The Shop's Tech Tips

Check out these tips!!

The advent of hydraulic and cable actuated disk brakes on Mountain Bikes have brought with them a myriad of questions in relation to setup, servicing and cleaning. Out of the box disk brakes won’t give bombproof performance, the brake pads and rotor need a brushing in period of about 30 stops.

After this brushing in period your brakes may suffer from a couple of aliments, all of which are easily corrected. Your brake pads can drag, this can usually be fixed by re-positioning the caliper. If your brakes have more modulation then you like or feel spongy, you should bleed your brakes with new Dot 3 or 4 brake fluid and increase the pressure inside the lines by closing the highest bleed screw while increasing pressure at the lowest point (caliper bleed screw) and then closing the bleed screw. A trick when bleeding your brakes is to use a large plastic syringe and a small piece of hose. These work better then the bleeder kit provided with most brakes.

Care should be taken when cleaning both hydraulic and cable brakes. Always wash your brakes off after a muddy or dusty ride. Isopropyl alcohol should be used to thoroughly clean rotors (available at most chemists).

Like V-brake pads disc brake pads come in differing compounds, harder pads give longer life while soft pads give gripper performance.

Here is some advice on adjusting Shimano SIS (indexing) gears. First ensure the gear cable is installed correctly and the shift lever is in the top or high gear position. That is the smallest cog on the back of your cluster. Turn the crank to keep the chain moving, and press the shift lever once to a position one down from the top gear ( for example the seventh gear position on an 8 speed shifter). This should normally shift the chain to the second smallest sprocket. If the chain shifts to the third sprocket, turn the adjuster barrel in (clockwise) until the chain shifts back to the second smallest sprocket.

The optimum fine adjustment is attained when the chain is rubbing lightly against the third sprocket while pressing the shift lever only to the extent that eliminates lever free play.

The fine adjustment can be checked by releasing the shift lever. If the chain runs quietly on the second sprocket after lever pressure has been released, the adjustment is correct. If the chain still makes noise rubbing against the third sprocket, turn the adjuster barrel in (clockwise) slowly to the point the chain runs quietly.

It is also important to keep cables and all shifting components well lubricated to maintain accurate SIS shifting performance.

Shimano chainrings (and most brands for that matter) have a correct and an incorrect way to be fitted to your cranks. If you have removed your chainrings from your bicycle for cleaning or replacement then ensure they are refitted in the correct manner. The chainweel size is always stamped into the chainring and this number always goes on the inside of the crank. The largest chainwheel has a chain drop prevention pin protruding from it. Ensure this pin is always mounted behind the crank. This prevents any chance of the chain from getting caught between the crank and the large chainwheel.

The middle and small chainwheel have a protruding "marker" on the inside of the them. This marker is to be situated behind the crank as well. This ensures correct orientation of the chainrings for optimum changing performance.

Fitting a new chain to your bike? Well you don’t just put it on. You need to cut it to the correct length using the correct chain cutting and joining tool. But what is the correct length?

: - For a mountain bike put the chain on the largest cog at the back and the largest chainwheel at the front. Stretch the rear derailleur to its maximum stretch then add two links. This is the correct length.

: - For a road bike, put the chain on the smallest cog at the back and the largest chainwheel at the front. The jockey wheels (or the little cogs at the rear derailleur) should then sit at a vertical axis to the ground. That is, when the chain is the correct length the jockey wheels should sit on top of each other.

Be aware of the fact that the new nine speed cassettes require a special narrower nine speed chain.

Do you have squeaky cleats (they are the plastic triangular shaped block on the bottom of your cycling shoe) on Look road pedals. The answer to stop this annoying squeak is to put a small amount of grease on the surface of the cleat. This will stop the noise. You will need to reapply it quite regularly. Often squeaky cleats on Look pedals is a sign that the cleat is wearing or is worn out. Worn or damaged cleats should be replaced immediately as they can disengage from the pedal accidentally causing a crash.

