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| Truck Reviews (15215 Posts)
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Message To Dave G
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On 6/6/2005 North Carolina Longboarder
wrote in from
United States
(166.82.nnn.nnn)
Dave, you lurker dude! Give me a call at the office some time when you get a minute. No rush.
Marion
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Randal Offseted
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On 6/6/2005 DAve G
wrote in from
United States
(207.69.nnn.nnn)
Guriously..I had Geezer modify a Randal 4or5 years ago. He cut it down to 108mm and flanged offsets onto it, in a "sweeping/trailing fashion,so that the axles are in alignment w/ the base of the kingpin..to this day it is the quickest turning front truck I've ridden..only bummer is it was for 8mm hubs only.
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Radikals
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On 6/6/2005
Paul K
wrote in from
United Kingdom
(195.110.nnn.nnn)
i think we need Mark or Sparky to jump in here....
I was under the impression that after the first round of Kingpin breakages, the manufacture of the Radikal KP was changed from Ti to Steel...is this the case
if not.....a few of us in the UK will need replacement KP, if we are supposed to change them annually
cheers
Paul K
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Kill City Radikals
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On 6/5/2005
Tod
wrote in from
United States
(12.148.nnn.nnn)
Chris,
If you put the two peices together, can you tell in which plane the stress is causing the break?? i.e. front to back or side to side? I've used mine alot practicing and have followed a strict maintainence program just because of your incidents...
Is the Radikal kingpin in fact made of titanium?? and would a dye penetrant test reveal any fatigue flaws if it is made of ti???.....cnova, you still on the air??
I'm prone to getting hurt just by not having my shoestrings the right tension so
if ordering new pins is in my future... I'm down wit dat...
PS Chris, bust out the aloe vera and chill dude... you ain't missin Chi-town
just cuz U got a little boo boo :-) Seriously, heal up quick and say hi to everyone for me, Later, T.O.
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hmmmm...
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On 6/5/2005
Dave G
wrote in from
United States
(207.69.nnn.nnn)
Just a thought C.B. If the problem occured below the baseplate on the same baseplate..Could it be that there is some "slop" in the threading near the exit of the baseplate? While the properties are hugely different between Titanium and Stainless, the threads are a sure weak spot..If the fulcrum is placed below the start of the smooth/strong section, that would explain the failure below the face of the base! I'd try to start threading an unloaded kingpin into th baseplate a few threads ..and see if there's and ply/slop, If so I'd venture to say the problem lies in the baseplate vs. the kingpin. Also..how much wedge were you using? Hope you heal soon!!!!
Off to the river to work I go!
Enjoy,
Dave G
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Swing Shift
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On 6/4/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
No, I actually meant flipping the direction of the swing arms of the rear truck and using it as a rear truck with more trail. The rear axle would be further away from the pivot cup, much like a Randal DH truck with with the 35 degree geometry. Of course this would shorten the wheelbase a bit.
The way it is right now, the slower turning geometry makes sense to me as a rear truck (minimizing oversteer), but I think that the stock position of the swingarms increases the quickness of the steering.
I'm guessing that if you used the swingarm hanger in the stock position on the (50 degree?) front baseplate, it would out-steer the normal front truck. In other words, the swingarms in their stock orientation add steering.
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reversed swing arms
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On 6/4/2005 Gareth
wrote in from
United States
(24.17.nnn.nnn)
CC-
Do you mean, flipping the rear swing-arms on the radikals and then using this "rear" truck up front as a "front" truck?
I don't know why I did, but I tried it. Felt REALLY weird.
G-
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Kingpin woes
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On 6/4/2005
Gareth
wrote in from
United States
(24.17.nnn.nnn)
Chris-
Sorry to hear about your crash - looks like a nasty rash. I have gone down hard twice due to broken king-pins. But they were both the original one's that were made out of titanium. I guess any material will fail under the right circumstances - even the newer hardened steel kingpins.
Both times that my kingpins broke I had a PVD on the rear. Each time with a different hardness of bushings and different angle plates on the PVD. Also, it was on two differernt boards - one a softer GS board and the other a super stiff TS board. In my case at least, I don't think the rear truck set-up had anything to do with it.
