I am in Chinese, I just had a savage 650,  I want to ask some questions about the modified ryca, thank you very much.
1.With the transformation of oil tank
2.With the transformation of Caferacer pedal
3.The rear wheel change 4.50-18 need to pay attention to what?
4.My drive belt without broken, can not buy in China, I think I do a, there is no detailed data on its.

My English is not good, feel shy.sorry

I will try and help....my Chinese is going to far worse than your English...so we will try English for now.

There is no oil tank - so I assume you are asking about the fuel tank modification.  They cut the bottom off the tank, then rebuild the tunnel to allow the tank to be lowered.  It is a very labor intensive change.  Some of us have adapted other tanks - those are a lot of work as well.

The rear set pedals are also very involved and a lot of work to try and duplicate on your own.

I don't know if a 4.50-18 tire is too big.  A 110/70-18 fits best on the 2.50x18 rim....a wider tire really should be on a wider rim.  a 130-70-18 tire is really made for a 3.50-18 rim.

If you can't get a belt...maybe a chain conversion would be better for you.  Since the sprockets are smaller then the belt pulleys...their is some problem in getting the chain to clear some of the RCYA bits....along with the top of the swing arm pivot area.

I like the belt too - but if you can't buy one in China....what can you do?

Here is a link to the bike build section, it has photos from folks on this forum that have modified their bikes.  Some use belts, some use chains.  Some have bought the RYCA pedal sets....others have built their own.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1383565946

I am not sure how hard it is to ship things to China.  If you don't have a lot of mechanical skills - you might be better off to buy a complete conversion kit from RYCA, and get them to ship a replacement belt with the kit.  I am sure they have access to used belts, as a lot of their bikes are switched over to chains.

Savage belt

Bando 133U 14M 40.0

I guess that means 133 teeth, 14mm pitch and 40mm wide

Made in Mexico, I think...

Superxin, are you permitted/allowed to import products from the USA or Mexico? Are you a member of a motorcycle club or organisation in China? Suzuki were making some motorcycles in China, I used to own a GN 250 made in China. You need to look at American websites such as Bike Bandit or Catalyst Cycles or JP Cycles to find  this Belt. If you have difficulties importing from the US, it may be possible to import from Canada or New Zealand

GN250 is good bike.I have a suzuki grass tracker Bigboy 250.same

and st250，it's good.but t' very small.

How long steel of 18"rim?