Shimano UN51 Bottom Bracket

The Shimano UN51 and is a mid to low tier bottom bracket which sits behind UN91 and UN71 in the pecking order.

This tidy bottom bracket has sealed cartridge bearings, offers easy installation and low maintenance. It is a little heavier that it’s big brothers, but it represents exceptional value for money.

It requires a Shimano TL-UN74 or Park BBT-22 tool for installation/removal.

Axle: 107-110-113-115-118-122.5-127.5mm
Shell: 68mm, 73mm
Thread: English
Colour: Silver
Weight:
RRP: £15.95
Made: Japan

 

HISTORY

The UN51 ppeared from 1993 to 1995 and formed part of the following Mountain and Road groupsets…

1993
M650 – Deore DX
M560 – Deore LX
M520 – Exage ES
C400 – 400CX
1055 – 105SC
A550 – RX100

1994
M560 – Deore LX
MC31 – STX-SE
C400 – 400CX
1055 – 105SC
A551 – RX100

1995
M565 – Deore LX
MC33 – STX-RC
MC32 – STX
C400 – 400CX
1056 – 105SC
A551 – RX100