Spokeless wheels
 

I saw that there has already been a tentative thread about this subject, but it went nowhere. So...

Are there any disadvantages whatsoever to spokeless wheels? By spokeless, I mean those made from cast aluminium or alu-magnesium alloy (or even carbon wheels). My impression would be that there isn't any.

Are you talking about disk wheels?

There are various levels of spokelessness. As UmneyDurak notes, disk wheels are truly spokless. But they can cause difficulty with handling in crosswinds. There have been a variety of wheels without traditional spokes. Spinergy, Specialized wheels with three "spokes", etc. These wheels can be different because they are often more like chariot or wagon wheels - the spokes suport the rim by being in compression, instead of by being in tension (as is the case with typical metal spokes).

Spokeless wheels are usually only seen in road racing, and then usually only in time-trial types of events. They are expensive, more affected by cross-winds because they have a lot more side-surface area, and are not repairable. They can give some aerodynamic advantage, though they are typicall heavier than high-level spoked wheel designs.

A nice article about various designs, and comparing them to typical-design tension-spoked wheels, is
http://damonrinard.com/wheel/grignon.htm
Interestingly, all but one of the aerodynamic wheel designs tested in the "data" part of the article are traditional tension-spoked wheels. The "spokeless" model is the Specialized tri-spoke that I'd referred to above.

I saw a concept bike (GT I think) in the late 1990's that had a true spokeless hubless wheel, meaning that the rim was a large bearing with small balls inside the huge races. Saves weight on spokes, hubs and the fork. I don't remember how the rear wheel was driven, but I think a belt was involved.

Anyway, the disanvantages are that they can't be trued and are usually heavy.

Depends on the individual wheels. Some 3 spoke in the past, for example, have had roundness problems. I'd imagine that a cast metal wheel would have a serious weight penalty compared to a wire spoked wheel.

No, I am talking about stuff like the Grimeca wheels:
http://www.grimeca.it/it/ruote/index.htm

For example, the Mag Aero:
http://www.grimeca.it/eng/ruote/m6.htm

Thanks for clarifying. I don't think anyone knew what you meant by cast aluminium or alu-magnesium alloy, although carbon spokeless wheels are common.

I should have included a picture. It really is better than a thousand words. But I saw ebay auctions where these items are called "pokeless wheels" so I thought that would be an understood expression. My bad, I guess.

So.... is there any disadvantage to using these kinds of wheels? I checked the weight for MTB-type wheels, and these "spokeless wheels" (that's a wrong term, I am becoming evermore aware of this, becuase they do have 3,4, 5 or 6 spokes, but they are cast) are comparable, or even lighter, depending on the material.

So if weight is not, in fact, an issue, it seems that these wheels don't have the slightest disadvantage, right?

There are 6-spoke wheels that are lighter than the lightest traditional spoked wheel. But I have no idea about their roundness. I would guess that, given precise casting and subsequent machining, their geometry could be made within the same tolerances as a well-trued traditional wheel.

So why don't you buy a set, ride them for 1,000 miles or so, and let the rest of us know how they work out for you?

It is obvious that I am trying to leverage the existing knowledge/experience to make myself a good choice. I still hope such knowledge/experience exists - but if really necessary, I might do what you say, and share my experience.

Durability and repairability. A huge disadvantage.

Well, I bought a pair of spokeless (cast Alu-Magnesium) wheels and set them on my mtb. Satinated black, look great with my black-themed bike. And riding is excellent. In fact, I feel no difference compared to the old wheels.

What did they cost? I expect significantly more then regular wire spoked wheels.

Well you're definitley not going to get a cost advantage by getting spokeless wheels, nor repairability on the road.

Such as? This sounds very fishy to me. The lightest traditional spoked wheels are around 500-600 grams for a front wheel, and 750 is easily achievable at a reasonable price ($100 or so). If you're ready to spend 3000 Euros or so, a front+back set of road racing carbon Lightweights comes in under 1000 grams. I'm absolutely certain that no 6-spoke aero wheel comes close to that. That's road wheels but MTB is pretty similar, I think.

As to the OP: for everyday use, they are just a pain. Expensive, heavy, unrepairable, sensitive to crosswinds. People buy them either for racing or for the looks.

Not always my old lester mag rims for my bmx were magnesium 7 "spoke" And weight about the same if not a little less than my spoked alloy rims. That was on my mx though. Magnesium is heavy than aluminum so lighter but ccast rims non spoked are possible. I think the main reason weve not seen them in road bikes is they havve a distinct aero disadvantage. To have like but strong mags like a bmx you have to make them the same way. This includes the I beem like structure of the spokes of the mag. With out the I beem shape the first corner you take would snap the ring away from the spokes and that would be all she wrote.

Skyway mags use to be made froma special plastic and had dozens of paterns 4 5 7 8 and spider web to name a few they were much lighter than any spoked rim but would fex under high loads. On a road bike or any thing above 24 inch youd be in almost constant flex.


That why other than spoked rims in road bike you only see carbon fiber rims and wheel sets.

Lester cast magnesium wheels were put in to a laythe and turned to true. From my under standing of the casting proccess the rims are made extra large in diam and turned down on the laythe. Most of the out of roundness comes from the edge of the rim and not on the inside towards the hub.

I personalyy dont know how far id trust a cast rim on mtb or roaad biike do to lateral flexxing esp around corners they could easly snap.

speak english please.

magnesium is certainly lighter than aluminum.

a 20" wheel is naturally much stronger than a 27" one, apples and oranges.

terseness rules the day.

I bought them on eBay, got them for 56 bucks, plus 60 for shipping. If you go for the "buy it now" option, they're going for 100 bucks, which is still rather cheap for front and rear, disk-brake ready wheels.

Here's the eBay shop of this guy: http://stores.ebay.com/Taibilllin-Bi...ims-And-Wheels

The wheels are made in Taiwan, which is actually good, since Taiwan has traditionally a good reputation in Alu and Alu-alloy casting and workmanship/expertise. At least here in Finland, having an Alu frame made in Taiwan is considered a plus.

I don't know if my testimonial is of any value, but here goes anyway: I have 130 Km on these 6-spoke Alu-Mg wheels by now, I corner very agressively, but I am light (only 61 Kg). I also drive rather agressively offroad. So far, no problems, and they feel fine even in very windy conditions. In other words, I just didn't notice them at all. What impacted my riding experience was mostly the tires, which I changed, but the rims, I had not noticed them in any way.

The day I should have some trouble with them, I will inform the forum.

I thought about buying some of those myself, but decided not to when posters here on BikeForums claimed:

1. The bearings were probably junk at that price

2. The bearings & freehub could probably never be maintenanced or replaced

3. The alloy wheels would be prone to cracking over time

4. When the cast metal fails, it will do so catastrophically, causing a possible wreck

I don't know if any of the above claims are valid or just yahoos blowing smoke. Please keep us up-to-date over time as to the performance of your wheels - I'd like to know. Thanks!

pics?

No experience with them, but my gut instinct tells me that they must not be any better than current, traditional spoked wheels. If there were an advantage, you'd see more of them, particularly in the pro ranks where cost and durability (to an extent) are not main issues. Pros can replace their equipment from race to race, and with sponsors, cost isn't an issue. So guess I'd just stay with traditional spoked wheels.

As i said id not be willing to trust a cast rim on a mtb or road bike