A word of advice here. Never walk in your road cycling shoes. This prematurely wears your cleats and worn cleats compromise your safety. Also it wears out your cycling shoe. It is far preferable to simply take your shoes off and walk in your sox.

When fitting new handlebar tape to a road bike, always start wrapping the tape from the bottom up. That is, start at the end of the bars by inserting approximately half the width of the tape inside the bar. The handlebar plug will then hold this in place.

Then, gently stretch the tape around the bar and work up towards the top of the bars. Do it carefully and overlap each layer by about one half to one third the width of the tape. The most important thing is to keep gently stretching the tape all the time.

When you get to the brake levers carefully roll the rubber brake hoods back and wrap the tape in a figure of eight around the brake levers. Then continue wrapping the tape until you reach the top of the bars, remembering to stretch the tape continuously.

When you reach the top, secure the end with some insulation tape and trim off the excess bar tape. By doing it this way, you avoid the problem of the tape rolling down on itself from where you hold the bars. Pulling it tightly stops the tape from unraveling when it starts to stretch. Happy Cycling!

  To grease or not to grease, that is the question. Should you grease the threads of your bottom bracket before installing it? Should you grease the threads of all the little nuts and bolts on your bike? Well the answer is a definite….Yes.

Next time when you are working on your bike, grease all those little nuts and bolts. For example, grease the threads of the deraileur anchor bolt and grease the thread of the deraileur where it threads into the frame. Grease the threads on the chainring bolts and grease the crank bolts that fasten the cranks to the bottom bracket.

You see, by doing this you will find that the nut will do up more firmly and there is a better chance that it will not rattle loose. That is the exact opposite of what you would imagine. You would think that the grease would help the nut to work loose, because grease helps things to turn.

The grease allows the nut to go onto the thread with less friction, enabling it to do up more firmly, with less chance of damaging the thread and of it coming loose accidentally.

Things to pay extra attention to, are to grease both pedal threads where they thread into the cranks as, without grease, over time, the steel pedal thread "welds" to the alloy cranks, making removal almost impossible. Also, just as importantly, your alloy seat pillar needs to be greased where it inserts into your frame, as does your handle bar stem where it goes into the frame.

There is one important exception to all of this. That is never greasing the taper of the bottom bracket axle where the cranks mount. If this area gets grease on it, then the cranks will tighten onto the bottom bracket too far. This in turn will prematurely wear the crank taper, allowing the cranks to go too far up the axle taper and stretching the square crank shoulders in the process, a very expensive mistake.

Boots on suspension forks are often overlooked. These little bits of rubber are a lot more important than they first appear. They are one of your seals from the harsh world of mountain biking. They keep out the water and most importantly the dust. Dust is the number one enemy for suspension forks. So make sure your forks are wearing boots.

Rockshox Jett C and Jett T2 suspension forks use oil for lubrication instead of grease. So next time you are servicing them, add 10cc.s of oil per leg before reassembling. Don’t just use any old oil. Use special suspension oil, as this will not damage the rubber seals in the forks. The easiest way to buy suspension oil is from a motorbike shop.

If you ever use lightweight tubes in your wheels, it is always a good idea to put talcum powder inside the tyre. This helps to alleviate the risk of the lightweight tube chafing on the inside of the tyre and getting a hole in it.

 Have you ever struggled putting mountain bike grips onto bars, or for that matter, taking them off? Well here is the answer from the Pros.
Before you attempt to remove the grips, slide a long-bladed screwdriver beneath the grip. Then lift the screwdriver up and spray hair spray beneath the grip. Then move the screwdriver around to get the hair spray all around the grip. The grip will then simply slide off!
To put a new one back on, spray hairspray inside the grip and slide the grip onto the bar. It is as simple as that. The hairspray acts as a lubricant, but then it dries like glue. But beware, it will take half an hour or so for the hairspray to dry.

