DIY Motor Mount Adapter for Cronins

like so often, okp was pioneering with motor mount adapters for the complicated cast ronin trucks, whose truck profile changes in a nontrivial way along the way from axle the kingpin!

for the interested readers, check this:

okp was nice enough to send me a few of his adapters, but they were made for 9mm belts - for 15mm belts you need the adapters even further in towards the kingpin, which is a completely different ronin truck geometry already and which is also problematic, since the max diameter for the adapter is 30mm with the alien power system mount and basically the truck at its widest part is 30mm very quickly.

I liked the way okp did it, but it felt a little messy to me, or well, I felt like I could make this a little simpler.

I ordered 30mm aluminum and stainless steel pipes with a very thin wall (1mm for aluminium, 1.5mm for stainless steel) and cut them in very short pieces - long enough to allow quite free positioning of the motor mount, but short enough that it wont interfere with the wheels. then sanded the cuts and in the case of the aluminium, I actually polished the pipes for looks - left 2 are stainless steel, right 2 are polished aluminum:

I brought the pipe all the way to the kingpin and decided to go for the aluminium, since the thinner wall allowed the pipe to go juust that little bit further that I needed for the 15mm belt:

I added the same pipe on the other side for symmetry and taped both of them firmly to an aluminium angle leftover from my very first enclosures. that way the adapters will be perfectly straight!

another pic to show the 2 pipes to make it clearer, why both of them simply have to be perfectly aligned and straight

used plastilin to seal the kingpin side (its much easier to add resin from the wheel side, because the opening is much larger):

I then used the slow curing epoxy resin I still had from my laminating adventures and added quite a bit aluminium powder to increase the heat conductance of the resin. id like to use the truck for heat dissipation as well, since the APS mount is 100% aluminium unlike the enertion CFK->aluminium mount:

and finally poured it into the pipe:

Im not sure if this will be awesome or not, but if it works out, its a fairly simple way to make custom truck mounts for just about ANY truck - should also work for torqueboard mounts, but they have another diameter … so essentially all you have to do is order smaller diameter pipes.

anyway, Ill keep you updated - tomorrow Ill know more and I hope my APS mount will arrive soon - bruno sadly isnt the fastest - my stuff is waiting since monday for UPS pickup. :stuck_out_tongue_closed_eyes:


Looks like a great idea, I keep fingers crossed that it works out!

Really don’t have a clue about this resin stuff, but how well does this bond with the truck? did you cut the pipe open? like one little cut so that when you put the mount pressure is also put onto the resin block inside the tube to be pressed onto the truck?

Should have added some rust and made the worlds first thermite infused motor mount


hehe, maybe next time! aluminum powder isnt uncommon for resin applications by the way - the heat conductance thing is just some icing on the cake ->

It [aluminium powder] enhances the impact and compressive strength of moulding compounds, and its low resin content helps to reduce shrinkage.

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think it will be a very very strong bond. thats why I wont cut it open - basically the pipe with the resin will become part of the truck. its the only downside compared to OKPs version I guess … it will forever be an APS mount cronin … but thats ok with me!

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Awesome dude thanks for sharing I might try this

Fantastic! What kind of resin did you use exactly? I have some bondo lying around that I could experiment with…

slow curing epoxy resin for lamination of cfk/gfk - dont think its anything special and there are better resins for this kind of casting/potting.

woke up early and had to take a peek even though the resin isnt fully cured yet - but its already hard to the touch - probably cured at elevated temperatures from the exothermic heat of the large resin volume confined in that space - so it might actually be cured when I think about it. :stuck_out_tongue:

results look very promising! this is the side where I poured in the resin - it shrank a little as expected, but still looks nice with the aluminium inside. few stains of resin on the pipe which Ill sand and polish off I guess:

same side, but the “thick” resin part towards the board:

kingpin side - you can see why you need the thinnest possible pipewalls for this: the pipe touches 3 of the 4 truck edges and really cant get in any further - so I would say for 15mm belt on cronins, there is only one possible motor mount right now: APS due to 30mm inner truck mount adapter diameter.

and the 3 touching points from another perspective:

now I need the motor mount to check how straight this will turn out and if it was actually stuck in far enough so that 15mm belts work! if it doesnt, there is no way around filing down the truck a little.


think I was a little lucky: its a perfect fit for 15mm belt and also really well aligned (tested with torqueboard v2 which got 28.xmm diameter)!


looks great. Great work as always. Looks like I need to remove a little material for 28mm pipe which shouldn’t be problem.

