Ultimate Pen Spring Mod to climb steep stuff! I use this on my crawler

[@samhulme]

Joe, where are them stands from pal?

[@JustScalin]

They are from a guy called Sam Dare. Did a little review on them here and his details are in the description: kzbin.info/www/bejne/e6rSf2Wkpp6GY6M I really like them and have one for all of my crawlers

[@samhulme]

@@JustScalin cheers matey 👍🏻

[@jasongreek4689]

Best spring mod video i have ever seen!! You explain this perfect!

[@allyoucando8486]

You explained really well, now i understand why i can climb 60 degree, thanks man

[@dwmahan]

Another great video! Can't believe your channel isn't much bigger! Stay with it, please. You give fantastic info!

[@JustScalin]

I appreciate that! Working on it, but it takes time

[@sebas888888]

I really like your content and how well you explain the techno babble. keep rocking and may the torque be with you

[@rekozma]

Really digging your content. Tomley is my very favorite rc channel but on the tech side rc clan and you are neck and neck. Your pulling ahead daily. Cheers.

[@JustScalin]

Yeah Phil is a sound bloke and I watch a lot of his vids too

[@ledistortioniste2758]

thanks! all well explained! noob me understood everything

[@babooll5632]

I like my chassis a little higher for clearance, then use 1/4 oz adhesive wheel weight around the inside of my rims. So I have decent clearance heavier wheels, and battery pack low over the front axle

[@DLB-1973]

Subbed!! You Rock! You Explain Perfect!! Look forward to viewing Other videos 💯

[@JustScalin]

Awesome, thank you!

[@mattrogers8280]

In the states you should be able to find the box of springs at Harbor Freight also.

[@JustScalin]

Awesome, thanks for letting people know!

[@morris4069]

I find it not how far the front unloads but how much the rear loads n squats that reduces your climbing angle. Doing the spring mod in only the rear may work better with the front normal but a low preset. Any amount of overdrive helps also.

[@need4drift]

Nice. Thanks for sharing brotha. 👍

[@ECG1OOO]

Nice! Good info there.

[@JustScalin]

Glad I could help!

[@ArmanRC]

i still confuse about hidrolic of shock, btw great tips

[@danweiss4928]

Nice video. I was wondering if you could use a longer shock? By using the longer shock would you keep all your articulation? Or would that just cancel out the droop you were trying to achieve?? Thanks 🙏

[@JustScalin]

It’d cancel out the benefit which is reduced upwards travel and limited articulation

[@tdro98]

Tanks for the tips

[@christianadkins2305]

This essentially makes the primary spring softer once it gets to that point, correct?

[@stuartolson8340]

Great information....thanks for sharing. Just a simple suggestion.....aim your camera a little higher. There were times when your hands and the shock were above the viewing area. The rest of the time, you were "working" in the upper third of the viewing area. You're taking the time to do the video so might as well make it a good one, right? Thanks again for sharing the information.

[@JustScalin]

Thanks for the tip

[@drift9089]

Good step by step video. What oil weight do you recommend for this pen mod?

[@JustScalin]

Check out my video on choosing the right oil. It all depends on your shocks and trucks spring weight

[@saltyguerrilla]

Great video! Can you explain to me when would the shocks in full droop would allow the shaft to extend out if the barrel, since the inner spring is always pulling the shaft into the barrel? Does the weight of the axels pull the shaft down?

[@JustScalin]

The inner spring is very short, so only affects it near full extension

[@henrymrowka1142]

Would this work with internal spring shocks

[@alifkhanfatihkara]

How if I only using inner spring from pen, not using outer spring anymore?

[@givemethetruth7232]

Why not just use a shorter shock?

[@briansrcadventures1316]

5.5mm by 17.5mm springs you say? I have tried a pen spring mod on the front shocks of my FTX Mauler, but I found I lost quite a bit of shock travel. Seems you can get 5.5mm by 17mm on Amazon for a few £, rather than ordering a selection box and not really needing the rest of the springs

[@zoranmihalic4900]

Dis is good

[@sneakyfpv8914]

I often did land and mud trail tracks in my location, do i need droop or just sprung setting to my shocks?

