chugger3

I bought a Specialized Allez (aluminum, carbon fork) in 2006. I was so dumb that I didn't realize that that particular model came without means to attach a carrier to the seat stays. The bike shop said that they could do it. They drilled, tapped a hole, and voila!, carrier works great and I've loaded enough junk to break a couple spokes in my rear wheel. (though I usually only carry lightish loads). Now I'm flirting with the idea of a new bike. Don't need one yet, less that 3000 miles on the Allez. And I'm 74, with a bad back, dunno how long I can ride. ANYWAY, I discovered that high class road bikes with carbon seat stays don't have means to attach my beloved carrier. I guess most enthusiasts look in horror at ANYTHING that adds weight, but I GOTTA have my STUFF. So... finally, my question is: could these carbon stays be drilled and tapped for securing a bike carrier without endangering the structural integrity of the bike? I've been looking at the Motobecanes on BikeDirect. I'm just dangerous enough with a tool kit to think I could assemble one, maybe have bike shop tune it after.

DataJunkie

No.
If you want to run a rack purchase a bike that has the mounts. Ex: touring, sport touring, etc.
Look at something like this: https://www.salsacycles.com/casserollComp08.html

Spreggy

You can also take a look at Carradice seat bags, which couple well with Brooks saddles. They can store a lot, without putting any weight to the seat stays.

bumperm

While I cannot imagine doing the following, it should work okay. Any good composite shop (the sort that does glider repairs etc - - most all new gliders being carbon fiber) should be able to do the job.

Fabricate the rack mounting brackets out of carbon fiber so that they either glue on to the lower chain stays near the drops or with a "cuff" to go over the stay and clamp gently in place. The brackets would have a small flange with a threaded insert for the rack mount. This avoids drilling the chain stays. You don't want to drill the chain stays as that would compromise their strength.

Or get a touring bike.

Hunt-man

Don't drill a carbon frame. Get something that has the mounting points on it already. A carbon bike for you would be nice as a second bike, if you can leave your stuff behind on some rides. A cyclocross bike might be a good choice to consider as some have mounting points.

halfspeed

Wrong tool for the job. Get the right one.

Retro Grouch 

The thing to check out is the dropouts near the rear wheel. If the dropouts have threaded eyelets, you're good-to-go. Most racks will include P-clamps for the seat stays.

cdubb

What about one of those racks that mounts to the seat post? Maybe that would work for you.

BigBlueToe

My Allez has mounting brackets. I put an old Blackburn Expedition rack on it. Sure, I'm a Fred, but I don't care. The rack hardly weighs anything, and it's certainly handy.

bonechilling

Seriously. There are literally dozens of bikes perfectly suited for the OPs purposes.

sstorkel

Drilling carbon will ruin the structural integrity of it. Even if you could drill it, I don't think you could tap the hole.

What you want is a Tubus Fly Rack and their Quick Release Mounting Kit. Keep in mind, though, that if a bike doesn't have rack mounts there's usually a reason. The one I'd keep an eye on is chainstay length. If the frame has short chainstays and you try to mount panniers, you may find yourself kicking them with every pedal stroke...

Chuck G

I think the reason is marketing and most manufacturers do not think outside the box. Full carbon road bike frames and those with carbon seatstays are marketed as racing or pseudo-racing bikes, and manufacturers assume consumers would not want to put a rack on that "style" of bike.

Structurally there is no reason a carbon frame bike that can handle my 180lbs on the saddle couldn't handle another 20lbs on a rear rack. I think Tom Boonen hammering away on Paris-Roubaix is way harder on a frame than me putting along at 18mph with 10lbs in a rack trunk. Obviously manufacturers can make the rear brake bridge strong on a carbon frame, so I do not think it would be that difficult to put reinforced eyelets at the top of the seatstays. It is not that they can't - they just don't.

RazorWind

Seems to me that it's not so much marketing as laziness. They figure the customer won't put a rack on it, so they don't bother with the extra $3 it costs to put the fittings into the frame, assuming instead that a customer wanting to use a rack would buy a different flavor frame anyway.

