H4ST SilverStar

[ReconRat]

Amazon.com has the H4ST Sylvania headlight bulb for sale on line for 16.18 each, with free shipping and a 5 or 10 buck rebate if you buy two. Print the rebate form.

The H4ST is the heavy duty anti-vibration motorcycle bulb, if your bike uses the H4. About 35% - 50% more light than the stock bulb. I bought two.

http://www.amazon.com/Sylvania-H4ST-BP-SilverStar-Performance/dp/B000AM8BN6/ref=sr_1_1?ie=UTF8&s=automotive&qid=1225554460&sr=8-1

[jagr]

Is the H4s a high and low beam combo bulb?

[ReconRat]

Yes, the H4 is one of the hi/lo bulbs. You have to check, like in the owner's manual or shop manual. There are lots of different headlight bulbs.

[jagr]

Thats what i need. Thanks bro.

[ReconRat]

Check mine when it gets here, a couple of days.

[jagr]

i just wanted to make sure all H4s are high/low.

[jagr]

I love wikipedia. yes H4 =high/low. sorry im slow.

The traditional European method of achieving low and high beam from a single bulb involves two filaments along the axis of the reflector. The high beam filament is on the focal point, while the low beam filament is approximately 1 cm forward of the focal point and 3 mm above the axis. Below the low beam filament is a cup-shaped shield (called a "Graves Shield") spanning an arc of 165°. When the low beam filament is illuminated, this shield casts a shadow on the corresponding lower area of the reflector, blocking downward light rays that would otherwise strike the reflector and be cast above the horizon. The bulb is rotated (or "clocked") within the headlamp to position the Graves Shield so as to allow light to strike a 15° wedge of the lower half of the reflector. This is used to create the upsweep or upstep characteristic of ECE low beam light distributions. The bulb's rotative position within the reflector depends on the type of beam pattern to be produced and the traffic directionality of the market for which the headlamp is intended.

This system was first used with the Bilux/Duplo R2 bulb of 1954, and later with the halogen H4 bulb of 1971. In 1992, U.S. regulations were amended to permit the use of H4-style bulbs. Named HB2 or 9003, for the U.S. market, and with slightly different production tolerances stipulated, these bulbs are physically and electrically interchangeable with H4 bulbs. Similar optical techniques are used, but with different reflector and/or lens optics to create a US beam pattern rather than a European one.

Each system has its advantages and disadvantages. The American system historically permitted a greater overall amount of light within the low beam, since the entire reflector and lens area is used, but at the same time, the American system has traditionally offered much less control over upward light that causes glare, and for that reason has been largely rejected outside the US. In addition, the American system makes it difficult to create markedly different low and high beam light distributions. The high beam is usually a rough copy of the low beam, shifted slightly upward and leftward. The European system traditionally produced low beams containing less overall light, because only 60% of the reflector's surface area is used to create the low beam. However, low beam focus and glare control are easier to achieve. In addition, the lower 40% of the reflector and lens are reserved for high beam formation, which facilitates the optimization of both low and high beams.

[g35tonv]

wikipedia is awesome indeed.