[E_braker]

For my Downhill riding I have always appreicated a larger tire (FRONTS: 2.7 Nevagal DH, 2.7 Minnion DHF, REAR: 2.35-2.7 similar model) for the bigger footprint, increase in traction. The bigger tire sucks however on rims with a "narrower" width, as you get a "floppy sidewall", increased pinch flats at lower pressures.

SO: I am considering a tubeless setup this season, mainly to (slightly) decrease rotational mass, increase traction/tire performance. Mainly, I want to run a lower pressure without the pinch flat problem and my tires ALWAYS slipping on my rim (thus turning my tube and messing with my air stem).

1) Is my solution a Crank Bros SAGE or OPIUM wheelset w/STANS? Are they wide enough at only 24mm internal width? Will the tire slip on the rim under hard braking?

2) If not, is my solution a super wide rim on a good 150mm hub and a Stans tubeless kit? Will sllippage be a prob?

3) Just freaking SuperGlue my tire to rim??


SUGGESTIONS please....

 

[lalocotequinta]

I ran a set of Opiums last year and never had a problem withe them. Set and forget pretty much, never needed any sealant at all. I would just check for proper pressure once a month and that was it. I ran Minion F&R 2.5 and I'm sure you'd be fine running 2.7s.

I will be selling them because I want to try something else so pm me if you are interestd, they are in excellent shape/condition and will give you a deal.

 

[weedkilla1]

IMO if you are having tyres spin on the rim now then tubeless is not for you. I'm tubeless on both xc and DH and I have made at least a few of the mistakes possible along the way! Tubeless on a dh bike often means higher pressure than tubes, just to keep the tyre on the rim, folding the bead of the rim means instant zero pressure and at warp speed in the middle of a berm......
However - I find I get the same grip at 28F/30R psi tubeless as i did at 22F/24R psi tubed and I get the extra benefits of better rolling, no flats etc. I doubt that you'll get much lower than 28psi reliably in dh, and if you can feel the tyre squirm in cornering ADD PRESSURE! This is the "Danger, Will Robinson!" moment, because what comes next is burping, folding off the rim and one of those moments that fills your undies!
If you do decide to go tubeless, definitely go ghetto rather than ust or stans, its by far the most reliable and read Bullcrew's guide on ridemonkey forum for all the tips you'll need - even if you dont decide to go tubeless then maybe try his stans on the bead idea - that should stick your tyre on plenty well enough.

 

[b-kul]

really? ghetto is more reliable than ust or stans? link?

 

[weedkilla1]

Yep, for dh use the biggest issue is rolling the tyre off the rim or denting a rim so badly it wont seal. Ghetto reduces the risk of both, as the cut tube is glued to the tyre with stans.
And link - http://www.ridemonkey.com/forums/showthread.php?t=240026

 

[Tim F.]

I prefere getto as well, even over UST rims. As far as folding a tire off the rim, I did it once on a steep section onto solid uneven granite...it's not a pleasant expiriance.

 

[b-kul]

Yep, for dh use the biggest issue is rolling the tyre off the rim or denting a rim so badly it wont seal. Ghetto reduces the risk of both, as the cut tube is glued to the tyre with stans.
And link - http://www.ridemonkey.com/forums/showthread.php?t=240026

huh. interesting read, thanks :thumbsup:

 

[SV11]

Yep, for dh use the biggest issue is rolling the tyre off the rim or denting a rim so badly it wont seal. Ghetto reduces the risk of both, as the cut tube is glued to the tyre with stans.
And link - http://www.ridemonkey.com/forums/showthread.php?t=240026

LOL, what a load of garbage.
A good mate of mine weights around 240, he's been using stans for the last 6-7 yrs, maybe more. He has never had the tyre roll of the rim, he has never dented his rims and he is a pretty aggressive DH'er. He has had zero issues todate.

 

[b-kul]

LOL, what a load of garbage.
A good mate of mine weights around 240, he's been using stans for the last 6-7 yrs, maybe more. He has never had the tyre roll of the rim, he has never dented his rims and he is a pretty aggressive DH'er. He has had zero issues todate.

it does make sense though. think of all the extra friction split tube ghetto puts on the bead of a tire holding it on. im not discounting your friends experiance but thinking objectivly...

 

[SV11]

it does make sense though. think of all the extra friction split tube ghetto puts on the bead of a tire holding it on. im not discounting your friends experiance but thinking objectivly...

I think I'll stick with real world experiences.

 

[Quarashi]

I think I'll stick with real world experiences.

Kind of silly to write off one a whole thread as rubbish due to the experience of one person. There have obviously been plenty of others who haven't been as lucky. Or perhaps aggressive DH has different standards.

Anyway, something a little more relevant. If I went ghetto, would it matter if I used an ultra thin BMX tube or one on the thicker side?

 

[weedkilla1]

I dont find any difference in what tube I use - just depends if you want to be a weight weenie.
And really sv11, you know someone who has been DHing for 6-7 years who hasn't dented a rim? Must be a lot smoother rider than me.

