Time to get the K2 out of the naughty corner

The 3 1/2 forum
penman
Posts: 325
Joined: 08 Mar 2016 09:20
Location: Milton Keynes, UK
Location: Milton Keynes

Re: Time to get the K2 out of the naughty corner

Post by penman »

72degrees wrote:
If all else fails give me a shout and I'll send you these VHB25BS bodies 'on approval'. Though I'm wondering if it might not be a bad idea to replace the robbed bits and try them as an alternative to the 28s. They might work better at some hills. The late, great, Cornish hillclimber Roy Opie used to say the secret of good times at very short courses like Tregrehan (440 yards) was small carbs and sticky tyres.
Many thanks for that. I'll see what Rob at NLM has to say on Tuesday and if necessary, I'll get back to you after that.

Interesting quote from Roy Opie re small carbs. Was he suggesting that small carbs are more responsive and any limitation on peak power doesn't matter on a short course, perhaps? A bit out of my experience, I'm afraid! Could be worth putting it to the test though, as you suggest.
1984 Moto Guzzi V65
1969 Honda CB450
1975 Triumph T160 Trident
2019 BMW F750GS Sport
1978 Morini 500
User avatar
72degrees
Posts: 1550
Joined: 31 Aug 2007 21:24
Location: West Midlands

Re: Time to get the K2 out of the naughty corner

Post by 72degrees »

I think the idea is that on a very short course the start is even more important. The time to 64 feet can find half a second or more on a bike that pulls extremely well without having to coax it off the line and needs to come out of tight hairpins on full song. To be fair, things have moved on since then in engine, carburation and ignition systems. The riders of modern supermoto 4T singles seem to cope just fine with a huge carb by yesterday's conventions and the tables in Phil Irving's 'Tuning for Speed'. Mind you, fuel injection is the real deal these days. The KTM350SXF I had was ace off the start and brilliant everywhere else.
penman
Posts: 325
Joined: 08 Mar 2016 09:20
Location: Milton Keynes, UK
Location: Milton Keynes

Re: Time to get the K2 out of the naughty corner

Post by penman »

72degrees wrote:I think the idea is that on a very short course the start is even more important. The time to 64 feet can find half a second or more on a bike that pulls extremely well without having to coax it off the line and needs to come out of tight hairpins on full song. To be fair, things have moved on since then in engine, carburation and ignition systems. The riders of modern supermoto 4T singles seem to cope just fine with a huge carb by yesterday's conventions and the tables in Phil Irving's 'Tuning for Speed'. Mind you, fuel injection is the real deal these days. The KTM350SXF I had was ace off the start and brilliant everywhere else.
I've never competed, so my comments are a bit in the armchair category! I attend the Piston Rally for pre-1980 bikes in Spain every year, usually on my 750 Bonneville. This is all steep hills and hairpins and how the bike makes the transition from idle to "progression" makes all the difference between huge fun and a pain in the neck. If this happens smoothly and quickly you are driving out of the bends, grinning like the Cheshire cat. Any hesitation and you are wobbling all over the place. The Bonnie works pretty well in the hills, but I suspect the K2, being even lighter and having slightly better brakes, would be even more fun. Pity it's outside the 1980 age limit! Still, let's get it fixed first before planning future trips!

I'm pretty skinny, so I'm finding the K2 suspension a bit over-damped for my weight (not ridiculous, just a bit harsh), so I'm already thinking about trying a lighter fork oil and maybe changing to Hagons with variable damping at the back. But this is fiddling about, like I say, I need to get the big issues sorted first. The good news is that I've regained enough enthusiasm to even think about fine-tuning the suspension!
1984 Moto Guzzi V65
1969 Honda CB450
1975 Triumph T160 Trident
2019 BMW F750GS Sport
1978 Morini 500
Post Reply