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not impressed with jba a arms(fixed)
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Author:  Boblemoche [ Wed Jun 10, 2009 9:56 pm ]
Post subject:  not impressed with jba a arms(fixed)
well seems like you need at least 3.5'' of bumpstop extention if you dont want to ruin them :?

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Author:  tjkj2002 [ Wed Jun 10, 2009 10:04 pm ]
Post subject: 
DUH :wink:

Lift a vehicle and extended bumbstops are needed.My JBA UCA's don't hit anything going up but the extended bumbstops my SkyJacker lift came with.




Oh and cutting the pockets is a bad idea,your CV's(even cut ones) will not like you.We already had to reconstruct one guy's UCA pockets to cure a nasty CV bind issue already.
Author:  Boblemoche [ Wed Jun 10, 2009 10:12 pm ]
Post subject: 
tjkj2002 wrote:
DUH :wink:

Lift a vehicle and extended bumbstops are needed.My JBA UCA's don't hit anything going up but the extended bumbstops my SkyJacker lift came with.




Oh and cutting the pockets is a bad idea,your CV's(even cut ones) will not like you.We already had to reconstruct one guy's UCA pockets to cure a nasty CV bind issue already.


I expected the need of bumpstops but a wooping 3.5'' seriously :roll: I need more bumpstop then the amount of lift I got. even with 2'' they hit the pockets before the bumpstops and there is more room for droop than what the ball joint will allow. seems like a bad design here
Author:  tjkj2002 [ Wed Jun 10, 2009 10:19 pm ]
Post subject: 
Boblemoche wrote:
tjkj2002 wrote:
DUH :wink:

Lift a vehicle and extended bumbstops are needed.My JBA UCA's don't hit anything going up but the extended bumbstops my SkyJacker lift came with.




Oh and cutting the pockets is a bad idea,your CV's(even cut ones) will not like you.We already had to reconstruct one guy's UCA pockets to cure a nasty CV bind issue already.


I expected the need of bumpstops but a wooping 3.5'' seriously :roll: I need more bumpstop then the amount of lift I got. even with 2'' they hit the pockets before the bumpstops and there is more room for droop than what the ball joint will allow. seems like a bad design here
Unfortunately you can't have it both ways,I've been beating my GENII JBA's for 4 years.Your coilover should be the limiting factor in the droop area,not the UCA,and a extended bumbstop should be limiting upward travel.Independant suspension is very difficult to engineer to keep a balance of strength and reliability while giving good travel.Seems like you have to long of coilovers for the IFS,and just remember that it a 2:1 ratio for the UCA/LCA movement on a KJ/KK so 2" lift you need a 4" extended bumbstop up front,3" of lift you'd really need a 6" extended bumbstop.
Author:  Boblemoche [ Wed Jun 10, 2009 10:27 pm ]
Post subject: 
my coilover are what is limiting the droop. what I mean is that the space in the pockets is not used properly since at full drop there is pleny of space left in the pocket under the arms but under compression your very limited. they sould be built so that at full drop its close to hitting the lower part of the pockets yet not touching then you would have enough room for a decent amount of uptravel.

also since the bumpstops are at the balljoint level its at 1/1 ratio :wink: the shocks are at a 2/1 ratio because they are half way between the balljoint and bushings on the a arms
Author:  tommudd [ Wed Jun 10, 2009 10:47 pm ]
Post subject: 
I am confused title reads not impressed with jba arms when in fact thats not what the real problem is. It looks as if you are mixing parts to get the most lift but they are not working in unison due to the longer than what will really work right spring/shock combination.
I agree with tjkj with the coilover being the limiting factor not the UCA, and also don't see how it will require 3.5 inches of bumpstop, if you only got 3 inches of lift. I guess I would need to see the complete cycle that the suspension runs through to see what is really the problem :?
Author:  Boblemoche [ Wed Jun 10, 2009 11:23 pm ]
Post subject: 
tommudd wrote:
I am confused title reads not impressed with jba arms when in fact thats not what the real problem is. It looks as if you are mixing parts to get the most lift but they are not working in unison

im not impressed by jba a arms because they could have been built to work better with the KK wheel travel whatever lift kit is on

Quote:
are not working in unison due to the longer than what will really work right spring/shock combination.


the problem is not that my shox are too long its that the A arms will not allow a decent amount of up travel. my problem would be pretty much the same with any lift kit. in fact it would be worst with other lift since im so lifted that I still have some uptravel available but with a smaller lift I would be riding on the bumpstops



