custom frames etc.........

[jason61c]

So custom frames, anyone got one? anyone building one?

Who would you go to?

Harris? Martek etc?

[gareth h]

TBH not much point these days, modern stuff does the job, although I do like the Suzuki classic racers (which I think have Harris frames). And the old Rickman Hondas.

[Benni]

Leftfield because dutch, but great builds, mostly with special front ends : Nico Bakker

https://www.bakker-framebouw.nl/home?lang=en

[jason61c]

gareth h said:

TBH not much point these days, modern stuff does the job, although I do like the Suzuki classic racers (which I think have Harris frames). And the old Rickman Hondas.

Ok, how do I improve a 80's design steel frame? its not like you drop it in a r1 chassis etc!

[gareth h]

jason61c said:

Ok, how do I improve a 80's design steel frame? its not like you drop it in a r1 chassis etc!

You could go for a frame change, but lots brace the existing one and upgrade suspension / brakes

[Tango13]

jason61c said:

So custom frames, anyone got one? anyone building one?

Who would you go to?

Harris? Martek etc?

What bike/engine are you looking at improving?

I've thought about building a Magnum IV a few times but to build one properly would cost somewhere in the region of £20~25k

There was an old Harris F1 endurance racer on fleabay a while back but again to rebuild it to a road going condition would've cost a bloody fortune, £7k just to buy the bike, £5k to re-build the engine, £3k to replace the magnesium wheels and then you have all the odds and ends that will add up at an alarming rate.

I'm not saying don't do it but be aware that it wil cost.

Edit to add...

https://www.giaengineering.co.uk/motorcycle-modifi...

Edited by Tango13 on Wednesday 1st April 19:14

[Pothole]

Spon..oh.

[jason61c]

Tango13 said:

What bike/engine are you looking at improving?

I've thought about building a Magnum IV a few times but to build one properly would cost somewhere in the region of £20~25k

There was an old Harris F1 endurance racer on fleabay a while back but again to rebuild it to a road going condition would've cost a bloody fortune, £7k just to buy the bike, £5k to re-build the engine, £3k to replace the magnesium wheels and then you have all the odds and ends that will add up at an alarming rate.

I'm not saying don't do it but be aware that it wil cost.

Edit to add...

https://www.giaengineering.co.uk/motorcycle-modifi...

Edited by Tango13 on Wednesday 1st April 19:14

its for this



Already got a proper motor/radiator/wheels/brakes/suspension. Seems a frame(i'd like an alloy one to make it lighter maybe) would just finish it all off.

[lukeyman]

I like it as it is!

[Tango13]

jason61c said:

its for this



Already got a proper motor/radiator/wheels/brakes/suspension. Seems a frame(i'd like an alloy one to make it lighter maybe) would just finish it all off.

That looks good

Aluminium is about a third of the weight of steel but also about the third of the strength so for the same strength there's not much difference between steel or alloy frame weight wise. An alloy frame won't be much lighter but big shiney alloy tubed frames always look good and would really suit the style of bike you're building.

[jason61c]

Tango13 said:

That looks good

Aluminium is about a third of the weight of steel but also about the third of the strength so for the same strength there's not much difference between steel or alloy frame weight wise. An alloy frame won't be much lighter but big shiney alloy tubed frames always look good and would really suit the style of bike you're building.

a few extra bits of bracing, good quality alloy tubing, should make it about 50-60% of the weight and stronger.

[rodericb]

Some carbon fibre bracing would be something different. I'm working what I need and want to do for a Ducati 851/88 restomod and am thinking of modifying an early 900 monster frame - getting rid of bracing tubes and doing some carbon sheet, rods and a carbon airbox to stiffen up the frame.

[jason61c]

rodericb said:

Some carbon fibre bracing would be something different. I'm working what I need and want to do for a Ducati 851/88 restomod and am thinking of modifying an early 900 monster frame - getting rid of bracing tubes and doing some carbon sheet, rods and a carbon airbox to stiffen up the frame.

it'd look totally wrong on this, given how you'd support it, i'd end up with a very 'messy' look.

[rodericb]

jason61c said:

rodericb said:

Some carbon fibre bracing would be something different. I'm working what I need and want to do for a Ducati 851/88 restomod and am thinking of modifying an early 900 monster frame - getting rid of bracing tubes and doing some carbon sheet, rods and a carbon airbox to stiffen up the frame.

it'd look totally wrong on this, given how you'd support it, i'd end up with a very 'messy' look.

