Stock bulb on the left, LED on the right. Second photo shows bulb size comparison.
I DON"T consider these inexpensive LED bulbs to be an upgrade, rather just an alternative to the stock bulb. I would only consider the tower style bulb that throws light out from the top and sides. The ones with a single set of top mounted LEDs are not suitable as they do not throw out enough light onto the reflector.
Note Urbaengineer is correct. The incandescent bulb does a better job of filling the entire signal light evenly with light. Whereas the LED tends to have a bright spot in the center. IMO the LED is little more visible in the daylight (I don't ride at night). THE LED is rated at 500 lumens and 50,000 hours.
If you want an upgrade go with the more expensive bulbs noted in this thread (not the ones I purchased), they will provide increased visibility but do come at a price.
Last edited by Jack of Heats JoH; 08-15-2017 at 10:33 AM.