Wheelbase vs trailing arm length

[theTman]

Originally Posted by SCREAMER

Although, any excuse to buy one of these beauties is a good reason. Major strength upgrade and look badass too. You get tuning options with these as well with link mounting location. If you're going shorter for better crawlability, go with TH length. If you do Wraith length, you'll just wish later that you had gone shorter. Wraith length should have been stock length in my opinion. TH length performs best and looks most correct scale wise. I've seen a couple guys with Wraith length say, "I shoulda got the TH length to begin with". The Yeti arms are just way too long and give no real benefits over Wraith length. This is from first hand testing. Even my go fast Bomber has Wraith length TAs.

What advantages do longer trailing arms offers? I have twin hammers arms now as I was leaning towards competitive crawling, but the even the local scaler comps are no longer fun. I'm looking at doing more trail runs and hiking. Though it will include some crawling, I won't be pursuing absurdly difficult climbs like the local comps force on you as of late. I am thinking maybe something more like G6 type driving minus actually driving with G6 rules, but rather just having fun.

I am debating on going back to stock length or wraith length. I have incision rear stock length uppera sitting around from my kit.

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[powder4breakfast]

I know its been said that I might regret not going to the shorter TH arms right off the bat; but, I'm leaning towards just dropping down the 1/2" to Wraith length wheelbase.

1) What are the options for Wraith length trailing arms? Apparently UCFab is done making them? ...and Dlux is out. Is Blue Monkey the only other option?

2) It was briefly mentioned back a few posts that someone could have kept their Twin Hammers length TA's and just added longer rod ends to get Wraith length. Would this be a realistic option allowing the ability to change to either? ...or would this leave you with an inferior product compared to the correct length TA's from the start?

3) If I go to Wraith length TA's, will I still be able to run my VP Antiroc swaybar in the standard position (forward frame mount not back of frame)?

For fit, I have the AR60 axles with Beef Tubes and don't plan to go to Currie or SSD axles at this time.

[Drm31078]

Scroll up. JEC makes stainless steel wraith length TAs.

[84yoda]

Originally Posted by powder4breakfast

I know its been said that I might regret not going to the shorter TH arms right off the bat; but, I'm leaning towards just dropping down the 1/2" to Wraith length wheelbase.

1) What are the options for Wraith length trailing arms? Apparently UCFab is done making them? ...and Dlux is out. Is Blue Monkey the only other option?

2) It was briefly mentioned back a few posts that someone could have kept their Twin Hammers length TA's and just added longer rod ends to get Wraith length. Would this be a realistic option allowing the ability to change to either? ...or would this leave you with an inferior product compared to the correct length TA's from the start?

3) If I go to Wraith length TA's, will I still be able to run my VP Antiroc swaybar in the standard position (forward frame mount not back of frame)?

For fit, I have the AR60 axles with Beef Tubes and don't plan to go to Currie or SSD axles at this time.

1. Blue monkey or JEC racing. I have a set of JEC racing SS wraith length trailing arms in the mail, hopefully have them today.

2. Yes its totally fine, but if you use a longer rod end, I would use RPM rod ends. Reason I got the wraith length is so I can run it with 2 revo ends and have wraith length or I'll try using one long RPM rod end to get yeti length.

3. Yes.

[Drm31078]

Just got the JEC trailing arms in the mail today. Wow. They are a piece of art.

[SCREAMER]

I just got my third set from JEC, love 'em. I use DLux arms when I'm trying to save weight and JEC when I want more weight in the rear. Blue Monkey arms would also be a great weight saving option and they are made with 7075 also.

[powder4breakfast]

Blue Monkey Wraith TA's ordered. Now I just need uppers. Hoping to find Incision SS uppers... even if I have to order the whole set just for the upper links. Maybe I'll throw the Bomber uppers I have in the kit and re-sell as a bomber SS kit since the rest is the same.

[Deckard]

Just ordered some Wraith TAs from JEC. These will be replacing the stock Twin Hammers TAs I have no my rig now. I like the way the rig handles with the TH TAs crawling, but it gets cray cray when I get hard on the throttle (I know it's a Bomber). I'm hoping the Wraith TAs will give me the best of both worlds.

I'll post some pics as soon as I get them installed. BTW, JEC is very cool and very helpful. So is Dlux, Holmes Hobbies, CI. We have some kick ass vendors in this part of the RC world.

[powder4breakfast]

I'll investigate once I get all the pieces together; but, does shortening the TA's affect the spring rate?

It seems that moving the wheel/axle line closer (1/2") in the case of Wraith TA's would affect the fulcrum point and stiffen up the spring since their is now less leverage. I wrote that wrong as the spring wouldn't actually get more stiff. Would the resting height and feel of the spring change?

Is this the case from anyone's experience? Or is any difference (if technically even there) too small to notice? Or am I missing an obvious physics key that disproves my thinking?

[Deckard]

Originally Posted by powder4breakfast

I'll investigate once I get all the pieces together; but, does shortening the TA's affect the spring rate?

It seems that moving the wheel/axle line closer (1/2") in the case of Wraith TA's would affect the fulcrum point and stiffen up the spring since their is now less leverage. I wrote that wrong as the spring wouldn't actually get more stiff. Would the resting height and feel of the spring change?

