I`m planning to travel this coming Saturday 30th from Brighton to Crewe where Im collecting my daughters push bike, staying overnight, and returning on Sunday 1st May bike in tow. I had hoped to use the Southern and WMT off peak ticket costing £38.85 with my disabled persons card. Unfortunately I fear the engineering works between Milton Keynes and London may scupper this plan on the return leg as Im unlikely to be able to take the non-folding bike on the replacement bus service. Another possibility is to get the stagecoach bus X5 with my freee bus pass between MK and Bedford as it certainly used to have a large coach style luggage area in which in the past Ive seen people load bikes, and then travel back to Brighton from Bedford on the Thameslink service which is arguably a Southern service too. Failing this, would I be covered by getting an any permitted route ticket costing £74.15 and maybe travelling via Birmingham Leicester then Bedford, or even via Reading/ Gatwick, or via High Wycombe (which would be a bit of a pain in London)? Anyone else got any bright ideas on cheaper options?
Both Avanti (who are running replacement buses between Rugby and Kettering, and Milton Keynes and Bedford) and WMT (who are running replacement buses between MK and Stanmore) state that they
do not allow non-folding bicycles on rail replacement services. Only Chiltern and Hull Trains state that non-folded bicycles are accepted on their rail replacement buses; CrossCountry and Grand Central also allow them if they are in a bike box.
Unfortunately, last year Stagecoach replaced the coaches on the X5 route with double decker buses, as well as curtailing it to solely run between Oxford and Bedford the year prior. So I suspect that non-folding bicycles may no longer be carried on that route - but you would have to ask them to be sure.
Whilst there is ticket acceptance for WMT passengers on the Underground between Stanmore and Euston Square, and an easement allowing Avanti Advance ticket holders to travel via Kettering/Bedford, neither of these are of any assistance to you as you will still face the challenge of getting your bike onto the replacement bus.
In a further unfortunate twist of events, there is generally no Sunday service on the Marston Vale line, so you cannot even cycle down to Bletchley and then take the train over to Bedford, as you would be able to do on the Saturday or Monday. That said, even if this were an option I suspect you would face difficulties using a route "Southern & WMT" ticket on Thameslink branded services (even though legally speaking, the restriction limits you to GTR services rather than one specific brand).
So the only feasible option I see for the return journey with your bike is travelling on XC & Chiltern via Banbury. Obviously this would either require an Any Permitted walkup ticket or some other combination of tickets. Which option is cheapest will depend on your exact travel times and what routes etc. you are willing to limit yourself to. It's also worth noting that websites such as TrainSplit won't be able to suggest the option which may be cheapest overall, which could involve buying a return for a cheaper route and obtaining a change of route excess in one direction.