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Discussion Starter · #1 ·
Hi all. I have a new GT Avalanche 1.0 built a couple of months ago with some good parts. The fork on it is a RockShox Tora 318 U-Turn which is nice performing but the weight is a bit high on 2.3 kg.
Today I received an eXotic carbon rigid fork after some search and the decision to run the bike rigid.
Reading the forums everybody suggests bigger high volume tires on rigid forks.
The rims I have are new Mavic XC717 which I like a lot and don't want (and have the money) to replace. The tires are Michelin XC-Dry2 26x2.00 on both wheels.

Mavic recommended tire widths are between 1.00 and 2.10:
http://www.mavic.com/mtb/products/xc-717-disc.323323.2.aspx
Anybody used bigger tires on these rims;
I would like something from WTB or Michelin.
Any opinions are welcome.
 

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I am currently running WTB Wolverine's 2.2 front and rear with no problem. Last month I ran 2.5 WWLT on the front and the fit was fine. I switched back to the wolverine's on the front cause I had more confidence on that tire.
 

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mipi said:
Hi all. I have a new GT Avalanche 1.0 built a couple of months ago with some good parts. The fork on it is a RockShox Tora 318 U-Turn which is nice performing but the weight is a bit high on 2.3 kg.
Today I received an eXotic carbon rigid fork after some search and the decision to run the bike rigid.
Reading the forums everybody suggests bigger high volume tires on rigid forks.
The rims I have are new Mavic XC717 which I like a lot and don't want (and have the money) to replace. The tires are Michelin XC-Dry2 26x2.00 on both wheels.

Mavic recommended tire widths are between 1.00 and 2.10:
http://www.mavic.com/mtb/products/xc-717-disc.323323.2.aspx
Anybody used bigger tires on these rims;
I would like something from WTB or Michelin.
Any opinions are welcome.
You can fit any size tire on those rims that will fit in your frame/fork.
But you may not like the handling of some of the wider tires. I have used, and liked, tires up to 2.6" in similar width rims.
 

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R.I.P. DogFriend
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Exceed the manufacturer's recommended spec's at your the risk of your own peril. If you are large and ride rocky terrain, you have increased your personal risk factors. Well, it certainly increased mine :lol:

Me: 270lbs
Tire size: 2.5" Nevegal @ 45psi+/-
Result:


There were no flat spots or dings that might suggest it failed from being hit while running low tire pressure.


Where it wasn't split completely, it looked like this along the entire circumference on both sides:


My $0.02: If you just want to try a larger tire for a short time and aren't going to bust too hard on it, GFI. If you now want to run larger tires through rough terrain, get wider rims. Largers tires perform better with them anyway.
 

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I beat the HELL out of some WTB Mutano Raptor Race 2.4's on 717 rims and never had an issue, well over a thousand miles with no concern at all for the tires or wheels. I rode that combo like I borrowed it from someone I hate. Best tire and wheel combo I have ridden yet, not the most traction in every circumstance but very fast and as predictable as the sun once you get to know them. It shouldn't work from what you read on the web but it worked outstandingly well.
 

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jeffj said:
Exceed the manufacturer's recommended spec's at your the risk of your own peril. If you are large and ride rocky terrain, you have increased your personal risk factors. Well, it certainly increased mine :lol:

Me: 270lbs
Tire size: 2.5" Nevegal @ 45psi+/-
Result:


There were no flat spots or dings that might suggest it failed from being hit while running low tire pressure.


Where it wasn't split completely, it looked like this along the entire circumference on both sides:


My $0.02: If you just want to try a larger tire for a short time and aren't going to bust too hard on it, GFI. If you now want to run larger tires through rough terrain, get wider rims. Largers tires perform better with them anyway.
The real question is why were you using 717s in the first place?
 

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Discussion Starter · #8 ·
Thank you guys for the replies. Looks like I will not have any problems on 2.3-2.4 widths I intend to use.
The Michelin XCDry2 I now have are almost new and fast rolling so I was wondering if by changing bars as well from aluminum to carbon, it will be comfortable enough with these narrow tyres;
A few days ago I bought a second hand Easton EC90 carbon low riser 685mm handlebars that are on their way to me. I have read that carbon bars give a bit more comfortable ride than alloy ones with rigid forks. You think that with the current 2.0 width it will be fairly comfy; (I don't intend to ride on extreme hard rocky terrain).
 

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270lb's and 717 and 2.5's ran at 45psi is crazy and bound to fail, the 45psi is likely beyond a 717's spec with a ex325 which would likely be suitable you'd be able to run 35psi without the squirm without a issue.

Personally, 717's are okay in the rear upto 2.35 area, but front as it's your steering I wouldn't go above 2.2's personally.

Carbon bars wise, myth kinda, Carbon bars do not flex at all which is an advantage, normal bars will flex then they'll spring back undamped and it's the springing back which smacks your hands around.

