ISSA - International Slalom Skateboarding Association

Has anyone thought of modifing a splitfire by adding a pivot bushing to the hanger (like a radikal has)? Would this be worth doing? Would it add any sort of improvement to the splitfires design? and Was this ever a design consideration for Splitfires?




PG

I've thought about buying one, sure. But I need someone to make it before I can buy it.

Chris Barrett wrote:I've thought about buying one, sure. But I need someone to make it before I can buy it.

Chris, Are you talking aboot wanting to buy a splitfire with a pivot bushing already installed? or wanting to find a pivot bushing to use for a modification?

you can find something that might work here:

http://www.mcmaster.com/param/asp/psear ... 922=154880

I am just scared I might screw up a perfectly good truck.

Paul

ps. you coming to chicago?

the former, Paul! I dunno how much improvement that modification alone would make, but it would be neat to feel! How exactly do they insert that bushing pivot on the radikals, is it the same kinda threaded insert dealy that they use for the kingpin sleeve?

regards,
Chris


{P.s. I don't think I can swing chicago again, its too bad I had a serious blast last year!!}

{p.p.s hehhehehe, aboot.}

the kingpin bearing is a press in. There is a flange in the hanger to prevent it from pushing all the way through.

... tells me that there is already one out there.

i heard tall tales of a pivot bearing [bushing] being
used in ohio. true or false?

Carl,

You are correct. I saw one in use in O-hi-O

Marty, was there any talk if the added pivot bushing was a worthwhile improvement?

paul

I don't think it would actually add to steering accuracy improvement, but it would likely add to a quicker-feeling turn-in. The friction on stock pivots is, um, ugly on most trucks. Lubes can help a good deal, as can finding harder, slicker plastics for pivot bushings. Delrin is sweet, and easily run thru a common wood lathe to shape from round-stock. Ryerson Plastics has that stuff.
If you're going to put a spherical bushing in the baseplate, be aware that the baseplate will likely need to be reamed to get a good fit from the bushing. After that, just get a good fitting axle from a stainless bolt that's had the head ground off, thread that into the truck hanger after tapping it out. Simple enough stuff, IF you've got the right tools.

I think what Paul may have originally been referring to is a spherical bearing at the hanger where it meets the kingpin. Not at the pivot point on the baseplate.

I think it would make quite a bit of difference. How could it not? The hole in the hanger where the kingpin goes through is almost twice as big as the kingpin. (most hanger holes are almost 5/8", kingpins are 3/8).
That's A lOT of slop.
I love the way a Radikal front feels because it's very precise.
In my opinion, that precise feel comes from the bearing at the kingpin.

I would love to try a similar bearing on a Tracker or Indy or whatever.

Yes, I am talking about the spherical bearing mounted in the hanger. Can anybody that saw the modified splitfire in Ohio give me a idea on how the spherical bearing was attached to the hanger? was it pressed in somehow? was there a mechanical fasterner?

PG

Interesting discussion here. It's true there are a few bearing-loaded splitfires out there *in testing*. I will not divulge who is using these, but they are on the podium regularly this season. We are still testing however, and have not decided to go into production with these. Again, and to Troy's point, I'm talking about a spherical bearing in the hanger, not in the pivot.

Why it works - The bearing does keep the hanger from having lateral movement in a turn. When you turn on a regular urethane bushing truck, there is a certain amount of side to side movement. You'd be surprised how much. The rod bearing/spherical eliminates that side wash. It does however put stress on the kingpin, as evidenced by the kingpin failures that the early Radikals were having. That has been addressed in the newer Radikals.

In the front, this gives you a little smoother turn, especially at the hardest part of the turn, when you're really cranking. It just gives you a more linear rate of turn all the way through the turn, rather than non-linear compression that a bushing-only truck gives back. There are a couple of other interesting things going on in there, but less important.
On the rear, I had a very different experience. Though the hanger bearing will keep the hanger from having lateral movement this is not necessarily a good thing in the rear truck. At least for me. I ride my rear trucks tighter than my Front trucks. Rear trucks tend to track as opposed to steer. And especially in long radius turns, such as GS, a little "dynamic tracking" is a good thing. What I mean by dynamic tracking is that side to side movement is proportional to speed and side load. This lateral movement actually sucks up some of the vibration that enters the truck. That big urethane donut does a lot of vibration control, which is perhaps why stimulators work so well also. What this means is more traction, and a little less reaction.
In any case, I didn't like rear sphericals for hybrid and GS, but that's just me. Jason continues to kick ass on his Rads, and Kenny seems to do well on his Chindy, and I'm still chasing both those guys, so take it all with a grain of salt. It's probably all in your head anyway. Reading that last sentence I realize, I'm a marketing idiot.

Sounds like they would kill for pumping though with less momentum lost due to the elimination of lateral movement. Those LDP guys who ride Splitfires would probably like it.