Tapeworm21

Get a BOB Trailor that hooks onto the skewers. Problem solved.

banerjek

There are a number of reasons for this. For one thing, the geometry of a road bike is different. Among other things, the chain stays are not as long as on a touring bike -- you'd wind up kicking your packs all the time.

kila kila kila

As mentioned, the Tubus racks can be equipped with a quick-release computable mount that doesn't require rack eyelets. Same goes for Old Man Mountain.

But, if you're wanting to class it up, then go custom. I'm sure Craig Calfee can manage to get a few reinforced rack eyelets on a frame, as well as design the frame and fork geometries (touring or sport-touring geometry) to suit rear-biased loading, standard road bike geometry that you'd get with an off-the-peg CF frame isn't well suited to rear loads.

halfspeed

From what little I know of CF structures, they are engineered for loads and stresses in specific directions. Racks don't load a bike in the same way as a rider, so it's a bit more than adding fittings to ensure that the bike remains "safe" with a "reasonable" load. But don't let that stop anyone. Drill and clamp away on your $5000 road bike.

TheEventHorizon

CF in general (it is different depending on the weave and epoxies used) is very strong in the direction of the tube and can be i a little more brittle when force is applied perpendicular to the tube although it is still very strong. Furthermore, most of these commertial bikes must be built to much more extreams than 20lb more will expert. for most companies there are two goals make money, and not get sued same goes for high end bikes. they have to withstand alot more than that to make it out of the factory to make sure they don't have to deal with lawsuits.

That being said, drilling into the frame could end up being a very very bad idea. furthermore, i think the heart of halfspeeds point is why spend that kinda money on a bike unless your going to put alot of time into riding it. maybe it's just the college kid in me but 5k is alot to be dropping on a semi casual hobby. as my friend always says it's the pilot not the plane.

Edit: i guess what i'm really wondering is if your worried about weight to the point were you are buying a CF bike why don't you just carry less stuff... i understand that less stuff is a deal breaker for you but is it worth it to drop more money on a new frame to drop 5lbs maybe just to put another 10lb worth of stuff on the rack?

Chuck G

If you just want to use a rack trunk then chainstay length isn't an issue.

I agree with larger panniers and/or big feet heel strike would be an issue, and handling would suck. But with smaller panniers and light loads I don't think it's that big a deal - move the pannier further to the rear. My 59cm touring bike has 17.1" chainstays (not very long for a touring bike), I wear size 13 shoes, and I do not have problems with heel strike. A 2009 60cm Madone 5.1 has 16.1" chainstays, and a 2009 58cm Tarmac has 16" chainstays, not a huge difference to shift the pannier back 1". Now I wouldn't want to or recommend carrying much weight way on the back of a rack mounted to a short wheelbase racing bike with steep angles.

If people didn't want to ride racing bikes AND carry more than they can stuff in their jersey pockets there wouldn't be a market for seatpost mount racks

I wouldn't drill into a carbon frame either, or put P-clamps on carbon tubes.

Drag

https://www.performancebike.com/bikes...00_20000_44501

nycphotography

Ever seen what happens to an otherwise strong tube when it has a lateral force applied at the mid point?

Let's just say failure can be swift and merciless.

I would NEVER mount anything of any substantial weight to MIDDLE of any tube what wasn't specificaly designed to carry the weight.

Especially not the seat stays of my carbon fiber frame. Rain Fenders? Sure. A rack that I'm going to load up with heavy stuff? No way.

If you want racks and/or panniers get a Trek 520 and enjoy. Or any of the dozens of touring bikes available.

halfspeed

Maybe part of the reason they don't install rack fittings is because they're building to weight and doing so would be a huge liability risk. Take a look at the seat stays on a Cervelo R3 SL some time.

There are lots of nice bikes built for racks. The frame will be a pound or three heavier than a weight weenie frame, but who cares if you're carrying 20 pounds of crap?

Eclectus

The whole rationale of CF is it's lighter than anything else. The mfrs figure that people who want to carry 20 lbs of stuff don't need to save 2-4 lbs on the frame. Eventually, if and when CF becomes the standard for all kinds of bikes, which is to say it becomes a cheap commoditized product, then they'll put on braze-ons for racks.

10 Wheels likes to use one bike, a Felt CF, for fast club rides and light touring. For the former, he rides stripped-down (the bike, not him), and for the latter uses a Topeak seatpost rack with trunk bag and panniers (on a CF seatpost), a frame pack, and other stuff. He's satisfied. You should PM him for more info.

