Question: Should I change my opening as a 1800?

Hi guys currently I am rated 1803 for rapid and to get there since about 1000 I have played the London System and the French Defense and know the ins-and-outs of both openings, however I have had aspirations to learn other openings such as the Nimzo-Indian to respond to Nf6 and The Sicilian. I have heard that switching openings hurts rating and I don't want to negatively impact my playing however I know that there are higher level players (titled level) that have many openings in their repertoire and want to know what I should do: stick to my current openings forever, or to learn others. I do not mind the studying and definitely have the time I currently spend 5 hours a day on studying. Preferably responses and opinions from 1700-1800+ due to experience and valuable advice.

I would get rid of the London System and start playing mainstream QP openings.  The monotonous nature of the Londin will stunt your growth in chess.  It is OK to play occasionally, but it should not be your primary opening.

As far as the Nimzo-Indian, how are you switching?  You say you play the French.  The French is a Defense to 1.e4.  The Nimzo-Indian is a defense to 1.d4.  You need one for each.

If you are going to play the French and Nimzo, switch the move order.  No reason to allow the Tromposky if you are a French player.

INSTEAD...

1.d4 e6! 2.c4 and only now 2...Nf6.

After 1.d4 Nf6, White can play 2.Bg5.

After 1.d4 e6, 2.Bg5 loses a piece, and 2.e4 transposes to the French Defense, which you play anyway against 1.e4.

Other moves, like 2.Nf3, the order of your first 2 moves makes no difference.  Since you play the French, use the 1...e6 move order to avoid the Tromp!

Not really necessary to change much. You have a good foundation so why should you start from zero again? If you want to, you can add some new London or French lines to your repertoire.

It is not "an opening" like playing Black.  Take myself, I am an e4 player.  I play the French and starting to bring the King's Indian back as Black.  With those, you need to know the opening in full.  MANY variations of ONE opening.

Foe White, it is the other way around.  You need to know ONE variation of MANY openings.

As White, I play:

Slow Italian against e4

Advance Variation against e6

Fantasy Variation against c6

Closed Sicilian against c5

Then you have to at least have something against inferior defenses - Pirc, Modern, Alekhine, Scandinavian, etc.

He has nothing as Black against d4

if your opening is sufficiently rich to allow imbalances and deviations for you at many different points then it is enough for a lifetime, given you do your work and stay unpredictable. so if the motivation behind trying to learn a new opening is to avoid being predictable or to avoid targeted preparation, then you can do that without a new opening.

however, if you just want to expand your horizons then go for it. 

i personally don't like the london even though it was my repertoire some 10 years ago. it encourages laziness especially from a calculation standpoint. you may even get rewarded for being lazy by winning against weak opposition, which makes it worse. but it's your call.

An alternative suggestion would be the English with white, which has some of the characteristics of a system opening like the London, (eg in many lines you can play the Botvinnik system, with bishop on g2, knights on e2 and c3, pawns on c4, d3 and e4) but is much richer, with potential to keep learning new ideas. There's an excellent series of blogposts on it starting here.

#1
"I have played the London System and the French Defense" ++ Both are good
"know the ins-and-outs of both openings" ++ Probably not, there is more to it than you think
"I have had aspirations to learn other openings" ++ Why?
"switching openings hurts rating" ++ For sure
"there are higher level players (titled level) that have many openings in their repertoire" ++ Professionals have all their games in a data base, so opponents can prepare
"stick to my current openings forever" ++ Yes
"I do not mind the studying and definitely have the time" ++ Time is better spent on endgames, tactics, master games, analysis of lost games

It's a very good idea to change up openings. In traditional teachings, I think it was suggested to change openings every few years. The idea is not to be overly concerned with rating right now, but to learn how to play a lot of different positions. That will greatly help chess improvement. 

Do watch out: changing openings is a big project. Do some research on how to study them effectively (quick tip: look at games by strong players). And don't try too much. I'd maybe start with changing openings for one color. 

If you have ample experience with 1. d4, changing to 1. e4 is the biggest possible change you can make. Where 1. d4 usually leads to a lot of strategical positions, 1. e4 lends itself very well to very dynamic play. I feel that good dynamic play is only possible with a solid strategical understanding, because making strategical threats is just as important with dynamic play as tactical threats. In that sense I would wonder whether you're already ready for that big step towards 1. e4, because you've only played the London system with white. Therefore my suggestion would be to switch to mainstream QP openings and pick some that are out of your comfortzone. That's likely the sharper lines, so maybe try and go for 1. d4, d5; 2. c4, dxc4; 3. e4 and some sharper Slav stuff, although against Nimzo, Queen's indian and Bogo you could just try and play some more solid lines too, as these positions will already be profoundly different from the positions you're experienced in. Whatever you pick, try and stick to the main lines to get a feel for playing those too.

I agree. I would try something else than the London. Short term you might lose a few rating points, but long term it will widen your understanding of chess and make you deal with different types of positions...

You could try the Colle or the Colle-Zukertort which is what I often play via a 1. Nf3 2. b3 move order if black plays 1... d5. The ideas are pretty similar to the London but there are some differences. Simon Williams has some great videos on both systems.

You definitely need something against 1. d4. I almost exclusively play 1... Nf6 and on 2. c4 I usually play the Budapest because it's fun and many players aren't sure how to handle it. On other second moves by white, I'll usually adopt either a KID or QID, depending on the situation. 

1. e4 as white is also a great option as far as learning more positions go. The Ruy and the Sicilian both are very rich in positional play (as well as tactical) and, as far as I'm concerned, they really teach you how to play chess correctly. Of course, I'm a Scotch player, so what do I know lol

Short answer is that you really don't have to change openings but you'd learn more by doing so. But again, you definitely need something against 1. d4 and 1. c4. 

First thanks guys for all the feedback, second I decided to stick to the London for now but have devoted a lot of time to learning the KID.