repairing a treadmill deck

[Eigenvector]

A long while back I posted a question about repairing a treadmill deck. Most of the responses were helpful pointing me in the direction of oak as the decking material of choice.

In the time since then I replaced it with more MDF, out of expediency more than anything. Well now that I have some proper time on my hands I priced out some rough 5/4 oak planks. But before getting into it, I was curious about how to do the replacement.

I'm wracking my brain trying to determine HOW to create the replacement deck. See, the deck is 17"x28"x13/16" and the dimensions are very unforgiving as it is supported in 6 places only - 4 corners plus 2 on the midspan edges. So I look at what I have available, for argument's sake 9" wide 5/4 planks of 6', 10', etc.. lengths. That would give me either 2 planks running lengthwise or ~3+ planks running widthwise. I could get

4/4ths just as easily too.

What would be best here, run the planks widthwise or lengthwise? I have to tie the planks together in a way that is very durable and strong - I will be running on these things and so it has to take approximately 300 lbs of impact for long periods of time. So I was thinking, okay, widthwise planks and tie them together on the bottom with thin plywood. But how to secure them to the plywood, would glue be enough or would screws be mandatory for bond strength? I can't see doing the planks lengthwise, as there is nothing supporting them in the middle and the middle is exactly where my feet will be landing.

See that's my problem, I can't get past the feeling that no matter how I tie the planks together, they'll never be strong because what ties them together won't be strong. And the chances of me finding an oak plank 18" wide is nill.

I can just as easily throw out the whole replacement scheme altogether. I sufficient MDF to last a lifetime if need be, I just wanted to go with something better.

I can post a photo of the original broken deck if you want to see where it's supported.

[Eigenvector]

Top posted

I gave wrong deck dimensions, been doing it all day in fact.

The deck is 27"x48"x11/16th Don't ask me where the other dimensions came from.

[dayvo]

There are several reasons why treadmill decks are made with MDF. FIrst, MDF won't shrink or expand along it's width. An equivalent solid wood deck would expand along the width and push out the side rails of your treadmill. Likewise it would shrink and fall off the support brackets. MDF also flexes when you run on it. It's much easier on your knees. My current treadmill has a method for adjusting how much the MDF flexes. The last reason I can think of is that MDF is smooth. Treadmill decks are waxed to reduce friction and wear. I break mine down and wax it every 6 months.

Because I run on a treadmill at 9 - 9.2 MPH and put about 20 miles per week on it, I've worn out plenty of consumer models. I've had plenty of talks with the repair guy on how to ruggedize one. He finally sold me on the idea of going commercial. Commercial models still have MDF decks. I'd advise against swapping it with a solid. If by chance you do it anyway then let me know how it turns out over time.

[LEGEND65]

I would try Baltic Birch plywood. This is not the junk plywood you get from Home depot, it is all birch plys throughout the thickness. You can get it in 5/8" (actually a metric size close to 5/8") and shim it at the 6 support points.

[Eigenvector]

Well maybe I should clarify.

Mind you I'm not critisizing your response at all. I could get whatever I needed to be sure - but that's not really the point of the post. The point is how to create a stable running deck from multiple wood sections. The answers I got a while back pointed me in the direction of oak and this post isn't really about what the BEST material is, but how to make it work with multiple sections. I heard some very helpful responses pointing me to oak flooring material - seems like a decent way to do it. But again the question - how to mount it so that the running platform is stable and still maintain its dimensions. At this point it's an exercise (forgive the pun) in how to make it work, rather than practical woodworking. I haven't seen the deck of very good treadmills, so I don't know how they do it. I've been told that they use oak decks -but potentially they use a much better support system which allows them to do that. And that may just be the answer - "can't do it on your model, sorry buddy". I've got 3 more MDF decks just waiting for that inevitability.

[J. Clarke]

That's very likely to be your answer. To use planking you need supports designed for planking. From what you're saying yours don't appear to be.

[Ross Hebeisen]

have you tried just flipping the old deck? my other half s a fitness coordinater at the center here in our town and I know on the commercial units they can flip the deck once worn on one side. ross

[B A R R Y]

My LifeFitness 9100HR has tongue and groove planks running lengthwise over a few cross supports. The supports are not attached to the deck, only to the frame. The machine has a wax dispensing tank that lubes the deck.

This is a pro treadmill with 45,000 miles on it to date. The deck has been flipped to the second side at 41,000 miles. My buddy that repairs these for living, and found me this one used, sees oak decks go

80-90,000 miles in commercial applications.

[Eigenvector]

Well I'll take a look at it from that angle then. I just remembered that the front edge does rest on a single channel section bar, and I see no reason why I couldn't run 2 more widthwise , plus a final one at the end where it cantilevers over the end pulley.

Thanks, a description of an oak deck was what I was hoping for.