I know a lot of people who have gone down this way (not all of them were on radikals) and it has to be one of the worst types of falls because it happens so fast you hardly have time to react to it. James Peters has broken more kingpins than anyone I know - he goes through them as if they were made of wood. And yet, just like the Energizer Bunny - he keeps going, and going, and going, and going!
Get better!
G-
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Heavy kingpins
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On 6/4/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
I know that it's important to some slalom guys to keep the weight of the components down but using a steel kingpin couldn't weight that much more, could it?
BTW, has anyone tried running the swing arms on the Radikal rear truck "backwards", to put the axle in a position of more trail? It seems to me that if the steering angle on the rear truck was at the same angle as the front truck, the rear truck would steer quicker than the front truck. My experience is that the axle's position relative to the pivot cup makes a truck more or less stable.
1. Axle over the pivot cup (Indy, Tracker, etc) = Unstable/Quick turning
2. Axle in line with the kingpin (Indy Offset, Split-Fire, TTC) = Stable/Medium turning
3. Axle on opposite side of the kingpin/away from the pivot cup = Very Stable/Slow turning
Of course the kingpin and pivot angles also effect the steering. I'd be real interseted in making a "universal swingarm adaptor" fo the Radikal rear truck that allows me to put the axles wherever I want them.
ChrisB, I thought it was your rear kingpin breaking, but I reread your post and gather that it was the front truck with "rear cushions" on it. My bad.
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Threading Ti
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On 6/4/2005 cnova
wrote in from
United States
(64.105.nnn.nnn)
Titanium is very notch sensitive. Unless the threads are either rolled or ground, then the threads are notch intensive.
If you unknowingly use a chlorinated solvent to clean threaded Ti then it is extremely prone to cracking.
If you can load it axially, in either tension or compression, or in double shear it works well, but if you load it in bending or in shear (through the threaded section) then it is just a matter of time before it fatigues and breaks.
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another broken kingpin
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On 6/4/2005 Chris B
wrote in from
United States
(68.60.nnn.nnn)
good points Chris....i'm not tightening my kingpin more than a thread or two past the nylon lock ring though, just so the nut wont loosen on its own. That would leave me with #2 or #3. I know Sparky changed the design of the kingpin at some point and this new one that cracked was one of the new styles. like the first one, the crack is below the baseplate line about 3mm's, which i think is strange too. #3 is the one that i'm wondering about. I'm not an engineer, but i think it's a pretty strong coincidence that this front kingpin keeps cracking when i'm running stiff rear bushings....there's got to be something quasitechnological about it....
And waiting for the skin to heal isnt too much fun...
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Kingpin woes
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On 6/4/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
This is my limited understanding of the challenges behind the Radikal Truck design and kingpin.
Titanium is stronger and lighter than steel, but can be "brittle". It tends to break where steel may bend. I believe that the material actually needs to be x-rayed to be sure that there are no irregularities. If it's not perfect, there could be trouble ahead.
The other issue is that the pivot is fixed in the pivot cup by a ball joint. This acts as a hinge for the hanger, and the cushion seat area moves up and down the kinpin on an arc. This isn't much of a problem on conventional trucks with an oversized hole in the cushion seat - there's plenty of slop there for ease of construction. But slop is the enemy to traction and precision, so the Radikal Trucks have a sperical bearing in the cushion seat to remove the slop.
The idea of the radikal is to NOT tighten your trucks in the usual manner, which is to force the locknut and washer down onto the cushion assembly. Instead, you keep the hanger perfectly perpindicular to the kingpin and use harder or softer cushions to tighten/loosen you trucks. This will keep some of the stress off of the kingpin and maintain the intended steering angle (geometry) of the truck.
The problem is that once a skater, always a skater. We like to take a 9/16" wrench and crank it down or loosen it up. Because our kingpins are straight and not on an arc, anything past "normal" will put stress on the kingpin.
My guess is that one (or more) of the following are happening:
1. You are tightening up the rear too much
2. Your kingpins were bad to begin with
3. The back truck gets more torque than the front from riding
I don't think that we're going to see a banana kingpin anytime soon, so perhaps the pivot cup bearing could be made to slide in and out a bit, to accomodate the straight kingpin. The other idea is to put shims (washers) under the bottom cushion before intentionally overtightening the locknut. This would have the effect of keeping the hanger level, but with more pressure on the cushions. Mark? Sparky? Kat?
