EXPERT WORKSHOP ADVICE
TECH Q&A
LOSING THEIR BITE
Is there any way of preventing my brakes’ bite point from changing as the pads wear? The more they wear, the further I have to pull the levers to get them to bite, and I’m pretty fussy with my set-up!
Brakes are, in theory, meant to remain consistent in feel as the pads gradually wear down, but that’s rarely the case, as you’ve experienced. Sticky pistons can have an impact, so it’s good to keep your brakes clean – include them in your bike-washing routine and give them a good spray of brake cleaner just before you put your steed away.
Some brakes come with bite-point adjustment at the lever. If yours do, try adjusting them. If not, you’ll need to manually reset the pistons. To do this, pop the wheel off, remove the pads and then very carefully squeeze the lever, watching the pistons extend – make sure they don’t go too far out, though. This will break any dirt-based friction and help the seals deform properly. If one piston moves but the other doesn’t, use a brakepiston pusher to hold the mobile one still, so the other piston gets pushed by the fluid as you squeeze the brake lever. Once both are moving freely, push them all the way back, replace the pads and wheel, pump the lever a few times and it should give you a consistent, earlier bite-point.
A PLUG’S GAME
Does anyone bother carrying a spare tube these days? Can I get away with a tubeless repair plug and a CO2 canister, or is that a risky move?
It’s your call, really, and depends on the situation. Our experience suggests that tubeless repair plugs will easily fix 90 per cent of punctures, but there’s always a chance you’ll get that one-in-10 that’s too big to heal, or a slashed sidewall that’s impossible to fix without a tyre boot and tube.
If you head out without a tube, taking a range of plug sizes will give you the best chance of fixing punctures on the trail. Our rule of thumb is that if we’re heading somewhere too far to comfortably walk out of in our riding shoes, then we’ll carry a tube. However, for short laps, bike parks or messing about in the woods, we’ll probably just take some repair plugs.
The CO2 in flator vs pump debate is almost a separate question. Pumps are more reliable in our experience, and can reinflate a slowly deflating tyre, but they take up more room in your pack. Several of us at MBUK have the One-Up EDC pump –a decent, highvolume design that also holds a multi-tool, repair plugs and a chain link, so works out pretty efficient, space-wise.
DIAL CONSEQUENCES
Do you guys have any preference on shoe closures – BOA dials, laces or otherwise? I like the idea of BOAs but am worried about snapping them.
Shoe closure preferences are subjective –a quick poll of the MBUK office suggests there are plenty of different opinions. BOA dials are quick and simple to fasten and undo, and work well in wet and muddy conditions.
Multiple BOAs, or one where the wire criss-crosses, can give good control over the tension of the shoe, too. Those situated to the side can be vulnerable, though – if they snag on vegetation, they can even undo. They occasionally break, too, but are replaceable, so shoes don’t need to end up in the bin if it happens.
Laces are easy to adjust, too, and let you tailor tension over the foot with precision. However, lace tension can migrate up or down a shoe, and when they get wet and muddy, they can be a pain. Using Velcro straps in addition to laces, and sometimes BOA dials, is common – they’re often placed at the top of the tongue to minimise heel lift, and can also help keep laces secure and away from the chainring. Velcro straps are also sometimes placed over the toe box, often in conjunction with BOA dials. Single-BOA shoes tend to only have two or three wire crosses – beyond that they easily bind when tightened – so a lower Velcro strap is useful to modulate tension.
Shoes that only use Velcro straps tend to be budget models.
They’re cheaper to manufacture but tend to be a little more basic in terms of their control of tension over the foot. The Velcro needs to be kept clean for optimal performance, too.
WALKTHROUGH
Trailside repairs
1 If a gear cable snaps on you, the mech will return to the smallest (hardest) gear. It’s possible to get the chain to sit in a gear that’s easier to pedal in by winding the high limit-screw in as far as necessary.
2 Crashes happen and sometimes things break. If a brake lever-blade snaps, use a stout stick as a splint and hold it in place with duct tape (we keep some wrapped around our tyre levers in case of emergencies) to get yourself back to safety.
3 A lost cleat bolt can mean difficulty unclipping and all the mayhem that goes with it. XC racers have been known to run as few as three brake-rotor bolts (to shave weight), so you should be safe to repurpose one of yours (assuming you have sixbolt, not Center Lock, rotors) to secure your cleat.
4 Snapping a brake lever bar-clamp can effectively end a ride. A combination of cunningly-placed zipties (again, an essential to carry in your pack) and duct tape can be used to secure the lever to the bar and hopefully keep the brake usable.
5 Saddle rails snap surprisingly frequently. If this happens to you, you may be able to use zipties to hold the hull of the saddle in a usable position until the end of the ride. Where they need placing will depend on the design of the seat, but this works in most situations.
6 If you snap a spoke, wind it around a neighbouring spoke to prevent it flopping around and potentially damaging the frame or, if the break is near the hub, piercing your rim tape. Duct tape can be used to help secure the loose spoke, too.
7 In the event your tyre is slashed so badly that a tube would bulge through the hole when inflated, use a tyre boot (or improvise with an empty gel or snack-bar wrapper) to reinforce the sidewall so you can limp home.
8 We’d advise carrying a rudimentary repair kit with the following items: rubber gloves; zipties; duct tape, wrapped around tyre levers; spare master-link; master-link pliers; multi-tool with chain breaker; tyre plugs with installation fork.
BLUFFER’ S GUIDE
Helmet safety tech
We take it for granted that wearing a bike helmet will protect our noggins when we crash, but what do the different elements that make up a lid actually do?
Foam
The EPS (expanded polystyrene) foam in many bike helmets contains tiny pockets of air. Upon impact, the foam is crushed, which spreads and delays (by a matter of milliseconds) the crash energy heading towards the skull, reducing the risk of brain damage. Once the foam has taken an impact, it doesn’t return to its original form and the helmet needs replacing.
Straws
Koroyd (Smith, Endura) and WaveCel (Bontrager) are newer approaches to cellular protection in helmets. These systems still work by crumpling on impact, like foam, but the way these straw-like structures are formed means they concertina instead of crushing. This helps them dissipate energy from a variety of angles, giving protection from rotational forces as well as direct, linear impacts. These materials are less insulating than foam and therefore cooler, but can make helmet vents less effective.
Anti-rotation
MIPS (Multi-directional Impact Protection System) is the second line in crash-energy management. It comes in various forms, but effectively creates a slip-plane between your head and the helmet, designed to deflect and dissipate any rotational energy on impact, before it reaches the skull and brain. MIPS comes in various forms and is licensed by many brands, while others have their own take on it, such as Leatt with their 360 Turbine Technology.
Cradle
The plastic cradle within the helmet is designed to hold it securely to your head. It hooks under the occipital bone at the rear of the skull and usually has an adjustment dial or ratchet to ensure a snug fit. When correctly adjusted, your helmet should stay in place without the chin strap, even if you tip your head.