Quote:
I agree with tjkj with the coilover being the limiting factor not the UCA,

its the case in terms of droop

Quote:
and also don't see how it will require 3.5 inches of bumpstop, if you only got 3 inches of lift.

what ever the amount of lift you do you will need 3.5 extended bump stops because the a arms hit before anything else . I bet those who did the 2.5'' and 4'' jbalift already dented their a arm pockets


Quote:
I guess I would need to see the complete cycle that the suspension runs through to see what is really the problem

Thats what I did

usually you use bumpstops to prevent damage to the springs and struts not the A arms :? the KK suspention will not allow any more than 2'' drop over stock and that is limited by ball joints/tie rods/cv's/a arm hittin the springs thus if you desing a good lift around that , you will move the struts lower by max 1'' (because of the 2/1 strut ratio) using either top strut plates/clevis lift like rock crawler/or different struts like jba. then you will need 2'' extended bumpstops to protect the struts or spring from being over compressed witch rock crawler dont provide hence all the problems with them. now if you want more than 2'' lift you need to play with the % of spring sag. stiffer spring will sag less. if you take the franken lift. half of the lift is gained using daystarr top plates (require bumpstop) and the other half is using stiffer ome springs. now knowing that the KK ifs will allow max 2'' more drop , it makes sence to design a arms that will allow at least the use of all the suspention travel (6'' on a KK)with 2'' extended bumpstops and seeing how much space there is in the KK a arms pockets it shouls be possible to design a arms that use all the travel without bump stops but no they require 3.5'' :x and thats why im disapointed. I think its a bad design what ever the lift is used
Author:  tjkj2002 [ Wed Jun 10, 2009 11:25 pm ]
Post subject: 
Boblemoche wrote:
my coilover are what is limiting the droop. what I mean is that the space in the pockets is not used properly since at full drop there is pleny of space left in the pocket under the arms but under compression your very limited. they sould be built so that at full drop its close to hitting the lower part of the pockets yet not touching then you would have enough room for a decent amount of uptravel.

also since the bumpstops are at the balljoint level its at 1/1 ratio :wink: the shocks are at a 2/1 ratio because they are half way between the balljoint and bushings on the a arms
Hence needing extended bumbstops since you got that CV shaft running through that clevis to worry about hitting,oh and it still is 2:1 ratio no matter what part of the UCA you go from.Plus the KJ/KK's IFS was never engineered to have alot of flex making it virtually impossible to re-engineer it and keep cost low to allow good flex.
Author:  Boblemoche [ Wed Jun 10, 2009 11:36 pm ]
Post subject: 
tjkj2002 wrote:
Boblemoche wrote:
my coilover are what is limiting the droop. what I mean is that the space in the pockets is not used properly since at full drop there is pleny of space left in the pocket under the arms but under compression your very limited. they sould be built so that at full drop its close to hitting the lower part of the pockets yet not touching then you would have enough room for a decent amount of uptravel.

also since the bumpstops are at the balljoint level its at 1/1 ratio :wink: the shocks are at a 2/1 ratio because they are half way between the balljoint and bushings on the a arms
Hence needing extended bumbstops since you got that CV shaft running through that clevis to worry about hitting,oh and it still is 2:1 ratio no matter what part of the UCA you go from.Plus the KJ/KK's IFS was never engineered to have alot of flex making it virtually impossible to re-engineer it and keep cost low to allow good flex.



please tell me how the cv's could hit anything or bind in some way while in the upper part of the travel. if thats the case then how a non lifted kj/kk can work without bumpstops :? the clevis is moving along with the cv's theres no way they can ever contact each other

2'' wheel travel = 1'' shock travel thats it... the 2/1 ratio dosent affect anything else. if you dont beleive me then measure the space between your a arm and bump stop then lift your wheel 1'' with a jack and measure again the space between the bumpstop and a arm :wink:
Author:  tjkj2002 [ Wed Jun 10, 2009 11:46 pm ]
Post subject: 
Boblemoche wrote:
tjkj2002 wrote:
Boblemoche wrote:
my coilover are what is limiting the droop. what I mean is that the space in the pockets is not used properly since at full drop there is pleny of space left in the pocket under the arms but under compression your very limited. they sould be built so that at full drop its close to hitting the lower part of the pockets yet not touching then you would have enough room for a decent amount of uptravel.

