NZCMRR Classic TT

Where the magic happens // Benelli at Hampton Downs 2013 // Medium format film

Mt Wellington May 2013

Mt Wellington May 2013

I forgot to post about the last track day I attended back in May, here it is:

Another great weekend at Mt Wellington, I was really enjoying myself and got some great starts which I was pretty stoked on. In the second points race I was following Henk around as he tried and succeeded to past Dave Diprose in the mid field. Feeling very confident in myself I started to line him up too but I ran out of talent and ate shit into turn one when I grabbed too much brake. Thankfully my dad was shooting on that corner and managed a few frames of me skipping along the concrete. I got away with a solid bit of rash on my hip which swelled up pretty impressively and a sprained thumb but otherwise pretty good… bike still goes.

Time to update the 13 and 7 year old tires, get a smaller rear sprocket and some more practice I think. Never the less I still managed a 31.03s PB lap in that last race which is my best time to date on Mt Wellington. SO close to that 30s bracket!

GP125 Seat

To be perfectly honest I had completely given up on this frame. With the engine in pieces and being worked on for my RS125/GP125 swap, this bike no longer has a heart.

I’ve always loved the simplicity of classic flat top frame bikes and after my usual internet trawl of delicious bikes this week, things started to brew again. I cut the end off the frame to shorten up the working area and started playing with a template for a steel seat. With no real intention to build something permanent I got to this point and I’m wondering if I should progress with it, I kind of like it. It’s not perfect as I didn’t intend it to be used and I don’t have any real sheet metal working tools (folder, band saw, roller etc) so I had to be a bit creative with some thick steel and some g-clamps.

I do have a gripe on the GP125s styling. The tank side profile is fairly nice on the eye but it’s chubby. If I was really keen/wreckless I’d cut about 80mm out of it’s width and follow suit with the tail piece but… I’m not to fond of the idea of cutting and welding a fuel tank.

On the RS/GP front, I have ordered a small dentist drill and some carbine tip burrs to port the 2 stroke cylinder. Otherwise, I’m just waiting really.

RSGP125 BUILD3

Suzuki GP125 engine strip down

Here are some more internal photos of the GP engine as I pull it down. I ended up drilling most of the phillips head bolts which hold the casings together as they were corroded down the thread. What a stupid idea it is to use a phillips head, honestly.

This last photo is of the tiny GP gearbox assembly. I wanted to show it to give you an idea on how a motorcycle gearbox works (although similar to a car) in translating the up and down movement of the gear changer to a change in gear. When you push up or down on the changer, a mechanism spins the grooved barrel in the top of the photos. In those grooves are the gear selectors which move left and right depending on the groove. The selectors move the gears on the input and output shafts which engage with each other to drive different combinations of gears and therefore ratios.

STREET PARADISE

ZARCO DERBI 125

A thing of true beauty

RSGP125 BUILD2

I swapped the Honda NX4 RS125 tailpiece from my 4 stroke onto its rightful home on the RS125 chassis.

A few NX4 RS125 expansion chambers also turned up on my door this morning, thanks Jesse! I know they’re not matched perfectly to what I will be doing to the GP engine but Rob has shown that they work well enough to get some great power figures from them. It’s also easier to use an RS one to get it going and rideable instead of stuffing around building one that is likely to be crap. I do plan to build a few in the future though…

RSGP125 BUILD1

I spent some time at Tim’s (a fellow F4 racer) place on Anzac day talking crap about bikes and figuring out how we can get some economies of scale going on with our GP125 builds. Being the good bastard he is, he gave me some… ummmm… used GP125 cases and a test bed GP100 cylinder for some time on the grinder before jumping into mine. THANKS TIM!
I started undressing her the other night and took some photos along the way:

Factory Suzuki GP125 crank case as provided by Tim

Tim’s degree wheel for port timing

Port side

Factory timing marks

Starboard side

Tokoroa GP 2013 Photos

Here are some more photos from the Tokoroa GP 2013. I cannot emphasis how awesome this event was, such great competition!

^Nathaniel Diprose took it out on his Honda NF4 RS125 powered by a 80cc watercooled Derbi engine putting out 21hp

Tokoroa GP 2013

Wow, what an awesome weekend that was! That was my first time visiting Tokoroa and it’s such a fun circuit, although hard on the body into those down hill sections. Huge thanks to the organisers, time keepers, flaggies, and everyone who drank beers with us on Saturday night. Congrats to everyone who raced and those who triumphed. The GP looked fierce, I was nervous before qualifying and I wasn’t even in the race!

I just wanted to point out that there were TEN, yes TEN Honda RS chassis’ at the GP (including a RS250) and not including the GPR diesel which is pretty much a RS. That’s more than a nationals round I believe…

Cheers to Glen for showing me a few improving lines during the track walk and to Cully for letting me pervertedly handle his RSGP125. On that note: