I purchased my Hope disc brake almost 2 years ago, so it has now seen plenty of action – probably over 4,000 miles. Regular riding in the peak district grit means that it has been subjected to some of the worst possible conditions. To give you some idea of the abrasive nature of the local mud, I have worn through a rim sidewall from new in only 4 months – this was a decisive factor in buying these brakes.The Caliper
The closed 2 caliper is nominally the second cheapest in Hope’s range, but when I bought it two years ago it was the new top-of-the-range model, suitable for everything from Pro downhilling to XC racing. The new open 2, downhill and XC4 models which have sprung up in such a relatively short period of time, as well as 2 major price cuts, just goes to show the impact of Shimano entering this sector has had upon the market.
“Closed” means that the pad spacing can be varied which alters the amount of free lever movement, unfortunately this also means that the brake doesn’t self adjust for heat build up or pad wear. I prefer a closed system as I like to run my pads “hair trigger” for fast singletrack, but allow the lever to come much further back to avoid hand cramp on long descents.
Unless you use the “gold” sintered metal pads in dry weather, this adjustment isn’t a major problem. I normally wind the dial back a full turn before a long descent, which allows the brake lever to come further back, and by the bottom of the downhill the heat expansion has normally brought the lever back to the original position.
The “2” refers to the two pistons, which are more than sufficient for most requirements. The XC4 brake has 4 pistons but less power. The Enduro 4 brake has more power but is an open system only and weighs slightly more. As I said before, when I bought the brake it was still being use in Pro downhill racing. I have had no problems with the available power or the reliability of the system. The only time I’ve had it apart is when I changed a caliper half in order to fit new suspension forks with a different mount. There were only 4 moving parts inside the caliper, 2 springs and 2 pistons! Not only has nothing ever gone wrong, but there is nothing to go wrong.
Aligning the caliper was a bit of a faff with my first forks (Marzocchi Z3) but when I swapped to Pace EVO IIIs, the disc mount alignment was far better and it took only 10 minutes to determine the correct quantity of spacer washers for perfect alignment.The Disc
I chose a 185mm disc for extra power. The original “Pro” disc with parallelogram shaped cut outs, which is now discontinued, proved to be a little too light. After a couple of nasty brake fade instances in the Lake District I swapped the 140g “Pro” disc for an ancient 225g “Hydro” disc which runs at a much lower temperature. Current discs weigh around 160g. I also use the old style aluminium spider, which I fitted with loctite for extra security and have never had problems with.The Lever
The “Pro” style lever (as of 2001, the only type of lever) is a very neat design. The master cylinder is incorporated into the clamp body to save weight, and it works faultlessly. The lever blade is comfortable, and the brake pad adjustment dial on the top of the reservoir is very smooth and easy to operate, even with the side of your hand while riding technical terrain.
The piston is pivoted on a high quality brass pivot, to eliminate any side pressure. This pivot occasionally needs a single drop of oil to prevent it from squeaking. Also the lever pivot sometimes gets a little sloppy and so the M5 nylok nut just needs tightening a tad.
I’ve never suffered any leaks from the lever, or anywhere else on the brake. Rapidfire triggers and windows take a little re-arranging to make space for the brake lever clamp. The double bolt clamp is great for getting the lever on and off the bars, but the tiny cut-out rubs on the thumb pretty badly – I filed mine smooth and it’s been fine ever since.
When using “gold” sintered bronze pads for the first time the heat generated was so great that my brakes locked on at the bottom of a steep hill – the adjuster simply wouldn’t release any more, so I had to wait for the fluid to cool down. The simple cure to this was to let a little excess fluid out of the caliper at the bleed nipple. Easy to do and no re-bleed was needed.
The reservoir holds enough fluid to allow for adjustment between the extremes of running worn out pads on a very cold day, to generating 350°C on a huge downhill with gold pads. Since I let a little fluid out, I’ve never had insufficient adjustment in either direction.The Pads
I use all three flavours of pad, and I’d recommend all Hope users to do the same. They’re a cinch to change and work best in their recommended environments.
