How wide can I go on a 700 rim?

[BJMcC]

I am looking at doing The Great Victorian Rail Trail and want to use larger tyres with more grip, as the trail is mainly gravel. I have a flat bar road bike and am using 700x28c.The frame has plenty of room for a larger tyre (over 1cm each side between the current 28c tyres and forks/frame). So the only issue is how wide could I go on the rims (Shimano RS31)? As long as the tyre is a 700, could I go as wide as they come?

[ldrcycles]

It all comes down to the internal rim width, which i can't find on a quick google. Shimano recommend 23-32mm tyres, if the internal width is 17mm or more then 35mm tyres would be fine.

[open roader]

I have a friend who rides rail trails - gravel roads and across cow paddocks etc on an old road bike with regular width rims (19mm methinks) fitted with some Maxxis foldable 35mm wide tyres (don't know which model). They look like ballons on a skinny rim but after several years of use he has never had an issue (and he sometimes runs the tyres way too flat in my opinion, tisk,tisk...)

I'd say so long as you're not expecting to take corners like a downhill expert and you keep a respectable pressure up to them you can go plenty wide.

[BJMcC]

Thanks for the replies. I'll give 35mm a go.

[BJMcC]

35s worked fine. Thanks for the advice.