PRESSURE is mounting on transport chiefs to rethink "shocking" cuts in bike spaces on key tourist and commuter rail routes, as campaigners warn cyclists will be driven away.

Rolling stock refurbishments and upgrades on the Glasgow-Falkirk-Edinburgh and West Highland lines will see bike capacity stripped away to boost the number of seats available to passengers to cut overcrowding.

On the Glasgow-Falkirk-Edinburgh line, the existing three-car Class 170 trains - which can accommodate up to four bikes - will be replaced by new electric Class 385 trains, each made up of four carriages but with only one cycle space with room for two bikes.

The new bike zone will be located alongside a row of folding chairs so that the space can double up as a seating area for passengers when it is not being used by bikes. However, cyclists fear this could result in a stand-off between bikes users and seated passengers if the latter are already in the space.

The Class 385s, due to be rolled out from late 2017, will also include a "flexible" bike space. As a result, Transport Scotland insist cycle capacity on the the service "will not reduce". However, campaigners complain that this is nothing more than a "leftover bit of space outside the accessible toilet".

Separately, an overhaul of services on the West Highland Line from Glasgow to Oban and Forth William will see the current Class 156s - which have six pre-bookable bike spaces - replaced by refurbished Class 158 trains with only two reservable bike spaces.

The changes are in line with the terms of the new ScotRail franchise set by Transport Scotland, stipulating a minimum of two bike spaces per train. Transport Scotland said this criteria had emerged from a "wide-ranging consultation process".

The situation has been criticised by lobbyists, Spokes Lothian, whose campaign is attracting widespread support.

John Lauder, the national director of charity Sustrans Scotland, tweeted that it would cause a "real problem" for people trying to access the Caledonia Way in Argyll. Broadcaster Lesley Riddoch added: "Only 2 bikes on Oban line in future - instead of 6? No way."

Ewan Jeffrey, spokesman for bike and rail at Spokes, said: "It means a family group can’t go [on the West Highland Line]. Or groups of friends. And for bed and breakfasts, bunkhouses, and little shops that get a lot of their income from cycle touring - the people won’t be able to get there. I find it shocking that Transport Scotland has been happy to let that happen.”

Colin Howden, director of Transform Scotland, said the cuts were "foolish". He added: “Limited bike carriage is already a key constraint to expanding bike tourism."

A spokeswoman for Transport Scotland said “Passenger numbers on our railways are growing fast and it’s important we can accommodate this growth for everyone’s benefit while meeting our obligations to make our railways more accessible to disabled people.

“Many of the new Class 158 trains due to be introduced on the West Highland Main Line will come with extra carriages to increase the number of bookable cycle spaces. This, together with the recent doubling of the number of services operating on the line, means that any negative impact upon cycle passengers brought about by a reduction in spaces per train will be mitigated. We will be working together with ScotRail to ensure that this stock is then managed to allow maximum provision for bicycles on the line.

“The fully refurbished class 158 trains that are to be introduced on the West Highland line will have two toilets - one accessible - two wheelchair spaces, companion seats, luggage racks, air conditioning plus new seating, lighting and carpets, all of which offers passengers a better on train environment.

"ScotRail will continue to carry cycles free of charge and, since the introduction of a more frequent service on the route and more carriages on certain journeys, passengers will still have the opportunity to take their bikes on one of the most scenic rail routes in the world.

“On train cycle capacity on the Edinburgh-Glasgow via Falkirk route will not reduce when ScotRail introduces new electric trains onto the route and it is looking at options which have worked successfully elsewhere on the network, such as in Ayrshire and North Berwick routes.”