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Old 29th July 2009, 20:36   #46
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If we change from 8" width to 10.5" width tyres and if proper rim pushes them out, then the track will increase by 2.5 inches at both sides. That takes care of body roll.

But I agree to everyone that safety and ride quality is top priority therefore I suggest you to try out with sets from other fellow jeepers. Try out 16" army rim and sandgrip (I guess they will hit the inner wall on full turn, as rims are equally important for bolt on setup) Also try tyres from Allens 550 if the rims are 139 PDC and few more.

I have 10jj rims and the only drawback I find while road/offroad is that the steering spins by itself on hitting a rock in front. This feels very annoying and could be dangerous for thumb. Therefore I suggest you to try tyre and rim sets with other jeepers and experience yourself.
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Old 29th July 2009, 20:46   #47
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Behrambhai, where can one get these Army rims? I believe and I have been told that NDMS are the best tyres to put on jeeps namely CJs. As i am a newbie to this section, i need to understand the basics properly. Keeping on the topic of raising the ground clearance, are bigger NDMS tyres availble, i.e. with a bigger profile. If so then it would be a good thing to put larger NDMS tyres to raise the GC, wont it?

@ DKG-Thanks Deepak for clarifying about the non existant and highly misunderstood relationship between SPOA and GC. I was puzzled re the same too but i was afraid to ask here. Thats because i thought there must be some technicality involved that i didnt understand as to how the GC was affected.
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Old 29th July 2009, 22:07   #48
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750-16 tyres on 'army' rims would foul in the rear wheelarch (with the recess for the front seats). 750-16 tyres are close to 32" in dia, even 31-10.5R15 tyres (which are closer to 30" in dia) hit that intrusion into the wheel well.
Another problem is that there are no good 750-16 tyres available in India.

You may not be able to go over 30-9.5R15 with the stock suspension.
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Old 29th July 2009, 22:27   #49
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Quote:
Originally Posted by Alfa_Kilo View Post
Another problem is that there are no good 750-16 tyres available in India.
Some jeepers have put Apollo Bullet 4x4 tires in 7.50x16. JK LT2000 4x4 is also available in this size. This is the OEM Gurkha tires.
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Old 29th July 2009, 23:08   #50
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What a lot of guys need to understand is SPOA improves break-over angle (right term?) which is not GC. It is the middle portion between the axles where most of you might be bottoming out, most of the time. And this is what SPOA solves and this is why "dime a dozen" garages, Khan_Sultan and extreme_power have done it.
Over and out.
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Old 29th July 2009, 23:21   #51
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Quote:
Originally Posted by 4x4addict View Post
Some jeepers have put Apollo Bullet 4x4 tires in 7.50x16. JK LT2000 4x4 is also available in this size. This is the OEM Gurkha tires.
Thse tyres have a very poor usefull life of 10-15K kms. The tread blocks are tapered, so the voids become narrowere as they wear down. All the tyres are tube type.
A Gurkha owner I spoke with was not very impressed with the JK LT2000.
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Old 29th July 2009, 23:32   #52
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Quote:
Originally Posted by Samurai View Post
GTO, I am a little skeptical about moving to 31x10.5 tyres on a 340, and this is why.

These were Michelin LTX by the way.
Samurai,

Your negative experience may have had more to do with the poor overall condition of the jeep and worn out suspension components.

Also, I would not recommend the 16 inch wheel configuration as this is a very stiff tire that gives very little tire sidewall flex compared to a 15 incher.

General comment on SPOA: Don't do it unless your jeep is a dedicated off roader.
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Old 29th July 2009, 23:41   #53
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Quote:
Originally Posted by DHABHAR.BEHRAM View Post
Dear DKG - thank you for clearly reinforcing what I have been saying all along. You just cannot play around with reliability. I have seen a dime a dozen garages just waiting to take away people's hard earned money and sopil their cars at the same time.
Dear Mr. Dhabhar a lot of very passionate Jeepers here can get a bit carried away and the only reason why I voiced my opinion is their life is at stake when the dynamics of a vehicle are compromised. I earnestly request fellow Jeepers to consult with you on all such proposed modifications. Knowing your credentials and experience one can safely assume your advice to people here will first and foremost be in the interests of their safety first.

@ V16 how far has your Jeep restoration progressed ? been wanting to ask you about it

Quote:
Originally Posted by nitrous View Post
What a lot of guys need to understand is SPOA improves break-over angle (right term?) which is not GC. It is the middle portion between the axles where most of you might be bottoming out, most of the time. And this is what SPOA solves and this is why "dime a dozen" garages, Khan_Sultan and extreme_power have done it.
Over and out.
How often do you ground a 80 inch wheelbase Jeep Nitrous to warrant an elevation? With the right angles of approach it would be a rare occasion when a short chassis Jeeps bottoms out. In my observation the greater problem in the Gypsy is the limited departure angle on account of the overhang not a poor break over angle.

SPOA makes sense only if you address the track and wheelbase upgrades, not to mention the very complicated science of monitoring weight transfers etc along with it which makes the whole exercise totally complicated. Usually in the US offroaders take long wheelbase trucks, change to extra wide track and then go for lift kits. End result is they may have something for the offroad terrain but the onroad manners get buggered up completely.

