Steel motor mounts welded, mountain board

Hi Guys

I’m really sorry if this topic has already been discussed before. I had a search and could not really see anything on the topic.

Most the home made mounts I have seen people make are Aluminium. I have steel trucks (on my mountain board) I’m handy with a mig welder so my plan was to make some out of steel. I have some 2.5mm some 3.5mm and some 5mm plate. I was either going to make it out if the 3.5mm stuff then run the 2.5 around the outside to act as a belt guard as well as a stiffener. Or just make it out of the 5mm stuff and model it on the ally ones I have seen other make.

I’m also thinking of using a couple of tensioner to maximise the contact between belt and pulleys while keeping the distance between the 2 pulleys as small as possible. I’m no good with KAD, I can sketch and photograph if this makes no sense.

I’m running dual motor so will probably also connect the 2 mounts together to help reduce flex and movement. I have built roll cages and done a fair amount of vehicle bodywork so it will be strong…

What are your thoughts? Good idea? Bad idea? Just trying to save some money on buying the pre made mounts.

The issue here are the steel mounts, for the eMTB you want the set up to be as light as posible, because the overall weight of the board will be around 35-40 lb. and for maneuverability weight is a problem.

I think its only a couple lbs heavier at most. mounts are pretty small. I say do it for science! you really have to get that alignment with welded mounts tho.

Im not quite sure if 3-5mm steel is much more heavy than 10mm aluminium. Perhaps, some material engineer can step in and give us a lecture how dense / heavy aluminium is compared to steel. Either way, I think it wont add extra 1-2kg to really worry about it. Though, these are just my thoughts, as Im also having 4mm steel on the motor part, the clamp part I’ve got is quite beefy, so yeah, for that part aluminium could have been better.

I’ve made motor mounts out of steel before. As other have said, because you can get away with thinner material, in the end it won’t be too much heavier. It will still definitely be heavier though. Given that mounts are pretty small in the grand scheme of things, I would give it a try.

Hell, one of my builds used a tubular steel chassis and it’s like 2 lbs heavier than my friends carbon fiber Bisek board

Thanks for the replies!

I will give it a shot!

I have the metal laying around the garage so I will mock something up.

Any idea what my centre to centre distance should be between the motor and rear axle?

I’m using 16t on the motor, and 80t on the wheel HTD5 belt, unsure of length at the minute.

Once I know this info I will start to mock something up and see what it comes out like.

I will also weigh it as well for the “science”



When I first built the drive train for my board I had the matrix one truck and used a steel flat bar to anchor the mounts to the truck plus I was running steel sprockets and chain drive, to me this was really nice ride. I did not mind the weight and I could handle the board really good.

Here are some pics of that :

Then I change to the matrix pro II with aluminum mounts, belts, pulley and drive cog.

The only change was the weight but the results really impressive.

And oh boy !!! :smiling_imp: the maneuverability of the same board was just in a different level. Overall around 5-6 lb of difference in weight but a 50-60% in maneuverability. One thing to have in mind is that once you are strap in and need to make a power maneuver or tackle a tight turn ( like and over pass ramp over a highway ) you will appreciate the weight reduction.

At the end of the day you can go about it as you see fit, given the current availing of material, budget and other constraints for a project like this. I just wish to point you in the direction that eventually you are going to end up going, that will be a eMTB as light as posible. :slight_smile:

Good luck on the build.

Hi, did you make the mounts yourself? They are very sexy looking!!

I am thinking of 3D printing the wheel pulley, my friend has kindly offered to draw up and then print it.



I designed the mount my self and if you need pulleys I can set that for you too

Where are you located in the USA ?

Uh i got it now. With thickness you had @kaly for your steel mounts and 2 motors - so 2 mounts, weight was really considerable.

Good point about maneuvrability. Had not thought about it but for some reason my board actually turns better on the back side where motor and battery is located.

lol way to revisit an old topic BUT is there any interference with the motors magnets in the steel?