also since the bumpstops are at the balljoint level its at 1/1 ratio :wink: the shocks are at a 2/1 ratio because they are half way between the balljoint and bushings on the a arms
Hence needing extended bumbstops since you got that CV shaft running through that clevis to worry about hitting,oh and it still is 2:1 ratio no matter what part of the UCA you go from.Plus the KJ/KK's IFS was never engineered to have alot of flex making it virtually impossible to re-engineer it and keep cost low to allow good flex.



please tell me how the cv's could hit anything or bind in some way while in the upper part of the travel. if thats the case then how a non lifted kj/kk can work without bumpstops :?

2'' wheel travel = 1'' shock travel... thats it the 2/1 ration dosent affect anything else. if you dont beleive me then measure the space between your a arm and bump stop then lift your wheel 1'' with a jack and measure again the space between the bumpstop and a arm :wink:
Stock KJ's/KK's do have bumpstops designed for the amount of stock droop and upward travel.

I have measured,the distance between the UBJ and the bumbstop follows the 2:1 ratio since it sits about 1" from the inside edge of the tire and follows the same arc.So if you lifted your KK 3" you will need another 4" of bumbstop added,may get away 2"-3".Just remember that when you get your bigger tires those extended bumbstops will save your fender flares from being ripped off.Many KJ's that failed to install extended front bumpstops have ripped front flares off when lifted and running larger tires.
Author:  2006 KJ [ Wed Jun 10, 2009 11:50 pm ]
Post subject: 
i see what you mean with the Arm pocket... your saying if they were made with a little bit of a downward bend coming out of the pocket that it would let it go down further (maybe 1/2 the gap thats left at full droop which is now limited by your coilover) towards the bottom of the pocket... and let the suspension go up further before contacting the upper part of the pocket. i can picture it but hard to explain. i think your best bet in this situation is to call JBA.. his customer service is outstanding and he WILL take your suggestion to heart.
Author:  tjkj2002 [ Wed Jun 10, 2009 11:54 pm ]
Post subject: 
2006 KJ wrote:
i see what you mean with the Arm pocket... your saying if they were made with a little bit of a downward bend coming out of the pocket that it would let it go down further (maybe 1/2 the gap thats left at full droop which is now limited by your coilover) towards the bottom of the pocket... and let the suspension go up further before contacting the upper part of the pocket. i can picture it but hard to explain. i think your best bet in this situation is to call JBA.. his customer service is outstanding and he WILL take your suggestion to heart.
Remember the GENV arms? That was what you explained pretty much but they allowed to much and had issues.
Author:  2006 KJ [ Thu Jun 11, 2009 12:05 am ]
Post subject: 
tjkj2002 wrote:
2006 KJ wrote:
i see what you mean with the Arm pocket... your saying if they were made with a little bit of a downward bend coming out of the pocket that it would let it go down further (maybe 1/2 the gap thats left at full droop which is now limited by your coilover) towards the bottom of the pocket... and let the suspension go up further before contacting the upper part of the pocket. i can picture it but hard to explain. i think your best bet in this situation is to call JBA.. his customer service is outstanding and he WILL take your suggestion to heart.
Remember the GENV arms? That was what you explained pretty much but they allowed to much and had issues.


right which is what yielded the 4.5v but for his lift/setup/kk perhaps they need something different. the pockets do look larger than a kj's... just saying it's worth a call to JBA. they are no doubt still very nice arm's but could maybe be better?
Author:  Inc [ Thu Jun 11, 2009 12:11 am ]
Post subject: 
tjkj2002 wrote:
2006 KJ wrote:
i see what you mean with the Arm pocket... your saying if they were made with a little bit of a downward bend coming out of the pocket that it would let it go down further (maybe 1/2 the gap thats left at full droop which is now limited by your coilover) towards the bottom of the pocket... and let the suspension go up further before contacting the upper part of the pocket. i can picture it but hard to explain. i think your best bet in this situation is to call JBA.. his customer service is outstanding and he WILL take your suggestion to heart.
Remember the GENV arms? That was what you explained pretty much but they allowed to much and had issues.


