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2002 bikeNOW P/L
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Warren Cay
bikeNOW P/L
Step 5
SUSPENSION
Jump down to Suspension seat poles
Jump down to Suspension frames
Suspension was introduced to bicycles in the late 80's primarily for control on rough terrain however, most recreational mountain bikes and cross bikes have taken advantage of the technology. For recreational city riding suspension is not a must have however does offer soft ride off gutters, the occasional steps and some unsealed paths. Because there are many suspension systems available, it is very important to know what your getting and what you're in for.
Travel
refers
to the amount of fork movement.
60-80mm fork travel is average and ample for recreation or Trail use.
Any more than 80mm of travel on a front only suspended bike can adversely
affect the bike’s handling. Long travel forks (80-180mm) are designed
for Downhill and Free-ride / dual slalom bikes and are best suited to
full suspension because front and rear travel together doesn't affect
the bike’s geometry.
Resistance
is what is stopping the fork under load. There are three basic forms of
resistance;
Elastomer is a urethane like tube that is compressed under load, but rebounds fairly fast and gives a springy feel. There are MCU elastomers that are similar but rebound slower to simulate a dampened return. These are found in less expensive forks.
Coil Spring are advanced coiled springs that offer a softer more progressive travel and are often used in combination with elastomers.
Air has a weight advantage but keeping the travel linear (not building up resistance as the fork is shock is compressed) is the challenge. Better quality forks have pressure valves that equalize as the fork comes under more pressure.
Dampening
refers to the control of fork travel. Dampened is usually used for rebound
only, although some performance forks also have compression dampening.
Most dampening is done with either an oil cartridge or open bath damping
piston. Dampening is designed for performance by slowing down the return
of the fork to stop skipping and bouncing on rough trails to keep the
wheels in contact with the ground.
Bushes
are
the ring sliders inside the lower fork legs that provide protection to
the upper leg and to prevent a sloppy fit. Most bushes are made from a
nylon base, however, Rock Shox use steel/Teflon that will need much less
service although they do have to be replaced by an authorised service
centre (bikeNOW). The alternative is nylon bushes that will distort and
wear sooner giving a sloppy clunky feel however the nylon bushes are cheaper
and replacement does not require special tools.
Service
is always a concern. For maximum performance and long life, forks need
to be dismantled, cleaned and lubricated regularly. A fork with easy access
service bolts is beneficial. It is advisable to read your fork manual
for how often your fork needs attention. If you do not look after your
upper fork legs, they can dry up, become clogged with grime or take moisture.
It
wont be long before they get "stiction" (resistance), bush slop
and subsequently need replacement parts...$$$. It is cost effective to
look after your forks.
Weight
is always an issue if you ride up as well as down. It is often a trade-off
between weight, performance and price. Our staff can help you with the
best decision.
Brand is very important but not for the obvious reasons. Most people shop for brand on reputation of the product however we feel that a more important concern is that the importer is committed to holding spares and can offer good support to keep your forks plush. The most common brands available are;
SR / Suntour make forks for recreation bikes, They are a very low price point and only offer light resistance to small bumps. Spares and service are a problem. If we have any Suntour item damaged we look at upgrading not repairing. They will not withstand aggressive riding off road.
RST have a few models made out of the USA that are very good however the majority of the forks we see are lower grade Asian fork. Of all of the non specialist forks available, RST have established themselves as producing a very good product for the price. Wholesaler support is a problem with keeping spares for all of the different forks available. The forks tend to be heavy and with nylon bushes will start to go a bit clunky within a year of light off road use. Great for the price but not worth writing home to the family about.
Mozo USA have been doing the fork thing since '93 although they are not on bikes OEM (Original Equipment of Manufacturer) which means they are available in our store as an upgrade. Although we have not tested the forks they do have a faultless finish, design, strength, great price and very good after sales support. We are not sure if they are USA made.
Manitou since the beginning have been bumping the top position. They provide an excellent range of forks for all different uses. Great supplier and a great product with respect to weight, service, function and price. Highly recommended.
Click
go to this website
Marzocchi are an Italian made fork with the most plush feel of any fork which has given them a huge following by the downhill and free ride fraternity. They are probably the strongest fork available which is why they are suited to the hard core rider although they are considerably heavier which has cost them the cross country business. They are a bit more expensive than their competitors but very easy to service and we have great wholesaler support.
