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Rear Suspension Question
ratty 63 - January 19th, 2004 at 11:13 AM

Hi all,

I am in the process of building a Baja for both Street and off-road use (ie: registered) and have in my possession a rear end from a country buggy which I would like to fit to it.

I have heard a number of bad things about the reduction box rear ends in off-road vehicles (wheel hop/jumping when traction is lost, rear end lifting under acceleration etc), however it is har to ignore the extra height that is gained by fitting reduction boxes.

Does anyone have any suggestions or ideas on how to overcome these problems, or are they really a problem?

Ultimatly, should I fit the CB rear, or should I just stick with the standard swing axle rear? (It's a '65 Baja)

Thanks

R


Baja Wes - January 19th, 2004 at 02:25 PM

I would say convert to IRS and use a kombi gearbox is the way to go.

I haven't driven a CB rear end car, but have been offroading with two and didn't like the way they were behaving. Up a sandy / muddy hill one of them was raising the susp to it's limits and losing traction due to the small amount of tyre remaining on the ground.

On a stock country buggy with stock small tyres Terry is showing us that a country buggy is quite capable offroad.

However I wouldn't use the CB set-up on any car with a decent amount of HP. It's still a swingaxle with all the swingaxles normal handling problems, plus it's still a type 1 gearbox with the type 1 gearbox's weakness problems.

IRS is still the better way to go, but installing the CB rear end you have will certainly be a quick cheap way to a lot of rear end ground clearance that your front end won't be able to match.

Just my thoughts... :thumb


ratty 63 - January 19th, 2004 at 03:10 PM

...hmmm...

Quote:

I haven't driven a CB rear end car, but have been offroading with two and didn't like the way they were behaving. Up a sandy / muddy hill one of them was raising the susp to it's limits and losing traction due to the small amount of tyre remaining on the ground.



...this is exactly what I have heard happens, is there no known way around the problem?


Quote:

IRS is still the better way to go, but installing the CB rear end you have will certainly be a quick cheap way to a lot of rear end ground clearance that your front end won't be able to match.



...unless I have a CB front end too...:D

I have considered doing an IRS conversion, but though that this would be a cheaper option. Is there a 'how to' or discussion of the best way to do and IRS conversion somewhere here (or on another site?) Just think it might answer some of my questions...

R


ibmoknegawsklov - February 12th, 2004 at 07:58 AM

As a country buggy owner i would say it comes down to how you are going to drive it. Wes and Brad are famous for going where others fear to tread, in thier cases a bus box and IRS is the ultimate way to go. But if you have a little mechanical sympathy and aren't going extreme off roading i would use what you have. The reduction hubs reduce the torque loading on the gear box and the handling isn't as bad as people will tell you. It does take a bit of getting used to, i found it to be at its worst in soft sand, I think because of its tendency to lift the back end up on acceleration it wants to dig the wheels in to the sand . I run on 9.5R mud tyres though they probably aren't the best for sand driving. Good luck with it i think useing country buggy suspension is the way to go, you can always upgrade latter if you feel the need.


ratty 63 - February 12th, 2004 at 09:00 AM

Hi all,

Funny that this topic should come up again now, I had the opportunity at Dubs by the Pub to have a close look at a Baja that was fitted with a reduction box (CB) rear end. It had also had a spring arrangement fitted between the axels, and attached in the middle to the frame horn ends. This vehicle was used mainly on sand by the owner, and from all reports it worked extremely well. The extra spring acted a little like a sway bar at the same time, improving the handing at the same time.

I quite liked the look of this set-up, so I will be looking to do something similar to my vehicle I think.

Any ideas what gearbox I should use (I have the old CB box, but I don't expect it to be in fantastic condition, considering the condition of the vehicle that I removed it from!:o ). I would like the vehicle to be able to do highway speeds, without loosing too much of the low speed crawling ability (much needed for off-road situations!:) ) I am thinking of using a box from a '68/69 swing axel bug, but I havn't done the speed/revs calculation yet...

R


Baja Wes - February 12th, 2004 at 09:22 AM

Yeah I had a look at Brownies Baja too. The spring set-up was essentially a camber compensator, similar to what alot of people fit to swingaxles to prevent tuck. It seemed like a good idea. His was a pretty cool single leaf compensator attached by rods and ball joints, we thought it was cool so Brad took a picture of it. It looks like the way to go if your going to run the CB gear.


ratty 63 - February 12th, 2004 at 09:39 AM

...yep, that was the Baja - fairly well sorted all over from what I could see. I will be looking into this set-up in more detail soon.

Unfortunatly the pics I took of Brownies Baja's rear end set up are not of the best quality but have a look below and see if you can make sense of what we are talking about....

....I don't believe it - I was so wrapped up in the mechanicals, I forgot to take a pic of the top side!! :o


Baja Wes - February 12th, 2004 at 12:16 PM

I think John Alder from Volks Engineering ? has done all the mechanicals on that car, so he would be able to answer your questions.

You may have also noticed the running gear out of that baja is for sale, as it is being converted to IRS and a reno gearbox very soon.


ibmoknegawsklov - February 12th, 2004 at 03:54 PM

The camber comensater would certainly help the handling but seems to reduce the ground clearance a bit.