 

[Pedal Shop]

LOL, what a load of garbage.
A good mate of mine weights around 240, he's been using stans for the last 6-7 yrs, maybe more. He has never had the tyre roll of the rim, he has never dented his rims and he is a pretty aggressive DH'er. He has had zero issues todate.

l have this set of Maxxis tubeless converters which are pretty much the same thing.

sorta

they're like a Stan's tubeless rim strips however, they actually extend past the rim so when you're all set up, you can see the rim strip sticking out between the tire and the rim.

l have used them for freeridin' but never DH. they hold air a really long time, much longer than tubeless or even tubes for some reason.

Maxxis stopped making them several years ago so, once these things go, that's it...

l don't use them anymore... l didn't like the weight of pure tubeless tires and l'm guessing they stopped making them because the tire can fold off the rim too easy. it never actually happened to me but l bet l just got lucky.

l had used pure tubeless on XC bikes (tubeless tires with tubeless rims) -- l had tires roll off the rim at least 4 times, not doing anything hardcore at all. cars, sure... motorcycles... not doubt.... l'll stick with tube'd when it comes to bicycles.

 

[b-kul]

Anyway, something a little more relevant. If I went ghetto, would it matter if I used an ultra thin BMX tube or one on the thicker side?

according to bullcrew it didnt matter. and really sv11? write off bullcrews findings because i hypothesised on the forces at play?

 

[Jim311]

I have burped maybe twice riding UST for several years now. Once off a 3 or 4 foot drop into a badly washed out rut. It let out a few pounds of pressure, it was not a complete loss of control and it did not result in a wreck. I've had a few pinch flats with narrow XC tires as well but that is more of a function of poor form and not enough air in the tires. There's something to be said for using a little finesse.

 

[E_braker]

So, it seems as though Stans w/rim treatment/ maybe Ghetto Tubeless is the way to go for my needs. So from everyones experience, how much does rim width play in the tire rolling?

It seems as though (expecially a larger tire, like a 2.7), has more sidewall and therefore should have a wider rim to decrease the likelyhood of the rolling, right?

 

[Quarashi]

Has anyone thought of trying to seal the rim at the spoke holes? It would be a boat load of work and you might get the hollow part of the rim filled with stans gunk over time but I'd imagine it would be a hell of a lot lighter.

Also, would a tire/ghetto tubeless interface really be more solid than a tire/rim interface? Seeing as the rim actually has a bead lock groove, which on some manufacturers is advertised to be especially strong (ie: syncros anti-rolling thingymajig), I find it hard to imagine how an adhesive, that really isn't that strong, could bond the tire and the bmx tube stronger than the rim/tire interface. Sure they'd stick together but with the jerking forces of hard riding and braking, wouldn't the rubber-on-rubber contact slide? Especially say in wet conditions? Thanks to anyone who might explain!

 

[Quarashi]

Just had an idea and I thought it deserved it's own post.

Has anyone thought of cutting thin strips of a DH tube and super-glue-ing them to the top of the wall of the rim (the pinch in pinch flat) and then using light XC tubes? Or why manufacturers don't make rims with some kind of durable soft rubber bit on that same top portion instead of just metal?

Never heard of an approach like that before. Anyone know why it wouldn't work?

 

[b-kul]

Has anyone thought of trying to seal the rim at the spoke holes? It would be a boat load of work and you might get the hollow part of the rim filled with stans gunk over time but I'd imagine it would be a hell of a lot lighter.

Also, would a tire/ghetto tubeless interface really be more solid than a tire/rim interface? Seeing as the rim actually has a bead lock groove, which on some manufacturers is advertised to be especially strong (ie: syncros anti-rolling thingymajig), I find it hard to imagine how an adhesive, that really isn't that strong, could bond the tire and the bmx tube stronger than the rim/tire interface. Sure they'd stick together but with the jerking forces of hard riding and braking, wouldn't the rubber-on-rubber contact slide? Especially say in wet conditions? Thanks to anyone who might explain!

just a guess, but i think the tube forms to the rim so well it forms to the bead hook too and with the tube its now rubber on rubber instead of rubber on metal. just my thoughts. but i know this for a fact, split tube ghetto adds like 30 grams without selant, just to plug the holes would probably be 10 grams. you are looking at maybe a 20 gram savings which i feel is hardly worth it.

 

[Quarashi]

just a guess, but i think the tube forms to the rim so well it forms to the bead hook too and with the tube its now rubber on rubber instead of rubber on metal. just my thoughts. but i know this for a fact, split tube ghetto adds like 30 grams without selant, just to plug the holes would probably be 10 grams. you are looking at maybe a 20 gram savings which i feel is hardly worth it.

30 grams... that's a lot lighter than I thought. Definitely going to give it a shot. Just going from a DH tube to an XC tube on my front wheel made such a big difference, the weight savings alone should make it worth it.