Titanium Kingpins - & - Making a Bennett Ball-Pivot Truk

Ian the Groove Worshipper · Titanium Kingpins - & - Making a Bennett Ball-Pivot Truk

I just found these on the Randall site. 22 bucks. Pricey, but if they are the solution, probably worth it. The thought of breaking a kingpin and smacking my head against the pavement before I know what happened is frightening. Is Titanium stronger than Grade 8? And if so, by how much?

[http://www.randal.com/parts_bases.html#tikingpin][/url]

pavedwave

My understanding has been that Ti is lighter, but slightly more brittle. Whereas grade8 steel would bend before it shears. I could be wrong, but I thought that Radikal changed from Ti pins to steel to solve part of their early kingpin issues.

bluebugbuster

Alright guys. I got my 3inch Ti Kp in the other day, and finally got to play around with it in the metal shop. That place is like a mad scientist workshop.

I shot some pix, Here is what I got.

The stock Ti KP vs. The stock Bennett KP

I cut .4000 of an inch off using the chop saw. Titanium is pretty gnarly to cut. You have to do it slow, or you might shear off more than you want. That and the sparks from the metal are really bright. It's like watching magnesium burn. Such a beautiful shower of white sparks. I'd have taken a pic, but no one was there to shoot it while I cut.

After cutting, I took it to the grind wheel, and ground off approximately .1200 of an inch, ran her back to "smooth" under the wire wheel, and chased her with a 3/8-24 thread die.

Modified Ti KP vs. Stock Bennett

Here are some specs:

Ti kingpin:
Overall length: 2.6528 in
Threaded lenth: .6585 in (approx)

Stock Bennett
Overall length: 2.7123in
Threaded length: 1.060in (approx)

I'm running the Ti kp a little shorter for two reasons,the Khiro top barell is a little shorter than the stock top Bennett bushing (.580in Bennett vs. .555in Khiro), and to compensate for bushing "squish" (the difference in durometers.) I plan to press this into a bennett 4.3/5.0 baseplate.

That's all for now. Thursday, I'll be modifying theBennett 6.0 hanger with one of these nice little 10mm ball end studs, in place of the pivot cup.

They fit so nice into a hard pivot bushing. It should, on paper, make the bennett a little more "turnier", and a little less wear on the pivot over distances. Not to mention, add a little more "tweakability" to the truck, introducing adjustible pivot angle and height.

I hate being cooped up all winter. There is nothing to do...

pavedwave

That's just freaking awesome! Nice work. Ti or not, I think moving from a splined pin to a smooth pin just under the hex head is a great move -- especially if you're still planning to mount the bolt with the threads pointed up as opposed to down through the baseplate. I'd love to try out a ball-end pivot Bennett as well!!

bluebugbuster

So yesterday, I got to go and spend some more time in the metal shop. And like I promised, I took a few more pics.

So I got done modding my kingpin, and now, it was time to mod my hanger with a ball stud.

So when cutting aluminum, always remember, its softer than you think. When using a high rpm cutting wheel like I did, make sure you go slow. Aluminum will melt like butter, and almost jam up the cutting wheel.

Measure twice, Cut once

Nice and Smooth

After smoothing out the cut, making it even with the truck, You have to drill holes. Selecting the right hole size for the tap is very critical. Too small a hole, and you risk snapping the thread tap. Too big of a hole, and you loose threaded area strength. Most tap and die kits come with a nifty little guide. For my 5/16-18 threaded ball stud, the reqired hole was .2570 in. Make sure you use an aluminum cutting oil when drilling.

When drilling, make sure you have a place to start. Try to find the center, and punch it with a center punch. Make sure the drill press is centered, and the clamps tight. Or your hole will end up off center. Like mine did, approximately 1/64th an inch. Make sure to go deep enough, but not all the way through.

When rselecting a tap, make sure it allows you to tap a "blind hole." A blind hole is a hole that does not go all the way through the piece. Again use an aluminum cutting oil to keep the tap from snapping inside the piece. oh yeah, and as the old shop mechanic says, "make sure you clean your piece after you tap that hole..."

Drilled and Tapped

After a nice little cleanup process, I fit my ball stud in the hole. The threads were good. I left myself a little room to play, so I added two copper spacers, to bring the ball to "stock" height.

Modded vs. Stock

After a few measurements, I pieced the truck together. Everything is close to stock. Right where I want it. I'm no GeezerX, but i think I'm pretty handy...

All Fitted Together, Closeup

Tonight's project in the metal shop, pressing the modded ti kingpin into the new Bennett 4.3/5.0 baseplate.

Stay tuned for more?

bluebugbuster

Here it is. The third step in the proces for a hand built truck.

This time I pressed the kingpin into the baseplate.

First, I had to start with all the parts.

