Tryall rims...

After searching for some new rims for one of my bikes, I came across these (http://www.tryallamerica.com/). Seeing the weight is far less than the one I’m using on my Hunter I thought I’d give it a try. Particulars, 26", 47wide, 41 ID, 720 grams (on digital scale), pinned/no welding, machined braking surface. According to the website, they come in 19"/20" and 26". Going to have to find some wide strapping tape to seal for tubeless. They can be had through Webcyclery for $65US.

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Those big holes are for tubeless spokes, right? That does look good, though. Do they come in 24"?

Those look a lot like Snow Cat rims. If so, they won’t be up to the rigors of trials–but great on snow and other extremely low pressure activities. They are single wall constructions? Those holes will compromize some important strength for trials.

David Maxfield
Mitchell, SD

My concern would be that the holes would fill up with water and dirt.

Will the strapping tape be able to seal the rim even when it gets wet and dirty?

One negative, IMHO, is the holes. Strapping tape would only keep it out of the tire, I wouldn’t be able to seal the outer holes. Water crossings more than a couple of inches, deep mud, and snow would probably best be avoided. I don’t see much of this with all the riding I did this summer. Most trails close around here when wet. Finding a WIDE rim with a braking surface can be difficult. I had a long talk, awhile ago, with the Snowcat people. Snowcat rims are single walled, thats why they wouldn’t be good for our sport. Anybody remember Sun’s Fat Albert rim? Small rocks could easily dent those rims. Tryalls are double walled without spoke eyelets. As for the sizes, according to the website, 19"/20" and 26". I noticed a huge difference when I swithed to tubeless. Losing a pound of rotational weight made me climb much faster and can throw it around easier. The rim I’m using now (Azonic Momentum DH) weighs a ton (1136 grams). Losing just shy of another pound will be an experiment to see how it rides. If it doesn’t work out, I can still fall back to the original rim, it does help to build you own wheels (thats for sure).

while the holes make it lighter, they also weaken the rim. so watch out.

Those holes are for weight savins only. they provide no actuall purpose other than to substantially weaken your rim and guarantee premature failure. Also rims with pins and no welds should be illegal. make sure to lace the rim so that it’s pulling the seam together, not apart.

Japanese and euro trials guys all use drilled rims as well as drill brake levers, pedals, some even cut every other knobby of of their tires. they get totally stupid about saving weight. the secret thing is that they only use these parts in competition and may only get a few uses out of each part, but they get them for free so it doesnt matter.

For urban trails and general riding only the lightest, smoothest riders i know have ever had success with such drastically drilled rims. and they have two wheels and alot more bike to use as leverage to finess landings.

I would not reccomned any uni riders using drilled rims, even for competition… they just have to take so much more load than they were intended for.

Hope that if you already purchased these that they work out for you, but you may want to looking into getting a full face helmet.

Nice comments, semper.

But…

…how the heck could you do that?

I assumed he was saying don’t put the seam in the part of the spoking pattern where the gap is. You know, the place you usually put the valve. Is this right?

Andrew

How the heck could you not do that?
Won’t the spokes always pull together on any part of the rim?

alright, you got me…

yes the spokes all pull the wheel towards the center of the hub, keeping a constant inward radial force always pulling the seam together.

But wheels are generally laced tangentially, where each spoke pulls at an angle to the wheels radius…

The gap area that is created when using a crossed spoke pattern has three or four spokes that pull almost parallel to each other. the four spokes on either side of the gap all pull at more of an angle inward, towards each other and would exert a small amount of force that would pull the seam together.

I suppose there really wouldn’t be a huge difference seeing that there are thousands of pounds of tension created by all the spokes pulling the rim inward.

I still don’t like things that are pinned, maybe they shouldn’t be illegal, but i think you should need a license to own them, like a gun.

Thanks for the comments. I have taken them into consideration. Though I own a full face helmet, I don’t think I will be using it. I have to agree that I, too, don’t like pinned rims. In this case, theres not much of a choice. SEMPER: Some friends (Non uni riders) are planning a gathering in southern Michigan that I plan to attend (with my uni). Details: http://forums.mtbr.com/showthread.php?t=398 . I’m planning on doing Saturday at Yankee Springs then driving home. If this rim survives, you’re welcome to come check it out. Bring your uni and come ride.

I rode trials with some bikers last night, and both of them were using drilled rims, and one had the exact same rim as described here. I saw him bottom out his rim about 8 times on some 6-8’ gaps, and not a single complaint. That doesn’t seem that bad.