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radikalroadrash
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On 6/4/2005 chris B
wrote in from
United States
(68.60.nnn.nnn)
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Bara's Bear
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On 6/4/2005
Dave G
wrote in from
United States
(207.69.nnn.nnn)
Chris...I certainly hope you didn't "dislocate" your elbow!!! When I spoke w/ you earlier, you had referenced the blood loss and skin ta' ta... It took over 5 months for my elbow to get semi corrected after truly dislocation!!Just a concerned citizen!
Then again, I need my elbow(s) 100% for the daily grind..but after 2259 stitches and 18 dislocations...my elbow hurt and impeded me more than any!!! Good luck if the Vica's and Brew hah's wear off, leaving you in torment after midnight!!! Call me tomorrow to let me know!
Enjoy (I mean it)
Dave G
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Frustrating Radikal Curiousity
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On 6/4/2005
Chris B
wrote in from
United States
(68.60.nnn.nnn)
Maybe somebody can answer this for me.
I have Radikals on a pistol with a 21" wheelbase. Red and Clear bushings up front. Usually black and clear or green/green in rear.
Last October, i went with a Black and blue in the rear and my front kingpin cracked the first time i took it out with that combo. Got me a bad case of swellbow. Sparky took care of it and told me to replace the kingpin annually, no problem.
But it appeared to be a coincidence between the rear bushings and the front kingpin breaking.
I switched back to black/clear in the rear anyway.
Then i put a PVD on the rear.
After riding Mandarino's board in St Lou, i decided to switch back to a Rad in the rear again, with the bushing set up he had, black and green
This is the first time since my front kingpin broke that i used 2 hard bushings in the rear.
I took it out today and again my front kingpin broke. This time i have bad road rash on my back, a dislocated elbow and a badly bruised palm.
I'm sure radikal will take care of their product, their service is great, but my question is this...
Is this still a coincidence?....two times now this happened
Could putting two hard bushings in a rear Radikal cause some kind of torsion pressure that the front Rad cant take, causing a kingpin to crack?
Mark or Keith, if you read this, please let me know. The kingpin that just broked is only about 6 months old and it's one of the newer styles.
anybody?
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More Cushion, More Pushion
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On 6/4/2005
Chris Chaput
wrote in from
United States
(66.116.nnn.nnn)
White JimZ's in a black Split-Fire.
Stock Radikals
Stock PVDs
Khiros
Randals
Tracker Stimulators and Radikals in a Split-Fire...
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CARVER TRUCKS
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On 6/3/2005 myke
wrote in from
United States
(68.116.nnn.nnn)
are there any other carver riders out there? i was interested in your board set up. i just got a C7 pair.
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Bushings
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On 6/3/2005 TK
wrote in from
United States
(66.30.nnn.nnn)
Joe, Richie C and The Professor are bushing masters. T
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Bushing Chart
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On 6/3/2005
Joe I
wrote in from
United States
(63.87.nnn.nnn)
In an effort to assist new skaters and ones uninclined to fiddling with their boards, I'd like to put together a bushing chart. I've had an influx of brand new and cross over riders here in CT and need to figure this out for them. I thought I would ask for your input and share it with everyone.
I'm using Khiro as a standard here in CT. The Big Bad Bushing kits offer multiple possibilities, I ordered a bunch for everybody and we've been test piloting them over the past couple of weeks. So when I conceived of undertaking this effort, I was thinking Khiro. While I think it would be useful to include Radikal, Bones, Doh Doh's, etc, there is no way I've got the smarts or time to manage that project. Please keep it Khiro specific for now. Maybe someone will volunteer to help me with the rest in round 2.
I'm looking for your bushing configuration. Bottom Front, Top Front, Bottom Rear, Top Rear. For these purposes Bottom is closest to the base plate, Top is closest to the kingpin nut. It would be helpful to know your truck choice, style of riding, and weight. For example Tracker RTX/S, slalom, 175lbs and then your bushing choice, or Randal 180, cruising, 140lbs, etc.
I set up an Email address to keep all your info in one spot. As soon as I gather a significant sample I'll publish the results here. All replies are confidential. Obviously this will represent no substitute for personal experience, but I think we can determine an excellent place for people to start.
