PAD IT OUT
I’ve just bought a new bike with LX disc brakes. It’s the first time I’ve had disc brakes and I would love to know the best place for good, cheap replacement pads. Also, what are the advantages/disadvantages of metal and resin pads? Any help would be great.
Nick Carver, email
Now that disc brake systems have become popular, the aftermarket choice of the main consumable – disc brake pads – is quite bewildering. Whilst it is not essential to go out and buy the most expensive pads available for your particular disc brake setup, fitting that bargain set bought off the internet could seriously hamper your disc brakes’ performance. When choosing tyres, the ‘right’ choice is dependent on terrain, bike type and riding style. The same is true of disc pad selection.
Forgetting about the ‘which brand’ issue for a moment, there are two main types of pad compound: metal and resin (or sintered and organic, depending on the
manufacturer’s chosen terminology). Metal/sintered pads generally cost a little more and tend to be labelled ‘performance’, leading many to assume the cheaper organic/resin pads are not as good. This is an incorrect assumption; each has its strong points and weaknesses.
In metal/sintered pads the friction material is partly, or in some cases fully, composed of metal. This type of pad usually produces a high co-efficient of friction (braking torque) and is resistant to wear, giving a longer service life.
Negatives? They take longer to bed in, are more expensive to produce, will wear out the rotor more quickly (although it should still take many seasons to wear out a rotor) and can be noisier. The biggest disadvantage is that with an increase in friction and stopping power comes an increase in heat. The metal-based friction material conducts the heat into the caliper piston and fluid unless an insulating barrier layer is introduced, such as ceramic pistons or a ceramic backing to the pad itself. Even then your troubles are not over if you’re running a small disc, as the disc rotor itself may buckle or warp due to the excessive heat buildup.
The non-metallic compounds of organic/resin pads are generally softer, giving quieter braking and quicker bedding in. The lower coefficient of friction gives a brake that has its ‘bite-feel’ reduced both when hot and cold which can make the brake feel more progressive. If the pads have a high carbon graphite content they will be good at stopping the heat that is generated from conducting through the pad material into the caliper. Negatives? The softer compounds wear out quicker, and when pushed really hard some pad types will glaze up, severely reducing their effectiveness. The lower coefficient of friction, in simple terms, means less stopping power.
Although there are exceptions, as a guide, choose metal/sintered pads if you require maximum stopping power or want long pad life, even when riding in wet and muddy conditions. DO NOT fit metal pads to your 160mm-rotor XC bike, then go hammering in the Peaks, or worse still, the Alps, as you will “cook” your brakes and end up with a set up that performs worse than a set of rod-pull brakes connected to leather-faced rubber blocks on a chromed steel rim! If you are on a light weight, small-disc setup then organic pads can help protect against overheating.
Most of the familiar brands produce good pads these days. My personal favorites have been the Goodridge G* pads
FINE TO ALFINE?
We are writing about the Mud Pluggers biketest in your Febuary 08 issue that featured bikes from Genesis and Orange. The Alfine hub gears, as featured on the Genesis bike, were highly praised by your tester.
We live in Sweden and our climate is similar to yours except that we have snow during the winter and it gets a lot colder! But this winter it has rained every day and there’s been no snow at all. This has made the woods wet and muddy and has awakened our interest in an alternative to ordinary gears.
Do you think that Alfine is a cheaper alternative to the Holy Grail, Rohloff and would be a good option for hard, long rides in the muddy woods?
I know the Nexus hub had seal problems and didn’t cope well with the Swedish climate. According to your test, the Alfine hub should work ok in the woods.
Are you about to test the imotion hub from SRAM or do you have information about it? Do you think it’s better or worse than the Alfine? Which of them do you recommend for our weather conditions and type of biking?
Robert and Petra Karlsson, email
Shimano has aimed the Alfine hub at the city and comfort-biking market. It seems to be living up to expectations within its designated market, but urban usage is quite a sheltered environment when compared to a Scandinavian off-road winter! We have insufficient feedback to say categorically that the Alfine will cope with all conditions, so you’ll have to take on the role of guinea pig and report back to us!
The SRAM i9, like the Alfine, is pitched at the city and comfort market but being an even rarer sighting, it will be some time before a meaningful verdict can be given.
