Tail Light Bulb Upgrade

By: BMWDUCMAN@aol.com
January 1996

On bikes that use a 1157 tail/brake combination bulb, a simple and inexpensive upgrade in the brake light illumination is readily available.

A 2357 tail/brake combination bulb, available at any auto parts store, will produce the same brightness for the tail light (3 lumens), but will produce 25% greater brightness for the brake light (40 lumens vs. 32 lumens).

The volts required to power the 2357 bulb are the same as the 1157, but there is a slight increase in the amps required (2.1 for the 1157, 2.2 for the 2357). The resulting increase in watts used is only 1.28 watts, or a 4.76% increase over the standard 1157 bulb.

The only draw back to using the 2357 bulb is the rated hours of service for the brake light element is much less (400 hours for the 2357 brake light element vs. 1,200 hours for the 1157 brake light element). The tail light element in both the 1157 and the 2357 are rated at 5,000 hours. Assuming one rides 4 hours per day, 365 days per year and uses his/her brake 25% of the time, if the brighter 2357 bulb is replaced annually, there should be little chance of in-service failure.

Cost for a 2357 bulb is about 97 cents.

In an effort to provide too much info on brighter tail/brake lights, the 1157(standard), the H1157(halogen) and the 2357(newer version of standard), I have the following info:

Specification                    1157          H1157        2357

Volts(high)                      12.8           12.8        12.8
"    (low)                       14.0           14.0        14.0
Watts(high)                      26.8           49.9        28.1
"    (low)                       14.0        unknown        14.0
Amps (high)                       2.1            3.9         2.2
"    (low)                        1.0        unknown         1.0
Base                             S8             S8          S8
Candlepower(high)                32            107          40
"          (low)                  3             25           3
Lumens(high)                    402          1,350        unknown
"     (low)                      38             38         320
Average life(high)            1,200            400         400
"           (low)             5,000            400       5,000 
The H1157 (halogen) is manufactured by Candlepower, Rockville, Maryland (301) 340-0224.

You can order the H1157 for $10.95 from Nichols Distributing, (800)323-4488.

The biggest concern is the increase in amps and watts(heat) when switching to a halogen bulb. The H1157 brake light element produces 86% greater watts(heat) than the standard 1157 brake light element, the 2357 brake light element only produces 4.8% more watts(heat).

Note: "Heat" is measured in "watts", hence, they are the same.

The other concern with using the H1157 or the 2357 is the shorter service life. The H1157 is rated to last only 400 hours on low(tail) and high(brake) elements. This is drastically down from the standard 1157 and less than the 2357 low(tail) element. Depending on your riding, this problem can be avoided by scheduled replacement.

Hope this info helps for safer riding.


All contents Copyright © 1995 - 2014 Internet BMW Riders & the original author(s)

K-Bike Tech Pages

Maintainer: Tom Coradeschi WWW - email
Last Update: 05 October 2007