I'm a bike mechanic and I recently had a customer wanting to switch over to fixed gear after seeing/riding my bike, only thing is he has a Trek Madone, which is full carbon with vertical drops. I don't know if the frame can handle the torque of being fixed, I've heard that carbon frames tend to crack and splinter under the stress and also I've heard that's a rumor. Just seeing if anyone has tried with a carbon frame or know anyone who has or have seen the end results of such a conversion. I know chain tension would be a problem and I could probably use an eccentric bottom bracket or hub to help out, but I just wanted to get some opinions or see if anyone has done/seen this before. Thanks everyone.

pretty sure people race carbon track bikes

pretty sure the madone can hold up to the wattage pro riders put out

this is where i insult you, insert some insult against you here.

you're a bike mechanic?

no

This whole thread is...interesting.

OP, when I first read your thread title, I thought you were a troll. A Madone conversion? Really?
As for the answer to your question, besides the fact that it's a Madone, vertical drops = vote of no for sure.

Considering this insult came from someone who named themselves after an old school anime character, I'm not insulted at all, but nice try, I commend you for it. I'm aware that people race full carbon frames, I'm not an idiot, my concern was with the torque of skidding and "mashing", which is what this guy wants to do. He keeps referring to the Fast Friday vids, and that type of riding, and how he wants to do/learn all of that, which is why I was concerned about the carbon holding up to the stress and pressure of that type of riding. If this guy was just using it for recreational purposes and relaxed riding, I wouldn't have any question. So, if anyone has any kind of real feedback, I'd appreciate.

To be honest, a Madone is too nice of a bike and too costly to be converted, you will definitely need some eccentric hub or bottom bracket. Your customer is probably better off selling his Madone and get an entry level track bike.
Or just go singlespeed with a simple chain tensioner...

+1

Or considering the cost of the Madone, the guy could buy a whole fleet of entry level track bikes.

I tried recommending him just buying one of the Focale44 bikes that we have on sale, but he's dead set on converting his Madone. Figured the cost of everything he wants done would equal up to the price I could give him on a brand new bike, but he still wants to go ahead with the conversion.

Even after telling him that vertical dropouts are a no-go?

(Unwarranted judgment time!) Sounds kind of like the unconverted Madone is a bit too much bike for this dude.

Show him videos of carbon fibre frames catastrophically fail then he'll stay away from it. Skidding on a Madone is a bit silly, the chain stays will flex quite a bit and it could possibly bend and snap. If he is still set with conversion, then...ask him to buy some insurance. I've never worked on a carbon fibre track bike before, or any sort of carbon fibre bikes...but conversion is still not recommended.

I tried talking him out of it, with this frame at least. I had a feeling the chain stays might flex/snap after a certain amount of force/torque was applied to them, and tried explaining that to him. And I don't want to go ahead and convert it even if this guy says "yes I'll use brakes..." because I know he's not going to haha. I tried telling him about steel and aluminum frames snapping, about having to use an eccentric bb or hub, and the other downsides of this frame, but he just really wasn't listening to me. Which is why I was trying to find a safe way, or maybe someone had a success story, so I could go ahead with it. But I just really don't think this is a good idea considering the style of riding he's looking to do.

Do it! If only to piss everyone off. A madone fixie? Hell yeah!
But yeah, other than just doing it for the sake of doing it this guys an idiot. Tell him to buy the cheapest all chromoly fixie he can and to just enjoy that.

Well if he wants to spend the money...

Welllll iff he wannttss.

Shouldn't you ask a more senior mechanic/the owner/manager about this? Do you want your shop to be the shop that responsibly turned an idiot away, or the shop that decided to do something ridiculous and notably dangerous in order to take this guy's money?

Dude sounds like a bonehead. Tell him he can do it if he wants but you'd rather not be responsible for doing any of the work.

White Industries Eno Eccentric hub. Done. Not that big a deal. Not that much work. He could probably keep his cranks and just get a SS chainring. Really not a big deal. Don't know why people are freaking out in here. Yeah, he could go buy an entry level steal fixed gear. But if he wants a nice carbon road race fixed gear, then the Madone will be fine.

I'd first check to make sure the dropouts on his Madone aren't carbon -- I can't remember if they are, and which year they started that, etc. The WI ENO hub might chew up his carbon dropouts if he's got them. Otherwise, just build a rear wheel around a WI Eccentric ENO and you're good to go.

Also, pet peeve of mine: people thinking/assuming riding fixed puts more stress on your frame, cranks, chain, etc. It does not. This "myth" is really annoying to me. The forces exerted when you "mash" or skid are not any more than any hard-effort standing start or sprint effort on a freewheel drivetrain. His carbon road frame is fine to fun fixed.

NO. seriously.. a ****ing madone? fg conversion?! Ill trade you that madone for my kilo, and then all your problems will be solved.

nice reaction to a non insult. pay no attention to the guy questioning your credibility as a bike mechanic.

tell me where in the equation it makes sense that a madone can withstand the stresses of a pro rider cranking the bike up a mountain pass, or sprinting for a finish, but Fred Trek will somehow snap the frame by locking up his legs while riding.

unless i've missed something big, there hasn't been a frame directly destroyed by skidding. or mashing.

the frame withstands someone accelerating up 150+ lbs of rider and bike, i don't see how suddenly locking up 1lb of wheel will DESTROY THE FRAME


real feedback: guy can do whatever he wants with his money. a madone isn't going to explode from skidding and improper pedaling technique. It could fail from leaving it on top of a car rack and driving it into a wall, or dropping it on a curb.

This is the only thing I would have worried about.

+100000, all of it.

I don't really see how it would be detrimental to the bike. Climbing a 15% hill will put more stress on the frame then skidding which really is not much stress beyond the initial locking of the wheel.

Exactly. Build him up a nice Eno rear wheel, strip off unnecessary parts, and send him on his way.

I think it sounds like a superfast road fixed gear. Pedal strike might be an issue, in which case you can sell him some 165 cranks. I would ride it, and I think it will be awesome.

Tell him to do this instead