1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Pitbull TRS twisting swingarms ?

Discussion in 'General' started by DBConz, Jan 4, 2021.

  1. motion

    motion Nihilistic Member


    With a Baxley, there is only a need to barely tighten the front straps.
    TurboBlew likes this.
  2. motoracer1100

    motoracer1100 Well-Known Member

    Cam buckles only ... ratchet straps are for Lumber
  3. moto316

    moto316 Well-Known Member

    Just adding some anecdotal evidence to this topic, ive now bent two zx10r rear axles over the past 3 years. The bike has never been crashed. It's transported via TRS.
  4. grapemustard

    grapemustard Well-Known Member

    pics of bent axle? axles are pretty strong. then they're sandwiched between wheel spacers, and the swingarm itself, then you slide the pins inside the axle, further solidifying it. I don't see how it's possible the forces on your axle while towing are stronger than the forces of a 200hp 1000cc bike on a racetrack... enough to bend not one, but two.
    Michael Hausknecht and cbush like this.
  5. moto316

    moto316 Well-Known Member

    theyre bent so slightly that its hard to capture via picture, but if you roll it across a flat surface its evident its not straight, and you can see a little bit of light peeking through if you look underneath.
  6. TWF2

    TWF2 2 heads are better than 1

    Try to picture what forces act on bike when you are in turn and hit bumps with trailer. Very different forces from what happens when riding. Don't know if it is bending axles but forces are different.
  7. grapemustard

    grapemustard Well-Known Member

    my point was that i don't think an axle is the weak link here. i'm willing to concede that a swingarm MIGHT get tweaked if outside forces (sudden swerve of the trailer or wreck) are great enough, but i can't see either scenario happening from a simple drive to the race track.
  8. cbush

    cbush Well-Known Member

    Did you happen to run the same test prior to using the TRS, thereby establishing that the axel wasn’t already bent?
  9. TWF2

    TWF2 2 heads are better than 1

    I can see something giving up under forces just due to leverage. You have 7' lever, personally I would secure front of the bike as well to minimize forces.
  10. moto316

    moto316 Well-Known Member

    i will be checking before and after every transport now, luckily stock axles are cheap enough off ebay that i can potentially sacrifice a good one.
    cbush likes this.
  11. TurboBlew

    TurboBlew Registers Abusers

    Ive been using a TRS system for a very very long time with all kinds of different hollow & solid axle types... I find that hard to believe. I cant imagine the force required to tweak such a short component something else has to be in play.
    grapemustard and cbush like this.
  12. E-Van

    E-Van Well-Known Member

    From an engineering standpoint, I can’t see how a TRS would bend an axle. The TRS fixes the axle at the same point the swingarm also fixes the axle. Theres no way to introduce a bending moment unless you’re hanging weight from, or applying force to the center of the axle.
  13. ChemGuy

    ChemGuy Harden The F%@# Up!

    Its a Kawasaki. It was like that from the factory,
  14. nlzmo400r

    nlzmo400r Well-Known Member

    For a rear axle to bend while in a TRS system you'd have to have a huge force either forward or backward. Neither of which could be achieved without ripping the plywood of the trailer.
  15. cbush

    cbush Well-Known Member

    Yeah, that’ll be good data to have.

    Isn’t George at @pitbull on the forum? Maybe someone can let him know about this thread.

    As others, I’m a satisfied Pitbull TRS user. I’ve used it with Ducatis, Aprilias, and Suzukis over thousands of miles without issue. I can’t see swingarms or axles bending with the TRS under normal transport conditions. Maybe in an accident, but not routine use.
  16. mastermind

    mastermind camping in turn 2....

    I dunno.... I have about 250,000 miles on Pitbull TRS'... never had a problem across a bunch of different motorcycles.... Ducati 749, Honda RS125, Triumph 675, '05 GSXR 1k, Benelli 135, Yamaha R1, Yamaha R3, Ducati ST4s.... nothing bending over here.....

    Banditracer and grapemustard like this.
  17. IrocRob

    IrocRob Well-Known Member

    The service manual that I have for a 2006-7 ZX10 says the service limit on rear axle runout is .0100 inch and standard runout is .0012 inch.
    This is measured over a length of 3.94 inches. So yeah, this is "a little bit of light" straight from the factory.
    03RumbleBee likes this.
  18. thrak410

    thrak410 My member is well known

    Maybe you're over tightening it and the only place it can flex is in the middle :D
  19. KrashBandit

    KrashBandit The other guy at Pit Bull

    I was watching this thread but figured ya'll would consider me a biased party on this one:) so I was just letting it run. As far as Kawasaki ZX6R/ZX10R axles, those(41068-0035 and 41068-0613) are the absolute softest material I've ever run into on a motorcycle axle. I'm not sure what they do differently on those two axles, but I regularly see axles that our pins won't fit into(when the customer first buys the kit) because the axle is deformed before they ever use our TRS. It happens from time to time on other bikes, but I would say those two Kawi axles are the weakest I've seen - with a few other Kawi axles being the other softest axles I've seen. It would not surprise me if those ZX10 axles mentioned earlier were deformed, but as I said - I've run into dozens of them that were deformed *before* using a TRS - and we hear about it because when people buy the TRS pins, they will tell us they don't fit. The axle(when it comes to ZX6 and ZX10) has been the problem 100% of the time. It's not a machining tolerance issue but a genuine deformity that happens after the bike leaves the factory.

    As for the TRS twisting swingarms, in a major collision event, there are numerous possibilities. I know you guys have heard about the rollover collisions (https://www.pit-bull.com/trailer-restraints-saves-bikes) over the years. One that never got mentioned online was when Rickey Gadson was driving through an intersection and got t-boned. His trailer got destroyed(split in half as I remember it) and he found his new ZX14 still attached to the TRS in the back half of his trailer that landed on the side of the road. He did not report any swingarm twisting nor has any other race team that's ever used our system. KWS Motorsports Suzuki was one of the race teams we worked closely with back when these first came out and they reported everything on their bikes were still perfect after their transport rig made an unexpected trip through a ditch while transporting bikes with the TRS. Team Hammer has used both the 1st gen TRS and the 2nd gen TRS since inception, and they have also not reported any issues. Not to mention countless other privateer racers, track day riders, etc.

    Now: Is it possible for a bike to get damaged using our TRS if the trailer is involved in a major collision event? Absolutely. Is it possible for a bike to get damaged using our TRS barring a collision event? No. The event where someone who uses our TRS finds out their geometry/frame/swingarm is bad on the bike is simply correlation without causation. Excluding extreme driving situations(running off the road, collisions, etc) there's no way the TRS will lead to any damage to a bike. There was too much testing done to ensure that was not possible before this product was ever introduced. And don't forget the concept of restraining a motorcycle from the rear axle was already being used by Moto GP teams before we even designed the TRS, and it would be fair to say they did some analysis to make sure they weren't damaging their bikes as well.

    Just my two cents...I've been around these a lot and talked to tons of racers over the years who use the TRS. I'll call them safe.
  20. backbone

    backbone scarred for life

    If you tie down the front of the bike as well it's highly unlikely, even with an R3 or MT07/R7.
    But, those 2 bikes mentioned have both bent swingarms from a chain break. Chain didn't wrap up around the wheels either.
    So, I'd make sure to tie down the front of the bikes too so there isn't as much of the twisting effect on the swingarm.

Share This Page