Upgrading Coker Wheelset

Unicycles and Equipment
1

I have had my Coker for a year or so and ride it everyday, I literally
don’t leave home without it as all my classes, the store, etc. are all
close enough to my house. I tell people that they can check if I am
home by just seeing if my Coker is on the front porch. My coker is
mostly stock, just upgraded cranks, peddles and an airseat.

I got off to a rocky start, when I first got the coker the cranks
worked loose, so I tightened them, only to discover that they now
touched the coker frame. After over a month of going back and forth
with Unicycle.com we finally got things worked out and my coker has
been great ever since.

Except the wheel strength. Coming off a curb late last year the rim
torked underneath me, went back to almost true but alarming
nonetheless. I trued the rim again and was a little more gentle,
however it tacoed several months later. I have trued the rim again with
professional help, and now am very aware that the wheel is not really
strong enough and can certainly feel it flex and bend slightly in
certain situations.

So I want to upgrade.
After reading on here I think the best option would be the airfoil rim,
the Unicycle.com super-wide hub, and tom miller stainless spokes.
Is it true that the upgraded coker wheelset that unicycle.com sells
does not have the wider hub as they show in the specs, or is this old
information?
Has anyone had any success ordering a built wheelset from them with the
airfoil rim, wide hub, and stock spokes?

I would prefer the tom miller spokes but would rather have someone else
with more experience build the wheel for me. Would the best way to this
be to have unicycle.com ship the rim and hub to a wheelbuilder and have
tom also ship his spokes to the wheelbuilder, then have everything
shipped to me. Anyone have any experience with this, or know what the
costs would be. I’m not even sure what the cost of the Tom miller
spokes would be.

I would love any help you guys could offer, or any suggestions.
Thank You
Lebn Schuyler

2

You need to talk to U-Turn, he makes the “strongest coker wheel in the world”. Airfoil rim, stainles spokes, and a wider hub.

I’m having one made by him right now.:smiley: :astonished: :sunglasses:

3

Not that this will be too helpful, but I concur with you about your observation that the wheelset that has the airfoil rim looks like it uses the narrower hub. I just bought the deluxe Coker and it indeed uses the wide hub along with the airfoil rim. It might take a little longer, but I’d bet that they would work with you on that. The Drummonds seem to be really top notch folks and although I haven’t tried to get things done differently from what they offer, I’d bet they’d be willing to do it (Kovachi built, wide hub, with nice stainless spokes). Hope this helps or encourages.

–Bob

4

The product pictures at Unicycle.com can be out of date (and often are). I’m certain that you could get the Airfoil wheel combo with the new super wide Unicycle.com hub. That wheel probably already comes standard with the super wide hub now.

The Unicycle.com wheels come with the stock Coker spokes. Unicycle.com doesn’t carry the stainless steel Tom Miller spokes.

I don’t know how much of a difference it makes to go with the Tom Miller spokes vs. the stock Coker spokes. You can tension the SS Tom Miller spokes tighter which will give you a stronger wheel. So the SS Tom Miller spokes can make for a stronger wheel if the wheel is built well.

If your plan is to ever run a brake then definitely go for the SS Tom Miller spokes and the best wheel build you can get. Anything less and you’ll have brake rubbing issues because the wheel will flex. And even with the SS Tom Miller spokes, a super wide hub, and an Airfoil rim, you’ll need a very good wheel build to eliminate wheel flex that can cause the rim to rub the brake pads. I had my wheel built by a local wheel builder. It was a good wheel build, but wasn’t tight enough. I had some brake rubbing problems. I took it back and he tensioned the spokes even tighter and the brake rubbing went away.

Cost for the Tom Miller spokes is going to vary. Tom Miller is like that, and the cost will depend on machine setup time and other factors. General ballpark is about $2 per spoke plus shipping. It’s a good idea to have a few extra spokes on hand in case you break a spoke. So figure on 40 spokes. Then you’re going to need some special nipples that you can get from Semcycle USA. They’re the nipples they use for their big wheel. The nipples are about $0.25 each plus shipping, I think. It was over a year and a half ago that I ordered everything so my memory is a bit hazy.

For the Airfoil rim and a super wide hub you can use the standard stock Coker length spokes. You just go with a four cross instead of a three cross. Magically the spoke length works out.

5

Re: Upgrading Coker Wheelset

That was likely due to a bearing that was not pressed on all the way or a bearing that was slipping on the hub. The bearings on a standard unicycle are just pressed on the axle. The press fit can slip and then you get problems with the wheel being off center in the frame (and likely rubbing) and/or the frame rubbing the cranks.

The fix is to use Loctite sleeve retainer when pressing on the bearings. The Loctite will make a stronger hold than just a plain old press fit. The high strength Loctite sleeve retainer (part no. 640) works well. Even though it says high strength the bearings are still removable when it comes time to replace the bearings.

