I'm looking to fit a pair of puncture resistant tyres to the missus' Giant Halfway Folding bike. The current totally useless Kenda tyres are 20" x 1.50 (40 / 406). I thought the Schwalbe Marathon Plus – Smart Guard tyres would solve the problem but they don't do them in 20" x 1.50… 20" x 1.75 (47 / 406) is the closest… Do you reckon they would fit? There is not too much tyre clearance around the mudguards. If not, any alternative suggestions considered.

there tends to be a bit of leeway with the guards, and Marathon Pluses are the best for the job.

Marathon Plus. Accept no substitute.

I use non plus marathons (marathon kevlar) in 16" on my Brompton – get about 2 punctures a year and my Brompton gets lots of use – everyday inc visits to construction sites. They wear well and are grippy for road and canal path