I need a 7 speed freewheel and chain. MTB shops only carry the later 9 or 10 speed cassette types. Cheap bike shops only seem to have the 5 speed frees. I also need a 27.2 X. 400 mm seat post. Thanks for your help

7-speed freewheels should be available generally, but you'll have to look around for bigger cog range than 14-28. 14-34 'megarange' available, but you may have to reset some adjuster screws on your rear derailleur. The chains for 6/7/8 clusters are all compatible.

There was a bike shop with 'LA bicycle' signage on Sukhumvit, almost as far as Ekamai, when I was last over that way. Otherwise, I have been told that in BKK Chinatown there is a street full of bicycle shops by day, butterflies after dark. AA

As for the seat post, if you can't get the right diameter, you can make a shim from PVC pipe if the post is too narrow, or get to work with an angle grinder if the post is too wide. My two bikes thus...AA

Thanks AA

I'll check out your suggestions next time I'm down that way. If I could get to talk to the mechanics in these bike shops I'm sure they would be more helpful, sometimes the sales people aren't very knowledgable. Will let you know how I get on

MS