So they knew there was an issue, tried to design the arms accordingly, and it didn't work so they went back to a design that doesn't really work either? :?
Author:  tjkj2002 [ Thu Jun 11, 2009 12:16 am ]
Post subject: 
Inc wrote:
tjkj2002 wrote:
2006 KJ wrote:
i see what you mean with the Arm pocket... your saying if they were made with a little bit of a downward bend coming out of the pocket that it would let it go down further (maybe 1/2 the gap thats left at full droop which is now limited by your coilover) towards the bottom of the pocket... and let the suspension go up further before contacting the upper part of the pocket. i can picture it but hard to explain. i think your best bet in this situation is to call JBA.. his customer service is outstanding and he WILL take your suggestion to heart.
Remember the GENV arms? That was what you explained pretty much but they allowed to much and had issues.


So they knew there was an issue, tried to design the arms accordingly, and it didn't work so they went back to a design that doesn't really work either? :?
Like I stated in a previous post that trying re-engineer the KJ's/KK's IFS to allow for full up/down travel is very hard while keeping it affordable,actually it's dang near impossible.You must give up something to gain something.
Author:  Boblemoche [ Thu Jun 11, 2009 12:32 am ]
Post subject: 
Quote:
Stock KJ's/KK's do have bumpstops designed for the amount of stock droop and upward travel.

I have measured,the distance between the UBJ and the bumbstop follows the 2:1 ratio since it sits about 1" from the inside edge of the tire and follows the same arc.So if you lifted your KK 3" you will need another 4" of bumbstop added,may get away 2"-3".Just remember that when you get your bigger tires those extended bumbstops will save your fender flares from being ripped off.Many KJ's that failed to install extended front bumpstops have ripped front flares off when lifted and running larger tires.


your right with the tires and thats why i had 2'' bumpstops already witch would have been perfect yet now I need more not because im lifted. the lift amount has nothing to do with the bumpstops in my case. I just need huge bumpstops to protect those A arms from self destructing thats why im pissed. they could have been designed to work with 2'' bumpstop or even 0'' yet they require a lot more. im sure diggers arms are dented like mine. everything on my ifs will allow the complete travel except those arms and even then they could work if they had a slightly different angle.

I already contacted jba about that. im waiting for a reply
Author:  tjkj2002 [ Thu Jun 11, 2009 12:36 am ]
Post subject: 
Boblemoche wrote:
Quote:
Stock KJ's/KK's do have bumpstops designed for the amount of stock droop and upward travel.

I have measured,the distance between the UBJ and the bumbstop follows the 2:1 ratio since it sits about 1" from the inside edge of the tire and follows the same arc.So if you lifted your KK 3" you will need another 4" of bumbstop added,may get away 2"-3".Just remember that when you get your bigger tires those extended bumbstops will save your fender flares from being ripped off.Many KJ's that failed to install extended front bumpstops have ripped front flares off when lifted and running larger tires.


your right with the tires and thats why i had 2'' bumpstops already witch would have been perfect yet now I need more not because im lifted. the lift amount has nothing to do with the bumpstops in my case. I just need huge bumpstops to protect those A arms from self destructing thats why im pissed. they could have been designed to work with 2'' bumpstop or even 0'' yet they require a lot more. im sure diggers arms are dented like mine. everything on my ifs will allow the complete travel except those arms and even then they could work if they had a slightly different angle.

I already contacted jba about that. im waiting for a reply
Yes it does since you lifted your KK over the stock height.

Oh and I believe Digger did not have(or has)extended front bumpstops.
Author:  Boblemoche [ Thu Jun 11, 2009 12:37 am ]
Post subject: 
Quote:
Like I stated in a previous post that trying re-engineer the KJ's/KK's IFS to allow for full up/down travel is very hard while keeping it affordable,actually it's dang near impossible.You must give up something to gain something.


your right and thats why I paid a lot and did a lot of custom machining to get it right and everything is working perfect except those arms. in fact they do work just not to my expectations :wink:
Author:  Inc [ Thu Jun 11, 2009 12:38 am ]
Post subject: 
Doesn't make sense to me to make a product that will limit travel like that. Especially in an IFS design that has such limited travel any way. Props to them for supplying us with aftermarket parts, but since these are known to fail, they seem really sketchy to me.
Author:  Boblemoche [ Thu Jun 11, 2009 12:40 am ]
Post subject: 
Quote:
Yes it does since you lifted your KK over the stock height.


no it dosent since my lift was designed not to use them


Quote:
Oh and I believe Digger did not have(or has)extended front bumpstops.


I want to see a pic of his arms
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