large marge

[ubersquish]

any here hear anything about the large marge rim from surly? not ready yet, but surly says it’ll be 26" and 65mm wide. i dunno if that’s inner or outer measurement, but that’s still pretty big

[jagur]

never heard of it,but if Surley gets involved;its bound to be a good thing.

[john_childs]

That’s a big rim.

Surly has some info about the rim in their catalog.
Surly 2004 Catalog (PDF document)
Scroll down to page 12.

It’s a 26" rim. No 24" version. Looks like they’re outdoing even the Snow Cat rims in the width department. And they’re double walled unlike the Snow Cats.

Here is the text from the catalog:

Large Marge™ Rim
Our friends, Pat Irwin (Surly-sponsored rider and owner of Pat’s Bikes, in Anchorage) and John Evingson (Hydracare rep and custom framebuilder), turned us on to the eclectic world of adventure riding. It seems there’s a need for a super-wide rim for snow bikers, sand bikers, rock crawlers and downhillers who want to run some really big rubber. We decided to make some rims for the same selfish reason we have for making other Surly parts…we want some to use on our own bikes. We introduce to you…Large Marge. Our doublewalled 26" hoop is 65mm wide. It’s eyeleted, because a lot of 'em will be laced to disc hubs, and hub brake systems put more stress on spoke holes. Of course, Large Marge is rim brake compatible, if you don’t want to use hub brakes. The cross-section profile lends itself to shedding snow and sand, to keep the rotating mass as low as possible. The black ano finish should help to melt off snow that might cling to the rim, and we think it looks cool. We’ll offer Large Marge in a few configurations: 32-hole and 36-hole downhill version, and 32-hole cruiser/cross-country version…all are drilled for a presta valve. What’s the difference? The cross-country version is drilled out to shave some grams; the downhill version is not. What’s the weight? At the time of this catalog printing, we don’t know yet. We’re still testing it to see how much material we can remove before we compromise the structural integrity of the rim. Stay tuned to our website (www.surlybikes.com) for updated tech info and delivery dates. Obviously, you are going to need a non-standard frame to use this product. There are custom builders, like John Evingson, who can build a frame for you. The disc-compatible Surly 1x1 will work, if you grind off the canti bosses (that does void your frame warranty, however), but you will be limited to a 2.7" tire width. Custom frames can be built to accommodate wider (3"+) tires, if you need maximum traction and floatation.

[Mojoe]

Right, they’re still testing it to make sure it’s Surly enough. I’m definately getting one and mounting a 26x3 Gazzilla on it. I don’t even know if my Yuni frame will have enough room for it with the wider rim, but I’m doing it anyway, even if I have to do a little violence to my frame to make it fit. I hope they get it into production soon so I can test it out in the snow here.

I’ll e-mail Dave at Surly and get the info dump on it. Dave is into muni, so he’ll be stoked to hear I’m building a muni around one. I’m going to get a Surly flask while I’m at it too.

Mojoe

[Mojoe]

All,

I got an e-mail back from Dave at Surly. This is what he had to say about the Large Marge and when it will be available.

…“I’m waiting for another round of Large Marge samples. Should be a week or two. Once they are approved, production can begin. It will be 3-4 months before we have any to sell. I mounted a Specialized Big Hit 3.0 on one rim today. It doesn’t really make the tire much wider. But, it flattens the tread out, so there’s more of it contacting the ground. The wider rim should help reduce pinch flats and keep the tire from rolling off the rim when using low pressure. I measured the Specialized casing width at 75mm and the tread width at 74.5mm. The width doesn’t change much, but the riding characteristics and performance do change. I’m hoping to get some 24” rims rolled out of the same extrusion, for munis and downhill rigs, but it’s going to be tough. We’ll get the 26" dialed in, and then we’ll push for the smaller hoops."…

That is all…

cheers… Mojoe

[Borges]

Even a 3" tire seems a little narrow for that rim.
Unicyclists use higher tirepressures than bycyclists, so there would be more force pushing the tire off the rim.
Would the tire still be seated after a sharp turn on a downhill?

Sun Double wide has a recommended minimum tire width of 2.35" and the double wide is “only” 33mm wide. Large Marge must be significantly wider.

[beelzebub_of_balance]

With this width rim, most people glue the tire’s bead to the rim–at least on one side.

David Maxfield
Mitchell, SD

[dazedNcontused]

I think they do that to keep the tire from slipping around the rim and shearing the valve stem off the tube. If the tire wanted to pull off the rim I doubt glue would hold it - especially if only one side is glued!

Having said that, the tire bead is what keeps the tire on the rim and that’s the same regardless of tire width.

I think the limit on tire width is that as the rim gets wider the tire gets pulled flat so that there’s less sidewall height - in the limit the tire would be stretched flat and there would be very little air in the tube. This might be OK for snow riding…

[johnfoss]

Large Marge used to be the world’s largest unicycle. I forget the wheel size, but it was somewhere between 64" and 72". It was built for Steve Gordon and listed in the Guinness Book. Later Steve had a 73" wheel called Intense Hortense. I think this one still holds the record.