[@Tuidkskiwjdhdbd]

Those tires are they the same compound as duratrax bc I don't feel much traction with my duratrax tires are these Louise rowdy tires

[@JustScalin]

Yes Louise and Duratrax are the same. I’ve found a good wash with degreaser to get the factory release agent out is a must with them

[@Nickeeefy]

Great tip! Have just been starting to look into my suspension, what can i upgrade to this year competion. I have just crawl about a year so everything is pretty new to me. I took my trx4 gts shocks and did the same as you but i cut half the pen spring and put into the front shocks and cut slightly more to the back shocks for more easy travel. I run the orginal spring rate 0.45/54 do u think it will work better if i change to softer outher springs with ratio 0.22? im also thinking about angle them abit atleast the back shocks. But im really unsure of everything..

[@JustScalin]

Angle will mess with the spring rates, so unless the mount point gives more or less articulation stay with the standard angle. Spring rates are discussed in another video I have. It all depends on what ride height you want really

[@Nickeeefy]

@@JustScalin Alrighy! Then il stay with the standard trx4 mount and angle for now. I know i want it low without loosing to much travel im afraid if i just go with the softest outer springs without an internal it wont climb as good and loosing degrees. But if i use the internal spring aswell the car might get stuck on a cliff edge without the backwheels touching the ground. So trying to make the best to get both :-)

[@JustScalin]

Yeah it’s a painful trade off. I ended up going without and using more anti-squat, but to do that you need either different frame rails or a different skid design and again more trade offs involved there. Technique is also a factor and remembering to try and “jump” at the top helps, although can result in unpredictable results

[@THATHATSALLFOLKS]

but every time the shock extends it crunches the spring

[@JustScalin]

Yes, that’s kind of the point.

[@blowback8852]

What wheel/beadlock is on the low cg setup (scatergun)?

[@JustScalin]

SSD 8 hole steelies. Super lightweight and tough as hell

[@cf5914]

Wouldn’t a thicker oil achieve the same thing by slowing the rebound rate? You could also you pistons that are tapered with smaller holes on the bottom side.

[@JustScalin]

Sounds interesting, but would be a different effect I think. The theory behind a pen-spring is travel limit (reducing from 25mm to 21mm for example) while also having a gentle / progressive reaching of the end of that travel. The alternative is simply some fuel tube instead of the spring, which will reduce travel, but the compression is linear (in a standard shock angle setup). With a pen-spring the compression ramps up near the end of travel to stop any kind of hard bump. I hope this makes sense?

[@cf5914]

@@JustScalin it does but limiting travel reduces articulation. It seems to me that a better compromise would be to slow the rebound rate thereby giving you enough time to complete a steep climb but still allowing for full droop and full travel to provide traction in uneven sections. Rebound rates can be independently controlled to a degree. You could just set the shock to very slowly reach full extension.

[@JustScalin]

Good point, although this mod is deliberately to limit articulation. So it helps on climbs and side-hills etc. The slow rebound sounds interesting though

[@joshlvn7732]

Are you running overdrive/under drive on your scattergun?

[@JustScalin]

Yes, around 27-50% so far, settled on 33% and it’s the best it’s been so far. TRX4 steering isn’t the best though

[@JuvsTagabanRC]

Does it also applies on the rear shocks? or it should be the front shocks only?

[@JustScalin]

It’s usually on the front to limit how far back it tips when climbing extreme angles. I’ve run it all round on trucks before and it’s interesting, although at that point I’d probably just suggest shorter shocks

[@JuvsTagabanRC]

@@JustScalin will it also help in steep side hills like 50+ degrees angle?

[@JustScalin]

It will improve your side hill, I don’t know your setup enough to say if it’s 50+. Again it limits body articulation so stops the truck tipping

[@JuvsTagabanRC]

@@JustScalin thanks for your tips bro!😊

[@Mudsuitable]

Why not run two springs with different rates on the same shock this way no travel or flex capability is lost

[@JustScalin]

Because the idea is to limit travel with soft / progressive stop instead of a hard stop

[@richardmarsden6516]

Dont suppose you have a part number for these please

[@JustScalin]

For the tiny springs? I went to Amazon and searched for “small spring” and that was about it. They aren’t specific to a shock

[@richardmarsden6516]

Thanks ive been looking at all the compression spring kits but they didn't look right

[@faiscas1]

sorry to bother you but, i have an RC, not a top of the range car, MN86, i installed a shock absorber and now it seems very high. this change, helps to lower the height of the car? thanks

[@JustScalin]

Please never apologise! Yes doing this mod will lower the ride height if you use the right springs. However it sounds like the shocks you’ve used have springs that are just far too stiff. Do you have the option of swapping the springs in the shocks or removing any pre-load?

