Power Kite Forum

First set of Doom wheel constuction

Suds after thuds - 3-21-2012 at 07:40 AM

I've been to the local bike shops and been searching for weeks online, now I finally think that ive found a suitable wheel:

Durchmesser: 310 mm
Breite Lauffläche: 55mm
Nabenbreite 54mm
Tragkraft: 75kg
Gewicht: ca. 980g
für Lagergröße 6201 oder 6002 (Aussendurchmesser 32mm)

they need these bearing:

Standard Kugellager 6002 2Z

Rillenkugellager, einreihig, DIN625

Standard Rillenkugellager der Größe 6002 2Z, mit beidseitigen Deckscheiben die den Innenbereich des Kugellagers vor eindringen von Schmutzpartikeln schützen.

Innendurchmesser: 15mm
Außendurchmesser: 32mm
Breite: 9mm

My first question is will this be enough to keep dirt and sand out? Or should I look for another 32mm bearing? I'd use plenty of fett/grease on the outside as a preventative measure. Since they call it the standard Kugellager 6002, and it's pretty inexpensive, i'm skeptical.

My second question is about the rails. I looked at a bunch of rollskis which all had plates mounted on the outside edge of an aluminum core. Does this make sense fo Doom Wheels too? I've read through a lot of old posts and am curious to see what materials have stood up over time. Yes, the steel rails 3/8 inch were the beginning, but Dan Doom's Moster Wheels look pretty sick and fuctional too.

thanks for input

furbowski - 3-21-2012 at 08:00 AM

Can't help with the rails, but can with the bearings.

The ones in the picture are, as far as I know, not possible to maintain. The cover for the bearing race won't come out in good enough condition to snap back in again, so one cannot clean and re-lubricate the bearing race.

However, the bearings will last well enough, depending on your conditions. I have the same on my coyotes, and they will only last two or three sessions for me. However my conditions are worse case: fine, dirty sand on wet saltwater beach hardpack. In drier conditions, you would get quite a bit more life out of them. The problem with using grease on the outside as protection is that the grease will ultimately pull dirt into the bearing race.

At least they are inexpensive. I always keep a spare set on hand, and part of session prep for me is checking the spin on my wheels and replacing bearings as needed, usually I need to change out a few. I think you may be best off treating them as somewhat disposable. Note that I ride worse case: in and out of salt water on sandy beaches. You'll get more life than me in any other setting, lots more in some. Even dry hardpack beach will be lots better, but you'll want a few on hand, ready to change out.

I've tried soaking in gasoline and solvents, didn't help and also took out the lubrication inside. Now I clean sparingly after sessions, trying not to soak them with the water i use nor use so much pressure that I'll drive water inside the bearings.

I'd love to be proven wrong as I hate disposing of a couple bearings every session, but that's been my experience so far.

I should mention that I'm cheap and buy my bearings used for about 25 cents each in street stalls in Hong Kong, where I live and do most of my riding.

The bearings on my mountainboard are maintainable, and so the MTB is my ride of choice for wet beach settings.

Good luck with the rails, there's info way back in the old pages of this forum somewhere... But others will be able to give you better advice. There are some tricks to the spacing and mounting of the boots, directly on the centerline is not actually best if I recall correctly.

PHREERIDER - 3-21-2012 at 08:04 AM

i used the exact same wheel set , very light, salt tolerant easy parts source as well,

i used Aluminum rails (1"x1/2"x30")with both 8" and 12 wheels. i much prefer the 8" .. the bearing are virtually disposable about 300hours and they fail faster with salt water intrusion.
really would not worry about it. rinse with water then WD40. ...ONLY IF THEY THEY GET WET.

the metal sheild are the worst IF THEY GET WET ALOT, rubber shielding is preferred they just wash better.

if u kept things dry, the bearings will last even longer

furbowski - 3-21-2012 at 08:05 AM

Hmmmm, maybe I should buy some new ones!