Clean off any grease and dirt from the hub before applying the Loctite. Apply the Loctite. Press on the bearing. Let the Loctite cure for 6 or 8 hours. Go ride.

When you get the new wheel I would recommend using Loctite when putting the new bearings on. It will save you the trouble of needing to do it later when the bearings eventually slip. And it’s no fun to have your bearings slip midway into a long ride (that happened to me when I first got my stock Coker).

6

Re: Upgrading Coker Wheelset

Wow guys thanks for the quick and helpful responses. I haven’t really
posted on this board before but I watch it, I’m impressed. I’m going to
contact the guys at unicycle.com and I’ll also send an email to u-turn.
Has anyone had any experience with the SS tom miller spokes in
comparison to the stock spokes? I don’t have much experience with
different unicycles and don’t know how much of a difference it would
make. There really are no hills where I am currently living, Walla
Walla, so I don’t think I am looking at putting on brakes any time
soon. It sounds like the upgraded spokes would take some weight off, be
a bit stronger, and would allow the spokes to be tightened more. I’m
just don’t really know if the difference is enough to be noticeable as
I have never really tried anything but what I have.

Also, do you guys have any suggestions on what to do with a stock coker
wheelset? It has been used and I would like something stronger so I can
push my riding further, but I think it would still be fine for someone
learning or who doesn’t plan to be going down stairs, off-road, or any
thing like that. I was thinking of buying a frame for it and selling it
to one of the other unicyclists here at school, but it seems like you
can’t buy the stock frame on it’s own. The custom frames are a little
out of my price range, although it would be nice someday.

I would love to get this wheel upgrade for around or below $200 but I
don’t know if that is really possible now, shipped on unicycle.com it’s
about $270 before tax. It’s strange, pricing out the components on
unicycle.com comes to about $145 for the super wide hub, the airfoil
rim, and stock spokes. Kovachiwheels say they charge $30 to build a
wheel for you. It seems like buying everything together they would give
you a discount… I imagine I am just missing something though, I seem
to do that a lot.
Any of you looking to sell a stock coker frame? Or want to buy a used
stock coker wheelset?
Damn it’s exciting to think about where I could take my coker if I
didn’t have to worry about hurting it. Now I just need to get the
torker 24" DX (I know not very flashy, but good and most importantly
somewhat affordable) and maybe the 5’ TX for the juggling club here and
I’ll be set.

Thanks again guys.
Lebn Schuyler

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Re: Upgrading Coker Wheelset

John_childs,
wow, you posted a second response before I responded to your first.
You are right about the bearing slipping, and right about the solution.
That is what I ended up having to do, unfortunately it took a very long
time to get there. the guys over at unicycle.com must have had
something going on because it took forever to get help from them at
first, however once we where communicating they were very helpful and I
have the feeling that the negative aspects of my experience with them
where not the norm. I will definitely apply the loctite to the
hub/bearings on my new wheel, I learned that the hard way.
lebn schuyler

8

I’ve been wanting to get the airfoil rim. Unicycle.com doesnt have any in stock right now though. I guess I’ll give them a call in the morning.

What are good square tapered cranks that dont cost more then $150 that would be good for muni too so I can switch them out. I weigh 210 so it would have to be strong. Black widows aren’t strong enough.

Also what do you think of putting one of the new kh hubs in it? The hub is plenty strong but its kinda narrow so that would make the wheel over all less strong. Right?

9

Hey Lebn, I don’t know too many folks with that name, so are you the ice skater from Bellingham, WA??
Pete P.

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Re: Re: Upgrading Coker Wheelset

I’m just passing along some knowledge I learned the hard way through experience. I didn’t know that bearing slipping was a problem on unicycles until it happened to me midway into a 20+ mile ride on my old stock Coker. Now I know. It’s a lot more fun to fix problems like that before they happen rather than after.

I’ve had the bearings slip on three unicycle (stock Coker, Pashley muni, and DM freestyle). Unfortunately the bearings don’t come from the factory Loctited. It’s something that you have to do yourself.

The wheel builds from Unicycle.com are a bit over priced. I don’t know why the custom built wheels are so expensive from them. When you add up the cost of the parts and figure the cost of the wheel build in that cost it gets to be an expensive wheel build.

I get my wheels built locally. I found a great local wheel builder who builds the best wheels I’ve seen, other than the U-Turn built wheels. My local wheel builds are about $30 for labor plus the cost of parts. Works out to be much cheaper than the unicycle.com custom built wheels and I get a better wheel.

