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LAV25 · 07-10-2010, 12:54 AM

Is there any difference in which end of the leaf spring I put the shackle on?

Working on a leafed scaler with a homemade chassis, and I'm trying to figure out if it makes any difference which side (towards the ends of the truck, or towards the center) of the axle I put my shackles on. I've checked the manual for the Hi Lift, which has the shackles to the outside (meaning the shackle on the front axle is in front, and the rear shackle is to the back), but the Knight Hauler has the shackle on it's front axle at the rear end of the leaf spring, towards the center of the truck. I don't know if this is an on-road/off-road thing, or just what Tamiya thought would look cool.

Confused yet?

If you followed what I said, and can let me know if there's any performance difference, it'd be a great help.

Thanks

-val

BigSki · 07-10-2010, 09:05 AM

on a 1:1 rig, most shackles are set facing towards the rear of the vehicle. The reason is while the vehicle is moving forward and hits a bump that causes the spring to flex, the spring gets longer as it flattens out. The energy that is in the moving vehicle and spring try to move rearward, so with the shackle at the rear of the spring it's a more natural pathway for the energy to dissipate.

Fastball · 07-10-2010, 11:45 AM

The primary difference I have found in the 1:1 world is really ride quality. With a trailing shackle the ride is smoother as the tire moves up and backwards slightly in response to a bump. I have seen and felt this on my 1:1 49 willys CH3a which has been configured both ways. Off road however it climbs better up ledges with the shackles up front as the tire is driven into the rock face as it articulates providing more traction. With a rear shackle setup the tire moves away from the rock face. Really in the RC world it doesn't mean a whole lot either way but I would put them at the front if it was me.

Fastball

LAV25 · 07-10-2010, 08:24 PM

Thanks to both of you! Both bits of info make sense in the context of the models I looked at, you'd want your big rig to have a smooth ride, and your 4x4 to get up those rocks. Building commencing soon!

-val

07-10-2010, 12:54 AM	#1
LAV25 Quarry Creeper Join Date: Jan 2007 Location: Osaka, Japan Posts: 425	Shackle question Is there any difference in which end of the leaf spring I put the shackle on? Working on a leafed scaler with a homemade chassis, and I'm trying to figure out if it makes any difference which side (towards the ends of the truck, or towards the center) of the axle I put my shackles on. I've checked the manual for the Hi Lift, which has the shackles to the outside (meaning the shackle on the front axle is in front, and the rear shackle is to the back), but the Knight Hauler has the shackle on it's front axle at the rear end of the leaf spring, towards the center of the truck. I don't know if this is an on-road/off-road thing, or just what Tamiya thought would look cool. Confused yet? If you followed what I said, and can let me know if there's any performance difference, it'd be a great help. Thanks -val

07-10-2010, 09:05 AM	#2
BigSki I wanna be Dave Join Date: May 2008 Location: Baltimore Posts: 4,442	on a 1:1 rig, most shackles are set facing towards the rear of the vehicle. The reason is while the vehicle is moving forward and hits a bump that causes the spring to flex, the spring gets longer as it flattens out. The energy that is in the moving vehicle and spring try to move rearward, so with the shackle at the rear of the spring it's a more natural pathway for the energy to dissipate.

07-10-2010, 11:45 AM	#3
Fastball Newbie Join Date: Feb 2006 Location: Ottawa Kansas Posts: 32	The primary difference I have found in the 1:1 world is really ride quality. With a trailing shackle the ride is smoother as the tire moves up and backwards slightly in response to a bump. I have seen and felt this on my 1:1 49 willys CH3a which has been configured both ways. Off road however it climbs better up ledges with the shackles up front as the tire is driven into the rock face as it articulates providing more traction. With a rear shackle setup the tire moves away from the rock face. Really in the RC world it doesn't mean a whole lot either way but I would put them at the front if it was me. Fastball

07-10-2010, 08:24 PM	#4
LAV25 Quarry Creeper Join Date: Jan 2007 Location: Osaka, Japan Posts: 425	Thanks to both of you! Both bits of info make sense in the context of the models I looked at, you'd want your big rig to have a smooth ride, and your 4x4 to get up those rocks. Building commencing soon! -val

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