I want to extend the axles on my MTB trucks

Hi all, I’m looking into putting these tires on my board:

The problem is that the hub width is 8cm and axles length is only 5cm. I noticed that the trampa vertigo trucks have setscrews on the underside. If I loosen them will the axle come out? Could I then replace it with a longer rod and tap the ends of it for M12? Thanks

inb4 Swamp Buggy, pic related

Just loosen the grub screw and see if you can compel the axle to slide out. I mean, what else is that screw doing there except stopping the axle from being able to slide out from it’s socket?


I guess I’m going to find out… Do you know what material the axle is? I can’t tell if it’s polished steel or aluminum or what.

The vertigo has hardened steel axles If i remember right :grinning:

“The VERTIGO hanger is also fitted with weight saving 12mm HOLLOW STEEL AXLES instead of the standard Solid axles found on the Infinity Truck.”

Oops, my bad, I meant I have infinity trucks. Do matrix II trucks have the same axle measurements? If this works I might just make a second board…

I was interested in getting the axle off too, Frank was kind enough to advise the following:

“Getting our axles out is possible. Heat up the hanger and pull them out, using a 12mm ID rod , so that you can use the axle nut to pull the axle pin out, winding on the axle nut. Sometimes the axle pins start to spin. In that case you need to make a tool that is not spinning the axle while pulling. Heat certainly helps, especially if you can cool down the pins with ice spray while keeping the aluminium hot.”

What does he mean by axle pins? The set-screws? Basically, remove the set screws, heat the hangar and carefully twist the axle out of the hangar?

I think the basic premise is that with a hollow tube 12mm ID but strong and thick enough to put force on eg 3mm+ wall which comes midway across the threaded part. So when you turn the nut the force on the hanger will start to pull out the axle, of course heating the hanger makes it much easier since it’s pressed in.

Spinning pins not sure, of course the grub screws should come out or at least be loosened off

Would this work on MBS trucks too? I’m a little afraid to do this with my existing trucks and I don’t really have the budget for another set of trampas.

No idea really, check the design for grubs like trampa and there’s a very good chance they are pressed on too

MatrixII trucks are a bit shorter than Trampa. They’re just over 16 inches total, by maybe 1/16 or so it looks (a little over). Set screws on the bottom as well. Interested to see if you’re able to pull them out or not. I’d like to get a little more length as well.

Thanks, I’m still trying to decide which, if any, to get. Adding shipping charges makes them work out to about the same, and there’s always the risk that I’ll just ruin a good truck. If anyone’s selling second-hand MTB trucks of any kind I’d love to know! Another idea I had is to drill out and tap the holes in the hangar where the axle goes through. That way you could use any appropriate length of bolt and theoretically have any reasonable width tires you want. Yes, it is considerably more stress on the four bolts serving as the axles, but what if you used, say, titanium bolts. I’ve checked, they exist.

Sounds doable. Interested to see what you come up with. I prefer MatrixII over Trampa, but I seem to be in the minority.

I’m using trampas, but I’m curious about the matrix II. I like the simplicity of it, how relies only on the shockblocks. Have you ever compared the two?

Yeah, I have builds with both. Trampa definitely looks more sturdy, but MatrixII are lighter, the adjustment screws are on the bottom so ESCs don’t get in the way if mounted on the tail, wider range of maneuverability, much more stable at speeds, and great customer service with MBS. All around better choice IMO. Definitely still prefer Trampa decks though.

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Heat the hanger, find a slide hammer that will secure on to the thread and yank it out


Okay, I’m starting to look at material options for the axle and here’s what I’ve come up with so far: Titanium- AMS 4928, AMS-T–9046 Aluminum- AMS-QQ-A-200/8, ASTM B221. Basically 6061, not sure which. Steel- really not sure here. Anyone have a suggestion? In short, I’m trying to weigh the cost versus the weight savings. What does everyone think?

I made a quick CAD file for axle extensions. First, here is the redesigned axle:

Here is a 3 cm extension:

I’ve also made a 5 cm extension in case anyone needs to add spacers. I’m still not sure what material I should use. Does anyone know which metal would be ideal?


Axles tend to be made in steel, so extenders should probably be the same else galvanic corrosion ensues. In saying that they should be loctited down which would give a protective layer between two diverse metals.

The extender should be made of steel as there is an inherent weakness introduced which the mating parts are with a thin thread piece (mm?) goes in…could break at the neck of you extender

Probably better designing something that encompasses the stock axle which then reduces back to 12mm…that would work in alum.

Alloy easier and usually cheaper to machine