Ninja 300 Track Bike Project – September Update

It’s been two months since our last update and as usual, things can sometimes get in the way of best intentions. But thankfully progress on our little Ninja 300 project bike continues and includes replacement parts that were damaged when we bought the bike from auction, a new battery and some nice upgrades to the front suspension.

Our big modification this month is for something you’ll never even see – the fork internals. The forks on a Ninja 300 are pretty basic which is not surprising given they’re attached to an entry level machine. They’re also setup in such a way to accommodate a specific rider weight which from our understanding is a 75 kilogram person.

This is what 5,000 kilometre old fork oil looks like.

So to fix this, we took the forks apart and replaced the springs with a set from Racetech which were configured for my weight (85 kilograms). But in addition to that, we also purchased some gold valve emulators – also from Racetch. Not only is doing this a much cheaper option than replacing the whole fork internals with a cartridge system, it’s also a modification allowed for the race seriers we’re entering (whereas cartridge replacements are not).

Dampening rod forks are a cheap way of dampening the front of a motorcycles suspension. That also means they’re not particularly good at what they do – generally they’re either too harsh and too easy to bottom. One can play around with things like the amount of oil in the forks, fork oil weight and even changing the size of the holes in the dampening rod, but that’s not a great solution nor is it an easy one to change all the time.

The original dampening rod is on the left and the right is the one we drilled.

Valve emulators essentially take over the role of the dampening rod. They’re extremely easy to install and fairly easy to adjust too. Modifying things to use valve emulators is a fairly straightforward affair – you just need to drill holes in your dampening rods so enough fork oil flows through them that they no longer have any effect on dampening. Anyone with a drill and a vice can do it (although a drill press is preferable).

There’s an incredible amount of technical jargon behind how dampening rod forks work and how things change with valve emulators and we’ll take a greater look at them at a later date, but for those curious you’re best to go to the source and read up on it at Racetech.

Obviously when changing the fork internals we replaced the oil seals and bushings, plus put in new fork oil.  As you can see from the image at the top of the page, the fork oil was pretty dirty and incredibly that’s only from the bike having done 5,000 kilometers.

Smashing down on new oil seals with a PVC pipe is oddly therapeutic.

Once the forks were placed back in we attached our new bars – a set of fantastic looking bars from Tyga Performance. Other options were clipons from Woodcraft or Driven, but those two particular products clip onto the top of the forks just beneath the upper section of the triple tree. That can cause issues with hitting and rubbing on fairings so we felt it was best avoided. Plus we think the ones from Tyga with their CNC machined aluminium look great.

We also placed some preload adjusters on top – these were cheap ones off eBay and while they look good and do a basic job, we don’t expect them to last long as they’ve already been chipped away when using a socket on them.

The Tyga Peformance bars are top quality. The preload adjusters from eBay are not.

The last few months also saw the arrival of our replacement parts for the damage on the bike. That included the front fairing stay, the right outer fork tube and the front fender stay. We replaced our dead battery with a new one courtesy of Dynavolt and we’ll be attaching a battery tender to it to make sure we don’t have another flat battery in the future.

So what next? Well, probably more than we can do in a month. As you can see from the picture below, we have a brand new fully adjustable rear shock absorber from Wilbers, Vortex Rearsets, new RK chain, sprockets, BMC air filter and more, as well as a set of Pirelli Diablo Rosso II tyres. But once they’re done we’re almost on the home stretch from a mechanical point of view.

New parts ready to be installed include a lightweight Vortex rear sprocket, a race spec air filter from BMC, a top of the range RK chain, Vortex rearsets and a bespoke rear shock absorber from Wilbers.

Leave a Comment