The trick is finding a good local wheel builder. Not all bike shops are good at building wheels. Ask a local bike club for recommendations. Find out where the freeriders and tandem bike riders go for their wheel builds. That’s where you want to go. Don’t just go to a random bike shop. Let the wheel builder know that unicycle wheels get a lot of side loads that bikes don’t usually get. The spokes need to be tight and properly stress relieved so the wheel can take those loads.

You should be able to find a local wheel builder who builds good wheels. You’ll need to bring in the Coker frame along with the wheel. The wheel builder will need to use the frame as a wheel building jig. The Coker wheel won’t fit in the regular wheel building jig. You’ll also need to have the bearings on the hub so the hub will fit in the frame so the wheel can be built.

The U-Turn wheel is going to be way out of your price range. His is the price is no object, quality is everything, it must be perfect kind of wheel build. You pay for that.

A little background on the Airfoil rim. Unicycle.com had the Airfoil rim custom made and they paid for the custom work. They found a company able to make the rim. It’s an existing downhill rim extrusion turned in to a 36" rim rather than a 24" or 26". Unicycle.com is the reason that we have an upgraded Coker rim. Otherwise we’d still be stuck with the stock rim. For that I’m very grateful.
(I had to mention that to balance out the comments about their overpriced wheel builds <g>)

Unicycle.com seems to be out of stock on the Airfoil rim and Coker spokes. I don’t know what’s up with that. I hope they’ll be getting new stock soon. They’re our only source of Airfoil rims. U-Turn probably has some Airfoil rims in stock for his wheels, but other than that we’ll be in a bit of a dry period till Unicycle.com gets some new stock.

Hopefully someone can chime in with the pros and cons of the Tom Miller SS spokes vs. the stock Coker spokes. My gut feeling is that for your needs the stock spokes will be fine. But that’s just a gut feeling and not based on experience.

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Re: Re: Re: Upgrading Coker Wheelset

IMHO, one of the top three upgrades on a Coker:
#1 Airfoil rim
#2 Tubeless kit
#3 Tommy Miller SS spokes

The spokes are just so much lighter (enough for me to notice!)and look cooler because they dont’ rust. I believe they are probably as strong if not stronger, but that will depend on your wheelbuild. If only they came double butted as well.

As for the hub- if you’re a heavy abusive rider using brakes on your Coker then I guess a widened hub is good. I use a unicycle.com hub which works well for me- lot’s of off-road racing/distance touring, no brakes. I prefer a narrower hub and q factor. I only weigh 60kg though.

Good luck

Ken

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Re: Upgrading Coker Wheelset

unisk8r,
wow, yeah I did ice skate in Bellingham many years ago. I haven’t
really skated in a long time though probably not since I was like
twelve or thirteen, so about nine years ago. So would you be the head
of the speed skating back then? I can’t think of many Pete’s from when
I played hockey. Now it’s mostly Juggling, Unicycling, and Disc Golf
for me as far as hobbies go.

and ken,
you say you prefer a narrower hub and q factor? anyone mind explaining
what that is or why someone would prefer a narrower hub. Also what’s
this tubeless kit? Have people really had success with this? It seems
like from bikes that going tubeless has always been more of a hassle
than it’s worth unless you are racing and really need to save the
weight and don’t mind having to do maintenance on it all the time.
thanks again guys for your help.
-lebn

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Re: Re: Upgrading Coker Wheelset

Those are 3 great hobbies - personal favorites, all.

About the Coker wheel upgrades, I read through and John and Ken covered everything you need. I agree that the airfoil rim by itself is the biggest single upgrade. But the whole package (especially if built by U-Turn) is overall a much bigger upgrade.

Good luck,
Nathan

14

Re: Re: Upgrading Coker Wheelset

Ken is what you might call a high-performance Coker rider. He races it and has used it in a 24-hour SOLO mountain bike race. So minor differences are much more meaningful to him than they might be to average commuters (like me).

Ken was willing to forego almost his entire seat for the MUni and 10k races at Unicon in Japan last summer. He had a carbon seat base with bumpers and some foam tape on it—nothing else. That’s serious dedication! And no, he admits it was not comfortable. Picture:
http://unicycling.smugmug.com/gallery/235111/6/9137539

So for a guy pedaling super fast, a narrower hub might be preferred for maximum performance. The Q-factor is the side-to-side distance between your feet. Narrower is generally considered to be better for performance, but wider makes for a stronger wheel. The biggest weakness in the stock Coker wheel is the narrowness of the hub. As wheels get bigger, they inherently get weaker. Increasing the space between the hub flanges gives the wheel much better rigidity, and makes it much more resistant to taco-ing.

I can’t speak for the tubeless kit, as I have no experience with it. Obviously it works for Ken, who in addition to being a high performance rider, also lives where parts are probably expensive, and take a long time to get there (NZ). So his advice is well taken. For me, my commute to work is intended for exercise, so a heavy wheel is just fine.

