brewerkz 

The tubular stem hole on the Mavic rims is not allowing the tire to seat at the stem. My specialized rim has a larger hole. Do I need to open the outer hole or is there a better tire choice (using Yellow Jersey tubulars)

1989Pre 

I took a look at one of my Nisi Corsa Stretto, and the inner drilling of the valve stem hole is noticeably wider than the outer, like with your Specialized. My diameter measurement for that hole is 12mm.

iab

Drill it. YJ tires are for spares, not riding.

brewerkz 

that is about the same as my mine, thanks.

MooneyBloke

Which rim is this? I've ridden GP4s, GL330s, GEL280s, and now Reflexes, and they've all have ferules. I've never seen a Mavic without.

Moe Zhoost

I'd widen the inner hole a tad with a countersink bit. Clean the burrs up afterwords with a file.

JohnDThompson 

A tapered hand reamer can easily enlarge the rim bed hole without affecting the other side.

brewerkz 

thank you went out and bought one !

gugie 

aka the comical reamer.

That’s what we called it in my LBS days.

SJX426 

Be careful about the taper. Make sure you don't accidently make the other hole bigger.. I would use something more like this
CONQUER Tools 5 Flute Metal Countersink Drill Bit, 90 Degree for 1/4'' Hex Shank Fit 1/8"-3/4"(3mm-19mm), Burr Removal, Deburring Beveling Chamfer Tool, Holes Shaping Trimming, Inner/Pipe Reamer - Amazon.com

repechage

Mavic did make a rim without, and one with just eyelets at the inside surface.
‘cannot tell from the image, looks to be an anodized rim, I have not seen a Mavic like that with anodizing, but I have not seen everything.
I think the hand driven taper reamer will not provide a large enough hole without enlarging the stem hole.
I would use a drill press, but to be fair, not sure how I would hold it with a built wheel.
might reach for the Dremel tool, think about the forces and go that way.

if the rim does not have even a single surface eyelet… take it apart and add washers.

smontanaro 

Gerd Schraner (The Art of Wheelbuilding) has a bit in the back of the book about this. He countersinks valve stem holes, as they are often not sized properly to accommodate the tire lump. Can't recall who he blamed (rim or tire mfrs), but he views it as pretty much necessary.

(From memory. Not hunting for the reference at 4am.)

oneclick 

Use a countersink as others have suggested - they're usually 45 or 60 degrees so it'll make the inside hole big enough without touching the inner hole
I'd put the bit in a chuck by itsellf and just use it as a hand-reamer; that ally is thin and you don't want to go too big.
Make sure you take the edge off what results as it'll be sharp - and have a look at the other holes, there's a bit of a ridge on the ones in your pics; even for those a pass with a round file might be a good thing.

mpetry912 

+1 on the reamer and smontanaro good call out on Gerd Schraner. His book is excellent

/markp

Chombi1 

The "budget" sewups you are using might have an overly thick profile at seam tape overlap around the valve stem area.
this causes the tire not to bed down completely. I experienced the same when I tried Vittoria Rallies.
I switched over to better quality Schwalbe tubulars on the same rims and I did not experience the problem anymore, after that.

blamester

I would say the same. I only got a couple of miles before they punctured. Don't glue it on first.
Pump it good on the rim and take a gentle spin.
See what it does. Then glue it or decide what needs doing.

Road Fan

I've mounted up a number of Yellow Jersey tires. Some have had a bit of extra build up at the valve hole, but none with serious problems. If you can see a way to de-burr and smooth the hole on that Mavic rim it can only help, and if the hole has roughness removed and you leave no new sharp edges, I think it should survive use for a good long time.

It is possible for careless installation to result in the valve pulling and the innertube being cut rignt near the valve, which is just about a fatal injury. But it's not due to the YJ, I've had those problems with much fancier tubulars, as well (well, they at least had fancy brand names, thought they were still low-priced Thailand casings and assemblies!).

As you glue on the tire, try to manipulate the tire near the valve to keep the valve as square as possible with respect to the rim contour - valve body points perpendicular to teh tangent to the rim at that point, pointing along a radial path AT the axle. If the glue cures in this position it will help guide the whole tire to settle well. Tires change just a bit over time as the new glue cures (aka the excess solvent evaporates).

Your tire and rim should be fine. I would maybe smooth the hole a little, but would not enlarge the hole. or otherwise modify the rim. Your tire installation really should work just fine.