So, I just finished my first stab at a doom wheel type setup but with a shorter wheelbase using Coyote Boots and partial Coyote frames.

I cut off the fronts and backs of some frames and enlarged the two smaller holes at the middle frame area to run bolts through and attach some "rails" of a sort.

These are thin steel rails with holes for easy wheel attachment. The holes lined up perfectly with the existing smaller frame holes, I simply cut the rails to the desired length.

The rails are a bit too thin and somewhat flimsy but that helped keep the weight down methinks. They actually bend inward as they stretch out from the midsection. I added some spacers to push the rails further away from the frame which helped keep the fat 200x50 wheels from rubbing the rails.

I did a general test skate outside and they seem to work fairly well.

I need to put the powerstrap and probably the laces back on the boots for a better overall feel.

Here is the pic:

Nice! Cool to see somebody innovating like this. I invested in some CNCed aluminum "rails" last year out of Germany that accepted 200x50mm setups like yours. I agree that such wheels are the right size for this application.

You are noting the side to side flimsiness of your basic concept. I bet it will be challenging to remove that side sway without a severe weight penalty if you keep with vertical side rails like this in steel and simply go up in steel thickness.

Just as an experiment, have you tried to build a single skate with doubled up rails? How does weight and flex feel for that? I'd think you could build that, put it on one foot and stand your other foot on the first step of an outdoor staircase and get a pretty good feel of side flex just simulating a push with the skate foot without moving. Just a thought.

With that shorter wheelbase, have you been able to carve a turn? My longer German doom setup didn't carve and I had to step turn.

I'm assuming since you are posting on PKF that you intend to kite skate. That will add considerably more side load than just skating around, a lot more.

Keep it up!

Good work.

A better powerstrap will hold top closed better than original...and you can rivet another buckle(s) on. Like this:


Most important to me was to get rid of the terrible liners and put in a firmer lighter thermo-moldable ski boot liner. Original actually caused a bad cant in one skate.

Still..... slightly longer wheelbase than original set up ...so you may still not be able to carve well( slalom or turn as quick).

You're going to kite with these, then? ..and on what kind of terrain?

Quote: Originally posted by skimtwashington

Good work. A better powerstrap will hold top closed better than original...and you can rivet another buckle(s) on. Like this: Most important to me was to get rid of the terrible liners and put in a firmer lighter thermo-moldable ski boot liner. Original actually caused a bad cant in one skate. Still..... slightly longer wheelbase than original set up ...so you may still not be able to carve well( slalom or turn as quick). You're going to kite with these, then? ..and on what kind of terrain?

A popular alpine skier powerstrap setup is the elastomeric BOOSTER strap:

https://www.skiboots.com/Booster_Straps_p/0031.htm

These straps have some stretch built into them by design, essentially trying to solve a problem that straps create. The goal of powerstraps for most skiers is to snug up the upper boot to reduce "shin bang" something that can get pretty painful over time. The problem created is that use of a non-elastomeric strap essentially splints the shank to the back of the boot and thereby takes a lot of ankle Doris/Plantar flexion out of the equation to the detriment of fine control of the turn in real time. By adding some stretch to the strap (offered in different degrees of stretch) the BOOSTER strap reduces shin bang but still allows for ankle mobility.

I might suggest taking a look at BOOSTER straps if you are looking to upgrade the Coyote straps as Tuck suggested.

WS -

I did briefly contemplate combining rails (x2 on each side) to provide a more solid system but I think now that the weight would just be a little more than I would like to handle.

I may need a bit more spacer separation though as I still noticed some slight rubbing of the wheel on the rail on the front left skate. This is only noticeable when angling my foot too much to the outside.

Then again, it may offer me a way to brake when I am about to hit a tree on a downhill :D

More on the wheelbase: I measured the setup at 16.5 in. whereas the Coyotes original setup is at 13.5 in. For comparison, the gateskate/trailskate has a wheelbase of 21 in. with its 2-200x50 setup.

