gholt

I have an older bike Giant OCR, that has Ultegra crank FC-6500 and the BB-6500. So, I thought it would probably be a good idea to replace the bottom bracket, but when I look to replace it, it appears that the BB-6500 are almost non existent.

Does anyone know of a way to see what bottom brackets would fit the cranks and the bike I have?

length 109.5 (9-speed),
Type V1 splined,
Chainline 43.5
BCD 130
Tread 147

If anyone knows of a good source to get these that aren't outrageous cost, it would be appreciated. (I saw one on fleabay, so hopefully, that one works out. Says new never installed. but would prefer a new from a store.)

desertdork

BB-5500 & BB-7700 are still around

HillRider

I know for sure the 105-level BB-5500 is still available in 109.5 mm (double) and 118.5 mm (triple) spindle lengths. I have the triple version in one bike and it's been very good.

Lickton's in Chicago has them in both lengths. Here is the link to the 109.5 mm version: https://www.lickbike.com/productpage....B='0229-13'

They don't list the BB-7700 Dura Ace version and, while it was light and smooth, it wasn't a sealed cartridge and required routine maintenance.

gholt

thanks. You guys are awesome. Do I need to pull my BB off to ensure the replacement is the correct size, or can I assume the size from the FC-6500 / 6503 crank arms for double from Shimano?

They list the BB as either 73, 70, or 68 as the the thread dimensions on Shimano's doc page.

HillRider

Octalink road bottom brackets (V1 that fit 105, Ultegra and Dura Ace cranks) only came in 109.5 and 118.5 spindle lengths and in English threading requiring a 68 mm bottom bracket shell width and Italian threading that requires a 70 mm bottom bracket width. Your Giant is English threaded with nearly 100% certainly.

A 73 mm bottom bracket shell is an MTB width. It uses English threads but a wider shell and is not used on road bikes.