# CAAD9 chainstay clearance sucks!



## Kuna (Oct 14, 2002)

I am running the Dura Ace wheelset with Hutchinson Bulldogs set up tubeless and noticed during warming up for a recent cross race a small "brrrp" during hard acceleration and a more noticeable "brrrrrp" when dismounting off the left pedal. At first I thought it was a bearing or drivetrain issues. I slowed down to figure at the noise and discovered it was the tire rubbing against the chainstay. I pulled the wheel out and had a guy put it in his truing stand as I thought the wheel needed truing, nope. That's when I saw the chainstay by the tire had been rubbed all the way down to bare metal (more so on the left side)! I put the wheel back on the bike and noticed the clearance is much, much, smaller at the chainstay then compared to the seatstay.

WHY??
Why on earth would you build a bike with tons of clearance on the seat stay and on the EC90X fork and minimal at the chainstay? Unfortnately being able to flex the chainstay just a couple of mm under hard acceleration and the force of dismounting the bike on the left side the tire has rubbed all the paint off down to the bair metal on a brand new 2008 bike. WHY CANNONDALE? By the way I am 165 pounds with all my gear on. I do realize these are big tires, but why not follow suit on the rest of the bike with clearance.

Anyone else had clearance issues running these big tires, tubeless or not?


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## cryoplasm (Jun 14, 2008)

Dodgy rear wheel. I find it hard to believe the chainstay is deflecting that much. Given the moment from the BB, the leverage won't be much to deflect the stays let alone several mm.


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## Corndog (Jan 18, 2006)

I agree that it's your wheel flexing and being the problem. But, that still doesn't excuse that tight of clearance. FYI, those bulldogs run REALLY big.... so that is contributing to the problem.


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## cryoplasm (Jun 14, 2008)

Corndog said:


> I agree that it's your wheel flexing and being the problem. But, that still doesn't excuse that tight of clearance. FYI, those bulldogs run REALLY big.... so that is contributing to the problem.


Have you seen the bulldogs on a Tarmac SL2?


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## tjanson (Nov 11, 2006)

Well, just trying to explain why there isn't much clearance, the chainstays are the hardest place to get lots of tire clearance because you've got the chainrings on the other side


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## cryoplasm (Jun 14, 2008)

tjanson said:


> Well, just trying to explain why there isn't much clearance, the chainstays are the hardest place to get lots of tire clearance because you've got the chainrings on the other side


Not really.

Some frames now have asymmetric stays, with the NDS being almost 1.5 - 2 times larger than the DS.

So the question being, is it really necessary to have a huge clearance? If so, look for a CX frame.


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## Tin Sloth (Mar 26, 2007)

tjanson said:


> Well, just trying to explain why there isn't much clearance, the chainstays are the hardest place to get lots of tire clearance because you've got the chainrings on the other side


Plus you can only weld the chainstays so close to the outer edge of the BB shell, especially with an aluminum chainstay that you want to be as stiff and efficient as possible (it's going to have to be a little wider). For what it's worth, my buddy rides the '08 XTJ frame with ksyriums, and a couple different maxxis tires (mimo, raze) and some tufo tubbies and he hasn't mentioned any unwanted tire rubbing. He's about 180lbs, and puts out a lot of power. The cannondale cross bikes are really all about racing and thusly aren't built to handle a huge tire out back. Another thing to check might be the dish of the wheel. If it's biased towards the left side, that would definitely cause some rubbing.

Also, part of the reason for having more seatstay clearance is to allow for mud to pass through and not build up around and on the brakes. Maybe they figure it'll get flung off by the time the tire gets to the chainstays?


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## Corndog (Jan 18, 2006)

cryoplasm said:


> Have you seen the bulldogs on a Tarmac SL2?


???? What does trying to put cross tires on a Tarmac SL2 have to do with tight clearance on a CAAD9 CX bike? Maybe I'm missing something here. :shocked: 

Lots of alu CX bikes have tons of clearance, so that is a poor excuse for why it might be tight at the chain stay. Specialized Tricross can run a 42mm tire back there, Redlines have a lot of room, as does my wife's Lapierre Scandium frame. 

Some racing frames have tight stays, designing around a max 35mm tire.... with little room for even mud clearance. I think they should always leave a bit of room for slightly bigger tires and of course mud/dirt. 

For example, Pinarello has been terrible about this in the past. Even their new carbon bikes have too little room between the tire and the seat tube.


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## jollydriver (Nov 12, 2006)

*C'Dale Cyclocross CAAD9 Optimo*



cryoplasm said:


> Not really.
> 
> Some frames now have asymmetric stays, with the NDS being almost 1.5 - 2 times larger than the DS.
> 
> So the question being, is it really necessary to have a huge clearance? If so, look for a CX frame.


I would assume the OP is using a Cyclocross CAAD9 Optimo frame, which in 2008 Cross XR 4 dress came stock with the noted Easton fork (see photo).

With a road road CAAD9, I'd be amazed if 28mm tires would fit, much less the 34-35mm CX tires.


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## tscheezy (Oct 23, 2005)

What about the Cannondale XR series? I am looking at an older (2003-2004) XR1000 and am wondering what sort of meat I can fit? Anybody run a 40c+ tire on one of those?


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## jroden (Jun 15, 2004)

Those bulldogs are tight on my bike also, they are just a godawful big tire.


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## oscar2 (Feb 18, 2005)

I have a CAAD9 with no tire rub problems at all. I'm 195 lbs. and ride all kinds of bad roads in Western PA. Up hills, down hills, potholes, etc. I'm running Maxxis Fuse 700x23 tires on Shimano aluminum wheels. I've had the bike near 60 mph on several occasions with no problems. 
Either your tires are too wide or your wheels are flexing way too much.


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## OneGear (Aug 19, 2005)

your tires are 700x23, his are 700x30+. read the thread again


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## PeanutButterBreath (Dec 4, 2005)

Psst. He's talking about the _cyclocross_ version of the CAAD9.


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## rensho (Aug 5, 2003)

The Bulldogs are 36mm wide, starts out as 35.xx and grows to 36.xx in a matter of days.

Next size down that works well are Michelin Mud2 at 34mm. Maxxis work well also at ~32mm.


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## oscar2 (Feb 18, 2005)

I didn't misread the thread. That was my point. With the proper size tire for a true road frame, there is no problem.


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## justinb (Nov 20, 2006)

oscar2 said:


> I didn't misread the thread. That was my point. With the proper size tire for a true road frame, there is no problem.


The OP doesn't have a true road frame. It's a CAAD9 cyclocross bike.


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## Streetking (Jan 5, 2007)

tscheezy said:


> Anybody run a 40c+ tire on one of those?


No chance!


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## tscheezy (Oct 23, 2005)

Streetking said:


> No chance!


Good to know. Tnx.


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## thighmaster (Feb 2, 2006)

One thing to think about is how wide those bulldogs actually are, they say 34mm but are more like 38 in other tires. I tried a buddys and they almost rubbed on my frame and I never have trouble with other brands. That said, they are as plush as a couch.


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## OneGear (Aug 19, 2005)

oscar2 said:


> I didn't misread the thread. That was my point. With the proper size tire for a true road frame, there is no problem.


you do know this is the cyclocross forum right?


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## OnTheRivet (Sep 3, 2004)

To everybody that doesn't realize that the OP is talking about a cyclocross frame and well geez this is a cyclocross forum........................... 

YOU FAIL!


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