As I frequently tell people, there are no unicorns. A bigger bike will make long road stretches easy and carry luggage effortlessly. But it will also be harder on chains, tyres and fuel, be a handful off road and be problematic to pick up when it falls over. The converse is true for a small bike.

To me, 700-900cc is the sweet spot for a mainly road based adventure tour. Maybe down to 300 or 500 if you're anticipating a lot of offroad action. No traveller ever said "I wish I'd had more expense/weight/power on that tour."

The T7 is a great bike (I used to have one) but I sold it because I wasn't happy about the top heaviness. I ride a 790 KTM now and love its performance and low centre of gravity, but not everybody likes KTMs. Consider also the Honda Transalp, it feels lower and more rider friendly than the T7 but you would have to spend a bit on accessories to "adventurise" it.

Re your journey. Mongolia is certainly achievable but there are parts of the route to India that could be problematic. I'll let others speak about those as I'm not an expert there. If you're after a 6 months ride then Mongolia would fit your bill. You could ride there directly through Russia then on the way back drop down to Kazakhstan, Kyrgyzstan and Tajikistan which offer incredible landscapes and history. Thence to the north of the Caspian Sea to Georgia and Turkey back to Europe. Enter Russia via Latvia (not Belarus and obviously not Ukraine). Or go via Georgia both ways to minimise time in Russia.

Russian visas are available and tourists are welcomed as guests. Obviously be sensitive to the situation but the ordinary people aren't the government and are very hospitable. Take enough cash to cover your stay, western cards don't work there, and be prepared to buy medical insurance in the first city you come to, for the same reasons.

Note some of the high passes in KG and TJ may be snowbound up to June.

Hey, another Belgian here...
Already some good advice given.

I've ridden to the Stans, India and Mongolia on different trips. As for timing, 6 months is enough to travel comfortably to India or Mongolia one-way, including the Stans.

I've traveled on the T7 and similar bikes. For me a mid-weight adv bike is ideal because the European leg I usually ride quite fast. Also in Turkey and Kazachstan distances can be huge. On the roads that you will encounter (gravel, bad tar, occasional muddy passes, ...) it is plenty capable.
That being said, a smaller bike has a lot of advantages also, as others have already said. Especially if you want to take the slow roads from beginning to end, or actively seek out more technical off-road stuff.

Talking about the T7 specifically, it has some annoying quirks, and it's quite top-heavy. Definitely not easy to pick up (unless you're Pol Tarres). Think well about the luggage system you choose or the handling will suck.

But maybe the biggest selling-point for the CRF is that you already own it! For sure it's a good travel bike, so get to know it well and start preparing

Good luck!

As a CRF 300 owner. Don't forget to factor in altitude. In the French Alps, my CRF 300 was barely getting by. And that was with "only" 100kg of rider, luggage and accessories. There wasn't much fun and passing campers was not safe.

If you plan to ride longer roads above 2000 meters, the CRF300 can do it but you will have to be in lower gear, higher RPM and a near wide-open throttle. Uphill you might top out at 70 to 80km/h depending on weight and streamlining.

At that altitude you have maybe 18 to 19 horsepower at the wheel. Meanwhile a Tenere 700 will have 50 horsepower to the wheel. Meaning you can still ride it normally and even have enough power for a bit of fun.

Hi all, interested in this as I'm planning such a trip with my wife pillion.
Contrary to all the perceived wisdom I will be doing this on a XT1200ZE (super tenere).
There's some very good reasons for this choice of bike-I bought it with this trip specifically in mind:
1. There's a history of this in "Himalaya Calling" available on a TV streaming channel where two chaps from Koln, Germany went from their home town to Goa.
They both used XT1200ZE bikes.
2. I own it already, obviously
3. I can lift it by myself, plus my wife will be with me to help in case it's in an awkward position, I could always take one of those lifting jacks if necessary.
4. The vast carrying capacity versus a smaller bike
5. The comfort, speed if necessary, and durability over such a long distance
6. Tubeless tyres-easy to repair puncture unless it's a catastrophic failure
7. No chain to worry about.
Yes, I know it's a heavy bike, but I'm not planning on going off road, despite that, it'll handle dirt tracks with ease with say Anakees on it.
There's a lot to be said for a light bike, but for me the shortcomings of a lighter bike outweigh the benefits that a heavier bike give especially one that has a pedigree and known to have bullet proof engines.
Once I have that bike moving even 1km an hour it feels like a moped. Given, I've been riding nearly forty years, so that helps.
I also have a Harley Sportster that's 1200cc and I did a 4200 mile (6000km) journey across France, all the way around perimeter of Spain and back again with my adult son on the back plus full camping equipment.
One thing I was acutely aware of was weight and space (I was over the gross vehicle weight for the bike and we had to economise on what we took because of lack of space and the weight).
This won't be an issue with the Super Tenere, I for one would not contemplate doing those distances on anything else to be honest, so don't rule out one of these or a V Strom

If you're touring two-up on paved roads then bike choice is radically different, yes

__________________
FreeBSD fan since before it was cool ...