Hello Ted,

Around Rama 9 MRT - Din-Daeng, your nearest motorcycle dealer is a Yamaha dealer if you follow Ratchada Rd to Sutisarn Rd. Then just after the Huay-Kwang intersection you will find a Yamaha dealer. I belief that if you follow, the road to Sutthisarn Rd, and turn right into Sutthisarn you will also find a independent motorcycle dealer with some Honda, Suzuki and Yamaha.

If you want to take a look at something bigger then 135cc you can follow the Rama 9 rd and you will find the Kawasaki big-bike showroom, where they sell the Kawasaki D-track 250, Kawasaki KLX250, Ninja 250R... and bigger bikes.

Also I belief that you can find a few motorcycle dealers in the beginning of the Rama 9 rd (Din-Deang) just behind the Fortune Tower...

Update on scooter locations.

I walked around today and saw 4 dealers near Phra Ram 9.
2 dealers were really tiny, only 15 or less bikes located on Pracha Songkhro 2.
They were selling new and used Hondas and Yamahas.
Didn't have the Suzuki I was looking for so I didn't get into pricing.

Then I walked Eastbound on the north side of Thanon Din Daeng (Rama IX) in between Thanon Pracha Songkhro and headed towards the Phra Ram 9 MRT on Ratchadaphisek.
There was a big ~30 bikes dealer near Thap Suwan selling new Hondas and a KSR.
No English spoken so I moved on.

Then somewhere near Sap Thani on Rama IX there was a big dealer selling Hondas, Yamahas, and Suzukis, probably 60+ bikes between the 2 sides of the building.
They had 3 of the Suzuki Skydrive 125i and let me test ride one but only with a guy on the back.
I couldn't tell how good the bike was because I had an extra 150 lb guy on the bike.
They wouldn't let me ride alone, poor sales strategy.
So I asked the owner which was better, the Skydrive or Nuovo 135, he said the Nuovo hands down.
I think he's right, the Nuovo has more power, a huge storage space under the seat and rolls on 16" rims.
The Skydrive (48000BHT) has 14" rims and the storage under the seat was a joke, about as big as a loaf of bread, no helmet could fit here.
I like the fuel injection of the Skydrive but I guess I'll be getting another carb bike after all.
The Nuovo is just a bigger and better bike but at 56000BHT it should be.
They would not haggle on price with me, 56K for the Nuovo 135 with alloy rims, pretty much the same price as what the big Yamaha Square guys quoted me.
Both this place and Yamaha square want a Passport and residency letter from my embassy.

I pulled these street names off Google maps BTW.