This is James from Full Force Racing Components, a suspension guru with more than a decades
experience in designing, manufacturing and tuning custom suspension components for V8 racing cars,
rally cars and all facets of motorbike suspension - motocross, enduro, speedway,
flat track, and of course adventure bikes. He'll be modifying the DR650's suspension in
various stages, this vid looks at his first steps in making that suspension work properly.
As we mentioned in the first vid, the DR650 is a brilliant budget bike to
transform into the sort of beast you want, once you work on a few major design issues.
The big one is suspension. If you are a featherweight and riding nothing harder than
smooth dirt roads, you will find the stock setup okay, but the problem of course is the moment you
are in trouble it won't be doing you any favours. The front end dives badly under panic braking,
and if you run off the road it will bounce you like a trampoline in the rough stuff.
The major problems? The springs are way too soft. The forks are the ancient 'rod' style. Pause to read more.
Then if you use heavier oil to get damping, you can't get good performance on both fast
and slow fork movements, unlike a modern cartridge fork. Just pause to read more.
The rear spring does have adjustment for the compression damping,
which barely makes any difference anyway. It is underdamped, and the
ratio of compression to rebound damping is way out of sync too.
The good news? You can transform the crappy stock suspension into a very sexy suspenders
for less than $1000, and the DR650 is so cheap that you'll still be well ahead in the long run.
There are budget do-it-yourself mods... if you are on a very tight budget have a look at these, but
So what did we do for our first suspension upgrade? For the forks, we just did a budget
upgrade first to see how much this improved things. We ditched the horribly designed dual rate
stock springs, and would urge anyone to do so. We put in stiffer springs to match my weight and the
19L IMS tank we'll be fitting. We experimented with 15W fork oil, this worked well on absorbing
big hits such as jumping the bushpig, but was too harsh on corrugations and small sharp bumps. We
backed off to a 10W fork oil that was an acceptable compromise.
But this is the issue with the old rod design forks, you simply can't get them
working well on short sharp hits, and also on big relatively slower fork movements. A
lot of riders solve this through using intiminators or emulators in the forks,
but James will be exploring some possible solutions in our next suspension upgrade.
Conclusions? This budget fork mod dramatically changes the forks performance, but still falls
short of a modern fork in terms of safety and comfort offroad. We regard new springs and
appropriate fork oil as an absolute bare minimum, but would strongly recommend going further.
On the rear, James felt the rear shock's damping was so poorly designed he didn't
bother with the budget upgrade of trying 10W shock oil replacing the stock 5W. The dyno
indicated the compression and rebound damping are too poorly matched to get reasonable performance,
so he custom made a new valve. Results? Brilliant. The rear end now behaves itself
on fast choppy surfaces, but also soaks up those big hits from jumps and the
like. James said there is quite a bit more that can be done to improve the rear shock
but we'll have to wait until the next upgrade to see what he comes up with.
Once we can get the front forks behaving in
a similar way the DR is going to be even more fun to ride!