15

Lebn, even if you’re still up north, feel free to subscribe to the Puget Sound area unicyclers’ e-list. Just send an email with “subscribe” in the header to:
<unicyclers-subscribe@iunicycle.com>

And btw, I agree that the Airfoil rim is pretty much a necessity.

16

Uh…what John said :stuck_out_tongue:

The thread about performing a tubeless conversion is well covered here:
http://www.unicyclist.com/forums/showthread.php?s=&threadid=35269&highlight=tubeless+coker

I’ve now had several months riding on the Stans Tubeless kit and it’s great- no punctures, no need to keep pumping it up (anymore than a tubed kit), great traction especially off-road, lighter and rolls better than a normal Coker.

If you want to stay tubed but drop some rotating weight, just try using a 29’er inner tube instead. It’s so cheap and easy to do I reckon that everybody should do it.

Ken

17

Oops, I need to add this thread about Tubeless Coker too- it’s got useful instructions and also gives credit to Dirtsurfer, who was the first person I’m aware of to try it out:
http://www.unicyclist.com/forums/showthread.php?s=&threadid=29349&highlight=tubeless+coker

Ken

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Re: Re: Upgrading Coker Wheelset

I wouldn’t worry too much about Q-factor unless you’re super obsessive about fit and ergonomics or you’re going for high performance or long distance rides. For recreational riding the differences in Q-factor don’t make much difference for most people.

Here’s a basic definition of Q-factor:


And an article with a picture showing the Q-factor measurement on a bike crankset:

On a bike it has more to do with proper fit. Some people have wide hips and others have narrow hips. There are other factors as well. It’s only really an issue with people who put in a lot of miles on a bike and who want to really fine tune their bike fit.

On a unicycle a narrower Q-factor will give you less flop forces on the wheel as you pedal. The lower Q-factor can help you keep the wheel going in more of a straight line and less of a serpentine wiggly “s” pattern as you ride. Particularly at high pedaling RPMs under hard acceleration. For example, during a 100 meter sprint race where you accelerate very hard and then max out at over 200+ RPMs. For that type of racing a narrow Q-factor is theoretically better for performance reasons.

When I switched to my new Coker with the super wide hub, it took me one ride to get used to the new wider setup. It hasn’t caused me any negative effects. No new joint problems due to the different fit. All’s good. I haven’t noticed that my riding has gotten more wiggly (the serpentine “s” or “~” tire track thing) with the wide hub. I’m a recreational Coker rider. Ken (GizmoDuck) is a performance Coker rider. Different riding styles. There is no way that I could keep up with Ken on a Coker ride. It would be like going on a bike ride with Lance Armstrong.

On things dealing with fit it is a personal issue. Q-factor on a Coker may be a bigger issue for some people than others. Shorter people are going to have a more exaggerated bow-legged stance on the wide hub than taller riders.

Short answer is that it is probably not something that you need to worry about.

The advantage to the wider hub is that the wheel is stronger. That makes up for a lot.

I’m not going to try the tubeless tire thing on the Coker. Too much trouble. More problems and issues than is worth it for me. I am, however, considering the switch to a 29er tube. You get the weight loss but without the fussy tubeless issues.

Oh, and while we’re talking about wheel stuff, check out this thread: Easy Coker Airfoil tire change. The Rox rim strip made a big difference in how easy it was for me to install the Coker tire on the Airfoil rim.

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Re: Re: Re: Upgrading Coker Wheelset

John! I’m really surprised! Too many issues? You have to be one of the most obsessive technical gurus on RSU.
It’s one of the most straightforward upgrades I can think of. Just email Stan, order a rim strip and kit. Take your tyre and tube off, put the rim strip on, stick the tyre on, add some gloop, and away you go!

Ok, I agree that having a wider Q factor is not a big issue. But then the slightly weaker wheel from the narrow hub is not a big issue for me either, because I don’t weigh that much and I don’t do 7ft drops on a Coker like some people on this forum :roll_eyes:

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Re: Re: Re: Re: Upgrading Coker Wheelset

I just highly value reliability and repairability during a ride. If I get a flat or have some other problem during a ride I want to be able to easily fix it. I want to keep things simple and easy. It’s the same reason that I use a heavy Intense DH tube in my muni. It’s the heaviest DH tube. It’s very reliable and very resistant to pinch flats. But it also weighs a lot and a lighter tube would offer better performance. The heavy thick tube doesn’t give the tire as much bounce or cushiness as a lighter tube, but it’s more reliable. Reliability is more important than performance for me.

If I got a flat with the tubeless Coker I don’t think it would be easy to repair. The rim strip will make it difficult to get the tire off to put a tube in for an emergency repair.

I think the 29er tube thing will be reliable enough. But I still have my doubts so I haven’t done it yet.