Been meaning to look into making the case for it, as part of the Great Western franchise consultation, which I think I've probably missed now. Are there franchise-specific BUGs to pester TOCs into doing things? There should be. Anyway, the BMA's 1992 book said (p104):
This may be partly owing to the fact that there are few stations with appropriate parking facilities such as cycle-lockers, charges are often made for the carriage of cycles, prior reservation has to be made for Inter-City travel with a bicycle, and new rolling stock has less room for carrying cycles than the old stock. Clearly, these deficiencies should be rectified for the benefit of cyclists and of British Rail which is estimated to have lost ??10 million per-annum (1985 prices) of potential business due to lack of services for cyclists.
Citing Harris Research Centre, Cycles (and other bulky luggage) on trains, 1984, which also came up here:
Mr Anthony Steen (South Hams)
Is my hon. Friend aware that the two most favoured recommendations in the report by the Harris people are that charges for bicycles on British Rail should stop and that the ban on the inter-city rail network should cease? Is he aware that ??7 million of additional income is being lost by the unhelpful attitude of British Rail? Will my hon. Friend say something about that, to ensure that British Rail gets more money from bicycle users?