Is this the case from anyone's experience? Or is any difference (if technically even there) too small to notice? Or am I missing an obvious physics key that disproves my thinking?

I noticed it when I went to the Twin Hammers TAs. There was definitely more bounce. Just let off the preload, soften the springs, etc. It's not hard to get it dialed in with a little tweaking.

[powder4breakfast]

Originally Posted by Deckard

I noticed it when I went to the Twin Hammers TAs. There was definitely more bounce. Just let off the preload, soften the springs, etc. It's not hard to get it dialed in with a little tweaking.

As my rig stands right now I feel like I'm right on the boarder of two springs (Red and Purple) and chose the softer of the two after crawling both on the same lines. I do feel I need to put a heavier weight oil in the rear. I am running 30wt now and will go to 40 or 50.

I was curious as to whether I should go ahead and make the changes at the same time I install the new links and TA's, or try it out first if there is a difference that can be felt.

[84yoda]

That is a good question. But spring rate is spring rate, it doesn't change unless your running progressive springs. But the difference is leverage, TA's just make it compress easier vs shocks on axle. Thats why the bomber has a lot of torque twist vs say a wraith with links and shocks mounted on axle. Moving the shock back on the TA helps with torque twist. Im sure someone will get all scientific with it but thats the simple verison. Lol.

Edit: also, people think adding more preload turning the shock collars down adjusts spring rate, which is not true.

[lotsalemon]

Read through the posts here, tried a combination of few things, but not sure I got this right.

Currently using JEC wraith-length trailing arms with BMRC wraith-length uppers. Stock rear axle. Shortened drive shaft length from the included RTR parts tree.
I'm not sure I have full suspension travel with this set up - there isn't any binding but it seems upper travel is limited when compared to the front.

Is there anything I'm missing?

[Brake Weight]

Shortening the TA will make the springs feel like they are stiffer. Increase the length and they will feel softer.

[shiftauto]

From what I've read, it looks like everyone is using the stock driveshaft with the shorter pieces from the parts bag. Are any of you running MIP shafts with the shorter TA's? I'm leaning towards the wraith length TA but not sure about what shaft to buy. Would I just buy the wraith Mip kit and it'll pop right in? Do I need to buy the bomber Mip kit from super shafty and try to modify it? After looking @ the wraith Mip shafts online I noticed they have 2 of the longer end pieces instead of 1 like my scx has. Any ideas, experience, or suggestions?

[YeeP]

Originally Posted by shiftauto

From what I've read, it looks like everyone is using the stock driveshaft with the shorter pieces from the parts bag. Are any of you running MIP shafts with the shorter TA's? I'm leaning towards the wraith length TA but not sure about what shaft to buy. Would I just buy the wraith Mip kit and it'll pop right in? Do I need to buy the bomber Mip kit from super shafty and try to modify it? After looking @ the wraith Mip shafts online I noticed they have 2 of the longer end pieces instead of 1 like my scx has. Any ideas, experience, or suggestions?

I am running stock but I also have a stock powerplant.

[SCREAMER]

Originally Posted by shiftauto

From what I've read, it looks like everyone is using the stock driveshaft with the shorter pieces from the parts bag. Are any of you running MIP shafts with the shorter TA's? I'm leaning towards the wraith length TA but not sure about what shaft to buy. Would I just buy the wraith Mip kit and it'll pop right in? Do I need to buy the bomber Mip kit from super shafty and try to modify it? After looking @ the wraith Mip shafts online I noticed they have 2 of the longer end pieces instead of 1 like my scx has. Any ideas, experience, or suggestions?

Give the stock driveshafts a chance and I think you'll be surprised how durable they are. My trucks running 3s and 4s brushless haven't managed to twist one yet. You can also try Traxxas Maxx shafts and yokes. Easy to trim to fit the exact length you need and very strong and quiet. MIPs are heavy, have loose tolerances, and don't like to stay together. They're also expensive and completely unnecessary in most applications. JMHO

[shiftauto]

Thanks screamer. Runnin mamba monster X with Holmes pp 2700kv and figured it's only a matter of time til the rear lets go. My yeti spun the rear into pieces on its 4th run out. Hate when a rig is down for something like that. Good to know yours is holding up on 4S, I'm only runnin 3S on mine @ the moment.

[SCREAMER]

I'm running an MMX with a Holmes Puller Pro 3500kv on 3s and 4s and I'm running an MMP with a Holmes 2200kv on 4s. No driveline issues yet and my driveshafts are definitely my weakest point being the only plastic part in the entire driveline. SuperShafty bombproof trans on the 3500kv combo and RRP upgraded Bomber trans on the 2200kv rig. Not a single driveshaft issue yet. I will add that I don't do a lot of bashing type driving but I do like to go full tilt now and then. Most of my driving is technical crawling or rock bouncing. There are a couple other variables to consider. On my go fast rig I run 30% punch control and both trucks have RRP slippers.

[shiftauto]

Good stuff. I like to get to the spot fast and crawl em slow too, no bashing. Have my 10+lb expensively upgraded yeti to beat the snot out of.lol I'll rock the stock driveline til I have a problem. You just opened my budget to buy something else for my rig!! Thanks