Wednesday, June 17, 2009

Time for another rant from your favourite cycleshop nutters. Ever present on most peoples agendas is the ongoing recession and the resultant financial burdens this imposes. For many this means having less to spend on recreational activities. So what can you do to ensure you get maximum wear and value from your drivetrain, brake pads, tyres etc.

For most of us drive train replacement is the major running expense. We’ve all been told many times to keep the chain and sprockets clean and lubed for maximum life expectancy. I use turps and a paint brush to clean my drivetrain but any good degreaser (preferably an environmentally friendly biodegradeable style) will do the job.

There are a number of companies who make brush cleaning kits but inexpensive alternatives include the good old toothbrush, old paint brushes, old dishwash brush or similar item. I have a couple of old toothbrushes that I have cut down so the bristles are only a couple of mm long for hard to get places. I also use a basic chain cleaning device. We have them in the shop from as little as $45 however a good clean with a brush will take longer but achieve the same effect. Removing the build up of grime from the gaps between the rear gears is important. If this accumulated grime is left in place the side plates of the chain will be pushed upward which means the rollers will not go right down to the bottom of the depression between the teeth of the sprocket. As you can imagine when the chain is only partially contacting the tooth of the gear both wear much faster and this is probably the biggest contributing factor to short drivetrain life.

Using a good lube is also critical in ensuring longevity. Many people are using the “dry” style lubes to keep their drivetrains cleaner. This type of lube certainly means you can make the gaps between cleaning intervals longer however there is still a considerable buildup of the “wax” in the gaps between the sprockets. Scraping it out with a small screwdriver will help prolong your drivetrain. Dry lubes require more frequent application as they have a self cleaning component to their function. They are a great way for the lube companies to sell more product!!!! Wet lubes are less clean but more economical.

Other issues affecting the life of chains and sprockets are the chainline and paying attention to crossover of gears. Chainline is usually to do with bottom bracket spacing and is best left to the cycle mechanic. For mountainbikers in Wellington who spend a lot of time in their easier gears having the chainline appropriate for these will help. For riders who spend more time in the middle or bottom part of the cassette a chainline that is straighter when they are in these combinations will help.

Brake pads. These wear at a significantly faster rate in wet conditions. Keeping your rims clean and true will help and developing a good braking style are probably the biggest contributing factors. Rims develop a buildup of brake pad material and road grime which contribute to wear and reduce the effectiveness of your pads. A good rub with steel wool will remove this and wiping them down with alcohol (not beer!!!!) or a good metal parts cleaner/disc brake cleaner will improve performance. This will mean you will spend less time applying the brakes because they are more effective hence decreasing the wear rate. A good braking style means spending less time on the brakes and not dragging them unnecessarily.

Disc brakes are much easier to deal with but premature pad wear is almost always the result of poor alignment or sticky pistons in calipers. Regular cleaning of the piston area in the caliper with a brake cleaner product (typically a solvent like acetone, used in a well ventilated area or your maintenance may end up making you light headed!!!!) helps and the use of a short bristle brush to scrape this area helps a lot. Brake calliper pistons can easily develop a memory causing slow retraction. Sticky pistons can usually be eliminated by moving the pistons in and out and dislodging the buildup of dirt and pad material from the piston area. Regular alignment checks and ensuring that you disc rotor is strait will greatly help reduce wear from unnecessary contact between rotor and pads. Never allow any lubricants to contact rotor or pads as this will dramatically reduce the brakes performance and will result in having to replace the pads.

Tyres. Pressures, riding style and compound all contribute to the rate at which tyres wear. I check my pressures at least once a fortnight. This enables you to detect slow leaks and ensures the tyre is functioning at its best. Too low a pressure will increase wear because there is significantly more friction generated between the tyre and the tube. This means the rubber is subjected to higher temperatures making it softer and wearing faster. We often have bikes in the shop that have been ridden for long periods of time with too little pressure. The friction and heat buildup between the tyre and the tube is significant enough to cause them to generate small particles rubber that detach and cause more friction. A self perpetuating cycle (terrible pun!!) Tubeless systems are great because they eliminate the friction between tyres and tubes reducing drag and enabling the use of lower tyre pressures. This results in better traction improved braking and steering, better tyre wear and pinch flat resistance. Tubeless systems obviously also save you money on tubes!!!!

Cables!!! The biggest causes of indirect wear to drive trains and brakes is poor cable maintenance. Poorly lubed cables wear much faster because the steel inner cable wears away plastic particles from the sleeve inside the outer cable housing. The resulting increase in friction causes the chain and gears to wear faster as the chain is less likely to be aligned with the gear correctly. Lube your cables and replace the rear derailleur cable regularly. I replace mine at least twice a year and more frequently if riding my MTB in mud over the winter. If you ride your mountainbike in wet conditions a lot use a full length outer cable. The front derailleur has a much stiffer spring than the rear and will handle significantly more friction before it gives grief. Sticky brake cables can lead to unwanted contact between pads and rim increasing both pad and rim wear.

Wheels. Hubs are the area we see most problems and this has been significantly increased with the use of disc brakes on mountain bikes. The heat generated from braking is transferred to the hub through the rotor and results in expansion and contraction as the hub heats and cools. This results in a much higher chance of cones coming loose with bearings failing and accelerated wear to the cones. Bikes with rim brakes are less affected. Loose, worn, cones obviously generate more friction resulting in more rolling resistance and maintenance costs. Check wheels for play in the hubs and regularly inspect disc rotor and calliper mount bolts. The bolts are steel and they are mostly thread into aluminium. These two metals have vastly different coefficients of thermal expansion. Aluminium expands much faster than steel when it heats up. This means the hole gets bigger faster than the bolt. Always use a thread locking type of product (ie loctite or similar) when mounting rotors and callipers. Wheels also need to be true (preventing unnecessary brake rub) and tensioned. Loose spokes result in a less rigid wheel. On a rear wheel this means every time you crank the pedals the whole wheel flexes and unflexes (is there such a word) which results in uneven (pulsing) transmission of energy. This increases tyre wear and means you are wasting energy.

The bottom line is: regular maintenance will save you money which you can then use to buy more cool kit at the bike shop!!!!!

On the retail front we have some outstanding distributor specials at the moment with companies specifically targeting dual suspension mountainbikes. Call for details as we have access to great deals on Jamis, Diamondback and Commencal dualies. Jamis have an outstanding range available with travel options from 100mm to 180mm. Jamis carbon road bikes have been getting awesome reviews by cycling journalists. At the entry level for road the Bauer Flite and Lyon stack up as some of the best packages available with great spec at sharp prices.

We have just received a load of Maxxis detonator tyres 700 x 28C size. These are great for training, commuting, or just to get a more compliant ride quality. Normally around $30 we have them available for $24.

We are still overstocked on women’s cycle tops so are able to continue offering the tops we have in store for 50% off the normal retail prices.

For those of you running tubeless tyres or tubes with puncture proofing goo inside we have a new liquid designed and made in Australia called True Blue puncture goo. Cheaper than other similar products on the market it has proved to be very effective in tubeless conversions utilising standard tyres. The product has no ammonia or glycol in it, the presence of which has occasionally led to the de-lamination of the carcass on some tyres.

The volatile exchange rate has begun to affect pricing so there are some great savings to be had on older model bikes and accessories.

Cold wet weather has limited cycling opportunities a little but there have still been some good riding days. Wear layers and don’t forget to keep your knees covered when it’s below 16 degrees. Medical experts all agree, if you plan on continuing cycling long term keep your knees warm or you will cause deterioration of the joint.

Till next time


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