RevoMikey Posted January 26, 2019 Share Posted January 26, 2019 Obviously in it's stock form it runs 4s. I rarely seem to have the ability to back flip, she is fast, I run a 20t pinion on it. No matter how high I jump it it just doesn't like going that bit further as you throttle it in the air. Are back flips just a struggle on 4s with the truggy? I just bought an Arrma Kraton and that's also a struggle on 4s, although at least I can just pop a 6s pack in there (on order) Is it just down to a good transition on the take off?Any thoughts gurus? Sent from my P9000 using Tapatalk Quote Link to comment Share on other sites More sharing options...
mond Posted January 26, 2019 Share Posted January 26, 2019 Try a smaller pinion size. 2 Quote Link to comment Share on other sites More sharing options...
Fly In My Soup Posted January 27, 2019 Share Posted January 27, 2019 If your running a truggy, you'll most likely have a 46-52 tooth spur......so with your pinion gear beings 20tooth...your geared to high for backflips..... As mond said....gear down....so maybe an 17t pinion...... You're aiming for a balance.....gea r too high and your rc may 'cog' at low rpm and launch....gear too low and you can't get the enough top speed, gear ultra low and you'll just backflip out anytime you apply throttle... 1 Quote Link to comment Share on other sites More sharing options...
Tug Posted January 27, 2019 Share Posted January 27, 2019 A Truggy usually has slightly smaller tyres than an MT, so less rotational mass. This will make it harder to flip. 6S should solve it, but monitor temps, you'll almost certainly need to gear down on 6S. 1 Quote Link to comment Share on other sites More sharing options...
PH001 Posted January 27, 2019 Share Posted January 27, 2019 I think the op is talking about backflips in the air... not on the ground. In which case the gearing is less critical and it’s all about wheel mass and inertia. You need some big beefy tyres on there like some badlands - the downside is you can wreck your drivetrain easier on landing. 1 Quote Link to comment Share on other sites More sharing options...
Fly In My Soup Posted January 27, 2019 Share Posted January 27, 2019 2 hours ago, PH001 said: I think the op is talking about backflips in the air... not on the ground. In which case the gearing is less critical and it’s all about wheel mass and inertia. You need some big beefy tyres on there like some badlands - the downside is you can wreck your drivetrain easier on landing. Doesn't really make a difference how or where he's trying to backflip.... And although wheel mass and Inertia are obviously the key factor......along with the rpm at the wheel.....it is Indeed his gearing that will alter 2 of the aforementioned values.... Inertia is directly affected by gearing...lower the gearing and you lower the Inertia. Wheel speed...the lower gearing allows for wheel speed to increase at a much faster rate.....think of it like trying to wheelie a push bike in gear 20 as opposed to gear 1. And although gearing won't alter wheel mass itself obviously, it will alter the motors ability to turn the wheel mass faster and quicker than taller gearing... And the trick to landing is roughly matching your wheel speed with the velocity of the car by fine control of brake and throttle....so when you land your wheels are spinning at 20k rpm 1 Quote Link to comment Share on other sites More sharing options...
Jumper Posted January 27, 2019 Share Posted January 27, 2019 (edited) My hyper ST backflips not problem on 4s when running 18/46 gearing. i think you need heavier wheels and tyres. The standard wheels and tyres were much lighter than the badlands i have now. even on 16t pinion with 48t spur i have no issues doing backflips. You also need a decently steep ram sometimes as well, that can help a lot. The other thing that helps is not going off the ram at full speed. you want to be 1/4-1/2 speed entering the ram unless you are getting really high up. Edited January 27, 2019 by Jumper 1 Quote Link to comment Share on other sites More sharing options...
RevoMikey Posted January 27, 2019 Author Share Posted January 27, 2019 Great advice all around guys thanks, it seems in my haste to make a top end fast, stable truggy I have lost that back flip ability.I don't run stock tyres, I run mini pin prolines on dish rims, they are the same size as stock but firmer, I guess the floppiness of stock tyres will help the centrifugal forces in the air. Once I get my Kraton dialled in properly I will make some changes using all your advice from these posts.Thanks fellas. [emoji106]Sent from my P9000 using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
Fly In My Soup Posted January 27, 2019 Share Posted January 27, 2019 If you find your still struggling after gearing down....try 6s. Had no issues flipping using dishes and grp mini blocks on wife's truggy ...but it spent most of it's time on 6s Quote Link to comment Share on other sites More sharing options...
RevoMikey Posted January 28, 2019 Author Share Posted January 28, 2019 I didn't think the truggy was strong enough for 6s, it seemed quite frowned upon when I mentioned it here a year or so back?Sent from my P9000 using Tapatalk Quote Link to comment Share on other sites More sharing options...
PH001 Posted January 29, 2019 Share Posted January 29, 2019 (edited) Will probably survive for a while with fully hardened differentials front centre and back. Wouldn’t stand a chance on the factory ones. Of course you cant run the factory esc on 6S so that has to be upgraded as a minimum. Motor is fine with the copper foil heatsink mod (search ‘halve your motor temperatures with this 5 minute mod’ for details). Edited January 29, 2019 by PH001 1 Quote Link to comment Share on other sites More sharing options...
Jumper Posted January 29, 2019 Share Posted January 29, 2019 i think this guy is doing it right 1 Quote Link to comment Share on other sites More sharing options...
BashingBrian Posted January 30, 2019 Share Posted January 30, 2019 Mad skills...!!! 1 Quote Link to comment Share on other sites More sharing options...
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