The red pads (Kevlar with a tiny amount of aluminium and copper swarf) are rarely seen, and are supposed to be for downhill racing only. I use them in the summer months (if we get any) and they work superbly in the dry, with very high friction, excellent modulation and minimum heat generation. They tend to judder and loose power in the wet. They last about 4 months of summer riding. These are definitely the pads to use if you’re off to the Alps or Colorado next summer.
The green pads are the general purpose pads (Kevlar, with aluminium and copper swarf). They are very similar to the reds, only a little less so. Power and modulation is a smidgen behind the reds, but they aren’t so ill-mannered in the wet. In extremely wet conditions they are a little out of their depth and can give some hairy moments and/or judder. They last about 8 months, or one winter if you don’t use the golds.
The gold pads are a completely different bag altogether as they are made from sintered porous bronze. Metallic pads not only generate much more heat at the pad/disc interface, but conduct it very efficiently into the brake fluid. Therefore the fluid expansion is very noticeable and an annoyance with closed brakes. These pads actually have the highest friction levels of any pad compound (0.7), but are quite snatchy and lack the feel of the Kevlar pads. They can also squeal, especially when used in the dry.
The advantage of the gold pads is that they can’t absorb water, they cut through mud easily (instead of it becoming embedded in the pad material), and last ages. I’ve eventually worn out my first pair in two years, just think how many sets of V-brakes pads you’d have got through in two winters! I used to reckon on 2 to 3 ride per pair of V-brake pads in the peak district, and now I never have to think about pad wear. This must accelerate disc wear, but I reckon the reduction must be from 10 years to around 5, as I’ve got no noticeable wear on my disc.
Don’t be tempted to use the gold pads all year round, as the modulation is poorer, they can squeal or even glaze slightly in dry weather, and you need all that mud and water around to keep them cool. A big downhill in summer using gold pads is a recipe for disaster, as many XC4 owner have found to their cost.Advantages compared to rim brakes.
As far as I’m concerned, the advantages that I’ve seen from using disc brakes instead of V’s are thus:
- Much improved modulation – you might think you don’t need better modulation, but once you’ve experienced it you’ll really appreciate it. Most users expect eye-popping stopping power, but the incredible modulation and hence control is the true benefit. I’ve ridden down a steep, sodden, muddy bank and deliberately stopped (and skidded) my front wheel momentarily, then let it roll again. Just try doing that with rim brakes without landing on your face.
- Secondly, because the cantilevers don’t push the suspension fork legs outwards, your forks work much better under braking. They track the ground noticeably better than when using V-brakes.
- Thirdly, they work better (but not faultlessly) in mud, water and even snow.
- Lastly and most importantly, they nearly eliminate pad and rim/disc wear, and are almost zero maintenance. They’ve been apart once (to change a caliper half to fit a new fork), and bled twice – once after the fork change, once after I’d let out too much brake fluid by mistake. Bleeding is a doddle, using about a thimble full of fluid, and easy to do with one person. I simply left a spanner on the bleed nipple and re-closed it after each pump of the lever – with two people It’d be a two minute job. I’ve also never had to replace a hose or had one burst, wear through or pull off – 100% better than mechanical cables, which I most certainly don’t miss! I’ve also replaced the brake pad split pins with hairpins, so that I can change pads without needing pliers.
- They’re slightly heavier and they make your fork twist marginally to the left. Also they generate a lot more heat than rim brakes. This leads to the previously unknown phenomena of pump and fade.
- Potential disc brake problems you may have heard of.
- Pump: When you brake, heat is generated at the disc/pad interface. This is transmitted through the pad and piston and into the brake fluid. Despite brake fluid being selected for minimum expansion, it will still expand slightly. With an open system it’ll self adjust for this heat expansion every time you apply the brakes; with a closed system you’ll have to adjust manually at the dial on top of the lever reservoir. Pump is not a problem provided that you have enough adjustment – when your brakes are new it is best to carry an 8mm spanner along with you, so that you can let out a little excess fluid from the bleed nipple if you run out of adjustment on a big downhill.
