Wider tyres

[BlueMeldon82]

I have a Viking fx100 fixie (circa/about 2012) which has 700x23 tyres as originally Specced, but I was wondering if I could go wider on the original rims which are deep profile Rhyno ?
Thanks

 

[Ajax Bay]

The dimension that matters is the internal rim width (may say on rim eg 622x13). Highly likely 25s would be fine. Rule of thumb is: max tyre width is double internal rim width. AASSIA (see diagram)
Limitation tends to be available tyre/fork/chainstay clearance.

 

[BlueMeldon82]

Thanks, thats something I'll check.
I definately have clearance and I was hoping to replace the 23's with 25's for a bit more comfort.
If I need to measure anything, I may keep an old 25 handy.