Any idea why?

[Pwalo]

I'd go with wheelbase, combined with steering angle and perhaps tyre profiles.

Ok I really don't know and can't be bothered to try and recall my high school/university physics. You could work on trajectory change, braking dynamics, weight, chassis bias, reider weight, etc, but I'm pretty sure that getting a simple equation would be problematic at best.

Also you must remember that a lot of this is pretty subjective. You always feel more cranked over on a sportsbike because of the riding position, c of g, etc. You also look more 'tucked in' which further enhances the image of leaning over.

[sAsLEX]

I have noticed a similar thing.
When following my mate on his Aprillia and me on Ducati, going the same speed (fairly quick) I lean alot more than him.

I put it down to wheel base and steering geometry,but only guessing.

Now this adds to the puzzule as surely, if he is on a race rep Ap as well, the rake and trail of your two bike are similar....... hmmmm

[Drunken Monkey]

Is one rider hanging off the seat more or less than the other? I have found hanging off the bike moves your weight enough that you can turn in the same radius with the bike more upright. While at the track this is exaggerated, you might find that only a slight shift of the bum is all that's required to make 2 apparently similar dimensioned bikes to turn the same radius with different lean angles.

[Fishy]

Is one rider hanging off the seat more or less than the other? I have found hanging off the bike moves your weight enough that you can turn in the same radius with the bike more upright. While at the track this is exaggerated, you might find that only a slight shift of the bum is all that's required to make 2 apparently similar dimensioned bikes to turn the same radius with different lean angles.

I don't think Beyond was shifting his weight (I don't think so) but I was sitting square in the saddle. We were both two up and riding at a medium pace.

[beyond]

Yeah, had my missus on the back so wasn't doing any moving around at all, just sitting in the middle of the seat normally. I also know sports bikes riders are more tucked in with more weight over the front, but lean angles for them are still more severe when you look only at the bikes actual lean angle and not the rider.

[sAsLEX]

Yeah, had my missus on the back so wasn't doing any moving around at all, just sitting in the middle of the seat normally. I also know sports bikes riders are more tucked in with more weight over the front, but lean angles for them are still more severe when you look only at the bikes actual lean angle and not the rider.

This brings it back to rake trail and wheelbase then as weight though your ride would be a little more we have excluded the use of your body hanging off to shifting the CoG of your bike inward to alter the cornerning characteristics.

GSXRthouh
Overall Length: 2030mm (80.0 in.)
Overall Width: 710mm (28.0 in.)
Overall Height: 1130mm (44.5 in.)
Seat Height: 810mm (31.9 in.)
Ground Clearance: 130mm (5.1 in.)
Wheelbase: 1405mm (55.3 in.)
Dry Weight: 166 kg (365 lbs.)

GSXR1400
Overall length 2100mm (85in)
Overall width 810mm (31.9in)
Overall height 1140mm (44.9in)
Wheelbase 1520mm (59.8in)
Ground clearance 130mm (5.1in)
Seat height 790mm (31.1in)
Dry weight 228kgs (502lbs)

Indication of your weights combined passenger weight on each bike?

Oh and anyone got rake and trail for these bikes?

[Motu]

Now this adds to the puzzule as surely, if he is on a race rep Ap as well, the rake and trail of your two bike are similar....... hmmmm

Have a read of Foales chassis book - he has a nice little diagram there to explain it.Wider tyre profiles require the CG to be higher,or move inward with the contact patch - that is why you slip of the seat and move your body to the inside of a turn,to put the CG over the contact patch.I don't need to with my skinnier tyres,I can stay on the seat and just lean.So I think it will be CG and tyre profiles that are making the difference.

[idb]

I'd expect tyre profile to be the most likely the difference in your example as the bikes are fairly similar and neither rider is climbing off much.

[Fishy]

Indication of your weights combined passenger weight on each bike?

Oh and anyone got rake and trail for these bikes?

Combined weight on the 1000 is about 145kg's.

[sAsLEX]

Have a read of Foales chassis book - he has a nice little diagram there to explain it.Wider tyre profiles require the CG to be higher,or move inward with the contact patch - that is why you slip of the seat and move your body to the inside of a turn,to put the CG over the contact patch.I don't need to with my skinnier tyres,I can stay on the seat and just lean.So I think it will be CG and tyre profiles that are making the difference.

Thats was along the lines of what I was thinking also, but surely rake and trail would come into it as this determines where the contact patch is?

I'd expect tyre profile to be the most likely the difference in your example as the bikes are fairly similar and neither rider is climbing off much.

Would the tire profiles therefor be not too dissimilar?

[Fishy]

Would the tire profiles therefor be not too dissimilar?

I am running standard sized tyres...

120/70/17F
190/50/17R

[beyond]

Combined rider weight for me and my missus 140kgs.
I'm running Metzler Z6's 190 rear.

I think Fishslayer is running Pilot Powers with a 190 rear???

[beyond]

GSX1400 full specs

Technical Specifications
Overall length - 2,160mm (85.0 inches)
Overall width - 810mm (31.9 inches)
Overall height - 1,140mm (44.9 inches)
Wheelbase - 1,520mm (59.8 inches)
Ground clearance - 130mm (5.1 inches)
Seat height - 790mm (31.1 inches)
Dry mass - 228kg (502 lbs)
Engine type - 4-cylinder, 4-stroke, air/oil-cooled with SACS, DOHC
Bore x Stroke - 81.0 x 68.0.mm
Max. power - 106 ps @ 6,800 rpm
Max. torque - 126 Nm @ 5,000 rpm
Piston displacement - 1,402cc
Compression ratio - 9.5 : 1
Carburettor - Fuel injection 34mm
Lubrication - Wet sump
Ignition type - Electronic ignition (Transistorised)
Starter system - Electric
Clutch - Wet multi plate
Transmission - 6-speed, constant mesh
Drive system - Chain
Front suspension - Telescopic, coil spring, inner cartridge, spring preload adjustable, rebound and compression damping force 12-way adjustable
Rear suspension - Swingarm, oil damped, coil spring, spring pre-load hydraulically adjustable, rebound and compression damping force 4-way adjustable
Rake/Trail - 26 degrees / 105mm (4.1 inches)
Front brake - 6-piston calipers, dual disc brake
Rear brake - 2-piston caliper, disc brake
Front tyre - 120/70 ZR17 tubeless
Rear tyre - 190/50 ZR17 tubeless
Fuel tank capacity - 22.0 litres
Colours - Blue/White, Blue, Silver

[The_Dover]

Combined weight on the 1000 is about 145kg's.

*cough* bullshit.

You gotta be 105 on your own, tubby.

[sAsLEX]

I am running standard sized tyres...

120/70/17F
190/50/17R

Combined rider weight for me and my missus 140kgs.
I'm running Metzler Z6's 190 rear.

I think Fishslayer is running Pilot Powers with a 190 rear???

So tire profile is out of the equation.

Weight is still there but only a diff of 55ish kgs so not that excessive.

back to rake and trail and chassis set up, maybe GoG, fishys would be alot higher what with the higher pegs and his mrs perched up there on the pillion seat.