When pressing the kingpin into the baseplate, you need some sort of adhesive. JB weld, C.A. Glue, Sleeve Loc, whatever... My favorite: Red Loctite. Not just the red stuff, the red Heavy-Duty stuff.

When you are ready to slide the kingpin in the hole, make sure you have enough loctite on the bolt. Don't be afraid of it. It doesn't harden untill you apply it with heavy mechanical pressure.

Loctite

When you press the kingpin in, flip the hanger and give the kingpin a few whacks with a hammer and a brass drift. that is your mechanical pressure to start the setting process on the loctite.

Then reassemble your truck. let it sit for a day or two in room temperature. Loctite needs time to cure.

Then you have yourself one custom built truck.

Bennett 6.0 hanger, modified with a ball stud pivot, set on a 4.3/5.0 baseplate, with a titanium kingpin for strength, minimal thread for bushing duration.

stocago

How much do you want for it? Wink

samhell

Sweet..
Could you give us the specifics on the ball stud pivot?
Size, part number etc...????

LDPanda

Id buy one.

I dont have the tools or shop space for this kind of project, but it looks sweet. I love the 6.0, but a shorter base for it would be awesome.

Hit me up if you wana make some $_$

bluebugbuster

As for the ball head stud, the Harley shop supervisor found it for me. It was right from the top of his toolbox. He said something about gas lifts for truck windows or boxes...

And to sell it would be to sell a piece of my heart. It was a labor of love.

So yeah... I'll see what I can find for the ball pivot part number.

pavedwave

One thing I'm curious about -- do you find you're wedging differently on this mod than with the stock truk? This angle makes me think that...

bluebugbuster

Yeah, but it's more of a change in bushings. The pivot angle makes the bushing seat sit at a different angle. I have'nt really gotten to roll around on this truck much lately. We just got out of a week long cold snap with daily temperatures running in the -20*F. The only trucks I like running in a cold warehouse are seismics. The springs don't get hard and cold like the bushings do at that temperature. Especially when you got to leave your board in a cold car.

I can't really do anything. The snow is too much, and the cold is a killer.

pavedwave

Damn!! -32?! Is that record-setting or breaking, or the norm for ND?

We need to develop LDP for Nintendo Wii.

bluebugbuster

No, not a record breaker. just you lower than normal cold snap temperature. temperatures bold enough to turn even the softest bushings to rocks.

dustm

You can get those balls from mcmaster-carr in the gas spring hardware section. I forget the part number, but you should be able to find the one you need. Beware, the balls with longer studs (uhg) have a much longer distance between the ball and hex, and stick out too far to use on a truck (or a truk).

I have used them on bennetts for ball pivot but made delrin cups... I like your idea better though as the delrin wears a bit loose after a while and the truck can feel darty. I bet the small hard cups work well though as they would be a bit more resilient. IMO ball pivot definitely frees the truck motion up. The lack of friction at the pivot is noticeable.

Another option is to use an actual spherical rod end bearing. The one I picked would require a 5/16 stud instead of a ball on the hangar, and the baseplate pivot cup hole would have to be bored to 5/8" (or was it 3/4)... The stock pivot cup is 5/8 I think, so I guess it was 3/4". The benefit of this option is much less play developing in the pivot over time.

petary791

bluebugbuster

I never had a father. I credit all my power tools skills to my Mother. And my hunting skills, and my wrenchning skills, and my culinary abilities... etc...

petary791

Well still, that's awesome. Without sounding arrogant, what exactly is the point? Are there big noticeable differences?

bluebugbuster

I've noticed that before i modded the hanger, i had no wheel bite with the risers and wedging on the board, after the mod, there was noticeable wheelbite, with the same bushing, risers and wedges.

I think it loosens up the turning radius of the truck, along with adding more response. Less input, more turn. Since I live in one of the colder midwest states, I haven't gotten time to test it out... ...yet.

But when the ice thaws from the streets, I plan on doing a review.

bluebugbuster

As it looks like the snow is still sticking around for a few more weeks...

I'm thinking of modding the ball pivot hanger with a spherical.

I'm not up to the challenge, but if someone would like to see it done, I think I might be up to the challenge.

It's either that or running an untimed cybermile through the local shopping mall.

LDPanda

See how many laps of the mall you can do before getting tackled by security?

bluebugbuster

No, more like start at one end of the mall, try some pedestrian slalom to the other end, where a getaway driver would be waiting, ready to roll...

pavedwave

I think these two black ones are ready for some mod-work. A little neglect goes a long way. Surprisingly, they still ride nice, a "bit" on the loose side.

bluebugbuster

Thats good work. I can do some more mods, I found more ball-end studs, and have a copious amount of free time in my schedule lately...

dustm

^^ whoa

James, send me those and the baseplates and I'll install spherical bearings and steel pivot pins in the hangar. Good as new