- Fade: If the brake disc and pads get hot enough (300°C plus) the friction coefficient will drop and the brake effect will start to fade. The harder you brake, they hotter they get and the more they fade (panic!) Fade is normally accompanied by a pungent smell (as found at the bottom of most Lake District passes). The only cure for brake fade is to use cooler running pads (reds if possible) and/or a heavier disc. Using the brakes intermittently on steep hills will allow them to cool better than dragging them – try alternating your brakes front to back if brake fade develops on a big hill.
- Contamination: Simple – don’t let any oil or aerosol lubricants near your disc (typical culprits are WD40, leaking oils seals on forks and bike polish). If you do, your brakes will become next to useless. To attempt revival, clean the disc with a solvent such as meths, and roast the pads in an oven, or on an electric hob (to burn off the oil), before scrubbing with rough emery paper or a wire brush. Beware of the undoubtedly nasty fumes when burning the contamination off brake pads – I’d don’t want to be held responsible for any dead budgies.
- Air Lock: If your brake lever feels spongy then there is probably an air bubble in your fluid line. As you apply pressure the bubble compresses (brake fluid doesn’t) and hence the sponginess. The cure is to bleed the system until all the air bubbles are removed. DO NOT bleed your system unless the lever is spongy. If the lever is solid and your brakes are still pants, then it is probably due to contaminated and/or dodgy pads. (EBC made an absolutely awful batch of green pads recently – one pair I bought lasted only 15 miles).
- Steam Lock: If you neglect your brake fluid, (e.g. open the reservoir too often to look inside, get dirt inside the system, leave it for more than 5 years without changing it) it could absorb water. The problem with this is that water will boil at 100°C forming steam in your fluid line. A steam lock is just like an severe air lock, except it happens unannounced when braking down a steep hill. You loose your brakes and will probably crash! If in doubt, change your fluid once a year- it only takes a few ml of the stuff. Also, ensure that you don’t use old containers of brake fluid which could have been sitting around in an old damp cellar or shed – this is probably a much easier way of developing steam lock than by not changing the fluid at all.
Don’t be scared off by these potential problems of hydraulics. Brake pump is a factor you’ll have to live with, and I’ve encountered both contamination and fade, but never any air or steam locks. Hydraulics are a great improvement over mechanical brake systems of any description.
It would be fair to say that the mechanical disc brake is a very poor relation – they have far more moving parts, are much less reliable, weigh more, work nowhere near as well, and costs almost as much as ‘proper’ hydraulic discs. It is easier to completely disassemble, rebuild and re-bleed my Hopes than it is to change the pads on some mechanical calipers. Also, many mechanical brakes (and single piston hydraulics such as the Magura Louise) require pad wear to be compensated for at the caliper – not by any means low maintenance.Ranking:
Value: 4/5 – (5/5 at current prices)Postscript:
If you are planning to buy now, you’d pay significantly less than the £200 I paid (currently £120 or so). If you prefer an open system the new mini O2 is both lighter and cheaper (£105?). For weight fanatics the XC4 is the lightest system (closed only) but the superlight discs offers less power and can suffer severely from heat build up – as Hope suggest, this is a brake for XC racers. For the ultimate in stopping power the Enduro 4 (open only) uses 4 separate pads of approximately the same size as the C2 /O2 for oodles of power. It won’t prevent fade however, but the special 225mm disc might be fun, and they aren’t much heavier than the 2 piston brakes.
With the entire Hope range costing less than my purchase price of 2 years ago, and not much more than a cheesy mechanical caliper, you are lucky lucky lucky people.
If you are considering buying a competitor’s system, then many other systems have had excellent reviews also – but just pretend that you need 2 tiny replacement ‘O’ rings for your calipers. With Hope, you’d probably have them within a few days. Rest assured that it would be a completely different scenario trying to acquire them from Shimano!Postscript 2:
I nearly forgot. The “splined suspension hub” (soon to be discontinued as it is apparently not strong enough(?)), is still running beautifully on its original bearings. Nice.
Kevin Hodgson 12/2000