Fancy a Langster but means big jump in ratio

[DaveyA]

I've been thinking about a new bike for a while now and like the look of the new Langster. Initially I was going to buy a geared roadbike, but through the winter I have been quite happily riding my singlespeed Olmo that I put together. All new road models seem to come with 11 speeds and I got to thinking that I don't need all those gears. I really enjoyed the simplicity of just pedaling and not using gears at all.
I have been riding on 42x18 with the Olmo and have never struggled on any of the climbs on our regular runs. There is only one in particular that I can think of where I have to really try hard and keep my momentum going to reach the top, if it went on for another 50 yards I think I would keel over but luckily it is short and sharp. The thing is the Langster is 48x17 I believe, and that is really quite a big jump from my present gearing. I think I could manage a slightly higher gear given that it will be a much lighter bike than my Olmo which is a bit weighty but I don't want to have to start fitting a new chainwheel. What would be the largest singlespeed freewheel I could fit to replace the 17? I know a few people here ride the Langster, I just wondered how comfortable it is on our rutted and potholed roads.
Thanks for any advice.

 

[zizou]

A 48x20 will get you a slightly bigger gear than what you have just now

 

[Tim Hall]

A 20 tooth should give a similar, although slightly higher, gear. There's loads around, from six or seven quid upwards. Does the Langster have a 1/8 or 3/32 chain ring?

 

[biggs682]

@User19783 rides one , sure he will or can offer some advice

 

[Ian H]

You change the gear to suit yourself. The shop might even do that for you.

 

[DaveyA]

A 20 tooth should give a similar, although slightly higher, gear. There's loads around, from six or seven quid upwards. Does the Langster have a 1/8 or 3/32 chain ring?

Looks like it's an 1/8th chain.
Had a look at a gear/inches calculator, and it shows 42x18 to be 61.6" and the 48x20 to be 63.5". That's not too far away from my current set up. It will be a much lighter bike as I say so it might be ok. So a 20 tooth freewheel and a new chain would be all I needed.

 

[al-fresco]

Yeah, KMC Z510X is a 1/8th chain. My (2011) Langster has 42x16 (69") gearing which I find ideal for 'rolling' terrain.