Yup, I read That wrong... Sphereical knuckle is in the hanger, between the bushings, tighter fit to the kingpin.

One thing I noticed with Radikal's truck is that the kingpin has to thread into the baseplate to access the lower bushing. I'm not fond of the bolt head (which requires a 7mm wrench) on that kingpin; I can't understand why an allen-head socket screw head wasn't fitted, or fathom why a 7mm is used there. It's difficult to get the kingpin seated at times.

One other thing I've noticed is the 'slop' that occurs if little tension is applied to the kingpin nut. The Spherical bushing tends to stick out, and the truck hanger dosen't fully contact the bushings (true even with stock bushings on a Radikal), thus the truck tends to be really loose in the first few degrees of movement off of center. The one pair of JimZ's I rode didn't have that issue, and felt very secure in turns.

I think that putting the spherical bushing into an Asphalt Playground truck is very do-able, and logical, too. I hope Gary finds a means to do just that (and reduce pivot-point friction as well). As it is, I'm a big fan of Asphalt Playground trucks. Tweaks like this would only make a great truck better!

Gary Fluitt wrote:Interesting discussion here. It's true there are a few bearing-loaded splitfires out there *in testing*. I will not divulge who is using these, but they are on the podium regularly this season. We are still testing however, and have not decided to go into production with these.

Gary,

I wasn't as concerned who was modifying your Splitfires by adding a spherical bearing to the hanger, but how to add the spherical bearing. I realize as a truck manufacturer there are a million reasons you wouldn't want to give out this information. But I was hoping someone on this forum (a 3rd party) was willing to discuss how a bearing could be installed. Building & tweaking equipment is a small part of what makes slalom fun.

PG

Paul,
Understood. The bearing trucks (that I know of) have all been done in the Splitfire factory. The hanger was bored to fit the bearing, then the bearing was pressed in, and glued in place with locktite.

I wouldn't recommend this modification @ home. The precision with which you need to bore the hanger is far too close to pull off with typical home tools. If you do have access to CNC you can do it yourself, I suppose.

You guys seem to be pretty interested in this mod. Is this something we should offer commercially? Of course this will ad a few $ to the cost of the truck. Would you want rear and Front, or just Front?

Gary

I saw one of the test trucks in Brixlegg, they look sweet man. Really I think that would be the a really good addition to the front TS truck because sometimes when I ride a DS 90 I don't like how loose you have to ride to get it to turn around some gates. I've had a DS 90 rear for about a year now I love it. Good stuff, when can I get one?

Hmmm, Very Interesting Indeed. So far, and maybe it's just me, but I have never like any rear truck for Tight and General as much as I LOVE the Phase I Splitfire(with the Tracker RT-X baseplate). What Fluitt says about keeping the rear truck as-is without the kingpin/hanger bearing interface makes a LOT of sense so it can ride on more of a cushion and sway side to side without turning so much. On a tangent, I've thought about trying to put a similar kingpin/hanger bearing into an RT-X for the front as well as a pivot bearing. Adios-P

all this positive talk about phase 1 splits makes me really want to pick one up today at the farm

Hey Adam, I think it would be worth getting one if there's one for sale in front of you. If you don't like it, I imagine it would be easy to sell on the buy-sell-trade forum here or on the "other" site.

I find I like it dewedged about 5-7 degrees on the back. I never have tried it on the front, but I bet it would almost be too grippy, I've got 2 so I'll have to test that out. Good Luck at the Farm. Adios-Paul

looks like i am getting a modded 3tc from geezer (he is the man)

"hey, do you know of a place where i can get some replacement pivot cups for vintage fulltracks?"

(geezer then wips out a bag full of his custom lathed pivot cups just for my trucks and he said they are normally a pain to get in.....mine fit in perfect)

Hey Adam, I forgot to add this, When I use the Splitfire Phase I (or one of my old TTC/3TC's- which by the way, Geezer has done 2 of mine and did an EXCELLENT job), I find it makes a great rear truck best combined with a twitchy front truck like an RT-X or Radikal. But this is likely a personal preference thing. I did like the Phase III Splitfire's up front but only for faster wider courses that I did'nt need to "twitch" on. Again, that could very well just be me since some do use the Phase III on pretty tight courses. Tell Wallgren Pauliwog says "Hey". Adios-P

I've just modified 2 90mm and 1 107mm front and one 90mm rear.
So far I can only say that they behave beautifully. Quicker turn, yes, but also more precise.
I’ve also lowered my wedging to 16 dgr, in front and flat rear.
So if anyone have any thought … just try it.

Johan Thiel wrote:I've just modified 2 90mm and 1 107mm front and one 90mm rear.
So far I can only say that they behave beautifully. Quicker turn, yes, but also more precise.
I’ve also lowered my wedging to 16 dgr, in front and flat rear.
So if anyone have any thought … just try it.