HarryStoddard

It just doesn't make sense to buy a $3K road frame so that you can haul junk around. They are built to be light and fast. They are not wagons. If the OP needs to haul his stuff around he should get a touring bike, hell, a nice touring bike. If the OP wants to show off some bike bling, well, that's different.

PaulRivers

They're completely capable of putting rack mounts on a full carbon bike - just check out the top end Specialized Tricross:
https://www.specialized.com/us/en/bc/...icross&eid=123
"Frame...rack and fender fittings"

I think they don't because they're afraid it won't "look cool" to certain people, and it would add precious grams to the frame. I've read people here insist they "couldn't possibly" put a much more comfortable seat on their bike because it weighed another 200 grams. I think they're crazy, my point is there's a lot of people in the racer crowd who would care about the extra weight.

I would definitely agree that you should NOT drill into a carbon frame for serious safety reasons. Ditto with using p-clamps on the seat stays.

While people are right to be concerned about putting weight on parts of a carbon frame that aren't designed to take it, I definitely agree with the other guy - the frame was designed to carry my 200 lbs of weight even if I'm a really really strong rider that puts a ton of stress on the frame as I pedal. The additional 20 pounds I might put on the rack is (relatively) nothing.

The trick is to mount a rack on parts of the frame that are designed to take a great deal of weight. The 3 parts racks use are the rear wheels skewer (designed to hold your entire body weight), the rear brake bridge (designed to handle the force of throwing on the brakes while speeding downhill at 40 mph), and the seat clamp (designed the hold your entire body weight sitting on it, and the seat tube is already at a funny angle anyways).

However, there definitely for sure ARE rack specifically designed to go on carbon fiber bikes without rack mounts.

I created a meandering thread on this topic some time ago here:
https://www.bikeforums.net/showthread...70#post8344070

The more compact version is that if you want a rack on the bike, there's 3 main options.

If you want something cheap but reliable, the Axiom Streamliner Road Bike Rack is IMO ugly, but it works - it attaches at the wheel skewer and rear break bridge:
https://www.eriksbikeshop.com/ride/pr...539B1FNG0V9NF9



If you want something nicer looking, as mentioned Tubus makes a couple of racks designed in a similar way (attaches at the rear brake bridge and the rear wheel skewer), like the Tubus Fly:
https://www.thetouringstore.com/TUBUS/Fly/FLY%20PAGE.htm


It's advantage is that's it's pretty easy to take on and off the bike if you don't want to have a rack on while riding with your more visuall sensitive friends (take out the wheel skewer and undo a nut on the top), and it's prettier. It's disadvantage is that the top is shaped to be narrower near the bike, so it doesn't work as well for trunk bags.

The third option is to mount a rack through the wheel skewer and the seatpost mount. You need a specially designed seatpost mount like this one:
https://www.treefortbikes.com/448_333...ck-Mounts.html



Using one of these plus the Tubus Quick Release Mounting kit someone else linked to, you can put pretty much any rack on your bike. It's just going to look more noticeable than a rack designed to be mounted below the brake mount.

All of the above solutions move the rack back an inch or two so you shouldn't have to worry about heel strike issues.

As for the opposition to doing something like this, there's just a bunch of people with a certain amount of snobbery. First you had the "I have my RACE bike - it doesn't have a stupid rack, because I never carry anything at all!". Then we got the reverse snobbery crowd "We hate carbon fiber because it's new, so we like to tell every one it's impossible to carry anything on it and they have to buy one of the bikes we like to carry stuff".

The 2nd crowd just refuses to accept the truth - at the cost of a lot of money, a full carbon bike is the best way to get a bike that's fast and comfortable. You can get a bike made out of more traditional material that's just as fast, but it's not as comfortable. You can take that same bike and make it just as comfortable by putting on much wider tires and running them at a lower psi, but it's not going to be as fast. A lot of us don't care about getting there seconds faster, but we do care about an hour trip taking another 10 minutes, or not being able to keep up with the people we're riding with because we're just a little to much slightly slower than them. Carbon fiber is the best way to do both, and sometimes we want to carry stuff - and it's completely feasible.