Types of rim brakes Bicycle brake

1 types of rim brakes

1.1 rod-actuated brakes
1.2 caliper brakes

1.2.1 side-pull caliper brakes
1.2.2 centre-pull caliper brakes
1.2.3 u-brakes


1.3 cantilever brakes

1.3.1 traditional cantilever brakes
1.3.2 v-brakes
1.3.3 roller cam brakes


1.4 delta brakes
1.5 hydraulic rim brakes

types of rim brakes

the following among many sub-types of rim brakes:

rod-actuated brakes

rod brake system. lateral play in pivot rear brake rod allows rotation of handlebar

the rod-actuated brake , or rod brake , (roller lever brake in raleigh terminology) uses series of rods , pivots, rather bowden cables, transmit force applied hand lever pull friction pads upwards against inner surface, faces hub, of wheel rim. called stirrup brakes due shape. rod brakes used rim profile known westwood rim, has concave area on braking surface , lacks flat outer surface required brakes apply pads on opposite sides of rim.

the rear linkage mechanism complicated need allow rotation fork , handlebars attach frame. common setup combine front rod brake rear coaster brake. although heavy , complex, linkages reliable , durable , can repaired or adjusted simple hand tools. design still in use, typically on african , asian roadsters such sohrab , flying pigeon.

caliper brakes

the caliper brake class of cable-actuated brake in brake mounts single point above wheel, theoretically allowing arms auto-centre on rim. arms extend around tyre , end in brake shoes press against rim. while designs incorporate dual pivot points — arms pivot on sub-frame — entire assembly still mounts single point.

caliper brakes tend become less effective tyres wider, , deeper, reducing brakes mechanical advantage. caliper brakes found on modern mountain bikes. ubiquitous on road bikes, particularly dual-pivot side-pull caliper brake.

side-pull caliper brakes

single pivot side-pull caliper brake.

single-pivot side-pull caliper brakes consist of 2 curved arms cross @ pivot above wheel , hold brake pads on opposite sides of rim. these arms have extensions on 1 side, 1 attached cable, other cable housing. when brake lever squeezed, arms move , brake pads squeeze rim.

these brakes simple , effective relatively narrow tyres have significant flex , resulting poor performance if arms made long enough fit wide tyres. if not adjusted properly, low-quality varieties tend rotate 1 side during actuation , tend stay there, making difficult evenly space brake shoes away rim. these brakes used on inexpensive bikes; before introduction of dual-pivot caliper brakes used on types of road bikes.

dual-pivot caliper brake.

dual-pivot side-pull caliper brakes used on modern racing bicycles. 1 arm pivots @ centre, side-pull; , other pivots @ side, centre-pull. cable housing attaches of side-pull brake.

the centering of side-pull brakes improved mass-market adoption of dual-pivot side-pulls (an old design re-discovered shimano in 1990s). these brakes offer higher mechanical advantage, , result in better braking. dual-pivot brakes heavier conventional side-pull calipers , cannot accurately track out-of-true rim, or wheel flexes side side in frame during hard climbing. common see professional racers climbing mountains quick-release undone on rear brake, eliminate drag source.

centre-pull caliper brakes

centre-pull caliper brake.

this type of brake has symmetrical arms , therefore centre more effectively. cable housing attaches fixed cable stop attached frame, , inner cable bolts sliding piece (called braking delta , braking triangle , or yoke ) or small pulley, on runs straddle cable connecting 2 brake arms. tension on cable evenly distributed 2 arms, preventing brake taking set 1 side or other.

these brakes reasonably priced, , in past filled price niche between cheaper , more expensive models of side-pull brakes.

u-brakes

u-brake on freestyle bmx bike

u-brakes (also known trademarked term 990-style ) same design centre-pull caliper brake. difference 2 arm pivots attach directly frame or fork while of centre-pull caliper brake attach integral bridge frame mounts frame or fork single bolt. roller cam brakes, caliper design pivots located above rim. u-brakes interchangeable with, , have same maintenance issues as, roller cam brakes.

u-brakes used on mountain bikes through 1990s, particularly under chainstays, rear brake mounting location popular. location benefits higher frame stiffness, important consideration powerful brake since flex in stays increase lever travel , reduce effective braking force. unfortunately prone clogging mud, meant u-brakes fell out of favour on cross-country bikes.

u-brakes current standard on freestyle bmx frames , forks. u-brake s main advantage on cantilever , linear-pull brakes in application sideways protrusion of brake , cable system minimal, , exposed parts smooth. valuable on freestyle bmx bikes protruding parts susceptible damage , may interfere rider s body or clothing.

cantilever brakes

the cantilever brake class of brake in each arm attached separate pivot point on 1 side of seat stay or fork. cantilever brakes dual-pivot. both first- , second-class lever designs exist; second-class far common. in second-class lever design, arm pivots below rim. brake shoe mounted above pivot , pressed against rim 2 arms drawn together. in first-class lever design, arm pivots above rim. brake shoe mounted below pivot , pressed against rim 2 arms forced apart.

low profile traditional cantilever brake.

due wider possible distance between mounts , pads, cantilever brakes preferred bicycles use wide tyres, such on mountain bikes. because arms move in designed arcs, brake shoe must adjustable in several planes. cantilever brake shoes notoriously difficult adjust. brake shoes of second-class cantilever brake wears, ride lower on rim. eventually, 1 may go underneath rim, brake not function.