Lock out 2 bikes, push both a normal and a Carbon down hard and notice the Normal flexs and the Carbon remains completely rigid.
 

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The Punk Hucker
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I tried 2.35s up front on my 717 a while back and didn't like it. I could feel the tire fold when cornering. Now with a higher pressure it's another story which isn't all perfect either.

I limited myself at 2.1's on those rims from them on.
 

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jeffj said:
Exceed the manufacturer's recommended spec's at your the risk of your own peril. If you are large and ride rocky terrain, you have increased your personal risk factors. Well, it certainly increased mine :lol:

Me: 270lbs
Tire size: 2.5" Nevegal @ 45psi+/-
Result:


There were no flat spots or dings that might suggest it failed from being hit while running low tire pressure.


Where it wasn't split completely, it looked like this along the entire circumference on both sides:


My $0.02: If you just want to try a larger tire for a short time and aren't going to bust too hard on it, GFI. If you now want to run larger tires through rough terrain, get wider rims. Largers tires perform better with them anyway.
That is a classic problem with rims and larger tires with higher pressures...

2.5 inch I think should have a max tire pressure of something like 40 psi, and then you at 270...ouch...

Anyway did it blow when you pressured it or during or after riding???
 

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The Punk Hucker
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mipi said:
So I shouldn't exceed Mavic's recommendations and stay at 2.1 or max 2.2;
Well, given the 2.35 I used was a wire bead DH tire and I felt it fold, I would say yes... but there are many factors involved, so maybe not.
 

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mipi said:
So I shouldn't exceed Mavic's recommendations and stay at 2.1 or max 2.2;
What no you can go much wider without problem you just can't go wide and high pressure...

Eventually the tire is wide enough that at the max inflation pressure the rim can stand, the tire starts to wander...

The trick is getting Mavic's pressure vs tire width pressure reccomendations...

I have that but not at work...

2.5 is about 40 psi 2.3 is about 55 psi 2.1 is about 65 psi...
 

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Discussion Starter · #17 ·
jeffscott said:
What no you can go much wider without problem you just can't go wide and high pressure...

Eventually the tire is wide enough that at the max inflation pressure the rim can stand, the tire starts to wander...

The trick is getting Mavic's pressure vs tire width pressure reccomendations...

I have that but not at work...

2.5 is about 40 psi 2.3 is about 55 psi 2.1 is about 65 psi...
Thank's!!!!
Now that's something I didn't know at all. (In fact I thought that every width has same pressure limits, or at least follow manufacturer's notes.)
 

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mipi said:
Thank's!!!!
Now that's something I didn't know at all. (In fact I thought that every width has same pressure limits, or at least follow manufacturer's notes.)
I learned it when I got my Mavic SLR's the table is included with the package...

Shimano XTR wheels have a max air pressure of 50 psi (maybe 55 psi??) with no tire size quoted...they are very close to mavic rims..

Stans also aas a max pressure quoted of 40 psi??? also with no tire size quoted...

I am betting that Mavic nailed it when they came up with the rim design.

Basically it is simply the hoop stress applied by the tire to the rim that will split the rim apart..

Bigger tire diameter or higher pressure equals more hoop stress.
 

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All the widths have the same, but with a 17mm you'd need 45psi for a 27lb person and for a 21mm rim you'd maybe get away with 35 just maybe.

I don't think they've really done the destruction testing on each rim, so it's just a vague guide.
 

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mipi said:
Hi all. I have a new GT Avalanche 1.0 built a couple of months ago with some good parts. The fork on it is a RockShox Tora 318 U-Turn which is nice performing but the weight is a bit high on 2.3 kg.
Today I received an eXotic carbon rigid fork after some search and the decision to run the bike rigid.
Reading the forums everybody suggests bigger high volume tires on rigid forks.
The rims I have are new Mavic XC717 which I like a lot and don't want (and have the money) to replace. The tires are Michelin XC-Dry2 26x2.00 on both wheels.

Mavic recommended tire widths are between 1.00 and 2.10:
http://www.mavic.com/mtb/products/xc-717-disc.323323.2.aspx
Anybody used bigger tires on these rims;
I would like something from WTB or Michelin.
Any opinions are welcome.
I've ridden up to 2.4 tires on some of my 17mm rims. Just got to ride 2 to 5 psi higher pressure than a wider rim to keep the tire stable. You're going rigid so are hardly going to be a downhill dude so can't see a problem . If you are a little hesitant run a lightweight tube. You will not notice any difference in ride quality.

The latest generation Michelin 2.25's are a wide comfy tire and are as comfortable as some 2.4's. The casing construction have a softish ride feeling so has to be run at a slightly higher pressure than some brands but still rides as good or better at that highr pressure.

I've ridden lots of alloy and carbon bars and the carbon does dampen the trail. I would have gone for a carbon rizer as they dampen even more.
 
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