I did do flameout once this year, fun but too much pedaling-BB- said:Don't you mean FLAMEOUT?:devil:
Actually the new and improved upper flameout that drops you at the top of Karpiel is really fun now.Well, N* did it again..............................
- Thread starter Brian HCM#1
- Start date
Actually the new and improved upper flameout that drops you at the top of Karpiel is really fun now.Am i missing something here? You'd sacrifice your top choice in Tires, but not the rim that seems to be the root of the problem?
Considering how many horror stories about those rims you hear, its kinda hard to feel sorry just cause you seem to be doin it to yourself...
DUmp the ****ty rims, go 321, 521 or Mag 30...that would seem to end the problem, and it can still run stans.
Considering how many horror stories about those rims you hear, its kinda hard to feel sorry just cause you seem to be doin it to yourself...
DUmp the ****ty rims, go 321, 521 or Mag 30...that would seem to end the problem, and it can still run stans.
You obiously DID NOT read my first post, I was using an EX729 (321) this time.dropmachine.com said:
Your brakes are too strong for the hub/spokes
buy maguras
buy maguras
Your bike has too much travel. Buy a Gary Fisher.
You think?kidwoo said:
I'll do that too.-BB- said:
Sorry my bad, i still get confused with the stupid numbers...thought you were still on the 823's or whatever...
A couple of things . . . 30psi is pretty high so you must have really hit something hard. Running Stans does increase your chances of damaging the rim because A) you're likely to reduce your air pressure because you're not worried about flats and B) since there's no tube, a little bit more pressure is transferred directly to the rim under hard hits. Anyway I'm surprised you're getting flat spots at 30 psi, I run my 2.5 Minions at about 21 up front and 24 in back on race day, and I'm riding a 6" bike this year.
More to the subject though, the 729 and 823 rims are designed to dent under hard impact rather than pinch-flatting your wheel. This doesn't make much sense to me when applied to the 823 as it's tubeless, but whatever. The 729 will flatspot, dent, and/or crack before you hit something hard enough to pinch flat a DH tube in a DH tire (at least that's the theory). You can go to a burlier rim like the Arrow DHX, Intense Mag 30, or Atomic Trailpimp and significantly cut back on dented rims, but be prepared for more tire damage, and less compatibility with Stans. The 729 seems like it was designed specifically to be Stans-friendly.
More to the subject though, the 729 and 823 rims are designed to dent under hard impact rather than pinch-flatting your wheel. This doesn't make much sense to me when applied to the 823 as it's tubeless, but whatever. The 729 will flatspot, dent, and/or crack before you hit something hard enough to pinch flat a DH tube in a DH tire (at least that's the theory). You can go to a burlier rim like the Arrow DHX, Intense Mag 30, or Atomic Trailpimp and significantly cut back on dented rims, but be prepared for more tire damage, and less compatibility with Stans. The 729 seems like it was designed specifically to be Stans-friendly.
Nope 2 dead 823's in 1 1/2 months is plenty for me. The 729 was a warranty replacement from Mavic, actually I'm waiting for another 729 to arrive anytime now. When I sent in my 823 I told them to replace it with the 729 since they were out of stock on the 823's.dropmachine.com said:
Who told you that? I'm not being a smartass, I'd really like to know since that's the first time I've heard it.James | Go-Ride said:
It's not something I heard from a Mavic rep or anything but I have heard of similar design characteristics from other companies. Have you ever seen the rim that WTB makes for DH? It looks almost exactly like the 729 except it's black. Those rims have a tendency to get destroyed really quickly because they are made of a soft aluminum that will bend before you get a pinch. The Sun Singletracks seem to be about the same but it's hard to tell if they're actually designed to reduce pinch flats or if they're just not burly enough for serious DH use. Anyway, short answer to where did I hear that is that I didn't really hear it anywhere other than insight from racer guys and some other companies.