PHREERIDER - 3-21-2012 at 08:17 AM

handling the bearings, messy PLUS solvent waste and exposure, disposal of the solvent is far more a problem than a bearing. roll thru the crunchy parts ..bearing still has a ton of life!

after a ride lube to free roll with a spin and your set to go next time... a little crunch to roll and some noise will be present but of no consequence. sometimes the lock if setting for a while and thats just needs lube and back and forth roll til its free. and the session ON!

on the parts choice for the bearing/axle/wheels you should stay within the ATB parts source (or bike) so it a common part and low buck. if you go to an odd ball size it will be $$$

furbowski - 3-21-2012 at 08:20 AM

OK, never mind the dirt, just crunch through it and light oil for lube?

PHREERIDER - 3-21-2012 at 08:27 AM


go through this thread lots of pics, 12"/8", offset spacer stuff.

should help

PHREERIDER - 3-21-2012 at 08:35 AM

Originally posted by furbowski
OK, never mind the dirt, just crunch through it and light oil for lube?

thats the ticket ! bearing will sound sick at first but within a few moments into the session ...its something new!

Mainekite - 3-21-2012 at 10:28 AM

Where did you find the wheels, and were they reasonable, I've been looking for some for awhile now. Im thinking of building mine on a platform with snowboard type bindings so that I can wear my own shoes or boots as needed.

Suds after thuds - 3-21-2012 at 12:59 PM

I Updated the original post to include links to the site where i Found them.
Here is the link.Wheel

Thanks for all the posts. I'll let y'all know how they turn out. There's a custom bike shop around the corner called PedalPower.de I wonder what they might have kicking around their scrap metal pile.

Suds after thuds - 3-21-2012 at 02:45 PM

so 4 aluminum 30" rails weigh six pounds and the wheels make for 8.6 lbs plus boots and frames = c. 10lbs a skate

did you do your own drilling or have them machined in a shop? Seems it would be easier to drill something not round.

1/2" {A} x 1" {B} 7075-T6 Aluminum-By the Inch
SKU: 75f.5x1
Length Tolerance: Plus 1/8", Minus 0
Material Inch Price: $0.96
Total Material Price: $115.20
Total Process Fee: $0.00
Approximate Piece Weight: 1.50 lbs
Approximate Total Weight: 6.00 lbs

PHREERIDER - 3-21-2012 at 03:30 PM

the weigh is stout ..legs will smoke in a hour session! coyotes are 7lbs. doomwheels far more stable 40+mph.

complete DIY after meaasure mark +30min ready to rock! common part knowledge from bearing size and hub width can make quick easy hardware store run.

not that 7505 alloy, you don't NEED that much caliber ...6061 is fine at dim.

you could but too heavy imho

here you go

Suds after thuds - 3-22-2012 at 01:54 PM

The 1" is enough to have 5mm around the axle hole. I was thinking that the 1 1/4" inch would cover/ protect the bearing better. Weight is probably more important than a two euro bearing though. and 6061 it wil be.

ghetto wheels

mdpminc - 3-22-2012 at 01:59 PM

I considered using a 10" junior BMX wheels, then use the front forks from kids bikes (found several at local recycling depot for pennys) and welding them to square tubing, then bolting on some old snowboard bindings or old hockey skates boots.
concept still in development .. :puzzled:

hm_doom_wheels.jpg - 129kB

Suds after thuds - 4-3-2012 at 01:34 PM

Gemmel Metalle

This is a shop here in Berlin. They've got 6060, which is also the same family of alloys as 6061, but maybe not as rigid and corrosion proof.

I've got a question about the length now. The diameter of the wheels is 310mm, so the radius is 155mm , so if I add 180 mm from the end of the inline frame, and drill a 15 mm hole centered at 170mm from the end of the inline frame, I think I will have 15 mm clearance on the frame and 25 mm to the end of the bar.

Length of frame (285mm) + 360mm= 645 mm

So Will that be long enough? Am I forgetting anything? This is a good bit shorter than 30" which is why I ask.

