Best 150-350cc fuel injected engine for small, light, aerodynamic reverse trike

[iveyjh]

This might bear a good look.

HONDA VTR250 2003 Pearl Shining Yellow.jpg
Manufacturer Honda
Also called Interceptor 250, MC33
Production 1988-1990, 1997-
Predecessor Honda VT250 Spada
Class Naked bike
Engine 4-Stroke, 4 valves per cylinder, 249 cc 90° V-twin DOHC
Bore / stroke 60 mm × 44 mm (2.36 in × 1.73 in)
Compression ratio 11:1
Power 23.9 kW (32.1 hp) @ 10,500 rpm
Torque 23.5 N·m (17.3 ft·lb) @ 8,500 rpm
Transmission 5-speed, wet multi-plate clutch, chain drive
Suspension 41mm showa telescopic fork (front), direct-link monoshock with preload adjustment (rear)
Brakes Single 296mm disc, 2 piston caliper (front), single 220mm disk, 1 piston caliper (rear)
Rake, trail 25°30', 96 mm (3.8 in)
Wheelbase 1,405 mm (55.3 in)
Dimensions L 2,040 mm (80 in)
W 720 mm (28 in)
H 1,050 mm (41 in)
Seat height 760 mm (30 in)
Weight 141 kg (311 lb) (dry)
Fuel capacity 13 L (2.9 imp gal; 3.4 US gal)
Oil capacity 2.4 L (0.53 imp gal; 0.63 US gal)
Turning radius 2.7 m (8 ft 10 in)

[renault_megane_dci]

In my book, torque peak RPM is very important in everyday driving comfort that's why I would go for a single.

Did you ever consider a DR 350 ?
It's 6 speed, oil cooled and I guess you could tune the inlet to boost torque.
Obviously you need the electric starter variant.

Or maybe even better a DRZ 250 which is DOHC and would allow for a fancy cam timing if fuel injected (see "atkinsoning motorbike engine" thread)

[jkv357]

Originally Posted by iveyjh

This might bear a good look.

HONDA VTR250 2003 Pearl Shining Yellow.jpg
Manufacturer Honda
Also called Interceptor 250, MC33
Production 1988-1990, 1997-
Predecessor Honda VT250 Spada
Class Naked bike
Engine 4-Stroke, 4 valves per cylinder, 249 cc 90° V-twin DOHC
Bore / stroke 60 mm × 44 mm (2.36 in × 1.73 in)
Compression ratio 11:1
Power 23.9 kW (32.1 hp) @ 10,500 rpm
Torque 23.5 N·m (17.3 ft·lb) @ 8,500 rpm
Transmission 5-speed, wet multi-plate clutch, chain drive
Suspension 41mm showa telescopic fork (front), direct-link monoshock with preload adjustment (rear)
Brakes Single 296mm disc, 2 piston caliper (front), single 220mm disk, 1 piston caliper (rear)
Rake, trail 25°30', 96 mm (3.8 in)
Wheelbase 1,405 mm (55.3 in)
Dimensions L 2,040 mm (80 in)
W 720 mm (28 in)
H 1,050 mm (41 in)
Seat height 760 mm (30 in)
Weight 141 kg (311 lb) (dry)
Fuel capacity 13 L (2.9 imp gal; 3.4 US gal)
Oil capacity 2.4 L (0.53 imp gal; 0.63 US gal)
Turning radius 2.7 m (8 ft 10 in)

The U.S. only got those in '88 to '90 as the full-fairing VTR250. Europe and Canada got the newer VTR250 naked, later with F.I.

Neat bike, but a V-twin 250 and tuned more toward top-end than a CBR. Not very common either. In the U.S. they briefly competed with the Ninja 250, and in many ways were a better street bike. Just a touch slower overall, but less top-end biased that the Ninja. Never caught on and was dropped quickly. Came back elsewhere as a naked "mini Monster" and eventually got F.I.

I liked them back in the late 80s (except for the paint) and would seriously consider a newer model if they were available here.

U.S. version -



Slightly modified newer European version -

[P-hack]

dual shocks are fine on a trike, especially since you are getting a side load. Make sure the rear wheel can handle it.

[mechman600]

Originally Posted by renault_megane_dci

Did you ever consider a DR 350 ?
It's 6 speed, oil cooled and I guess you could tune the inlet to boost torque.
Obviously you need the electric starter variant.
Or maybe even better a DRZ 250 which is DOHC and would allow for a fancy cam timing if fuel injected (see "atkinsoning motorbike engine" thread)

DRZ400 would be better. Liquid cooled and much higher compression. DOHC for fiddling with the timing if that's your desire. Throttle position sensor on the carb for a slightly more sophisticated timing map. I owned the dual sport version. Spectacular mileage and lots of power.

[Extremetrikes]

I know what I've created will never set record breaking fuel economy but the horse power and looks you get while driving it make up for the lack of mpg ;-). It's an injected 2005 Honda Silverwing powered reverse trike. I used the front brakes , suspension , shortened steering column and modified pedal assembly from a 1993 Mazda Miata.

[Extremetrikes]

I have been considering the drag or friction difference between the 215/40/18 front tires and something smaller like 175/50/15's. but not sure how to calculate the difference

[American Viking]

Originally Posted by Frank Lee

Chain drives need replacement every 3rd or 4th oil change? Who knew!
The bodywork must be removed to change this chain and sprockets? Who knew!
Passenger weight? What passenger?

The OP stated he wanted to build a reverse trike that could carry two people at speeds up to 60mph.

I was just pointing out that the chain and sprockets will wear a lot faster with the added load (compared to just the bike). Also adding the body work will make it more complex compared to just servicing the chain on normal bike.
Therefore they will need a heck of lot more maintenance than shaft drive and why I would look for a shaft drive bike to base it on.

[American Viking]

The later efi equipped vtr250 is a great choice. I just don't know where you could find one here in North America.

Another bike that would fit very well would be the VFR400. 400cc v4, but its not a US market bike, so finding one would be tough and the few that were imported have a cult following, so your not going to find a running one cheap.
There are several great bikes that would fit into trike really well.
Honda CB-1, Honda hawk gt, Yamaha fzr400, ..
But they all have a cult level following, so finding a healthy example to hack into a trike is not going to be easy.

[Frank Lee]

Originally Posted by American Viking

The OP stated he wanted to build a reverse trike that could carry two people at speeds up to 60mph.

I was just pointing out that the chain and sprockets will wear a lot faster with the added load (compared to just the bike). Also adding the body work will make it more complex compared to just servicing the chain on normal bike.
Therefore they will need a heck of lot more maintenance than shaft drive and why I would look for a shaft drive bike to base it on.

Is that so...

Originally Posted by OP

My project is a small reverse trike for 1 person for highway travel, probably using a 125 to 250 cc engine and weighing between 300 and 500 lbs, cruising typically at 55mph, and getting over 125mpg I expect.

One person only.
Trike estimated to add 75 lbs.- a good deal less than a passenger.
Divide the weight between three instead of two wheels AND put proprtionally more on the front and voila! less weight on the back wheel.
We don't know if the body covers the chain, or if it wouldn't have a simple access panel.
I've got chain drive bikes and none of them have needed replacement chains/sprockets anywhere near that often.
OP wants efficiency and chain drive is far more efficient.
Belt drive is probably better yet.
There is absolutely nothing wrong with drum brakes either.