Hypothetical Track Bike Build - Hornet 600

[KungFooBob]

This isn't going to happen, it was just something I was thinking about last night after a few beers.

How light can you make an early Hornet?

Wikipedia says the dry weight was 176kg...



Got to be a good few kg in that pipe. Junk the grab handle and mirrors. Replace the headlamp with a bikini fairing, maybe 10kg lost?

Could you get it down to 160kg wet?

Then it's just a shock, some springs, jet kit and some sticky tyres?

Could you fit a pre-tuned engine out of a Steelie Pre-injection racer?

[Le_Fromage_Grande]

CBR engines don't fit straight in, the heads are different for the different carb angle.

They're not great handling either, a CBR handles better.

I think you'd be better off starting with a Fazer or a Bandit

[weeksy]

Oh wow... that's not aged well... look at that swingarm !!! I always liked a Hornet... but that... just makes me barf.

[wull]

160 wet, no chance!

[KungFooBob]

I reckon there's a chance, but to do it would cost more than the cost of the base bike.

Replace the tank with a fuel cell and a CF tank shaped cover.

Light weight wheels.

Rearsets (getting rid of the pillion pegs).

All body work in CF, all fasteners in Ti.

Got to be in with a chance of 160kg then?

[Mr. Dazzle]

Yeah you can get it down to 160kg, it'll just cost alot

Hacked down/new subfame - you don't need the pillion seat and you probably don't need as much strength margin in a track bike either. Small rear body work too. Next level up would be ditch most of it and have a structural CFRP seat unit which picks up off the same mounting points.

Bin that exahaust for sure and the rear peg hangers.

Where does the rear shock mount at the top? Straight into the main frame or via a sub structure?

Carbon wheels.

Aluminium sump, unless they've got one already (looks like maybe it has)?

S'probably got the big old lumpy sliding brake callipers?

Titanium wheel spindles.

Plastic fuel tank.

Titanium springs - they're a bit scary though!

Probably a few brackets you don't need on the frame.

Fancy bolts.

I bet it's got some heavy flappy bollox in the inlet system? My similar aged CBR does and the HRC race kit strips a load of wires, actuators and pipes out.

There's gonna be a million other tiny savings.

Don't need most of the wiring loom, again HRC did a race one for the CBR.

Cheapo digital rev counter, bin the clocks and drive cables.

Lithium battery. Total loss system maybe? Alternators are heavy.

By the same token make it roller start only and lose the starter motor. Then you only need a little battery.

Only put 1 litre of fuel in it

[Supermofo]

It'd be cheaper to tune a 690 Duke to Hornet power. Dukes are 160 claimed wet and that's with the dustbin underneath still attached. The later models are around 72bhp at the wheel so race cams, remap, airbox and zorst will probably see you close to Hornet power and I bet that would be cheaper than cutting weight off the Honda.

[KungFooBob]

But... you can buy a tatty Hornet for a grand to cut up

[Mr. Dazzle]

You know, thinking about, just binning the road electrics would save you loads. It's a carb bike so all you really need for the track is a bit for the ignition. A big battery, starter motor, alternator and all the associated fat wiring adds up to quite a lot.

[dern]

The only way it would make sense for me would be to buy it for that much, junk anything not useful on track and ride it. I can't see it being worth spending any money on when you could pick up a ready to go track bike on ebay for a couple of thousand or so.

[mangocrazy]

It really all depends on how much money you want to throw at it. Sure, you can bring the weight down to 160kg wet if you throw titanium and carbon bits at it, but you'll be spending way more than it costs (and is worth), and it would be much cheaper to buy a track-ready bike off ebay.

You could go down the weight cutting route and bin everything that wasn't needed on a track bike, but you'd still be left with a bike whose brakes and suspension are budget items and will limit the track performance quite a bit.

It's like the punch line from the old joke: 'If I was wanting to get to there I wouldn't be starting from here'...

[Mr. Dazzle]

You did all read the bit where he said he's not actually going to do this right?

Besides - plenty of mad shit done in the name of motorsport regulations. Maybe he's gonna race in the Hypothetical Hornet Cup

[KungFooBob]

Yeah I'm not going to buy a Hornet, or if I do I'm not going to convert it to race spec.

I did once watch a guy win an open 600 race on a Hornet, Retford and District club at Cadwell late 1990's/early 00's.

Remember the motor is very similar to the CBR, as mentioned by Cheesy the head is different, but I bet the cams and big valves could still be fitted. Not that I'm going too.

[Skub]

Weight loss on bikes is akin to weight loss with people. The first load comes off easily,then it gets more difficult.

I dropped the wet weight of my Z1000 from 221kgs to 207kgs by not doing much more than junking the cat/emmissions gubbins and any pillion stuff. Any further losses will cost significantly more for smaller increments.

There is probably good and noticeable saving to be made on the likes of a Hairnet by replacing the wheels,but modern stock wheels are much lighter than they used to be.

Titanium wheel spindles are harder to come by now,machine shops dislike working with the stuff,so even if you can get someone,they'll sting you for the pleasure.

I knew a man back in the mid 90s whose mission in life was lightening a ZZR100. His weighed the same as the first Fireblade and punted out 160bhp,it went like stink,but it looked rough and he spent 20k getting there. That was crazy money back then.

[Mr. Dazzle]

Pfff...I once replaced an aluminium (bicycle) seat post clamp with a 3D printed plastic one to save 5g.

[wull]

Pfff...I once replaced an aluminium (bicycle) seat post clamp with a 3D printed plastic one to save 5g.

the crazy lengths the hill climb boys go to, I had a supersix evo hi mod that was set up at just over 5.6kgs with Fulcrum 60 wheels.

Can’t remember the weight it was with the climbing wheels, maybe 5.2kg, can’t even remember what wheels they were.

[Mr. Dazzle]

Bit higher spec than hill climb, this was some guy called B. Wiggins

[Le_Fromage_Grande]

Buy a tatty SRAD 750, take the fairing off and fit mandlebars.

[dern]

You did all read the bit where he said he's not actually going to do this right?

Besides - plenty of mad shit done in the name of motorsport regulations. Maybe he's gonna race in the Hypothetical Hornet Cup

Yebbut the only scope for joining in was therefore to either play along and imagine he might or reply telling to stop wasting our time... the former seemed less rude and more fun

[mangocrazy]

You did all read the bit where he said he's not actually going to do this right?

Besides - plenty of mad shit done in the name of motorsport regulations. Maybe he's gonna race in the Hypothetical Hornet Cup

Yebbut the only scope for joining in was therefore to either play along and imagine he might or reply telling to stop wasting our time... the former seemed less rude and more fun

And Mr D did bite multiple times, and with the longest post, so it's a bit late to try and back out...