R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric Off-Road

Reply
 
Thread Tools Search this Thread
Old 02-01-2006, 02:16 PM   #1
Tech Rookie
 
Join Date: Oct 2005
Posts: 12
Default Universals vs. Dogbones

Is there a significant difference between the two? What are the advantages/disadvantages?

Thanks.
Dr Gonzo is offline   Reply With Quote
Old 02-01-2006, 05:32 PM   #2
Tech Regular
 
brianhackett's Avatar
 
Join Date: Nov 2004
Location: columbus ohio
Posts: 336
Default

my first question to you would be what platform (vehicle are you inquiring into?) it varies from 2 wheel to 4wheel to truck.
brianhackett is offline   Reply With Quote
Old 02-01-2006, 07:38 PM   #3
Tech Regular
 
Join Date: Feb 2005
Posts: 432
Default

universals are more reliable in a sense that they dont pop out like dogbones do. I also like using them in the front of the car because thay have less binding
Genius is offline   Reply With Quote
Old 02-01-2006, 08:00 PM   #4
Tech Elite
 
jamescam's Avatar
R/C Tech Charter Subscriber
 
Join Date: Jul 2005
Location: Dallas, TX
Posts: 2,047
Trader Rating: 10 (100%+)
Default

Dogbones offer less overall performance compared to CVDs which are more efficient in transfering power to the wheels but in extremely bumpy conditions you may find pros using dogbones as they let the rear suspension move more freely under heavy load.
jamescam is offline   Reply With Quote
Old 02-01-2006, 08:39 PM   #5
Tech Elite
 
WheelNut's Avatar
 
Join Date: Jan 2003
Location: Edmonton, Ab
Posts: 3,210
Trader Rating: 5 (100%+)
Send a message via MSN to WheelNut
Default

I would be interested in knowing if anyone has ever really done a proper test comaring the efficeincy of dogbones versus MIP CVD's. I myself highly doubt that the CVD's would have any real advantage.

According to everything I've read though is that CVD's will give you better forward traction, and dogbones will give you better in corner grip and better compliancy over the rough stuff. This is becuase the CVD's want to return to being straight more than a dogbone does, thus apparentally putting more pressure on the rear tires, and also binding up the suspension action.

I'm actually going to pick up some dogbones to try out at the big winternats race in march, the track will most likely be very rutted up from the 8th scales. I figure that the dogbones ought to help a bit, I'm going to try some RPM 2 stage pistons as well...

Last edited by WheelNut; 02-01-2006 at 09:03 PM.
WheelNut is offline   Reply With Quote
Old 02-01-2006, 10:23 PM   #6
Tech Master
 
sim600's Avatar
 
Join Date: Dec 2003
Posts: 1,624
Trader Rating: 15 (100%+)
Send a message via ICQ to sim600
Default

Universals are tightened against the axle hubs, so they dont slide around on that end but they slide around the diff cup end when the suspension arms go up and down.

Dogbones slide around the diff cup end as well as the axle end so if they are too short, they fall out, if they are too long, they hit against the cups and bind the suspension (preventing full travel). Unfortunately being short enough not to bind most off-road suspensions also means being short enough to fall out unless the dogbones stay right smack in the very middle between the two cups. This means you need some greased o-rings in both cups to act as springs to push the dogbones back to the middle. At just about any time, the dogbone is touching one of these o-rings so there's always going to be a little more friction with dogbones. Also, the dogbones are never really in the center of the diff cup since the cups are always going to be just slightly bigger than the bones and gravity would pull it down to the bottom of the cup when the car is stationary while the rotational forces would bounce it around inside the cups once it starts spinning. The same thing happens with the boney end of the universal shaft but at least the axle end is bolted to hub center (theoretically anyway).

I don't like the idea of dogbones on the front of any car since the steering combined with suspension travel puts quite an angle on the joint, and most axle dogbone cups don't really allow a sharp angle without binding.
__________________
ModRC.com
sim600 is offline   Reply With Quote
Old 02-01-2006, 10:26 PM   #7
Tech Elite
 
mafiaracers's Avatar
 
Join Date: Mar 2004
Location: West Linn, Oregon
Posts: 3,759
Trader Rating: 22 (100%+)
Send a message via AIM to mafiaracers Send a message via MSN to mafiaracers
Default

Universals rock my world!
__________________
Chris Woods

MAFIA MOTORSPORTS
http://www.rctech.net/forum/r-c-items-sale-trade/168239-pit-board.html

TEAM WAVE
www.teamwaveonline.com

TQ Racing Wire
www.tqracing.com
mafiaracers is offline   Reply With Quote
Old 02-02-2006, 07:14 AM   #8
Tech Regular
 
mremtr's Avatar
 
Join Date: Nov 2005
Posts: 420
Trader Rating: 1 (100%+)
Default

Dogbones when worn , will cause so much grief you might think your chassis is tweeked , I have found universals actually caused less bind in the rough stuff and allowed better forward bite going through a really long washboard section than bones, but you really have to do your shocks up proper or the car will kick .
mremtr is offline   Reply With Quote
Old 02-02-2006, 07:29 AM   #9
Tech Elite
 
macnkitty2002's Avatar
 
Join Date: Jun 2004
Location: Montgomery, AL
Posts: 4,920
Trader Rating: 7 (100%+)
Default

Universals all the way. you don't have to rebuild them!
__________________
Team Associated RC10B4.2
Losi Rock Rey
macnkitty2002 is offline   Reply With Quote
Old 02-02-2006, 08:09 AM   #10
Tech Champion
 
Davidka's Avatar
 
Join Date: Oct 2004
Posts: 9,927
Trader Rating: 77 (100%+)
Default

This is a comparison best made on the Associated B4. This car has a chioce of CVD universals or Dogbones. The dogbones are used as a tuning aid for rough tracks or situations where more rear sidebite is desireable. The CVD in particular has a subtle binding effect that maked the joint want to straighten out under load. It feels like adding a degree of anti squat compared to dogbones. In good condition, dogbones actually allow the suspension to work more freely under power. CVD's help the car to "square up" and accelerate more aggressively. The effect is caused by the larger cross pin that goes through the axle.

Most Losi drivers change out their CVD's in favor of molded universals because Losi cars have superior forward bite but do not rotate in turns as well as the Associated car.
__________________
"I have no idea what you're talking about, so here's a bunny with a pancake on it's head."

In mind and body, we're all heading towards old age. It is slower to go by bike.
Davidka is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bent Dogbones? Danie Nitro Off-Road 11 01-08-2008 11:32 PM
Looking for xxx-nt dogbones jg727211 R/C Items: Wanted to Buy 0 10-20-2006 07:39 AM
HPI Nitro MT keeps losing dogbones... Help! kramsnewo Electric Off-Road 7 09-22-2004 09:47 PM
CVDs vs Dogbones psbarger Electric Off-Road 17 06-16-2004 09:35 PM
XXX CVD's &/or Dogbones jg727211 R/C Items: Wanted to Buy 0 06-16-2004 07:17 AM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:31 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net