APS order arrived - was a pretty disappointing experience, really sloppy wrapping, obviously used motor mount, scraping sounds on both motors, missing screws, screws that were meant for the 9mm set and do not fit the 15mm one, sharp edged wheel pulley teeth that will slice up my belt … but no problem because the belt isnt fitting my ordered 15/36 anyway - looks like its made for 15/32. Im not super happy and wrote bruno a mail about it - lets see how he responds. think he is getting too many orders. I might have looked beyond a few things, but considering his 15mm motor mount set is by MILES the most expensive one, I simply expect more. torqueboard and enertion mounts always arrived in absolutely flawless quality.

/rant off

anyway, I used the mount, despite scratches, motor-, pulley-, screw- and road marks because I didnt feel like waiting another 4 weeks for bruno to post another mail.

conclusion: it worked great. after swallowing my disappointment of the APS order, I was fairly happy, because the mount fits 100%, extends the motor far enough to the center of the board so that it does not touch the weird croning pin holder part of the base plate - but at the same time its far enough away from the carbon enclosure.

here you can see that the motor is out far enough to get past the croning base plate pin holder. I even had 5mm room on the mount, so I couldve gone further.


How does belt tensioning work on that mount?

That looks so bad (in a good way) And the motor looks good too

you guys really got to try ronins if you havent yet :heart_eyes:

paris, caliber, bear, indies - I tried them all on different boards and they are all very similar - you pimp them with some urethane pivots, add some riptide/otang goodies, maybe a precision cupped washer and theyll feel alright, but these cronins are just OMG.

I got really expensive dont trip poppies with pivot and kingpin spherical bearings on my pump board - they are super precise and sensitive, but nearly a little too sensitive and the damping isnt so nice due to the spherical bearings instead of urethane pivots.

the cronins are just right in between and it feels like the perfect mix. that cronin spike that holds the truck is rubber dampened and makes for a superplush ride, while, at the same time, it really adds incredibly precision and sensitivity to the truck … but in a super smooth way, not that crisp spherical bearing precision truck sensitivity. and with the tall barrels, the lean feels super juicy … my vanguard really got pushed to the next level with that mod.


Oh I want to use Roinins so bad

Very nice and clean work. Maybe a possibility to add motors on SKOA Stream7 trucks. I like them even more than my ronins for higher speeds, but they are really tricky to mount something.

dont really know any other precision trucks except for the DT poppies - those skoa look very light but fairly standard otherwise … what makes them special? just measure the trucks - if the thickness in the mount area is not larger than 28mm, then this is a way to go for sure!

imo that ronin support pin is a genius concept that really set them apart in feel from any other truck — and for a price thats pretty much in the same league as caliber & co. its just incredible :smiley_cat:

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Do you think the epoxy will hold up? Do you think something like jb weld is okay or should I look at something stronger?

Ronin trucks are great it’s hard to explain like you can run the softest bushing and it’s still very stable at high speeds and at the same time very turny at slow speeds and after testing calibers and Ronins back to back the Ronins are noticeably more shock absorbent they’re great

Very nice work! I am strongly considering this for my next build. I will most likely mill out an Enertion mount though. Would there be enough room for a dual 15mm setup? Looks very tight.

@Chris1 you wouldn’t be able to fit dual 15mm setup on a single truck as the hanger is only 177mm even 9mm belts is a very tight fit. Only diagonal would work