Bending/losing Hinge Pins?

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OnThatPipe

On a vacation
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63
I've seen a lot where people are bending/losing their hinge pins, and want to shed some light as to why it is and how to solve it.

Why:
Landing is the easiest way to bend/lose hinge pins with a stock Savage, This is due to:

  • During a nose dive, ton the Savage, often the tires will hit the ground before the bumper begins to absorb the impact. This causes the A-arms to spread, the and the lower hinge-pins (unless protected) will bend. They are the .
  • Neither of the upper or lower aren't captured. This is a major flaw when it comes to front or rear impacts.
  • The bulkhead is simply not protected. The lower hinge pins are held in by thin, nylon stops and those will wear very quickly.

Stronger A-Arms?
Thinking the arm was a POF, I opted for the RPM A-Arms. Are you kidding me? Both the lower and upper arms bind the suspension severely. Company recommends to "drill a hole" or ream it out. Really? I mean come on. Trust me, I wrench. Unless you have the special tools needed to due that properly....everything you have done for your suspension will be moot. These hinge pins are a pivotal design to the suspension and if there is a ......01% of play they will wreak havoc on your suspension.. The RPM arms also don't have sway bar mounts. Only disadvantage to using those IMO.

Steel Bulkhead?
Yes and no. A steel bulkhead itself is not going to protect the hinge-pins. The metal plate, will however, prevent the hinge pins from from coming out on that side however the opposite end still needs to be captured, Again, often with the kit, but I only needed the toe blocks I am used to. This also saves me a tremendous amount of weight.

How to Fix It

  1. Use something to capture the upper pins (not zip ties) in their existing toe block. The HPI sway bar kit comes with perfect mounts for the upper pins. You can use them without the Sway bar as well.
  2. The Alza toe block kit uses a normal toe block design you see in most flat-chassis vehicles. They are a little heavy for toe-blocks, but Dejan did a good job recognizing this flaw.
  3. Tbone Racing Bumper. As noted, using the stock bumper, the a-arms spread on front end collisions. The T-Bone bumper stops that. Completely.
  4. Alum shock towers. While this was not having an affect on the lower hinge pins bending, it was causing an issue with the joint posts bending. This nylon stock flexes and impacts the bulkhead. Once this happens, the truck will be tweaked and you will burn spurs all day long.

I hope this helps you guys.
 
guess I am either lucky or just good, in almost 5 years I have not bent even 1 hingepin, I have crashed flipped barrel rolled and just about every other type of crash and it is holding strong all with stock X suspension to boot...... I did zip tie the bumper so it does not spread too much, if it becomes a problem I will drill some small holes and install setscrews to keep them from sliding out of place. so far so good tho....DSCN7038.JPG
 
I broke one in my flux and bent one. I've busted 3 of the lower hinge pin braces in half over the past year. The last one I put on it was a FLM one I think. Haven't driven it much since then.

2018-0723-SavageFlux-FLMHingePinRetainer01.jpg
 
guess I am either lucky or just good, in almost 5 years I have not bent even 1 hingepin, I have crashed flipped barrel rolled and just about every other type of crash and it is holding strong all with stock X suspension to boot...... I did zip tie the bumper so it does not spread too much, if it becomes a problem I will drill some small holes and install setscrews to keep them from sliding out of place. so far so good tho....

That's awesome! Yep..you have been damn lucky, and perhaps the only person I know who has gotten busy with their Savage and not had issue with their hinge pins. They had to have been freak collisions and don't understand how zip ties held the pins in place. All they do is wrap around a flimsy piece of bumper plastic to hold the (even flimsier) plastic stops horizontally from popping out vertically. Wow. You should play the lottery. Pretty much everyone I know has thrown a hinge pin during their first 8-10 nose/ass dives from 10-20 feet in the air. Either that or you are a damn good at landing on your wheels each time.

