The Motorcycles of AMA Pro Flat Track - Twins
Grand National Championship Experts (Mile and Half-mile)

About the AMA Pro Grand National Expert Twins Championship
http://www.amaproracing.com/ft/about/index.cfm?cid=21650
・Top Speed: Over 130 mph（208km/h）
・Engine Displacement: 550cc - 1250cc with the following restrictions, racing only engines may not exceed 750cc, engines greater than 1000cc are restricted to air/oil cooled.
・Eligible Bikes: Aprilia RSV 1000/550, BMW FS 800, Buell CR1125/XBR/1200, Ducati 748/848, Harley-Davidson XR 750/XR1200/883, Honda RS 750, Kawasaki 650 Ninja, KTM 990 Super Duke, Suzuki TL 1000/SV 650/680/750, Triumph Bonneville Scrambler/America/Speedmaster, Yamaha Tenure 750
・Minimum Weight: 310 lbs with fuel.
・Fuel: Sunoco Supreme 112
・Front Tire: Dunlop/Goodyear DT-11 27.0x7.0-19 D3616/CD-5
・Rear Tire: Half Mile and Mile: Dunlop/Goodyear DT-11 27.5x7.5-19 D1637/CD-8
・Short Track and TT: Dunlop/ Goodyear DT11 27.5x7.5-19 D1657/CD-5

AMA Pro Grand National Expert Twins are the most powerful machines on the circuit. Reaching speeds in excess of 130mph, the large-displacement motorcycles are based on a rule set that allows for a variety of performance modifications.

All machines run on purpose-built Goodyear tires and are fueled by Sunoco Supreme 112 race fuel.

As impressive as the machines are in the Twins Engine class, it is the all-star lineup of riders that truly put on the show. Bryan Smith will be looking to defend his title in 2013 on the back of his Kawasaki. Smith dominated on mile-long tracks and got the most out of his machine on the lengthy front and back stretches each course had to offer. However, like in 2012, Smith will be flanked by the likes of Sammy Halbert, Jake Johnson, Jared Mees and others as each competitor will be hungry for a shot at the Grand National Championship Expert Twins class in 2013.


ハーレーのワンメイクなのかなと思っていたら、いろんなエンジンを積んだマシンがあるようで。
遠目では見分けがつかないが・・・
公道レースとは違う危険なレース。
アメリカンライダーの速さの秘密は、フラットトラックがベースにあるという話も・・・
（そうとう昔の話だったような気もするが）
このタフさ経験していたら、ロードレースは精神的に楽でしょうね。

モトクロッサーベースかな↓
Round one of the 2014 AMA Pro Flat Track Grand National Championship season heated up quickly on a chilly night on Thursday, March 13, 2014 at the DAYTONA Flat Track.


Expert Twinsかな↓
Watch the stars of AMA Pro Flat Track go bar-to-bar and wheel-to-wheel to win the 2014 Springfield Mile Grand National Main Event! Bryan Smith, Kenny Coolbeth, Jared Mees and many other expert class riders made for some great racing.


大丈夫だったようだが危険なクラッシュ↓（バイク折れてます）
After Nichole Chezas bike slips out from under her Chase Sconyers has no where to go and collides with Chezas motorcycle, sending chase flying over his handlebars. This is an extremely dramatic crash and it is very lucky that all riders have recovered and are ok.

2014 DAYTONA Flat Track I - AMA Pro Flat Track Grand National Championship Main Event
https://www.youtube.com/watch?v=STttYqrbQ7E
2014 Springfield Mile - AMA Pro Flat Track GNC - Expert Main Event - Full Race (HD)
https://www.youtube.com/watch?v=dhb40UMVbhw
Motorcycle breaks in half at the Indy Mile Flat Track - WW #2
https://www.youtube.com/watch?v=QxA9l5RdxP4