PHREERIDER - 4-3-2012 at 03:19 PM

about 26+" , i left more room for wheel clearence and room for tooling the ends. also i bought 60" sections ...so one cut and done. clamp together drill center axle hole ....when you're tired of the 12 '' , you can drill centered holes for 8" wheels.

axle diameter ?bearing size? 15mm ? is that common? i think 12mm r cheaper....hub size on the wheelset must 15mm bike ..

anyway seems ok

Suds after thuds - 4-10-2012 at 04:03 AM

15mm is Shimano's standard for MTB Front axels. Hard to find for a decent price, but I've got a friend in Switzerland with a machine shop and a budding kite addiction, so the price to make 8 axles is actually less than it is to make 4.

He's going to mill down a 20mm rod of 6061 aluminum to make plugs to put on a 8mm thru bolt. Back wheel will be centered 10.5mm from the rails and the front will be 5mm from the inside rail.

I should be done by the end of the week, just as my recently thrashed kite comes out of the repair shop. I'll post pics when I get back to Berlin

PHREERIDER - 4-10-2012 at 05:52 AM

6061 for the axle? seems too light . axles should steel.

just waiting for axels

Suds after thuds - 4-23-2012 at 02:15 PM

decided on the steel tube for the axels, set on 8m stainless steel thru bolts. Have to wait until my friend finds time to make them, though. Meanwhile I''l stick to the powerslides on the tarmac.

A note on the wheels that I bought, the bearings are set at different depths one side is at 3mm

and the other at 7mm

Kamikuza - 4-23-2012 at 05:24 PM

You planning on riding over hills, gutters and small children in those?!? Damn, those are some Wheels of Doom! I'd go so far as to call them Wheels of Wailing and Gnashing of Teeth :o

PHREERIDER - 4-23-2012 at 06:04 PM

off set built in!

Bladerunner - 4-24-2012 at 04:59 PM


If you have some wide open space you should be able to hit some amazing high speeds on those !

PHREERIDER - 4-24-2012 at 06:04 PM

i just noticed, those wheels are HUGE...HEAVY?

the rails are SO wide. managing those will be challenging . careful

rectifier - 5-3-2012 at 06:22 PM

I work with bearings on a daily basis so I can give you some tips on the dirt problem.

You can get 6201 or 6002 bearings at any local bearing supplier (SKF, NSK etc...). Both are common bearings and are available in 2RS (2 rubber seals) or what is often called VV (2 non-contact rubber seals).

6201 have a smaller shaft (12mm), 6002 are a weaker bearing with tiny balls but a thicker shaft (15mm). Your choice, 6201 is significantly tougher under impact loading... and you are unlikely to bend the 12mm shaft.

Drag from the 2RS seals will slow down something like a skateboard pretty bad. But as you have plenty of power, they may be OK. They keep almost all dirt out and most splashed water, though they are not made to be immersed.
The VV's are close but not quite touching. They are much better than the ZZ (metal shields) but do not drag. They are great on a skateboard.

Consider bearings of that size disposable, not worth re-packing. However, when they are new, you can pop off the seals carefully and add more grease. This will help keep moisture out and make them last longer so you don't have to take your wheels off quite so soon.

elnica - 5-4-2012 at 10:54 AM

What is the advantage of a long wheelbase like this over something like coyotes? Just speed? I've only ever ridden coyotes but it seems like they are heavy enough and fast enough, at least for soccer field riding.

Long wheel base = more torque when falling = ankle death?

Heavy = sucks when not wind powered (setting up).

Good design & materials could mean less weight than coyotes?

I guess you can go faster but if you fall those things aren't "popping off", they are "popping ankles". Maybe install a ski mount rather than bolting the ski boots on so the ski boots pop off under torque.

Falling is just a matter of time.

Suds after thuds - 5-8-2012 at 02:43 PM

The axels/ spacers are done and in the mail. Thanks for all the contructive comments-- can't wait to try them out (and Weigh them;)

Bladerunner - 5-8-2012 at 05:37 PM

Originally posted by elnica
What is the advantage of a long wheelbase like this over something like coyotes? Just speed? I've only ever ridden coyotes but it seems like they are heavy enough and fast enough, at least for soccer field riding.