there several brake types based on cantilever brake design: cantilever brakes , direct-pull brakes - both second class lever designs - , roller cam brakes , u-brakes - both first class lever designs.

traditional cantilever brakes

this type of brake pre-dates direct-pull brake. centre-pull cantilever design outwardly angled arm protruding on each side, cable stop on frame or fork terminate cable housing, , straddle cable between arms similar centre-pull caliper brakes. cable brake lever pulls upwards on straddle cable, causing brake arms rotate , inward squeezing rim between brake pads.

traditional cantilever brakes difficult adapt bicycle suspensions , protrude frame. accordingly, found on bicycles without suspension.

v-brakes

linear-pull brakes or direct-pull brakes , commonly referred shimano s trademark v-brakes , side-pull version of cantilever brakes , mount on same frame bosses. however, arms longer, cable housing attached 1 arm , cable other. cable pulls against housing arms drawn together. because housing enters vertically above 1 arm yet force must transmitted laterally between arms, flexible housing extended rigid tube 90° bend known noodle . noodle seats in stirrup attached arm. flexible bellows covers exposed cable.

since there no intervening mechanism between cable , arms, design called direct-pull . , since arms move same distance cable moves regard housing, design called linear-pull . term v-brake trademarked shimano , represents popular implementation of design.

v-brakes function suspension systems found on many mountain bikes because not require separate cable stop on frame or fork. because of higher mechanical advantage of v-brakes, require brake levers longer cable travel levers intended older types of brakes. mechanical (i.e. cable-actuated) disc brakes use same amount of cable travel v-brakes, except described being road specific. general rule, mechanical disc brakes so-called flat bar bicycles (chiefly mountain , hybrid bicycles) compatible v-brake levers, whereas mechanical disc brakes intended drop-bar bicycles compatible cable pull of older brake designs (cantilever, caliper, , u-brake).

poorly designed v-brakes can suffer sudden failure when noodle end pulls through metal stirrup, leaving wheel no braking power. although noodle can regarded service item , changed regularly, hole in stirrup may enlarge through wear. stirrup cannot replaced, quality v-brakes use durable metal stirrup.

mini v-brakes (or mini v s ) v-brakes shorter arms, typically between 8 , 9 centimeters. reduces required cable pull, making them compatible brake levers intended cantilever brakes. mini v-brakes retain advantages specific v-brakes such not requiring cable stops. on downside, shorter arms provide small tyre , wheel clearance , make less forgiving setup: can accommodate smaller tyre sizes compared cantilever brakes, may pose problems mounting fenders, can clogged more mud, , can make harder change wheels.

roller cam brakes

roller cam front brake.

roller cam brakes centre-pull cantilever brakes actuated cable pulling single two-sided sliding cam. (first , second-class lever designs exist; first-class common , described here.) each arm has cam follower. cam presses against follower forces arms apart. top of each arm moves outward, brake shoe below pivot forced inward against rim. there in favor of roller cam brake design. since cam controls rate of closure, clamping force can made non-linear pull. , since design can provide positive mechanical advantage, maximum clamping force can higher of other types of brakes. known being strong , controllable. on downside, require skill set , can complicate wheel changes. , require maintenance: u-brakes, pad wears strikes rim higher; unless re-adjusted can contact tyre s sidewall.

the roller cam design first developed charlie cunningham of wtb around 1982 , licensed suntour. roller cam brakes used on mountain bikes in 1980s , 1990s, mounted head tube , seat stays in standard locations, , below chain stays improved stiffness not protrude interfere crank. not unusual bicycle have single roller cam brake (or u-brake) combined type. still used on bmx , recumbent bicycles.

there 2 rare variants use roller cam principle. locations centre-pull inappropriate, side-pull toggle cam brake developed. first-class cantilever, uses single-sided sliding cam (the toggle) against 1 arm attached link other arm. cam presses against follower, force transmitted other arm via link. , suspension forks housing must terminate @ brake frame, side-pull sabre cam brake developed. in sabre cam design, cable end fixed , housing moves single-sided cam.

delta brakes

a pair of campagnolo delta brakes

the delta brake road bicycle brake named due triangular shape. cable enters @ centre, pulls corner of parallelogram linkage housed inside brake across 2 opposite corners, pushing out @ other 2 corners on brake arms above pivots, arms below pivots push pads in against rim. feature of design mechanical advantage varies tangent function across range, of other designs remains fixed.

many consider brake attractive, , has lower wind profile other common brakes. however, bicycle quarterly criticized delta brake being heavy, giving mediocre stopping power, , suffering disadvantageous variable mechanical advantage. in particular, small parallelogram, pad wear causes mechanical advantage rise dramatically. however, high leverage, stroke of lever not enough apply brake, rider can have brakes feel normal in light braking cannot applied harder hard braking.

the basic design dates @ least 1930s. made prominently campagnolo in 1985, brakes based on same mechanism manufactured modolo (kronos), weinmann, , others. no longer made , uncommon.

hydraulic rim brakes

magura hydraulic rim brake

this 1 of least common types of brakes. mounted either on same pivot points used cantilever , linear-pull brakes or can mounted on four-bolt brake mounts found on many trials frames. available on high-end mountain bikes in 1990s, declined in popularity rise of disc brakes. moderate performance advantage (greater power , control) offer on cable actuated rim brakes offset greater weight , complexity.