My first bike, Underbones and Backbones?

[oracle_dfx]

Hi,

I'm planning on purchasing a new motorcycle with a displacement below 125 cc. My choices are:

Choice 1 - Kawasaki Fury (Kawasaki Athlete in India)

http://www.kawasaki-motor.co.id/product-athlete.htm

The specs for the Kawasaki Fury:

Dimension
Dry weight 96 kg
Ground clearance 145 mm
Overall height 970 mm
Overall length 1,920 mm
Overall width 645 mm
Seat height 765 mm
Wheelbase 1,245 mm

Engine
Type 4-stroke, Air Cooled, Single Cylinder, SOHC
Displacement 125 cm3
Bore and Stroke 56.0 mm X 50.6 mm
Max. Power 6.6kW / 8,000 rpm
Max. torque 8.9 N.m / 6,000 rpm
Starting Kick and Electric
Transmission 4-speed, Rotary

Frame
Type Steel, Backbone
Suspension : front Telescopic fork
Rear Single shock
Tire : front, rear 70/90- 17, 80/90- 17
Brakes : front, rear Single Disc, Drum
Fuel tank capacity 5.2 liter
Caster (Rake angle) 26.5°
Steering angle L/R 42° / 42°
Wheel travel FR/RR 100 mm / 100 mm

Compression Ratio: 9.8:1
Ignition System: DC-CDI
Starting system: Electric / Kick
Carburator: Keihin PB18 18mm
Spark Plugs: NGK C6HSA
Lubrication System: Forced Wet-Sump
Engine Oil: 10W-40 Multigrade
Type: API SE, SF, SG, SH, SJ, SL, JASO MA
Capacity: 1.1 Liters (1.2 Quarts)

Transmission Type: 4-Speed, Rotary Shift (Down)
Clutch Type: Centrifugal
Driving System: Chain Drive
Primary Reduction Ratio: 3.409 (75/22)
Final Reduction Ratio: 2.571 (36/14)
Overall Drive RAtio: 9.529
Gear Ratios:
1st Gear: 3.000 (36.12)
2nd Gear: 1.938 (31/16)
3rd Gear: 1.350 (27/20)
4th Gear: 1.087 (25/23)

Rim Sizes:
Front: 17 x 1.40
Rear: 17 x 1.60

Electricals:
Battery: 12V 3 Amps
Headlight: 12V 35Watts
Tail Light: 12V 5Watss
Brake Light: 12V 21Watts
Park Light: 12V 5Watts

Choice 2 - Yamaha Crypton Z
Specs can be found here :
http://www.yamaha-motor.com.ph/product/ ... -info.html

Choice 3 - Honda Wave 125
Specs can be found here :
http://www.hondaph.com/products/motorcy ... s/wave125s

The first option features Uni Trak (Mono shock) suspension and a backbone frame; the other two features an underbone fram and a two shock suspension.

I also wanted to know the difference between a backbone and an underbone frame, the advantages and disadvantages.

My second and third choices are very popular here in the Philippines due to the tons of visual modifications. I am more into performance rather than aesthetics, considering all these bikes fall under $1300.

Here in the Philippines, people would use these underbone motorcycles for drag racing. I also wanted to know if there are any advantages using backbone frames over underbone frames, when it comes to handling and cornering. I'm more of a closed circuit guy than an illegal strip punk.

Oh and yeah, I have complete gear, from head to toe. Better safe than sorry.

[RhadamYgg]

Its just so unfair.

I can't help you man, they are all bikes I'll never see in person, most likely.

RhadamYgg

[oracle_dfx]

Thanks, I figured someone would say that, well I've read articles regarding the suspension and found the answers that i was looking for.

But about the chassis, I'm still confused about it. I still dont know whether which chassis will perform better during circuit races.

In general, I just want to find out if a backbone frame is different from an underbone frame.

[Johnj]

Ahh I looked up underbone frames. For closed course work your going to want a frame as rigid as possible. The backbone style frame use the engine to complete a box or triangle between the front forks and the rear swingarm instead of those points just hanging off a bent tube.