Long wheel base = more torque when falling = ankle death?

Heavy = sucks when not wind powered (setting up).

Good design & materials could mean less weight than coyotes?

I guess you can go faster but if you fall those things aren't "popping off", they are "popping ankles". Maybe install a ski mount rather than bolting the ski boots on so the ski boots pop off under torque.

Falling is just a matter of time.

Yes, I see it pretty much like you do.

I seem to have a wall at 40mph that I can't break through on the Coyotes. Part the blades but I think almost as much mental. If I was younger and didn't already have one rod in my leg I would go to this style to try and beat Bob Childs 50mph but like you said I would incorperate bindings.

Badam - 3-28-2015 at 04:13 AM

Those wheels are ideal, thanks for doing the leg work, they're better than anything I've found. Did you finish your build yet? If so, how did they turn out? I'm getting a wee bit obsessed by Doomwheels now...!

Suds after thuds - 3-28-2015 at 11:18 AM

they wound up being 4.5kg each and worked really well as I was cutting my teeth kiting. I had a much smoother ride than on the powerslide xc trainers and they never collected grass between the rails and bearings. I had some interesting crashes, but I'd put on par with learning to telemark. I never had issues with the ankles until I broke the skate boot (this happened in a suitcase i think): , then it was a little loose as the crack just kept on growing.

I went with a xsjado L for my new boot, but it turns out I am a S. The couple of times I went out with them after the re-boot I had issues holding an edge. Need more ankle strength or a tighter boot. Before they broke I felt really confident carving and sliding with them. I keep missing on ebay auctions to get the same boot as I had before. I decided to focus on building board skills to help transition to water.

It was a fun project, and the initial results were a lot of fun, but heavy!

Badam - 3-28-2015 at 12:51 PM

Sounds like quite a ride (in more ways than one). I'm really excited to build these things and just want to make sure I make as many good decisions early on as possible. I'm going to build a pair for myself and my girlfriend and, while I don't mind being a guinea pig I don't want to build her a death trap (though "Doomwheels" isn't exactly subtle!). I'm planning on getting used to the skates with some off-road nordic style stuff and then starting on a 5m kite (Peter Lynn Hornet). I don't know how sensible that is but I'm pulled in that direction. I've just heard back from the wheel company and they reckon they should be able to ship to UK. Would you rate your choice of wheels? I like the look of them.

Suds after thuds - 3-28-2015 at 02:42 PM

I chose skates because I felt more comfortable with my feet working independently. The doomwheels were a fun side project as I got to know kiting. As I started I flew static and with the XC trainers with a 4m fb kite on a bar. I learned about survival mode before I figured out speed control and heading upwind. Good armor, falling practice and luck kept my injuries limited to road rash. Just saying that a small kite can deliver way more than one's initial skill set can handle.

I was really tempted to start with a 5m kite too, because I wanted that first kite to be able to do it all. Well no one kite can do it all. Seeing as you aren't going it alone I would start with a 3m FB kite on handles learn to control it or even fly it blind as it says on so many first kite threads here. I usually read all of those as they pop up–the injury stories too. Wife got me to pick up an additional disability insurance recently. If you're not careful, at least be sensible.

Once I could roll where I wanted to most of the time, I started to get frustrated by the guys cruising past my sining kite and by watching them boosting floaty jumps, so I got a bigger kite and it was like going back to zero. It was easy to be overpowered.

If you're obsessed, your quiver is going to grow and you'll eventually have the right kite for the conditions. I'd just highly recommend not trying to skip steps along the way.

I was happy with the performance of the wheels, but I was surprised that the internal spacer was set to different depths. I incorporated this detail into the plugs I had built for my axels, so the front wheel was just 5mm off the rail and the back wheel could be either centered or 4mm off center. I noticed an advantage heading up wind compared the the trainers.

I think 8"-9" Mtb wheels would be lighter, which makes it more fun sometimes. many options:
What sort of surface will you be riding, Badam?

