How light can a dirt bike get? What are the most cost-efficient ways to reduce
weight? And is it really worth it? If you like riding hard gnarly terrain,
then light weight dirt bikes are in their element. They are less tiring, easy to throw around,
have a great power to weight ratio, and they are easy to lift when you are completely stuck.
The world's lightest bike that could still be loosely seen as a dirt bike is the FX5,
and interesting concept that bridges the gap between mountain bikes and dirt bikes.
While the small engine won't appeal to many, something close to this weight and
decent power could be possible when electric engines and batteries improve dramatically.
Sick of that big heavy pig? Slip us two thousand dollars for our Wonderlight program,
as seen on the Scams International TV show.
For slow hard terrain, the hybrid bikes span the gap between trials bikes and fully fledged
dirt bikes. There is always a compromise though. The incredibly light Ossa Explorer
is simply a trials bike with a bigger tank and a seat, so it's very limited the moment you try
and ride at a moderate pace. And the weight increases as the models become more capable
at speed. My current bike is a Beta Xtrainer which is brilliant for technical riding, very
good for everyday dirt riding but it's definitely unstable when you ride aggressively at high speed.
If you do want a sub-100kg (220lb) bike you can ride hard and fast,
then there's always the motocross conversion we investigated recently.
There are inevitable drawbacks with these, but fast experienced riders often find they
can exploit the highly strung nature of these engines and revel in the light weight too.
If price is no object, how light can you make a motorcross bike? Motocross
Action magazine did exactly this, and spent US$10000 to trim almost 8kg or 17lb from the
bike. The crazy part was the titanium bolts and axles alone were over $6000.
Before we look at practical ways to make your bike lighter, let get this into perspective
with three key principles. First, focus on your own weight. Many riders get obsessed
with losing weight on their bike instead of working on their riding skills. Most guys
would benefit way more by spending money on coaching and fuel for their bikes,
than the latest titatanium bling. And it's ironic how often these guys are overweight. I never
criticise anyone for how they choose to live their life, but if you are overweight you will become
a much better rider by losing a few kilos from your body, than a few kilos taken off your bike.
Second, it's more important to lose unsprung weight of your bike,
than sprung weight. So start with the easy cheap ways to make your wheels lighter first.
And the third principle when looking at reducing sprung weight - put more
focus on weight higher up on the bike. A custom seat that is one kg heavier will
affect the bike's handling more than a skidplate that is one kg heavier.
So at a practical level, what are some basic ways to reduce weight and not spend a fortune
in the process? Starting with unsprung weight, lets start with the free stuff. Avoid bling if
you don't need it. Things like heavy duty chain guides, disc protectors and extra rim locks are
great if you need them, otherwise they are just extra unsprung weight. Tyres. These vary a lot
in weight so if you don't need tough tyres, choose a light set next time. The same with
tubes, if you rarely get punctures then thin tubes weigh much less than ultra heavy duty
tubes. If you do need better protection but want light weight, then the TUbliss
system can be well worth the money, and may not cost more than tubes in the long term.
What about sprung weight? One of the most obvious ones is don't fill up your fuel tank if you don't
need to. If it's a short ride, or you keep looping back to your base, only half fill your fuel tank.
It costs nothing and saves you around four kg. Again think about bling before you add it to
your bike. Do you really need it? And if so, do you really need the heavy duty versions of
hand guards and skidplates? In some cases the carbon fibre versions are no more expensive,
so if you don't need a heavy duty skidplate you can save a bit of weight compared to
the alloy ones without extra expense. If you are going apeshit about losing
weight and want to throw money at your bike, often the next step is a lithium battery which
can drop a kg or two. If your standard exhaust is heavy then look at aftermarket one but for
God's sake get a reasonably quiet one if you ride anywhere near the general public.
Personally I think that wraps it up for commonsense weight reduction that doesn't
cost a fortune. Again, I think most guys go way overboard on this crap, and inevitably you start
to run into compromises with punctures, insufficient protection for your bike,
and simply wasting money on expensive hit. Keep it all in perspective,
focus more on your own riding skills and body weight, and enjoy your bike for what it is.
Oh and remember you can always try laxatives and taking a big dump before your ride too.