The Shop's Tech Tips
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
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
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).
V-brake pads disc brake pads come in differing compounds, harder pads
give longer life while soft pads give gripper performance.
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
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.
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.
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
Be aware of the fact that the
new nine speed cassettes require a special narrower nine speed chain.
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.
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
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
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
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
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
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
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
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
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Thursday May 09, 2013