Ok so I'm not exactly a financial wizard but with the Ruble being very weak right now this would mean it is a very good time to exchange money and to buy train tickets etc yes?

I think ruble will be weak long time yet.
You can not hurry specifically
In Russia will be cheap for a while.

Maybe it will be cheaper, but maybe not. Buying today will at least be a lot cheaper than a few weeks ago. For instance today, for 1 euro you will get 66 roebel, while just 4 weeks ago you got 50 roebel for 1 euro. Prices of foreign products will be raised, but local services will still be almost the same, meaning you can buy a lot more for your euro (or pound) than a month ago.
With sanctions and low oil prices, it is highly likely the Ruble will continue to slide.
Thanks for all the input everyone. It sounds like a bit of a selfish question but was just curious to know. It's kind of the same thing that happened with the pound and euro at one point as you may know. Hopefully for the Russian people it will soon get better!

Not selfish at all. Going to Russia now and spending your money, taking advantage of lower prices (in hard currency terms) all helps their economy.
If you travel independently, that is pay for hotels/hostels when you're there, then you'll be paying rubles. Russia is cheap now who knows for sure how much longer it will last?
Just go... ;-)