Bangkok's Bike Shops

The Bike Shops listed here are meant to give you an overview where to look for your fancied bicycle brand or where you can get your bike repaired while sipping a Flat White. The listing isn't a recommendation per se as I don't have experiences with most of them other than talking to the owners and looking at the shops.
If you are looking for cheap bikes who don't need to last very long you may check out the supermarkets Tesco and Big C.
A good place for used bicycles (other than Sombats Bicycle Room) is the Train Night Market (Talad Rot Fai), which recently moved to Seacon Square in the south eastern part of Bangkok (click for Google Maps).
For more information about bike shops in Bangkok (and the rest of Thailand) as well as everything related to riding your bike here I recommend the site www.bicylethailand.com.

AIM Bike

Open: Daily 9:30 – 19:00
Area: Pakkred / Muangthong Thani 
Address: 55/450 Bond Street / close to Sukhothai Thammathirat Open University
Phone: +66 2 984 0427
Website: www.aimbike.com
How to get there: BTS Mo Chit or MRT Chatuchak, take a Taxi from there (around 100 Baht one way, depending on the traffic)
Map: click for Google Maps
Bicycle Brands: Bianchi, Bonnet Noir, Bruno, Chevrolet, Dahon, Giant, Gios, Java, Louis Garneau, Merida, Scott, Surly

Aran Bici | Cycle House & Coffee

Open: Daily 13:00 – 22:00
Area: Phaya Thai / Ari
Address: 128/1 Soi Phahol Yothin 2, Sam Sen Nai
Phone: +66 81 821 9603
Website: www.facebook.com/ARANBICICLETTA
How to get there: BTS Ari
Map: click for Google Maps
Bicycle Brands: Custom Bikes

Bicycle Room at Sombat Kanamuji

Open: Daily 9:00 – 18:45
Area: Pathumwan 
Address: 5-7 Chula Soi 28-30
Phone: +66 81 423 1428
Website: www.sombatkanamuji.com
How to get there: MRT Sam Yan (Exit 2), 450m down Rama 4, then turn right into Chula 5, after another 250m the Bicycle Room will be at your right
Map: click for Google Maps
Bicycle Brands: mainly used Bikes from different Brands, new Bikes from Chevrolet

Bike Mart

Open: Daily 10:00 – 18:00
Area: Khlong Toei / Upper Sukhumvit 
Address: 31/4 Soi Methi Niwet (Sukhumvit 24)
Phone: +66 2 260 3706
Website: www.facebook.com/Pom.bikemart
How to get there: BTS Phrom Phong (Exit 6), turn around and go right into Soi Methi Niwet (between Benjasiri Park and Emporium), Bike Mart will be on your right after ca. 250m
Map: click for Google Maps
Bicycle Brands: Araya, Bianchi, Brooklyn Cruiser, Louis Garneau, Surly, Tern, Trek

Bike Station (Khet Suang Luang)

Open: Tuesday to Friday: 10:00 – 19:00, Saturday & Sunday: 10:00 – 17:00
Closed: Monday
Area: Khet Suan Luang / Hua Mak
Address: 2456 Phathanakan Road / Soi 58, Khwaeng Suan Luang
Phone: +66 2 722 9999
Website: www.th-th.facebook.com/BikeStation.Company
How to get there: Airport Rail Link / Hua Mak Station, take a taxi from there
Map: click for Google Maps
Bicycle Brands: BMC, Cipollini, Colnago, Dahon, Focus, Gary Fisher, Gios, Java, Pinarello, Specialized, S-Works

Bike Station (at K-Village)

Open: Tuesday to Sunday: 10:00 – 20:00
Closed: Monday
Area: Khlong Toei
Address: 93/95, Sukhumvit 26
Phone: +66 2 661 5629
Website: www.th-th.facebook.com/BikeStation.Company
How to get there: BTS Phrom Phong, then about 1000m down Soi 26
Map: click for Google Maps
Bicycle Brands: Chevrolet, Dahon, Focus, Vanmoof

Bike Zone

Open: Daily 10:00 – 19:00
Area: Pathumwan / Chit Lom
Address: 2nd Floor, Outdoor Unlimited Zone, Amarin Plaza, 496-502 Ploenchit Road
Phone: +66 2 652 1559
Website: www.bikezone.co.th
How to get there: BTS Chit Lom, follow the Skywalk for a few meters, Amarin Plaza will be on your left with direct access from the Skywalk
Map: click for Google Maps
Bicycle Brands: Cervélo, Marin

Cannasia

Open: Tuesday to Sunday: 10:00 – 19:00
Closed: Monday
Area: Khlong Toei 
Address: 45/39 Soi Atthakrawee 1, Sukhumvit 26
Phone: +66 81 567 8886
Website: www.thaicannasia.com
How to get there: BTS Phrom Phong, then about 1000m down Soi 26
Map: click for Google Maps
Bicycle Brand: Cannondale

Culture Cycliste / Lumphini Park

Open: Daily 10:00 – 19:00
Area: Pathumwan / Lumphini
Address: Sarasin Alley, Lumphini
Phone: +66 2 651 4114
Website: www.culturecycliste.com
How to get there: MRT Lumphini, then 600m up Wireless Road, 10m left into Sarasin Alley
Map: click for Google Maps
Bicycle Brands: Avenue, Cube, Infinite, LA E-Ride, Look, Wilier