Rohloff’s Speedhub 14 is a different beast. It is designed with the serious or competitive cyclist in mind, and more importantly, has proven itself to be reliable over many seasons of hard use, even when used by those of us not living in sunny California. The Speedhub is expensive but the numbers produced are quite low and until there is a much larger demand, allowing Rohloff to look at larger batch manufacturing, the unit cost is unlikely to drop.
Ironically, Shimano and SRAM’s entrance into the market could work to Rohloff’s benefit by upping the publicity given to hub gears, growing the market and ultimately increasing the amount of potential customers.
Be brave and try out the Alfine hub, but be sure you report back to me as I’m in the market for a hub gear myself!
I currently have the pleasure of riding an 05/06 Giant Reign 2, that I am very pleased with. From the standard spec’ I have changed several things that have improved the ride, such as upgrading the fork to a Fox 36R, fitting a larger front rotor, Michelin All Mountain tyres, Charge Spoon saddle, ODI Cross Trainer grips, XT groupset and DX pedals (I think that’s all of them).
My question relates to the possible benefits of fitting a shorter stem and then a layback seatpost?
I seem to remember these were ideas suggested in the Reign’s reviews. Are there any particular stems and posts I should consider — with a budget of up to £150 for both?
I tend to buy from both my LBS and the internet, so if you could advise me of any necessary dims, such as lengths, diameters and degree rises etc it would help!
It sounds like your Reign has been more than upgraded. Morphing from a trail/all-mountain bike into an all-mountain/freeride bike, in fact, it mirrors what Giant has done in creating the Reign X. The Reign really is a bike that can be thrashed when the going gets technical, but to release its potential you do have to do what you are suggesting, which is “tweak” the cockpit setting. Fitting a shorter stem and layback seatpost will lighten up the front end, shifting some of the weight placed on the front wheel and forks, putting the rider in a more centred riding position and giving you quicker steering input. You will be surprised at how much more relaxed you feel on the descents or when tackling drops and jumps… but, you will be compromising the bike’s climbing ability a little.
That said, it’s amazing how everyone is learning to adapt to shorter stems when climbing. The trick is to bend your arms more and at the same time lower your chest/upper body towards the handle bars, compensating for the weight shift by transferring your weight back over the front wheel again.
It may not be necessary to fit a layback seatpost, I would suggest you first try sliding your seat as far back as it will go on its rails.
If you really want to be ripping-up the local descents and BMX tracks, but still keep a useful amount of trail capability then you’re budget of £150 has got to go on a matching set of Thompson Elite components. Layback seatpost in 30.9mm diameter for the Reign and a 70mm or 90mm 1 1/8 stubby stem, non-oversize if you are still with the original bars.
I ride an Anthem 1 ‘opp over the Malverns a few times a week. I love the bike and it’s ideal for these faster routes. However, the front end can dig a little and be twitchy on the faster sections, making it fast on singletrack but requiring me to grab the bars tight for the 35mph+ sections.
Recently I read your comments regarding the Anthem benefiting from a longer stem. Does this actually help? My only issue is I don’t want to be too over the bars (ride a large at 6’2”) nor have my back cranked at an acute angle (being an old fart at 43)…
So would a 120mm stem help? And if so, what would you recommend to complement this lightweight racer?
The reccurring theme when altering the handlebar position via a stem or bar change is one of compromise. Most people now understand that shortening or raising the reach to the bars will make the front feel lighter and gives quicker steering. The opposite is true if you lower or lengthen the reach to the bars, the front feels more planted/heavier and the steering response is slower.
Your aim when modifying the riding position is to create a riding position that feels relaxed and comfortable for the majority of your riding but still allows you to move around on the bike and compensate for extremes in terrain.
You mention that the front end can “dig” a little and that the bike feels twitchy on faster sections. The steep head angle of the Anthem combined with a forward weight bias is what causes these traits. Raising the bar position would remove some of the load on the front end, helping to minimize front wheel “dig”, and the more upright riding position should remove the need for a death-grip on the bars, hopefully ensuring that you descend with a more relaxed bent arm, which will help in controlling the bike. This modification doesn’t shorten or lengthen the cockpit and doesn’t create a wheelie-prone bike on the climbs; all it requires is that you lean onto the bars a bit more to compensate for the height change. If you achieve the bar height gain by changing to riser bars rather than changing the stem, at 6’2” you will probably find the extra width the risers tend to offer, an advantage as well.