Great Western Coffee Shop

As the "name" might suggest I am a rail user who cycles, with a Brompton.
I dislike there and back journeys, get off at one station and then cycle get on another train at another station.
I am Reading-based. For example yesterday got a return to Portsmouth Harbour. Cross-Coutry to Southampton. SWT to Hamble, then cycle to Gosport, ferry to Portsmouth Harbour Station, SWT to Winchester & XTC back to Reading.

Now the question is, I want to cycle from Bedwyn to Swindon using the old railway line from Marlborough to Swindon. Is the only option a return to Westbury (with Senior railcard), allowing for the fact I like to have an escape route (possibly back to Bedwyn)?
All advice welcome, ask because the price jump between Bedwyn and Westbury is noticable.

There is a magic line between Bedwyn and Pewsey, and another between Didcot and Swindon, that mark the end of the old Network South East area and a switch from London commuter fare pricing to Intercity pricing. So anything beyond the line is going to cost you £££.

Advise ... buy a very-off-peak return from Reading to Bedwyn - assuming you're going at times that are very off peak.  That will cost you £10.30 before railcard discount, as opposed to £10.20 for a single, so you're paying 10p for the insurance of a return ride if you stop at the Three Tuns and make it no further.  Then a s-o-p single Swindon to Reading, at £14.30 - can't see a split or anything else to make it cheaper than that. 

P.S. If you're doing multiple days, note that the Thames Rover does not cover Swindon, even though it's in the watershed of the River Thames and indeed has been known as "Thamesdown".  If the ticket were geographically logical, it would include Swindon and Kemble ... and I suppose it would cover all of London and take you to Southend and Whitstable too!

Try a Kennet Day Ranger http://www.railrover.org/pages/kennet-day-ranger.html

Excellent ticket if you were cycling from Bedwyn to Basingstoke.  Alas, Swindon is out of area  :-\

Newbury to Westbury Off Peak Day Return (CDR) £11.15. Plus an Off Peak Day Single (CDS) from Newbury to Reading £4.15. Prices with Senior Railcard.

Do the cycle in the other direction.

That first fare is valid via both Didcot and Bedwyn. Start at Reading. Train to Swindon and end outward journey there. Cycle to Bedwyn. Start return journey there with return portion of Newbury to Westbury CDR plus the Newbury to Reading CDS.

Ticket conditions for Off Peak Day fares allow you to start and end your journey at intermediate stations on permitted routes. Time restrictions must be adhered to. First valid weekday train from Reading to Swindon would be the 1011. No evening restrictions on return portion from Bedwyn or the single from Newbury. You can stay on the train from Bedwyn to Reading. Must call at Newbury though.

BNM, with respect, but is the Newbury/Westbury ticket really calid via Didcot?

I just checked the GWR site  ;D and was offered Newbury to Westbury with changes at Reading and Bath Spa. So the arithmetic is:

London to Reading - £18.60 single, £18.70 return (super off peak)
Newbury to Westbury - £11.50 single, £16.90 return (super off peak)

That's £30.10 single Paddington to Bath, and £35.60 day return, though you are restricted to certain services at these prices.  Compares to £33.10 super off peak single, Paddington to Bath Spa, and £57.50 for the cheapest conventional return - though that latter is less resrictive as it's a period return, so you're not comparing like for like.

Yes in view of there not being many direct services between Westbury and Newbury there appears to be an easement where you can travel via Bath and Reading.

Yes.

(https://drive.google.com/uc?id=0B8VBuNEcQ7EgeXJGSWUyc3Nsa1k)

Reason being is the paucity of direct services between Newbury/Westbury and points west thereof. It does create a fares loophole that can be exploited for other journeys, which is a bonus.

You can actually do Newbury to Reading then double back through Newbury to Westbury too. Thanks to a Routeing Guide easement. That makes it possible for the OP to do his original intended journey on just the Newbury-Westbury Off Peak Day Return. However it's rarely possibly to get itinerary with doublebacks shown. Using both a doubkeback easement and starting at an intermediate station can (no, likely will) put you into disagreement with rail staff. Best only done if you can confidently argue the validity.

I once used a doubkeback easement and started at an intermediate station and the end result was an unwanted meeting with BTP. I was fully exonerated and compensated by the TOC, but it wasn't a pleasant experience and its not a position I'd want to put another person in by advising they attempt it. Hence suggesting going via Didcot on the outward, with a valid itinerary and buying a Newbury to Reading Single on the return. Still a substantial saving over the fares the rail industry would like you to buy.

Thanks, and I'm sure the OP likely feels more confident with that explanation too

Thanks for the advice and collective knowledge. I will just have to get on my bike and use it.

Enjoy the ride from Marlborough to Swindon. Reward yourself with a coffee and some cake at the Three Trees farm shop at the end of the track in Chiseldon if time permits  :)

Many thanks to those who shared their knowledge.

Did the trip yesterday, Bedwyn to Swindon via Marlborough because of a southerly wind and I will take any assistance I can get. No great problems, but no cake at Chiseldon because that was about where the heavens opened. Old rail track generally in good condition (no problem for the Brompton), the odd wet patch and mind the elbows where the nettles are trying to meet.