  Having trouble clipping out of your SPD’s (your clipless mountain bike pedals)? Well you see, after you have ridden through a creek or mud or something, the 4 large springs that you can see inside your pedal get very stiff. This can make it very hard to clip into the pedals.….or even worse, clip out of them.
Simply lube these springs with Finish Line oil or, even better, White Lightening lube. They will be as good as new again. Simple as that. By the way, you are much better doing this every time you clean your bike, rather than waiting for it to become a problem.

  99 model Rockshox Judy forks have hydracoil springs inside them. These springs have a tapered end. Make sure this tapered end is up as it fits into the top cap assembly.

A word of advice with Shimano chains. When cleaning a Shimano chain it is far far preferable to clean the chain on the bike rather than removing the chain to clean it off the bike. You see all modern Shimano chains have flared chain pivots. That is the chain pivot is flared at the end and basically resembles the shape of a dog bone. This is to enable the chain to withstand the large sideways forces that modern deraileur gear systems place on chains.

If you press this pin out then rejoin it again then the hole that it goes into will be slightly oversized. This in turn weakens the chain and greatly increases the risk of the chain breaking.
Therefore I would recommend cleaning the chain on the bike. The easiest way to do this is with a Finish Line chain cleaning tool.

If for any reason you have to remove the chain from the bike then you MUST rejoin the chain with a special joining chain that is available. This special pin will not damage the chain like rejoining the chain with the old pin will. Therefore the strength of the chain is not compromised.

Be aware there is a special pin available now to suit the new 9 speed chains that are now available. They are slightly shorter in length to the 7 and 8 speed ones.

  When washing a bike use hot water in a bucket that has car wash in it. Using a sponge, sponge the bike down using the suds to clean the bike more so than using the water. This ensures that you don’t get water into the bearings of the bike. The reason why hot water is best is that the hot water will evaporate quickly leaving the bike dry reducing the risk of rust developing and also this quickens the washing process.

Ensure that you never use a garden hose to hose your bike down. This is the worst thing you can do as water will get into the bearings of the bike.

  Fitting new pedals to your bike? Did you know that there is a left and a right hand threads on bicycle pedals. The left hand pedal has a left hand thread (anticlockwise). The right hand pedal has a right hand or clockwise thread. Don’t forget to grease the thread before inserting them into the crank. Use a 15mm spanner to tighten. For the technically minded pedals have a 9/16 of a inch axle with 24tpi or 24 threads per inch.

  If you use road tyres that have a maximum inflation of over 125psi, for example Continental Grand Prix 700/20 tyres, then I recommend to you to use special tubes. You see tyres like Grand Prix 700/ 20 mm run best at a whopping 150psi. This high pressure decreases rolling resistance and decreases you chance of bottoming the tyre out over bumps. Better all round.

The trick is though that inexpensive tubes a not reliable enough at these pressures over 125psi.

I recommend using Continental, Clement or Tioga tubes. These will give you better reliability at these higher pressures. I am sure there are other tubes out there as well that are just as good but I have had good experience with these brands.

  Having just told you how good 20mm tyres are I still believe that slightly wider tyres are better in virtually all situations. Most people believe that 18 or 20 mm tyres are going to be faster that the wider 23 mm tyres. And in the perfect world this would be true. That is on a perfect hotmix bitumen road without any bumps at all, 18 mm tyres would be faster. But welcome to the real world of ripples and small imperfections in the road surface.

I believe that in the real world 23 mm tyres are faster and more reliable and more comfortable than their narrower brothers. That is because a narrow profile tyre will "fall" down into every nook and cranny in the road surface where a slightly wider tyre will tend to roll over these imperfections in the road. This makes the 23 mm tyre faster to use, even in most racing conditions.

  If you are lucky enough to have disk brakes on your mountain bike then here is a tip for you. Always ensure the disc rotor and pads are clean and oil free. Clean pad material and rotor with acetone. Make sure both surfaces are free of dust dirt and oil.

  When riding in adverse conditions don’t forget to clean your rear shock as well. Mud and grit on the shaft lead to premature shock failure. Keep it clean and extend the life of your shock. 

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