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AFT have released a handful of updates to their rulebook in advance of combining the Twins classes. Below is the wording of individual changes and how we think it could affect things. First the new rule, then my take on it. Gary Inman, editor


The Racing Program: For the AFT SuperTwins class, the top 32 from combined qualifying will be seeded into two Heat races. The top 6 from each AFT SuperTwins Heat will advance directly to the Main. Riders finishing 7 – 16 in their respective Heats will be seeded into a 10-lap LCQ. The top 7 riders from the LCQ will advance into the Main, plus 1 spot for a provisional starter will complete the 20-rider grid for the Main. The AFT SuperTwins purse will pay down to 32 positions: 1-20 from the Main, 8-20 from the LCQ.


Firstly, it seems the combined twins class will be called SuperTwins.

Until the end of the recent season, the SuperTwins and Production Twins classes both had a number of timed practice session (depending on the event it has ranged from one to three practice sessions), then a timed qualifying session to determine their grid position for their semi. The semis confirm qualifying/grid position for their main (the final). During 2022 there was also a Mission Foods-sponsored dash for cash for the SuperTwins class, the top four qualifiers racing a four-lapper for a cash prize, but no extra championship points. Production Twins didn’t get a dash, but the top four finishers in their main were given a back of the grid start in that event’s SuperTwins main later on in the same day.

We took a quick look through the 2023 timings sheets and found a number of races that had slightly more than 32 riders when combining the two Twins classes. If those entry numbers continue (and nothing is pointing to a big increase in entry numbers), then only two or three riders will be eliminated before the heat races. Even then, they could use one 'provisional' start per season to enter a main they didn't qualify for, if they have the right criteria.

What was called the semi in 2022 will become the heat race, with an additional race for those riders not transferring directly to the main. That is in the form of the LCQ – Last Chance Qualifier. The big difference will be, assuming the entry numbers remain at 2022 levels, that 12 or more riders will not make a main at every race.

The SuperTwins grid will increase from the current maximum of 17 to a maximum of 20. If they are sticking to four riders per row, which was introduced for safety reasons, the back row is a long way back. Anyone put on the penalty row (the sixth row) will be in a different zip code.

Some fans have wanted to see more competition to make the mains, but how will this affect the riders and teams, especially those lower down the pecking order who are likely to already be struggling? Yes, AFT has said they will pay prize money down to 32, but, according to riders we’ve interviewed, prize money for finishing outside the top 3 in Production Twins isn’t enough to cover tyres. Riders who are not making mains will struggle to attract sponsors, even if the class is more competitive, whereas Production Twins riders were making mains throughout the last few seasons. They were gaining experience and building a programme, even if it was in the 'support' class. That is going to be harder now. Racing at the top level isn’t supposed to be easy, but a pro sport that is struggling to grow can and should view things differently to a series flush with money and interest.

Personally, I don’t think the 2022 season was short on drama or suspense. Even through there were only 13 riders in the SuperTwins class (plus the four Production Twins qualifiers), there were four riders with a chance of winning the title going into the final weekend, and none of those four actually won either of the last two races that weekend. Meanwhile in Production Twins there were two riders fighting for the title.

I’m not sure combining the twins classes is going to solve any of the pro sport’s problems.


Timed Practice and Qualifying: During any session, if a rider is in jeopardy of being lapped by the leader a second time, AMA Pro Racing officials may black flag that rider.


This replaces 107% qualifying rule. Previously all riders had to post a time within 107% of the polesitter's qualifying time (but we are sure there were occasions this was was ignored). With 20 riders in a main, and short track badasses at the sharp end, we can see a lot of people being lapped twice in an 8-minute short track or TT main.


Motorcycle Usage / Backup Bikes: For all classes, once a rider enters the track with a motorcycle during any session, that motorcycle may not be changed during that session.


This will penalise any team with enough money to have a back-up bike, and even middling Production Twins teams have back-up bikes. Imagine driving from Washington state to Florida or Georgia and having a mechanical as you ride out for your one qualifying session and not being able to put in a qualifying time on your spare bike. How many $1000s of transport costs go down the drain? Who is this rule actually helping? Surely Mees doesn’t want to win the title because Daniels has a flat tyre as he lines up for the heat race or vice versa. Do the fans want that either?

Is any team who can afford a back-up bike actually not going to build and take one to the races now? Of course not.


AFT SuperTwins Technical

Rules 4.2 Engines 1.