Bladerunner - 3-28-2015 at 02:58 PM

I trust that you know about Coyote Rollerblades?

They are my choice for a few reasons. The 3 wheels under foot makes for a much shorter wheel base. With the shorter wheel base I can revert to a ( clumsy ) run if I hit soft sand or anything that stops the wheels. There is FAR less chance of busting a leg. ( if you do a thorough search on here you will find a good number of broken legs with the wheels of doom). I can walk around in the soft sand with little extra effort. I can carve a sharp turn. With the longer wheel base you need to carve a huge turn or step turn. Coyotes run on amazingly rough turf and hard pack sand.

The only big draw back I see is the fact I can't go more than 40mph on them. If you can find them on Ebay etc. they don't cost much more than it will cost you to fabricate doom wheels.

If I was fabricating a set of these I would definitely incorporate a binding to release them!

Badam - 3-28-2015 at 03:18 PM

Cheers for the advice Suds and Bladerunner. I think I'll likely experiment with a variety of surfaces. I have ready access to hills, dirt back roads, beaches so will see what works best I guess. I have looked at picking up a set or two of Coyotes but no joy yet. I've looked at those Powerslides too and, though they look nice, don't seem quite so versatile as I imagine Doomwheels would be. I must admit to being slightly apprehensive about the height of Dooms and have looked at a variety of wheel sizes. As yet I only have the inline boots so might rethink before collecting more materials for the build. I thought a 5m kite might be pushing it to begin but after reading about folk using really massive kites thought it might okay and there's a lovely one going cheap on Ebay right now. As well as trying Kite Skating I want a pair of skates for some nice off-road nordic stuff and thought I might be able to get both out of one pair of skates. I currently skate indoor on quads (Roller Derby) and want to get some more outdoor skating done away from tarmac.
Cheers again, certainly food for thought!

Bladerunner - 3-28-2015 at 03:55 PM

I have been assuming you have previous kite experience?

If you don't then starting out with a 5m kite will be a big mistake. This game is all about KITE CONTROL !!!!!!!!!

Putting your partner on a 5m kite with no experience is a great way to turn her off of the sport! Start out with a quality 3m 4 line fixed bridle foil. ( I suggest the 3.3m Buster Soulfly if you are buying new ) Used from a reputable forum is also a good way to go. You will likely want something larger down the road but the 3m will always have a place in your kite collection. It won't be wasted money.

The 3m is the tried and true size for learning kite control. It is big enough to work as a true engine and still small / fast enough to control easily. You can force it to fly in very low wind and keep flying it until the power is too much. This way you can fly and learn in the widest wind range. It is all about getting time on the ropes and setting memory reflexes before you strap on the blades. Not having to think / look at the kite as much makes figuring out getting in motion much easier.

Trying to skate with Coyotes is kind of a drag. They are clumsy and slow with the pneumatic wheels. The short wheelbase starts to work against you using them down hill. Toss up a kite and get dragged by it and all of a sudden :wow:

Badam - 3-28-2015 at 04:04 PM

Sounds grand, I'll be keeping an eye out for some of those but they don't crop up a lot in the UK. I only have stunt kite experience and nothing over 1.5m. I definitely plan on honing kite skills before attaching myself to it, whatever wheels I have on my feet. This has only recently become an obsession (last three days) and I still need to finalise exactly what it is I'm making so this advice and info is invaluable. I think smaller wheels might be a better idea to begin with and am now looking at second hand mountain boards to cannibalise.

Badam - 3-31-2015 at 03:52 AM

Hello again. Okay, I've settled on some 8" wheels and have the right inline boots. My next question concerns the correct type of metal for the skate frames. I have found a local company hat can quite cheaply supply some 1/2" (or any other, equal dimension) aluminium square bar but the only compound they seem to offer is the alloy 6082T6. I know nothing of alloys and wondered if anyone knows if this is going to be good/strong enough. I have read that others have used 1/2" aluminium but not of this alloy.
Any metallurgists out there?