Regarding the lower and outer pins that is even more amazing! Not only are you one of the few Savage owners whom I've know that hasn't ever bent a hinge pin....but perhaps one of the only RC owners who haven't bent one. Remember, they are one of the most serviceable items in the industry (perhaps second to bearings because of bearing strain). So due to the importance and short life-span of hinge pin I'd say they are the second most replaced part (hmmm....)

Hey,I assume you check them often, correct? The lower/outer ones can't be really detected without inspection. I can't remember every finishing a qualifiers/main heat without having at least one hinge pin needing to be replaced. Yep, we have certainly had different experiences. lol

Regardless, assuming everyone else who gets big air with their Savage isn't as fortunate as you (and I suspect they won't be), what I wrote above is the solution to the problem...as I know it to be. I went through at least 15-20 hinge pins before I worked out all the kinks, and of course have had some pretty viscous collisions during the years.

But running these things "hard" is very subjective, so I've learned. Don't you think?

Finally, even doubling up on the tow blocks will not help, as the issue is the pins not being captured. The Savage is the only 1/8 vehicle I've ever seen that doesn't have captured hinge pins. The Alza kit just provides normal toe-blocks (that are caprtured). Had the stock been captured, I doubt I would probably still use be using it. But wow I'd say it's probably the # design flaw on the Savage as front-rear end collisions are very frequent when landing,. :-(
 
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What's funny with my experience with hinge pins is I don't recall ever breaking or bending one until I got a flux. I've had a savage for the better part of 15 years in one form or another as nitro. It wasn't until last year when I got the flux that I started breaking them... or stock arms... or the hinge pin braces... Maybe I should try and weigh my nitro vs flux. Maybe the flux is heavier causing the extra damage... or the speed of it...
 
That's awesome! Yep..you have been damn lucky, and perhaps the only person I know who has gotten busy with their Savage and not had issue with their hinge pins. They had to have been freak collisions and don't understand how zip ties held the pins in place. All they do is wrap around a flimsy piece of bumper plastic to hold the (even flimsier) plastic stops horizontally from popping out vertically. Wow. You should play the lottery. Pretty much everyone I know has thrown a hinge pin during their first 8-10 nose/ass dives from 10-20 feet in the air. Either that or you are a damn good at landing on your wheels each time.



Your sarcasm is noted:rolleyes::rolleyes:, be it luck or good driving either way I check them between fuelups and bashes and make sure they don't work out of place, yes I am old and picky about my toys, maintenance is key to getting enjoyment out of them, when I go bashing I take a few rigs so I can let one rest while I bash the other one, my XTM MMT is actually my favorite one to play with, it is a tough rig that takes quite a beating and comes back for more time and again......
 
I don't know why hpi changed the pin keeper design to that stupid looping brace that requires tie straps. I have the original short braces from the originsl s25. They screw into the bulk head and the stops are close enough to hold the pins but plyable enough as not to bend the pins on front impacts.

Personally i have gone through a few lower pins. Ive never had trouble with the uppers. Lucky? Maybe
 
Your sarcasm is noted:rolleyes::rolleyes:, be it luck or good driving either way I check them between fuelups and bashes and make sure they don't work out of place, yes I am old and picky about my toys, maintenance is key to getting enjoyment out of them, when I go bashing I take a few rigs so I can let one rest while I bash the other one, my XTM MMT is actually my favorite one to play with, it is a tough rig that takes quite a beating and comes back for more time and again......

Ha ha. Okay man, it's cool.

Yeah, I think it just comes down to what one's definition is of "running hard" or "beast mode" means, that's all. :cautious:

I have no problem saying I run my vehicles as hard as anyone I am of aware of and is in as many different fashions. I'm sure your sh*t is bad to you, and that's really all that counts. I know my sh*t is bad so yeah, it'll be okay. lol we are just two old timers saying hello, so it's good fodder. (y).

To that end, I've done some sh*t with my Savage though, and encourage others to do the same because it can do some pretty cool things., Stuff will break when you jump, but that's how you know what to upgrade. ....,

So we just differ on what's truly hard and what's not in this hobby, that's all it is. But I know you would probably build a Savage that looked cooler than mine. I still try to keep it sharp on the bench but I just care about running, and then running some more. That's all.
 
