Taking your bicycle on trains is now possible on all lines.
現時巿民可以攜帶單車登上所有鐵路路綫.

MTR Lines and Light Rail 港鐵及輕便鐵路

Are bikes permitted?: Yes.  You may be asked to remove the front wheel.
容許單車嗎？正確，只要拆下前輪，乘客可以攜帶單車進入車廂

Cost for carrying bike:  Free
費用：免費

MTRC 24-hour enquiry 港鐵24小時熱線:  2881 8888
MTRC website 港鐵網站
System map 港鐵路綫圖
MTR By_Laws 港鐵附例  (large file 大檔案)  or read the HKCAll comments on the MTR By-Laws 按此閱覽香港單車聯盟對附例的評論

Notes: On 16 December 2011, MTR quietly announced at the regular Transport Department meeting with cycling organisations that bicycles were permitted on all MTR lines with the front wheel removed. MTR consider that once the front wheel is removed, a bicycle becomes ‘luggage’. In our experience, it is perfectly possible to get bicycles onto the MTR. Simply walk quietly and confidently through the station, and show plenty of respect to everyone else (make it obvious).  We are on display here, and need to gain public support.  Don’t wear your helmet.  Often the front or back of the train have more space. Once on the train, do not block the exits. If you are confronted by the staff at any time, be courteous and polite.

注意：在2011年12月16日，港鐵於與單車團體的例行會面中低調宣佈，將在所有路綫中容許攜帶拆掉前輪的單車上車。背後的邏輯是：只要沒有前輪，單車就立即變成一件普通「行李」。在我們的經驗中，攜帶單車上地鐵絕對可行。只要充滿自信，靜靜穿過車站，尊重其他乘客就可以了(請明顯地表現尊重的態度)。單車人士正好親身示範良好態度，並盡量爭取公眾認同及支持。請勿戴頭盔。一般在頭卡及尾卡車廂會較寬敞。進入車廂後切勿阻礙門口位置。任何時間遇上港鐵職員，謹記保持謙恭有禮。

Through train to China 坐火車返大陸

Are bikes permitted?: Bicycles can be carried as consigned luggage
容許單車嗎？將單車視為行李即可 

Cost for carrying bike:  Depends on weight
費用：視重量而定 

MTRC 24-hour enquiry 港鐵24小時熱線:  2881 8888
MTRC intercity trains website 港鐵城際直通車網頁
MTRC intercity trains conditions of travel (Beijing/Shanghai lines) 港鐵城際直通車運送規則 (北京/上海線)
MTRC intercity trains conditions of travel (Guangdong line) 港鐵城際直通車運送規則 (廣東綫)

Notes:  Bicycles should be carefully and securely packed according to the conditions of travel or they might be refused.
注意：根據運送規則，乘客需事先將單車小心牢固包裹好，否則有可能被拒上車