One good thing is they really aren't up too high vertically, probably about the same as the original Coyote configuration. I think you can turn a bit or try lifting the toe to pivot, similar to the Coyote regulars, but its obviously not quite as nimble.

Finally, I just like using the off road builds for downhill and general off road use, with some on road as well. I do not kite skate.

Quote: Originally posted by jcardin

I do not kite skate.

Me neither (at least any more). Here is a little tail about when I did:

http://www.powerkiteforum.com/viewthread.php?tid=32253

When I did kite skate I really liked these frames:

https://www.cadomotus.com/nordic-scout-chassis-only.html

I'm not suggesting you buy them (yes, they are pricey), but they got the job done in CNC aluminum style and you could mount your coyote boots to these frames. I'm showing you these more for design ideas than anything else. They solved the rigidity issue you are struggling with. Good luck!

Well, I tweaked the skates some but it ended in failure.

I realized that I needed longer axles (bolts) for the wheels in order to straighten the rails out more perpendicular. After getting that in order, I was still getting some wheel rub on the front but it was from the front of the frame rather than the rails.

So, I moved the front wheels forward to the next hole on the rails. Then I tested them on some downhills. Soon after during my attempts I had a fall and bent the left front rails and wheel over about 45 degrees.

So those rails are toast pretty much now.

I think I also realized that anything longer than a standard coyote wheelbase isn't good for downhills as you need to be able to turn quickly and effectively and I don't think any doom wheels or skis with wheels are going to be the right choice for this application.

Oh well, I still have my other Coyotes with modded frames that have 2 200x30? or 8x1.25 wheels that have worked well for downhill and general use.

I just wanted to try some fatter wheels with more cushioning that might could also allow a lower psi and still work well enough.

Quote: Originally posted by jcardin

Well, I tweaked the skates some but it ended in failure. I realized that I needed longer axles (bolts) for the wheels in order to straighten the rails out more perpendicular. After getting that in order, I was still getting some wheel rub on the front but it was from the front of the frame rather than the rails. So, I moved the front wheels forward to the next hole on the rails. Then I tested them on some downhills. Soon after during my attempts I had a fall and bent the left front rails and wheel over about 45 degrees. So those rails are toast pretty much now. I think I also realized that anything longer than a standard coyote wheelbase isn't good for downhills as you need to be able to turn quickly and effectively and I don't think any doom wheels or skis with wheels are going to be the right choice for this application. Oh well, I still have my other Coyotes with modded frames that have 2 200x30? or 8x1.25 wheels that have worked well for downhill and general use. I just wanted to try some fatter wheels with more cushioning that might could also allow a lower psi and still work well enough.

Pssssssttt.... don't tell anybody I showed you this, but check this out:

http://www.extremekites.com.au/forum/28-kite-skates/

:saint:

I just finished reworking my Doom Wheels. I should have gone this route to begin with as I had thought about using these other steel tube "rails" (shown below) but tried to go lightweight first.

I first built one skate with the more solid steel rail and was using it on my right foot while I pushed off or kicked with my left wearing a standard tennis shoe. I could even ride one footed down some short downhill slopes, though mostly in a straight line of course.

My partial Coyote frames or boot would be more likely to bend or break compared to these super solid rails.

I am also planning on making short extension rail sections of a possibly lighter material like aluminum that I will bolt onto the existing rails so that I may be able to attach larger 12" wheels. This way I don't have to have separate rails or another skate built altogether.

I may just try putting the bigger wheels onto the fronts rather than both front and back. This would keep the weight down, allow me to more easily lean back on the rear 8" wheel to turn/pivot and avoid obstacles/terrain that the 8" wheel might get caught up on.

I have previously found that being at a bit of an angle with your toes higher than your heels helps avoid face planting when doing offroad downhill as well as aiding in turns.

Fun Stuff!