FYI _ Investigando en internet...
Near Ueno Train Station (on the Japan Rail JR), four stops North of Tokyo Central Station, there is an area in the Korin-Cho District that has numerous motorcycle shops (for motorcycles and gear). This area is well known throughout the tourist world and along with going to the Akihabara District (2 stops North of Tokyo Central Station), which is the world's largest area of ANYTHING and EVERYTHING electronics...these two areas are a must for a visit to Tokyo...
For the Motorcycle Neighborhood, exit the Iriya Exit (Iriyaguchi - "guchi" means exit in Japanese) of Ueno Station and it is about a two minute walk North.
For Akihabara, there are signs in English saying, "Electronics Area Shops" or something to that effect...so no worries there...and most people speak enough English to guide you...if you really get into a jam...just stop into any Police Box, located in ALL JR Stations as well as all over the country...they can help guide you to where you want to go...
Ok, now one of the largest Motorcycle Shops for Gear is called "NAPS" and there are like 4-5 locations in Tokyo along with a lot more all over the country...they carry EVERYTHING...i
Video de Youtube sobre la zona de las tiendas de motos
http://www.youtube.com/watch?v=huBnoWOZDrs
Un artículo sobre la zona
http://www.motoaus.com/features/motorcycle/japan-s-ueno-motorcycle-district.html