Culture Cycliste / Phutthamonthon Branch

Open: Monday to Friday: 11:00 – 19:00, Saturday & Sunday: 10:00 – 20:00
Area: Sam Phran
Address: 2/388 Image Mall, Phutthamonthon Sai4 Rd., Moo8, Krathum Lom
Phone: +66 2 404 2185
Website: www.culturecycliste.com
How to get there: best to take a Taxi, its about 400 Baht (one way) from Lumphini Park
Map: click for Google Maps
Bicycle Brands: Avenue, Cube, Infinite, LA E-Ride, Look, Scott, Wilier

Faster Than Walk

Open: Daily 18:00 – 24:00
Area: Phra Nakhon / Rattanakosin
Address: 457 Mahachai Road, Samranrat
Phone: +66 81 933 3541
Website: www.facebook.com/fasterthanwalk
How to get there: XXX
Map: click for Google Maps
Bicycle Brands: Araya, Birdy, Brompton, Bruno, Fuji, Dahon

Nava Bike

Open: Tuesday to Sunday: 10:00 – 19:00
Closed: Monday
Area: Bang Khun Thian
Address: 78 Rama 2 Road, Thakham
Phone: +66 2 898 6655
Website: www.navabike.com
How to get there: XXX
Map: click for Google Maps
Bicycle Brands: Biceco, Dahon, Gios, Java

One Fine Day

Open: Tuesday to Sunday: 11:30 – 19:00
Closed: Monday
Area: Bang Na / Bearing
Address: 27/2 Lasan 23 Sukhumvit 105
Phone: +66 2 744 4077
Website: www.onefineday-bicycle.com
How to get there: BTS Bearing, Exit 1, about 2km up Soi 105
Map: click for Google Maps
Bicycle Brands: Brompton, Strida

Pedal Lane

Boutique Bike Shop focussing on well designed city and commuter bikes including accesories for everyday cycling.

Open: Tuesday to Sunday: 10:00 – 21:00
Closed: Monday
Area: Pathumwan / National Stadium
Address: Ground Floor BACC
Phone: +66 81 615 6592
Website: www.facebook.com/pedallane
How to get there: BTS National Stadium (Exit 3), there is a Skywalk connection with the BACC, Pedal Lane is on the ground floor 
Map: click for Google Maps
Bicycle Brand: Public

Probike

Open: Monday to Friday: 10:00 – 19:00, Saturday: 8:30 – 19:00, Sunday: 8:30 – 17:00
Area: Pathumwan / Lumphini
Address: 237/2 Rajadamri Rd, Lumphini
Phone: +66 2 651 4114
Website: www.probike.co.th
How to get there: MRT Silom, then 600m up Ratchadamri Road, 100m right into Sarasin Alley, Probike will be at your left
Map: click for Google Maps
Bicycle Brands: Trek, Tern

Sixty Bike

Open: Tuesday to Sunday: 12:00 – 20:00
Closed: Monday
Area: Watthana / Upper Sukhumvit 
Address: Sukhumvit Soi 31
Phone: +66 84 123 6655
Website: https://www.facebook.com/pages/Sixty-bike-Bangkok/
How to get there: BTS Phrom Phong (Exit 5), ca. 250m up Sukhumvit, turn right into Soi 31, after ca. 500m up Soi 31 there is a crossroads, turn left and follow the street (it is still Soi 31) for about 500m, you will head straight into Sixty Bike
Map: click for Google Maps
Bicycle Brands: Bianchi, Chevrolet, Cinelli, Dahon, Fuji, Gios, Louis Garneau, Specialized, Vanmoof

Thonglor Bike & Café Symphony

Open: Tuesday to Sunday: 9:30 – 19:00
Closed: Monday
Area: Watthana / Thonglor
Address: 49 Shukhumvit 55 (Thonglor)
Phone: +66 2 712 5425
Website: www.facebook.com/CafeSymphonyThonglorCoffeeBike
How to get there: BTS Thonglor (Exit 4), turn left into Soi 55, Thonglor Bike will be at your left after ca. 120m
Map: click for Google Maps
Bicycle Brands: Bruno, Cipollini, Dahon, Fuji, Giant, Louis Garneau, Merida, Miyata

Tokyobike (with Laliart Café)

Open: Tuesday to Sunday: 11:00 – 20:00
Closed: Monday
Area: Phaya Thai / Ari
Address: 20, Soi Ari 2
Phone: +66 2 117 1016
Website: www.tokyobike.co.th
How to get there: BTS Ari (Exit 3), left into Soi Phahon Yothin, after ca. 100m turn left into Soi Ari 2, Tokyobike will be at your right after another 200m
Map: click for Google Maps
Bicycle Brand: Tokyobike

Velayenn Bike & Coffee Shop

Open: Thursday to Sunday: 10:00 – 20:00
Closed: Monday to Wednesday
Area: Watthana / Thonglor
Address: 808/15 Soi Thara Rom 2 (Sukhumvit 55)
Phone: +66 80 900 2610
Website: www.th-th.facebook.com/velayenn
How to get there: BTS Thonglor (Exit 4), then about 1100m up Soi 55, then turn right into Soi Thara Rom 2, Velayenn will be on your right after ca. 40m
Map: click for Google Maps
Bicycle Brands: Custom Bikes