Engine Displacement i. Minimum 649cc with the following restrictions on maximum displacement:

1. For 2023, Production (Street Bike) Engines

a. Production engines may not exceed 900cc.

b. Bore and stroke may be modified to meet the maximum displacement limits listed above. 2. For 2024, Production (Street Bike) Engines a. Liquid-cooled engines may not exceed 800cc. b. Air-cooled engines may not exceed 900cc. c. Bore and stroke may be modified to meet the maximum displacement limits listed above. 3. Racing-only Engines: a. Liquid-cooled racing-only engines may not exceed 750cc. There is no provision for overbore. b. Air-cooled racing-only engines may not exceed 750cc with a maximum allowable overbore of 0.045” per cylinder. 2. To prohibit the practice of “twingling” a twin, any modification of engine components to alter the stock OEM firing order/spacing of cylinders is prohibited.


There’s quite a lot here, but the things that really jump out to me are:

1. Indian FTR750s and Harley XR750s are still legal. Not too much of a surprise.

2. KTM’s 890 twin was welcomed into the series (see a full feature on the Wally Brown KTM Twin in Sideburn 50), only for it to be outlawed for 2024, due to rule 2 a.

3. Having said that, bore and stroke can be altered, so a KTM team could reduce either bore and/or stroke to reduce their cylinder capacity. On the other hand, increasing the stroke might help Royal Enfield increase capacity and power, if they are on the limit of the bore dimensions (starting, as they did, with a 650).

4. For those who aren’t sure, twingling is altering the firing pattern of a twin, to make the two pistons fire simultaneously, or very close together. They effectively make a twin feel like a single, hence the name. The idea is to lengthen the time between power pulses to give the rear tyre more time to ‘recover’ and gain traction between power pulses. I don’t know for sure how many races the Estenson Yamaha team used a ‘twingled’ MT-07, but they definitely experimented with it. That option is now off the table.

There doesn’t seem to have been a lot of support for twingling in the paddock, but there have been lots of fans saying that other teams should step up to Indian. This was one way of stepping up without making a prototype race-only engine – which no factories are currently willing to do. If Yamaha were using twingling to be more competitive, the advantage has just been taken away.


Engine Control System/Electronics/Traction Control

e. Production (Street Bike) Engines: i. Only OEM sensors may be used to provide input to the ECU unless otherwise approved. Race-Only Engines will be limited to a maximum of 11,500 R.P.M. (same as 2022)


Traction control remains, but who wanted it in the first place? It seems like this rule is trying to limit the usefulness of it, by restricting it to the use of the OE road bike sensors. Of course, this is only a limit if the stock traction control is basic. If a team uses an engine that has very sophisticated and tuneable TC, and a team with the resources to make the most of it, then it becomes a different matter. Kick TC out of dirt track.


Intake Manifolds, Carburetors, Fuel Injection and Restrictors b. Throttle Body Specifications: i. Carb/Throttle Body Maximum Inner Diameter: 1. Production Engines: a. Liquid-Cooled: i. 649-800cc: 40mm ii. 801-900cc: 38mm b. Air-Cooled: i. 649-900cc: 40mm 2. Race-only engines: 38mm ii. Race-only engines will be required to utilize AMA Pro Racing issued intake restrictors with a circular I.D. of 34mm. (same as 2022)


Hands up, we’re out of our depth when it comes to throttle body sizes and the affect they might have on individual different engines, but, as many people suspected, the restrictions to the Indians, introduced for 2022, hit the private teams harder than the factory teams, that had more knowledge and opportunity to experiment with heads and cams to make up for the restricted intakes. In case you missed it, an Indian FTR750 won the AFT title for the sixth consecutive season, with another FTR750 in second.

There is an additional rule about crank position triggers on race-only engines, which we are looking into. We don’t currently understand the significance of it.


Fielding 13 bikes in the premier class has been regarded as not a good look for AFT, but is it a huge problem? Look at the race series that is attracting all the hype at the moment, MotoAmerica King of the Baggers. It was a seven race series, with (it seems) two races on one day at Daytona, compared to 16-18 rounds of AFT. King of the Baggers had 13 starters for their race at the Daytona 200. They had 16 at Laguna Seca and back to 13 for their finale at New Jersey. Did anyone care they only had 13 entries? Did it affect the drama or the spectacle of the series? It didn't seem to, no.

Combining the Twins classes, when the FTR750 is still such an awesome machine being ridden by one of the greatest of all-time, is a tough call. Even the best Production Twins are going to struggle against the best riders on the best dirt track bike of a generation (perhaps of all time). But is that just life? The cream rises, that's racing, etc, etc. Yes, but it doesn't help a series that is trying to maintain or grow entry numbers.

Privateers on Production Twins will not be able to build and fund a race programme on finishing 14th to 19th in the combined twins main. So what do those riders do? We have been told that Indian have already stopped making spares for the FTR750, so buying one of them doesn't make a ton of sense, and developing one to work with the restrictors has not been easy (though two Indian privateers won the final two races). I really don't know the answer, but we were big fans of the Production Twins class, and killing it doesn't make a lot of sense to us.

Photos: Scott Hunter/ AFT

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