[@faiscas1]

@@JustScalin they already are with no pre load, however, they may be a little too big 90mm.... any idea if relocate the socks will help? Thank. I really like your channel.

[@JustScalin]

Thanks! I’d say they might be a bit too long, but relocating the shocks would help, also if there’s the option of laying them over so they are angled instead of up-down that would soften the spring rate. Or as you’ve said do the pen springs mod which will soften the spring rate

[@faiscas1]

@@JustScalin thank you very much, i´ll see what i can do :p.

[@JustScalin]

Let me know how it goes!

[@al-baghdadi7854]

So u have full Droop at the Front and semi at the rear ?

[@JustScalin]

Droop usually refers to internal springs or no springs, so I use “sag” instead. For my LCG truck it’s pretty much full sag, there’s a spring but it’s weak and allows some resistance on the front and a medium spring on the rear for a 40% sag. Trail trucks are always 50% front & rear for me

[@al-baghdadi7854]

@@JustScalin Sry my English ist not that good , does sag means that the spring Pulls the Car to the Ground ? And you say internal dampers are better for drooping mods ?

[@JustScalin]

It’s all good. Sag is the amount the spring has been compressed. I don’t like droop setups where the truck is pulled to the ground

[@al-baghdadi7854]

@@JustScalin i am confised a little bit right now 😆 Sag means the Car pulling the tires to the Body and Droop means it pushes the tires away from the Body ?

[@JustScalin]

Sag is resting on the springs, droop is the springs pulling down

[@jamessmith2411]

Great video... This is the setup I was looking at doing but the KZbin video I watched he used a small spacer or nitro fuel pipe.

[@JustScalin]

Yeah spacers or pipe are just to restrict travel, this adds a bit of a bump or progression to the mix to reduce a hard hit at the end of the travel. Instead you kind of ease into it

[@Avtoinstruktor-78]

👍👍💰❤️

[@Djkommode]

Interesting

[@raven5347]

U need a shock tool

[@JustScalin]

For sure!

[@jakubmenousek3333]

Less oil, more air, setup at high pressure. The same function as your solution :-) And without pen spring *LOL*

[@al-baghdadi7854]

Do you have Video ?

[@JustScalin]

Then you're affecting damping quite significantly, so not quite the same

[@mwcockre]

so no flex?

[@JustScalin]

It’s to reduce upward travel on the front. So yes limits flex too but that’s the trade off for better climbing ability

[@Breezio69]

You could do this mod how I did it to gain your flex back. I bought shocks that are 10mm longer than stock and then I did the internal spring mod. Gained a bit of flex/droop and it still sits at the stock ride height.

[@JustScalin]

The point of this mod is to limit articulation and travel, so not sure that makes sense. Why not just unwind your preload so you get the right ride height?

[@Breezio69]

Although I see your point I thought the main reason of internal springing the shocks was to limit body roll on side hills, to keep the springs from unloading at a certain tipping point and causing a roll over. There is a way to achieve both flex and low COG. Your way, which works, but limits droop, or buying slightly longer shocks to achieve the same thing and still having at least a stock amount of shock droop, because when the internal spring is compressed in the longer shock you still have the same travel as stock. Also. To your point of why not just using the threaded collars to set ride height. That also changes the compression characteristics of the spring. The more preload you put on it the harder (granted not a ton on lightweight springs) force it is to compress, so I try and not use them a lot in tuning a shock. Mostly to just get maybe a little spring sag out of shocks that aren't internally sprung

[@Breezio69]

But either way dude, not bashing your theory or any of the points that were brought up in the video. At all. I was just referring to the comment that was made that you would have no flex, putting the option out there that this can be done and maintain a stock amount of flex or possibly gaining a little more, and limiting body roll.