Ask Nick: Roadside tubular flats

Editor’s Note: VeloNews tech editor Nick Legan is a former ProTour mechanic who most recently wrenched for Team RadioShack at the 2010 Tour de France and elsewhere. His column appears here every Thursday. You can submit questions to Nick at asknick@competitorgroup.com, and be sure to check out Nick’s previous columns.

Q.Nick,
I just purchased two sets of ENVE tubular wheels and I would like to use one set for everyday rides. My only concern is getting a flat on the road with a tubular tire. How can I prepare for this and what precautions should be taken?
– Derek Stewart

A.Derek,
First question: Are you adopting? Congrats on not one, but two new sets of sweet wheels!

Training on tubulars is super fun. After all, life is short. What are we saving them for? I ride on tubulars as often as I can. But I make sure I can fix two flats when I leave the house. I always carry a pre-glued, pre-stretched spare tire in an Arundel Tubi bag and a can of Vittoria’s Pit Stop. Either a frame pump or Co2 inflator are a necessity too.

For the tire, I recommend using an inexpensive, 21mm model. No need to break the bank and the smaller size packs down more easily in your seat bag. It also weighs less. Stretch the tire, then apply a thin layer of glue. Let that dry and then stretch the tire again. The second stretching is really helpful when you’re struggling roadside.

I’ve had good luck with Vittoria’s Pit Stop and unless I’ve completely slashed a tire, I try it first. It seals most small punctures very effectively, so well that I’ve happily ridden tires with Pit Stop in them until I wore through the tread. If it doesn’t work, I can still get home thanks to my spare tire.

Lennard Zinn also carries some Tufo gluing tape and that’s a great idea. It means that you won’t have to creep around corners after changing a tire far from home. It also means you need to have a clean spot to install it and that’s not always easily found on a dirt shoulder. It’s still good to bring along though.

More important than what you carry may be your comfort with the process of removing and installing a tubular. If you’re not adept at it, a flat can be a real bummer. When I’ve become frustrated changing a tubular by the side of the road, I try to remember that it’s a rite of passage. It used to be that was the only option cyclists had. The truth is that most modern cyclists make too much of the so-called hassle of tubulars. With some preparation and practice, they’re no worse than a clincher and the ride can’t be beat!

Q.Nick,
A friend is offering me her son’s 2001 LeMond Buenos Aires frame, which he used back then while racing on an area college team.

One of the first things I tried to do was slide my 27.2mm American Classic Ti post in so I could clamp the bike in the stand to start cleanup. I found little evidence on the Internet (mostly specs on pre-2000 and some post-2002 frames). Eyeballing the seat tube and seatpost, it looks like the right size post, but the fit is so tight on initial insertion that I’m afraid if I actually succeeded in getting the post into the frame, it would then spend eternity there.

Is this the right sized post, and there’s something I need to do besides grease the post to make this work? Is this ti post — an elegant leftover from my ’95 mountain bike — somehow not suited for this steel frame?
– Clay

A.Clay,
Take it to a shop where they can check the internal diameter with vernier calipers. It may be the correct size, but over time, the tabs on steel frame seat clamps can stretch. Honing the seat tube or possibly reaming it back to size may be necessary. This is something best left to those with the correct tools.

(Commenters, can you confirm the seatpost size of Clay’s LeMond?)

Using your titanium post in your steel frame will give you a beautifully smooth ride. It’s a great compliment and entirely suitable for this application. But be sure to use anti-seize inside the seat tube (putting it on the post is less effective than brushing the inside of the seat tube). Nothing worse than a telescoping seatpost that won’t budge.

Q.Nick,
I have been experimenting with different combinations of tubulars and rims.  Personally, I really like the Vittoria Corsa CX tubular with the Zipp 404 rim.  But, I have a problem.  The base tape on the Corsa CX bunches slightly at the base of the valve stem.  When the tubular is mounted, the valve stem section of the tire doesn’t completely seat in the rim causing a high spot on the tire and a not-so-smooth ride.  What is the best way to overcome this issue?
– Nathan

A.Nathan,
Hops in tubular tires at the valve stem are very common. They occur for a couple reasons. Mostly I feel that it’s due to improper technique when mounting the tire.

It’s really important to insert the valve into the valve hole straight. If it’s even a little off you can get noise from the valve stem ticking against the valve stem hole. It also means that the tire bulges because the tire is a bit twisted at the valve.

Additionally if you don’t really push (or pull as the case may be) on the tire when first mounting it (valve first) on the rim, you won’t have even tension from the tire’s casing against the rim. A loose spot gives slack. The tire has to go somewhere, so it bulges out of round at that point.

The other reason that you get a hop at the valve is that many valve stem holes in rims are too small. Some tires, like the Vittoria, have a fair bit of excess base tape at the valve. A bigger hole on the gluing surface gives it the opportunity to go into the rim instead of creating a hop on top of the rim.

This, of course, will likely void your warranty. But that doesn’t mean that I haven’t done it on plenty of rims, both for pro teams and for personal use. Just don’t overdo it! Many rims have a smaller hole for the valve stem than they do for the spoke holes. Opening up the hole to that size should be safe.

Some rim manufacturers actually countersink the valve stem hole for this exact reason. Psimet, for instance, does this and I think it’s brilliant.

Q.Nick,
I am upgrading my bike from Ultegra 6500 and am considering Ultegra 6700 and Dura Ace. I was surprised to look at Shimano shifters and see large open sections exposing the internals to contamination from dirt and spray. The engineer in me says, “that may be a problem.”

What’s the experience in the pro peloton (both road and cyclocross)?  Do they worry about dirt getting into the internals of Shimano shifters? How do they clean out dirt and dust?

I am thinking about inserting low-density, soft poron foam in the opening.  Poron is an open cell foam.  I am thinking the foam will keep dirt from entering but should not affect operation due to its compressibility.  I may have to occasionally wash it off, but that is no
problem. What do you think?
– Scott Kelley

A.Scott,
I see where you’re coming from, but frankly it isn’t a big problem except in sandy cyclocross races when you crash (and completely bury a shifter in sand). On my personal bikes and those of my clients at The Service Course, I periodically take off the hoods and spray some WD-40 into the shifter and cycle through the gears. This is usually sufficient in cleaning and gently lubricating shifter internals. Don’t forget to lube your shift cables inside the shifter body too. Some oil or grease is good.

I think that in many cases, hands are covering the shifters and keeping much of the grime out. I also think that both Shimano and SRAM feel it’s better to give dirt a way out than it is to trap it inside.

I would strongly advise you NOT to spray the foam you describe into shifters. That seems like a disaster waiting to happen and would probably void any warranty. It would also force any debris/bits into the shift mechanism.

Modern shifters are amazingly resilient items. Much like a Timex watch, they’ll “take a lickin’ and keep on tickin’.”