Haha, you should hear the arguments a friend and I have gotten into with one your team guys about this......mr Rogne. That guy goes through about 10 WTB rims a summer. "There great because they're soft and you can bend them back" Classic.
Another local guy, John Percy and I both ride 321s and do about 1 wheel every season at most. I don't ride as fast as Karl, but John does and neither of us understand Karl's seeming enjoyment of having to build so many wheels. But yeah, he said the same thing about the WTBs but not Mavics. To be honest, he's the reason I stay with mavics. Even the flatspots I have gotten with them are barely noticable, I get way more pinch flats than rim damage, so I may not be quite convinced of that theory..........yet that is. Maybe mavic is just getting slack with the material they're buying? My current wheels are about a year old now and so may be pre-problem era.
Another local guy, John Percy and I both ride 321s and do about 1 wheel every season at most. I don't ride as fast as Karl, but John does and neither of us understand Karl's seeming enjoyment of having to build so many wheels. But yeah, he said the same thing about the WTBs but not Mavics. To be honest, he's the reason I stay with mavics. Even the flatspots I have gotten with them are barely noticable, I get way more pinch flats than rim damage, so I may not be quite convinced of that theory..........yet that is. Maybe mavic is just getting slack with the material they're buying? My current wheels are about a year old now and so may be pre-problem era.
oops, off topic. The chairs werent down, there was thunder so they had to close.Private Joker said:Bromont's lift was down again?!!!
Damn...that's crazy...It's been down 5 weekends this whole summer.
Glad I went to Diablo instead of Bromont this weekend.
They need to throw the chairs back on the detachable quad.
aren't you one of them that was telling me I was running too low of a pressure when I started to rant about my UST rims flat spotting? and I was running close to 35psi...James | Go-Ride said:
A big guy, or an agresive guy, on 2.5s, at 30psi, would definitly run the risk on a very sharp impact. I thought that he was on 2.7s, but evidently not. It's boarderline IMO. A 140lb rider may get away with it just fine on 2.5s, but a 180lb probably has to go to 35 or so, 200lb maybe 37. The air volume on the 2.5s isn't the biggest ever. I see many people that run lower psi than they should, but they simply get away with it and have never hit a rock "just right". I'm not trying to knock brian here, but going to 35 wouldn't hurt much, give up a little traction, but in the end it just may make more sense.James | Go-Ride said:
I agree with JM I am 155 without amour and when I go below 30 psi with stans, 2.5 high rollers and 734 I start getting flat spots on my rim. This is in conditions at Diablo aka Mt. Creek, NJ where there are a lot of small rocks you can hit a high speed.
I dunno, I guess maybe there are bigger, sharper impacts at Northstar than there are at Deer Valley or Bountiful, although I doubt anything short of Bootleg is worse than Bountiful. Anyway, I weigh 195 so I'm not a lightweight and I don't have too much trouble with my rear tires or wheels at 23 - 26 psi in a Maxxis 2.5. But, I'm also slow so that might factor into it
Luc, Michelin tires are a whole different story, but I don't think I would have suggested 35 psi unless you were running a 2.2.
Luc, Michelin tires are a whole different story, but I don't think I would have suggested 35 psi unless you were running a 2.2.
My rear tire never goes under 40 when I ride northstar. I had to keep it high at Bootleg canyon too actually. I had to keep slightly higher pressures than that when I ran tubeless. Ah the beauties of soft tire compounds!
James: Have you been to northstar? It's rougher than bootleg but you're usually not going as fast because of the complete lack of anything for your tires to bite on. We have to use the rocks for traction so we kind of have to aim for them
Oh well. Rims bend. It's a rough sport no matter where you ride.
James: Have you been to northstar? It's rougher than bootleg but you're usually not going as fast because of the complete lack of anything for your tires to bite on. We have to use the rocks for traction so we kind of have to aim for them
Oh well. Rims bend. It's a rough sport no matter where you ride.
that is retarded...heck I don't even run that on my trail bike.kidwoo said:
I personally don't think I could ride a tire that is inflated that high.
