mattfrox

I bought a set of homemade snow rims which are very wide (2 regular rims bonded together). The rim has a ridge in the middle where the two smaller rims are bonded. I have tried mounting the tire on the rim. When i begin to ride one entire side of the tire blows off the rim. I have tried different pressures with no success. It appears that the bead is setting...i just dont know. It looks like the previous owner had glued one side to the rim. The front tire and rim are the exact same..i have had no problems with this one (riding it about a week). Any suggestions are welcome.

Moose

Are the tires the same? I'd like to see a pic of this rim, I have never heard of anyone bonding two rims together. Is this common in winter biking?

Avalanche325

Sounds like a good way to get hurt to me.

Tires are designed to be on a certain rim width range. I think you are exceeding the width that your tires can safely go.

mattfrox

The tires are the same...Gary Fisher Bear Trax 26 x 2.6 . The rims are made by bonding two 22mm rims to give a combined width of 44mm. They are commom in winter biking. The brand name is SnowCat rims. These are essentially the same idea.

phantomcow2

44mm is a pretty wide rim...i dont know if a tire can sit on that correctly.

mattfrox

the previous owner glued one side of the tire to the rim...i think this is so the tire can be run at lower pressures but maybe it keeps it on the rim

AndrewP

2.6" = 66 mm so the tire should be able to go on a 44 mm wide rim with no problem. Maybe there is a problem with the tire. Try swapping the tires.

mattfrox

I took the 2.6" tires off and put on some 2.3"...i did a short ride and they are seeming to stay on. The 2.6 tires are Gary fisher bear trax..i never heard of these...even a google search doesnt give any results. Could it be that the bead in the 2.6 tires is bad? If so, how can i check this? The 2.3's are tioga factory DH's. Should i glue one side of the tire to the rim just to be safe? any ideas? thanks to everyone who replied.

2manybikes

Check the ICEBIKE website, putting two rims together for riding in the snow is common. Someone made so many they started making them and selling them. They are called Snowcat rims.

The glue on one side is so that the tire can be run as low as 5 psi for certain snow conditions. Sounds like you had a tire that just did not seat on that bead as the wide rim does change the way the bead hits the rim.

mtbikerinpa

How wide is a Sun Doublewide, for comparison?

2manybikes

Sorry, this is the first time I have heard of a Sun Doublewide rim. I don't remember the exact width anyway, that’s why I suggested the web sight.

The ICEBIKE sight has a link to lots of details about the snow cat rims. There is even a high end model with huge holes in the rim. They started welding two rims and then grinding out the center two walls. I have the impression they have their own extrusion now for their rims. I even found a place to buy Nokian studs from that sight. I think it's from a bike shop in Alaska where snow riding is 6 months long. They shop apparently does support for the IDITABIKE race on the Iditarod trail. There is a huge amount of good stuff about winter riding there

mattfrox

thanks for the feedback guys and gals.

The difference between these rims and the snowcats is these still have the ridge in the middle where the two rims were bonded. these where raced in the IDITABIKE race.
The Sun Doublewide are 45mm wide these are about the same 44mm. But i think the Sun Doblewide are 24" and the snowcats and these are 26".

I rode home today (~2Kms) and the tires stayed on. I will keep my fingers crossed!

Now i have to find a way to hook up my V-brakes. Because the rim is so wide the brakes dont have the proper clearance. I have tried reversing the brake arms ...but no dice. Any ideas?

mattfrox

i think the reason winter riders dont use the Sun Doublewide is because these are DH rims...they are heavy, and there is no braking surface...because most DH riders use disc brakes.