I don't know why hpi changed the pin keeper design to that stupid looping brace that requires tie straps. I have the original short braces from the originsl s25. They screw into the bulk head and the stops are close enough to hold the pins but plyable enough as not to bend the pins on front impacts.

Personally i have gone through a few lower pins. Ive never had trouble with the uppers. Lucky? Maybe

Interesting. Can you please post a pic of that original design...having a hard time imaging it but would love to see it.

Yeah, I broken in two of my neighbors Savages and threw upper arm pins both times. One time on a jump, and another time on a field ....even though I used nylon zip ties (his clutch bell came off in that run too on like it's 3rd tank). I then switched to cable ties, but they they kept spitting out impacts each time he would land on the front or the rear.

We had a Savage club here back in the day where our local track let us have it to meet, run, wrench, tell tales, swap ideas, etc. When someone new came we'd give their truck an inspection and warn/predict them of things we felt would not make it. I think I batted like .900 on throwing upper pins it was the common. Outside of losing wheels hinge pins were probably the second most common.
 
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I neglected to mention that I myself there probably only threw 4+ sets of upper arms, bending at least 6 pins over the course of the first 7 gallons. Every vehicle I have run has a weak area. This was probably tops for me...second to the available end-float available for most after-market clutch systems.

I did see an reduction in this when I began securing the back of the bumper arms on the inside of the tower with small cable ties (*see circled below). This is a stop-gap if no major collisions in my experience.

I tried difference solutions and some worked but they affected the suspension so finally captured them. But....securing the back definitely helps. Trying the front bumper arms together also reduces the chances of them coming out, but that solution has failed for myself and others...so obviously have to address it. I would love for someone to make a carbon/graphite one such as below.

I laugh at HPI and their "hop ups" though. Have you seen that "Race Kit Upgrade" the one where they make the truck heavier

So yeah, It's not the pins fault nor the arms or tower. After capturing them I can get about a gallon per pin so the pins (while heavy) are not too bad.
 

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When they redesigned the towers/bumper supports with the X, they made it so it doesn't screw to the bulk, but rather go through two new ears on the lower part of the tower, then a big plastic c-clip behind the tower holds it in place. They put little ears on teh bumper supports so it would only rotate so far, but it rotates too far and the little tab holding in the upper pin isn't in the way of the pin enough and allows it to work it's way out.

This is the pre-X bumper support/pin retainer:
2004-0708-SavageBumperBolt.jpg


This is what the Flux/XL/X have, I removed the c-clip from the back of the tower so you can see how it connects:
2018-1130-SavageFlux-FrontSkidSupport-C-Clip.jpg


I got tired of snapping zipties all the time, so now I use velcro straps to hold the little support parts that retain the pins, to the center.
 
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Interesting. Can you please post a pic of that original design...having a hard time imaging it but would love to see it.

Yeah, I broken in two of my neighbors Savages and threw upper arm pins both times. One time on a jump, and another time on a field ....even though I used nylon zip ties (his clutch bell came off in that run too on like it's 3rd tank). I then switched to cable ties, but they they kept spitting out impacts each time he would land on the front or the rear.

We had a Savage club here back in the day where our local track let us have it to meet, run, wrench, tell tales, swap ideas, etc. When someone new came we'd give their truck an inspection and warn/predict them of things we felt would not make it. I think I batted like .900 on throwing upper pins it was the common. Outside of losing wheels hinge pins were probably the second most common.
 

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Thanks guys...I get it now. I forgot about those C-clips going in to the bumper. In fact those parts helped me determine something I was struggling to understand and that was it led to determine my joint posts where bent I noticed that one arm of the bumper was able to slide back much more due to the chassis being tweaked.

That's when I started using the small cable ties as one of the C-clips had too much play. The cable helped but were a PIA to take off (so I'd just go jump it-ha ha)

Thus hooray for that nylon tower "flex" I've never understood people claimed is an advantage, I'd rather the shock towers on any vehicle stand its ground.
 

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