Widening wheel hubs

ducktaperules · December 15, 2019, 3:22pm

I got the MegaDeep mounted to my front 2 wheels so that I can put some miles on them.

They do look slightly wider but not by as much as I was expecting.

The tyre center has gone from 350mm to 367mm so 17mm wider. The outer edges from around 410mm to 430mm so about 20mm wider.

Just taken them out for a first ride and they feel ok. Had them at around 30psi. Did some small hops and dropped off some pavements but they seem to be holding up so far.

It’s hard to tell if there is much difference in grip when it’s cold and wet outside but when I got home and rolled into the garage I noticed something interesting.

The wet tyres picked up the fine wood dust wherever they touched the floor. This provided me with an accurate measure of the contact patch.

What I found is that the width of the contact patch is about the same front and back.

It’s got me thinking . . . Does widening the hub actually make the contact patch wider on curved profile tyres?

RyEnd · December 15, 2019, 4:48pm

Negligibly. The biggest thing you will notice is changes in sidewall characteristics, and how different levels of inflation effect grip mechanics.

What we really need is ~70mm+ wide tires to put on these.

ducktaperules · December 15, 2019, 5:29pm

care to elaborate?

RyEnd · December 15, 2019, 5:46pm

Namely their height (which you noticed) and their willingness to flex. Depending on how the tire is made, being above or below square to the rim will increase or decrease sidewall flex.

kook · December 28, 2019, 5:24am

This is cool AF… and I really like where you all are going… but…

threadus Interuptus:

what are your thoughts of buying the “deep dish” offset Megastar half rim?

Trampa · December 28, 2019, 10:48am

The 9" deep dish can take the 8" tire and increases contact patch. Contact patch and grip is mostly determined by inflation pressure. What makes more difference than widening hubs is the tire design. That’s why we designed the new 9" Mud Pluggers.

ducktaperules · December 28, 2019, 11:20am

Yeah this is the conclusion that I have been coming to after doing some testing. You can get the wide contact patch Benifits by just dropping the pressure by a few psi so unless you just want it for the look I don’t think wide hubs are worth it just for the performance gains.

Riako · December 28, 2019, 11:51am

ho didn’t notice that too !

So one more thing to add to the list

So, 9" Megastar rim can be an easy solution?

Range compatibility = from 6 to 11"
Offset position
Contact patch increased
Counterbalance valve weight
You can reuse your previews Superstar spokes

plus they are full Alloy Cnc, black anodizing or raw finish, many spokes colors options …etc.

Trampa · December 28, 2019, 4:05pm

I never tried 6", but 6.5" to 10" definately fits.

Pedrodemio · January 5, 2020, 11:35pm

What a pain in the butt is to assemble this, specially when only at the end you remember that you need bigger screws

I’m not sure if I liked it or not, 8" tires may be a little on the small side

malJohann · January 6, 2020, 1:21am

You didn’t go for offset, bolt length would be the same? Do they still fit a standard Trampa hanger like that?

malJohann · January 6, 2020, 1:22am

Oh, you did, what went wrong?

Pedrodemio · January 6, 2020, 1:24am

It’s offset, keeps compatibility with anything, pulleys, gear drives, etc

It worked really well, need to change the dimensions a bit to fit better, but if I had a board to try them I could ride right now

The hardware have to be 10 mm longer than the standard

malJohann · January 6, 2020, 1:33am

I’ll keep that in mind when the time comes. Thinking of using Taulman Alloy 910 nylon for mine. What did you use to print?

Pedrodemio · January 6, 2020, 1:36am

I’m using regular ABS, the wall are pretty thick, and the screws compress everything down, I don’t think anything more than that is needed

malJohann · January 6, 2020, 1:46am

Also, still wondering why you didn’t go for spokes like @ducktaperules did? Are you afraid the spokes will break under pressure?

Pedrodemio · January 6, 2020, 1:49am

What do you mean? The spokes on his pictures on his pictures is the Trampa ones

@ducktaperules could you share some pictures of how you sliced yours? The bottom surface of mine ended looking like crap. Do you use soluble supports?

malJohann · January 6, 2020, 2:03am

@Pedrodemio must have been only the first prototypes, right @ducktaperules?

ducktaperules · January 6, 2020, 7:43am

Yeah I got rid of these on the ones that I’m riding, I don’t they they are necessary.

jeorghe · January 11, 2020, 10:35am

(I am not english …)
Hi, as first a thank to @Pedrodemio and @ducktaperules for the idea.
I apply the idea to trampa hypa hub to use 3.00-4 off road wheel.

For each hub I used two ring to adapt the diameter from 9cm to 10mm and a space to adapt the hub from 3,5cm to 6cm.

Obviously this is not strong as the Trampa Megastar 9’’ but it is a low budget solution for sure ( 20 euro of PETG roll from amazon).

Perhaps over time the bearings could be put under stress, and it is necessary to carry out a periodic check that there are no play on the hubs.
But the bearings are very cheap …
I am using this set up since one month in off road as grass and dirt road.

Now you can travel with greater comfort path that before were a blender for the legs and ankles.