point here is twofold. From the rider's position you can tell when the Campy quick releases are open without having to look. The second point is safety. When you open the Campy quick release, the brakes still have full power.
The brake lever is allowed to move out from the bar in the Campy design to release more cable. The Shimano design releases the cable at the caliper. If you release the Shimano brake you have lost all the brakes on that wheel. If you hit the brakes on a Shimano bike with the quick release open it simply pull the lever to the bar and you get little or nothing. The Campy design allows the rider all the braking force he had before the release was open. This can be an issue of significant safety especially in the rain. The Campy calipers also have a nice feature that Shimano seems to have forgotten. The Campy calipers still have a place to put a brake wrench to hold the caliper in position while tightening it. It is a minor feature, but a nice one. The last point of difference is in the cable adjusters. The Campy units are all aluminum and Shimano uses steel. I find the Campy adjusters easier to use and they never rust stuck in the calipers. The Shimano adjusters are steel bolts with rubber covers that slip and are hard to grip. The other neat thing about Campy adjusters are that you can remove the cables from the calipers with the crimp ends still on them because the adjuster barrels are not captive like Shimano. When you travel with a bike taking the bars off requires pulling the front brake cable and it is a pain to keep putting on cable crimp ends back on every time you fly.
As far a dual pivots are concerned I feel it was the answer to the question nobody was asking. The new calipers are extremely heavy compared to monoplanars and braking force was not a big issue. The Record calipers are about 408 grams and the Dura-Ace are about 422 for 1996 models. You can get a set of BRS-200SL calipers from Dia-Compe for less money and about half the weight (250 grams per pair). That weight differential is nearly half a pound. Taking that much weight off the bike was never so easy or cheap. Give them both a five yard penalty for weight. The lower line monoplanar brakes from both companies are significantly lighter than the top-end dual-pivot models.
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