Click
go to this website
RockShox have been a USA made fork until recently when they started having their cheaper forks made out of Asia. They are by far the most successful brand for many reasons. They have a steel bush with Teflon coating throughout the whole range which means it will last much longer before the fork gets sloppy. Their service support and upgrade program is fantastic. Rock Shox forks are light, inexpensive and whether you are a recreation, free ride, hardcore downhill of cross country rider they have forks and rear suspension units for everybody using spring, spring/oil and air/spring oil forks.
Some other suspension manufactures website links links
Suspension forks are on almost every mountain bike above $400 however the lower priced forks only offer a softer ride. The more expensive forks with advanced compression and dampening systems offer a softer ride and keep the front wheel in stable contact with the terrain. Forks also look after your equipment by absorbing much of the shock that may otherwise damage components. They can be a very complex piece of equipment with hydraulic pistons or valves combining air pressure with release valves etc.... we could go on for ever. The picture below is an example of the internals of a Rock Shox Hydra coil fork with lock out. Our staff can help you make certain the fork is suited and set up to your requirements.
The biggest problem with purchasing suspension forks is that bikes are made in all different sizes for different weigh riderrs but they all use the same fork. This means if your heavy and your ride rough terrain, you will bottom the forks. Most of the forks have adjustabel dials for pre-load not only (how much the fork sags with your weight) but actually does not give any real adjustment to the resistance however consumers buy the product thinking that they are adjustable. If your light or heavy or you want to jump or ride pavement, the resistance of the forks will need to be tuned for you. Only hydro forks or air forks can be tuned easily, the rest you will need to buy replacment stronger or weaker springs. In short, if your heavy or jumping or light and not, use careful consideration when choosing the bike.
Suspension forks are a very nice comfortable addition but make sure they are suitable for your weight, remember the adjustable dials on top of the forks are usually pre-load not actually resistance adjustment, If your heavy or light, you may Do you need a fork that has real adjustment.
Click
to see larger image
Suspension seat posts have a very different purpose to forks. Suspension seat posts do nothing for handling or control to keep the bike in contact with the ground on rough terrain. Their only purpose is to give the rider a softer ride. Some cheaper posts have a little bit of free play which allows the seat to twist from side to side which makes it feel like the seat is loose. The best post available is made by Rock Shox and has no movement but comes at around triple the cost. The cheaper models do the job fairly well and are adjustable for different weight riders. If you use clip in pedals and you pull up on the pedal during drive you will get PISM (Pedal Induced Shock Movement) Because most Hybrid bikes put you in a very upright ride position there is less shock through the handle bar however the rider takes the bumps through the seat. This is why most Hybrid bikes have suspension seat posts before suspension forks.
Click
to see larger image
REAR SUSPENSION FRAMES (either called Dual Sport "DS" or Downhill "DH")
Rear suspension bikes are complex and suit a wide range of uses from a soft recreational ride, street “free-ride” to downhill racing. It is easy to be attracted to the frame design and colour without looking into the system. Each Dual Suspension design feels very different to ride and you should understand what you want and how it feels before purchasing.
Manufacturers design dual suspension frames to suit one of a variety of uses for example, a down hill rider needs lots of active travel and a heavy construction frame for the extreme rigors of downhill riding whereas a cross country rider will need less travel, light weight construction for climbing and steeper geometry ideally with less active travel or even lock out to give a bit a better power transfer. For this reason and unlike a rigid bikes, you must know a lot more about what you want and shop harder.
The consideration with buying a dual suspension bike is that the bike will be heavier, more expensive or lower quality parts to a rigid bike in the same price point. When considering rear suspended bikes the drive issue is the most complex. In short the enemy is “pedal induced shock movement”. PISM is when some of the pedal motion is absorbed in compressing the shock instead of propelling the bike forward therefore rendering the bike slower – a slight trade off for a more comfortable ride over rough terrain. How it happens is when the distance between the crank-set to the seat or crank-set to the rear wheel varies. You will have to decide before you shop whether you are riding cross country, downhill or free-ride. There are bikes made for each purpose and they are very different in equipment, weight, PISM efficiency and price. If you buy a downhill bike and want to use it for XC, you may soon realize you have made a terrible mistake. Another negative of DS/DH bikes is a low resale price.
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