Other then the wedging what mod's did you make to the Splitfires? Did you add a spherical bearing to the hanger? if you did is it possible to post some pictures?

Paul

Yes I've mounted a spherical bearing in the hanger
I have Pictures but can not figure out how to upload to this page.
Give me your email and I'll send them.

johan, send em too altrego@gmail.com

What about the others? Can they subscribe for a newletter or RSS feed?

rmn

Take a look and ....

these are what Johan sent me...sized down slightly

for your help

for the pics

rmn

my god......that is awesome.

by any chance do you want to mod anyone else's?

Hey, A picture is truly worth a thousand words. Nice Work. Maybe I should have tried that before I sold my Phase III front to a guy here in the Northwest. Thanks-Paul

Does anyone offer the spherical bearing as a custom modification? if so, whats the price?

PG

Well I can do it ... just that I live in Sweden and you need to ship your hanger to me ....

I get the bearing for 20 usd and then some work so around 40 - 50 usd plus shipping cost

can you post how you went about putting it in, followed with pictures to assist? i really want to try this

You need to get the bearing ... no need to tell

Get hold of a drill that will make it possible to fit that bearing.
mine is 19 x 6 x 10 mm. 19 mm in diameter, 6 mm thick and 10mm "inside" "kingpin".
So you need in this case a 19mm drill.
Fix the hanger firmly in a "controlled" area.
Place the drill carefully centered in the kingpin "hole" and carefully expand that hole.

Clean the cut/edges.

Gently push in the bearing in the new expanded hole, you may need loctit to keep it in place.
I've used it on one hanger and on the other ones not. both works.

use your old kingpin , with some gap... it works but can be more perfect with a 10 mm...
or
get a 10 mm kingpin and also redrill the kingpins hole in the baseplate.

Prepare the bushings, make them more like radikals, a kind of spheric cut out.
I used my 19mm drill to adjust my khiros. And I have modified radikals as standard use.
Since the bearing take some space both top and bottom in the hanger you need to adjust the bushings just a bit.


Hope this will help you ... otherwise send it to me... and if you could get hold of cheaper bearings ... tell me. The ones I use is "no maintenance needed" kind.

Johan Thiel wrote:I get the bearing for 20 usd and then some work so around 40 - 50 usd plus shipping cost

I might take you up on your offer, but I'm gonna wait until winter. I don't want to be with without my board while the weather is still nice

Paul

Johan,
check yor PM

you all need to put jimz pivot cups in your split-fires....it rules. all that you need to do is shave a little bit off of the height of the jimz pivot

just keep in mind....they are a pain to setup. but if you have jimz speed hangers, you allready know the pain in store

minor upgrade, but smooth turning

remember to put thick lube or light grease in the pivot cup because it is very snug

who is JimZ and where do you get his pivot cups?

JimZ is a world class downhill racer and you have to contact him directly to get his pivot cups. try the kebbek website www.kebbek.com

I could not find anything on the kebbek website

on 8/15 Paul Graf wrote:"Does anyone offer the spherical bearing as a custom modification? if so, whats the price?

PG"

Take a look at Asphaltplayground.com
Initial testing is done, and Gary is polishing up the 1st batch, they are quite nice, and I cant wait to get my hands on a 107....

I´ve now modified 12 hangers all with new happy skaters on splitfire setups

So if you allready a splitfire fan .... just modify and keep on skating

And it sure makes a difference

Just got my R3's with the bearing. They rock.
SL

I have a couple of the R3's in Paris if any of the locals here would be interested. Fronts and rears.

/Jani

Sorry I've been remiss in letting you all know about the SplitFire Pro <a href="http://asphaltplayground.com">now available</a>. The Pro model is like Rev 3, but now with a spherical bearing pressed with a 2 ton press and glued with lock-tite. I also beveled the outside of the hanger where you might get some interaction between the bushing and the hanger.
I had a couple of people testing these for the past year. Pirnack, Maysey, Kramer, Wax, and myself. Consensus is they increase quickness and precision. Works great as a front truck in all categories and as a back truck in TS and Hybrid. Jury is still out on the application of a bearing truck for a rear GS truck. You can read my comments on that above.
The nice thing about this truck is that it's very simple. Just slot the kingpin like usual. I've noticed that you do need to get the pivot bolt at a very precise depth so that the kingpin lines up. Don't have to do that with the big bore non-bearing splitfire.
I've been messing around with bushings and found that "regular old" Khiro white bushings work great with the Splitfire Pro. Evan St. Clair and Marion Karr introduced me to the double stack idea. Use a 3" long kingpin and use two bushing on top of the hanger. Gives you more arc in your turn and there is just more meat to return the truck to center. Give it a try.
Here is some hanger porn for you all.
<br><center>
<img src="http://asphaltplayground.com/images/new_split/sfpro.jpg">