Please email: Khirochart@yahoo.com
DISCLAIMER: I am unaffiliated with Khiro or any other skate company, except as a customer.
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spring rubber
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On 6/3/2005 Duane
wrote in from
United States
(68.15.nnn.nnn)
I was thinking more along the lines of taking a light spring and pouring urethane around it, perhaps even foamed urethane
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urithane spring
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On 6/2/2005 herbn
wrote in from
United States
(152.163.nnn.nnn)
i wasn't really thinking of a solid elastomer to replace the spring actually it could look just like a regular spring only be made out of a hard urithane like a core(wheel) material it would be very elastic and for speedy runs the shallow geometry trucks would be the ones,but they could be formulated for lower resilience less rebound and reduce wobbles by that aspect rather than tightness. I gotta go out and ride, it's been way to long of just riding back and for to my car, even though it a pretty quick return run.
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Seismic Stuff
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On 6/2/2005
Steve in AZ
wrote in from
United States
(192.175.nnn.nnn)
Steve-O: Yup, there are some recent posts about using Seismics as both front and rear trucks in combination with other trucks. I'm wondering if anyone in the Pro ranks (or upper or mid-level Open racers, for that matter) use Seismics Front AND Rear for TS, Hybrid, GS or Super-G.
Hit the "Older 25" button a few times on this forum, or Search "Seismic Rear".
Herbn: Yes, there were some urethane Seismic bushings at one time...I even held them in my hand. But I haven't seen them for sale anywhere yet. My guess is that Danno is being very particular about these, and for good reason: Each of the Springs in a Seismic are mounted on the outer part of the truck turning angle, when compared to a standard bushing on a "dual-action" truck, where the bushing surrounds the kingpin. It stands to reason that any return medium (bushing or spring or ??) would require many X's the useable travel the further outward they're mounted. On top of that, Seismic metal springs have the smaller spring in the center to further "expand" the length of the spring when un-loaded on one side.
If you mounted a metal spring around the kingpin under a nylon bushing so that the one spring suspended BOTH sides...well, then you'd have an Original truck...or an old Speed Spring!
The current Seismic metal springs do a good job with this..but it's MUCH harder for that to be done over the same positive and negative travel space with an elastomer or bushing. Suspension forks on Mtn. bikes began by using urethane elastomers, like in the old, old Manitous. Eventually, a Micro-cellular Elastomer (MCU) was chosen for this because of the little air pockets that would "deflate" upon compression, thereby increasing travel. The problem still is with the un-loaded elastomer and keeping it in place when turning the other way.
Once Dan has that figured out (Maybe a MCU main spring with an internal long-reach spring), I'm sure we'll know more about it.
In the mean time, is there any opportunity to develop an Air/Oil/Pneumatic spring-cell to replace the existing Seismic springs...on the rear truck or F&R on a DH set-up? Man, would that be a sweet, stable ride. You could even keep an air or oil reserve on an external cylinder to increase travel & adjustable valves to allow for little or heavy dampening.
Wheee! The Spreadsheet Geek has gotta love this.
-=S=-
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rear Seismic
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On 6/2/2005
sc
wrote in from
United States
(64.60.nnn.nnn)
... just wondering ...
... didn't Maurus Stroebel win the tight at Morro Bay 2004 while running a rear Seismic?
... does anybody regularly place highly in races while running rear trucks that are not offset or TTC-based or Radikal?
... just wondering ...
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NOS Tracker Stimulators
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On 6/2/2005
Geezer-X
wrote in from
United States
(68.239.nnn.nnn)
I bought all the remaining inventory Tracker and O.S.S. had about a year ago. I've got about 300 packs left about with more mediums than softs or hards. I have about a dozen packs of soft yellows.
I obtained them to use on the MMW Team Trucks I modify and sell, and began selling them by themselves until I had a few transactions which were so time consuming I was giving away irreplacable bushings, so now they're availble on MMW trucks only.
For my money there is still no higher rebound bushing except perhaps one cored out of a modern wheel.
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CC bushings
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On 6/1/2005 Ready2Rip
wrote in from
United States
(69.167.nnn.nnn)
I've been quietly hoping ABEC11 would find a business case to get into the bushing market. Count me in!
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