Whistler three days full speed below 30 psi and the trails are just smooth compared to Diablo but this should be no surpise. I remember my XC days I changed tire pressure depending on conditions.
You haven't seen N* this weekend, its real bad and I mean REAL BAD, worst conditions I've ridden in a long time. The traction is almost non existant with 35-37 psi, I was fighting it enough with 30.Jm_ said:
I've been running an old Intense tire at about 8psi for about 2 years and no flats yet.
Of course, now that I said that, I'll get a flat tomorrow.
Of course, now that I said that, I'll get a flat tomorrow.
It's not like I never tried running lower. Trust me, it doesn't work. Wasting half your day fixing flats is retarded. And my xc tubeless setup is lower too. But I don't go as fast as I do on my DH bike at northstar either.Acadian said:
are you guys sure you're running the proper spoke tension, and then actually re-checking it after each riding day? because it always seems to be the same people who have problems with whatever they're running.
823s still good....
823s still good....
Good point. You guys know you're supposed to retension spokes after your first ride on a new wheel right? With DH wheels, I just ride around the neighborhood, up and down some stairs etc. before I take them on any serious dh terrain. That way I'm not likely to be riding the second half of the day on a loose wheel.zedro said:
kidwoo said:
i was thinking just the same, the whole "designed to bend before pinchflatting" seems a bit too far fetched to me, maybe there is a way to predict what sort of force it takes to pinchflat a tube but it would be really hard to predict the shape of the rock also.
i was under the impression (well someone said this) that when Doublewides were popular back in the day, some pros would run them because of that.vitox said:
The shape of the rock doesn't really matter, the issue is the tube being pinched between a sharp corner and the edge of the rim bead hard enough for one or two holes to develop. It's not that far-fetched in reality, all it takes is softer aluminum and no vertical support beneath the bead. Look at the 729 vs the 721, that's a good example of why you don't hear as much about flatspots with the 721, they've got that big tall sidewall that doesn't allow for flex.vitox said:
although denting can become an issue.James | Go-Ride said:
i wish Mavic simply made a UST version of the 721....oh wait my 823s still seem fine
Did you do this on the wussy rock drop on sticks, yet??? Oh wait, you cyclocross that...Brian HCM#1 said:This time a flat spot on my EX729 :mumble: :mumble: :mumble: :mumble: :mumble: Been running Stans with 30lbs of pressure and N* claims another wheel. 1st ride on this wheel :mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble:
Do they make Tuff wheels for MTB's
:mumble: :mumble: :mumble: :mumble: :mumble: :mumble: :mumble:
You have to ride your bike to damage rims.zedro said:although denting can become an issue.
i wish Mavic simply made a UST version of the 721....oh wait my 823s still seem fine
gosh...just not hardcore enough for you guys...Brian HCM#1 said:You have to ride your bike to damage rims.
have only had two days on them really, would of gotten more but i took a break after i beat my ribs up.
Made sure i put extra tension when i built them. After the first punishing day at St-Anne and all their lovely rocks, had to re-tension a bit and correct a 3mm lateral wobble that developped. Also i'm running a few psi higher in the 34 range. I'm not too concerned really, i dont race and i'm not hard on wheels...and i maintain my stuff
hey Brain seriously maybe try a different rim maker...Arrow, Sun, WTB, etc...see what happens either that or go to Intense or Kenda tires...I have had zero problems with both...D
I rode Intense tire for the last 4 years, with no issues, just within the last year I made the switch to Michelin. It sucks cause I really like the tire.BMXman said:
pot making fun of the kettle...Brian HCM#1 said:You have to ride your bike to damage rims.
yeah, yeah, yeahAcadian said:
little sensitive today? as brittle as say.....a Mavic rim? :devil:Brian HCM#1 said:yeah, yeah, yeah