Last edited by DKG : 29th July 2009 at 23:44.
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Old 29th July 2009, 23:50   #54
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Quote:
Originally Posted by DKG
How often do you ground a 80 inch wheelbase Jeep Nitrous to warrant an elevation?
Ask the thread starter.
Quote:
Originally Posted by DKG
In my observation the greater problem in the Gypsy is the limited departure angle on account of the overhang
That was solved ages ago with Headers doing the chop followed by Khan_Sultan.
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Old 30th July 2009, 01:31   #55
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Hi gto 31" tyres should do fine but only if you got 10j size rims with good offset. One of my friends had maxxiss mudzillas on his cj3 petrol and it was working fine on and offroad, the only thing is while offroading if you hit a stone the steering tends to turn very sharply,lowering the tyre air pressure does help to absorb the impact. On the whole the jeep was stable. There is one more thing that can help you gaining more ground clearance is by modifying your jeep shackle mounts, this is a shackel reversel kit check these pictures. You may get some ideas. (not the SPOA).
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Old 30th July 2009, 02:41   #56
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Quote:
Originally Posted by ex670c View Post
Hi Rahul,

Measure the tyre height(diameter) with a tape when they are fitted in the vehicle. (Static Loaded)


275-70-16 = 31.15inches

31-10.5-15 = 30-31" on 8.5" wide Rim.

7.50X16 = 31" = but when fitted in an MM550XD is actually 30.5'-31" depending on the brand of the tyre, Apollo Bullets being the tallest.

Regards,

Arka

31-10.5-15 = 30.6 inches

275-70-16 = 31.4 inches

Source
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Old 30th July 2009, 07:30   #57
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Shackle mount or longer shackle itself or may be the longer spring plates, as shown in the video here:



One more interesting blogpost by some with suspension over axle, the same way our Khan_Sultan done it for his Gypsy, Here is the important point as quoted in the link

"In order to make room for the 35” tires, Rod moved the leaf springs above the axles. Six leaf Rancho lift springs, originally intended for the rear of an early CJ-5, are used up front. These 1 3/4” wide and 45” long springs are used in conjunction with a shackle reversal and Rancho shocks. The rear suspension uses 2” wide Rancho springs intended for a later model CJ. Other than the width, the spring length, number of leaves, and shock configuration mirror the front of the rig."

Checkout the picture which are self explanatory

Courtesy: Rod Womack's 1953 Jeep CJ3A - Off-Road Adventures Magazine

Last edited by trammway : 30th July 2009 at 07:35.
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Old 30th July 2009, 10:24   #58
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Quote:
Originally Posted by whicked wheels View Post
...modifying your jeep shackle mounts, this is a shackel reversel kit check these pictures. ...
Quote:
Originally Posted by trammway View Post
...."In order to make room for the 35 tires, Rod moved the leaf springs above the axles. Six leaf Rancho lift springs, originally intended for the rear of an early CJ-5, are used up front. These 1 3/4 wide and 45 long springs are used in conjunction with a shackle reversal and Rancho shocks. The rear suspension uses 2 wide Rancho springs intended for a later model CJ. Other than the width, the spring length, number of leaves, and shock configuration mirror the front of the rig."
...
Here are some pro's and cons of Shackel reversal.

Pros and Cons of Shackle Reversal

It's looks simple and is an effective one too. However there are things that people should understand before doing it. That way they will be better informed and would know what all aspects they need to address during this mod job.
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Old 30th July 2009, 10:37   #59
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Hello guys,

No new inputs about the higher GC from my side however would like to point out that shackle reversal at the front results in a stiffer ride speially in on-road performance. GTO has already mentioned in the very first post, is not in favour of.

The reason: The front leaf springs are normally straighter. When the wheel hits a bump the front leaf springs contract reducing the length of the end to end straight distance of the leaf. Now the rear end of the leaf is fixed to the chasis.The front shackle thus moves backwards alongwith the wheel to compromise the contraction of the front leaf spring. Hence it absorbs some of the impact. Its just the opposite with the rear springs.

Regards...Saikat
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Old 30th July 2009, 14:34   #60
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Quote:
Originally Posted by Samurai View Post
GTO, I am a little skeptical about moving to 31x10.5 tyres on a 340, and this is why.

These were Michelin LTX by the way.

That is because of the following reasons.

1) Sand does not allow the steering to re-center because of the additional resistance caused by the contact patch and flotation of the vehicle vis-avis the surface i.e how much you are digging/sinking/biting in, try driving on sand track/rails

2) Maybe your steering is not setup properly.

3) Broader tyres reduce the steering re-centering.

Quote:
Originally Posted by DKG View Post
How often do you ground a 80 inch wheelbase Jeep Nitrous to warrant an elevation? With the right angles of approach it would be a rare occasion when a short chassis Jeeps bottoms out. In my observation the greater problem in the Gypsy is the limited departure angle on account of the overhang not a poor break over angle.
Depends on how often, one goes OTR and with whom.

IIRC at least one CJ3B per OTR during 2005-2006 Feb OTRs.

I have bottomed out my CJ3B once every other OTR in 2005. (12/6)

Definitely even CJ3B's get stuck, we are discussing how to facilitate it's not getting stuck.

1) Power - XD3P

2) Better Suspension - Uprated shocks

3) Taller Tyres - maxxis 31-10.50-15

4) TRACTION AIDING DEVICES - Dog-Clutch LSD

Regards,

Arka

Last edited by Jaggu : 30th July 2009 at 15:38. Reason: Please EDIT the original thread instead of back to back posts, Thanks
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