Yeah. that's the look I'm going for. So you can see that the original "20th Century" structure is there but with modern addenda to drag it into modern levels of rigidity. The look of what you desire is the key. Its the wildcard when you're restomodding or building a custom and there's a vague line between a restomod and a custom, which is probably different depending on who you talk to! It sounds like you're going for the opposite of what I'm after - do you want to keep the twin cradle? Or hang the engine like the old specials (Harris, Spondon etc)?

The ZRX1200 was still sold in Japan for quite a few years after they stopped selling it everywhere else. It ended up getting fuel injection and a six speed box. You've got a heap of nice parts there already - I'm looking forward to seeing your next installment!

[Turn7]

Pothole said:

Spon..oh.

About the biggest tragedy of the whol bloody saga tbh,,,,,,,Loved their stuff

[jason61c]

rodericb said:

Yeah. that's the look I'm going for. So you can see that the original "20th Century" structure is there but with modern addenda to drag it into modern levels of rigidity. The look of what you desire is the key. Its the wildcard when you're restomodding or building a custom and there's a vague line between a restomod and a custom, which is probably different depending on who you talk to! It sounds like you're going for the opposite of what I'm after - do you want to keep the twin cradle? Or hang the engine like the old specials (Harris, Spondon etc)?

The ZRX1200 was still sold in Japan for quite a few years after they stopped selling it everywhere else. It ended up getting fuel injection and a six speed box. You've got a heap of nice parts there already - I'm looking forward to seeing your next installment!

I'll keep the crade most likely as thats how the engine was designed. Keep the twin shocks(as they're new!).

That'll look ace on your bike.

Its a I want it to 'work' as a priority, then form will follow function

[anonymous-user]

jason61c said:

Tango13 said:

What bike/engine are you looking at improving?

I've thought about building a Magnum IV a few times but to build one properly would cost somewhere in the region of £20~25k

There was an old Harris F1 endurance racer on fleabay a while back but again to rebuild it to a road going condition would've cost a bloody fortune, £7k just to buy the bike, £5k to re-build the engine, £3k to replace the magnesium wheels and then you have all the odds and ends that will add up at an alarming rate.

I'm not saying don't do it but be aware that it wil cost.

Edit to add...

https://www.giaengineering.co.uk/motorcycle-modifi...

Edited by Tango13 on Wednesday 1st April 19:14

its for this



Already got a proper motor/radiator/wheels/brakes/suspension. Seems a frame(i'd like an alloy one to make it lighter maybe) would just finish it all off.

Now that is really really nice

[jason61c]

Thanks. Is a lovely motor(170bhp and 101lb/ft at the wheel), with the chassis, should be handle really nice also. While still making rattly noises from the carbs and having zero electronics to play with.

[Steve Bass]

jason61c said:

Tango13 said:

That looks good

Aluminium is about a third of the weight of steel but also about the third of the strength so for the same strength there's not much difference between steel or alloy frame weight wise. An alloy frame won't be much lighter but big shiney alloy tubed frames always look good and would really suit the style of bike you're building.

a few extra bits of bracing, good quality alloy tubing, should make it about 50-60% of the weight and stronger.

You'd think so but not really...

A good frame can be made from Cromoly which will allow the tube wall thickness to be reduced for a moderate weight saving. However the real benefit is increased rigidity for the same/slightly lower weight negating the need to add bracing or gussets to the original steel frame to increase the torsional rigidity. However, it's not just the tubes that make up the weight, the weld filler rod is surprisingly heavy as well as the thickened plates for the swing arm pivot and foot pegs but, it ain't cheap and you'll need to be honest, is it for performance or looks?
If it's for performance, the biggest component affected by torsional flex is the swing arm. Any twin shock swing arm suffers lateral flex as the shocks have very little lateral resistance and will allow the wheel to move side ways under lean and load. And once they are flexing, they don't operate so well causing the bike to feel weird. You've basically lost your rear suspension for a moment.....
That's why the under-braced swing arm became so popular and was still used on the early big bang R1's.

If it's for aesthetics however, you can strip and polish the existing frame, add a few gussets at the triangulation points and a few cross braces here and there. Weight will go up a little but it'll look nice. And maybe paint it a striking colour, Kawasaki green????
As an example, the Pierobon CRo25 frames for Ducati's aren't that much lighter but offer huge improvements in torsional rigidity and so improve the performance by not twisting so much and affecting the suspension geometry and operation.

Cracking bike BTW, I'm on the lookout for a nice ZRX in the future...

[Tango13]

Turn7 said:

Pothole said:

Spon..oh.

About the biggest tragedy of the whol bloody saga tbh,,,,,,,Loved their stuff

If you follow the link I posted their home page make interesting reading...