My GB600

[bob181]

Hi all, this is my first post so thought I share some infor on my mighty GB600 which I’ve been hoppin up for over 10 years now. This has been a real project which started out by wanting more Power! As anyone who has been down this track before knows that power = Money and Time! lol Here’s a basic list of what I’ve done:

Re-sleeved barrel and fitted wisco forged piston-598cc
Had cam built up and re-ground by CLS camshaft services
Stronger valve springs fitted to cope with higher rev range
Chrome Cycle Works exhaust system
Koni rear shocks and progressive front springs fitted
Bikini flaring from Euroglass in Christchurch
Excel 2.5” x 18” front rim and a 3.5” 17” rear rim laced up in stainless spokes from Wheel and Spoke services in Auckland
Running BT45’s 100x80-18 front and 130x80-17 rear.

I’m in the throws of making some rear sets to suit my 6 foot frame, I’m finding this a fucken nightmare sorting out the brake lever linkage as I’ve put the foot peg up about 1 ½” and back about 2”. Has anyone else done this before? Also I’m fitting an oil cooler off a GSX400 to help out keeping the oil cool.

I’ve also read that a 6 speed CBX250RS gearbox almost slides straight in without a problem
in these forums, has anyone actually done this? If so, what’s involved?

Any questions about what I’ve done or anyone with any information please have your say as there is always a wealth of information obtained thru doing these kind of projects.

[blacksheep]

very cool bike,the old retro look is on the way back.

[vifferman]

Very nice, Bob! Wel done!

Oh - and welcome to KiwiBiker.

Sorry - I can't help you with your questions. I did have a CB250Rs for a while, that had an XR500 donk shoehorned into it, so I can at least verify that there is much commonality of parts between many Honda models.

Oh - and by the way: some vandal seems to have scribbled all over your rego plate!

[jrandom]

That is a very cool bike.

Any idea how much power it's putting out at the rear wheel now?

[tri boy]

Wait till Bonez and Exer see this
Lovely bike mate.
Welcome. Enjoy the madness.

[HenryDorsetCase]

I think thats the nicest one of those I've ever seen.

chapeau!

[bob181]

I have had it on the dyno after the big bore kit and cam. It was putting out 38hp at the back wheel with 55nm of torque from idle. Huge torque but not a great HP gain, found I had breathing problems from 7,000prm upwards. I have since sorted out my carb problems but haven't had a chance to put on a dyno. Should be around 42 hp at the back wheel? Nice and light to ride with plenty of wind on power in top gear.

[98tls]

Welcome Bob,love your bike shes a beauty,glad to see another afflicted with the modding disease.

[nudemetalz]

Very nice looking machine.

I've always liked the GB range and still kick myself for not buying that brand new GB400TT2 back in '87 when for the same money I bought a second-hand CBX400F !!

[Blackbird]

Beautifully made and well done! It was a new GB400 TT (dark metallic blue) that got me back into bikes in 1987. I subsequently put a full fairing on it, modelled on the RZ 350.

Again, warmest congrats

[Pwalo]

That almost makes me wish that I still had my FT400 so I could do something similar.

Nice work sir.

[kiwifruit]

looks mint, well done

[xwhatsit]

Dude, that is very very cool. I'm seriously considering a GB400/500 when I upgrade, it's just the right sort of bike for me (and NZ roads, really).

Even the 400 produces a wondeful cracking sound with a nice open silencer on the end, I'm sure a 600ified version would sound just delicious.

Very jealous. Enjoy yourself

Wouldn't be surprised regarding the CBX250RS gearbox, these were both the early RFVC engines, and the bottom end looks damned similar in photos. Might find they're geared with too narrow a ratio spread though, the CBX250RS is just as revvy and top-end heavy as the CB250RS I own. You'd probably find yourself with a very tall first gear in order to keep a useful top gear. On a big torquey thumper I wouldn't have thought you'd need 6 gears anyway...?

[Paulo]

Hi Bob Nice work!! , i'm riding a Gb500TT as well same as your's but stock motor (I have a fairing in the garage), I put some Tomoselli clip ons on for an even lower riding position (but I'm not that tall so still have roomto stretch) sorry can't help you with you mechanical questions. That's a pretty fat tyre on the back ( I run Meztlers) How's that handle?

[bob181]

Handles great, the BT's have a nice profile and the size tyres I'm runing fit the rims prefect. I use to run a 100 x 90 front and 120 x 90 rear on the standard rims but didn't handle very well.