Technical FAQ with Lennard Zinn: Wheel choices for big ‘crossers, drain holes, and hand numbness

A reader wonders whether cyclocross tubulars have an inherent weight limit, or if bigger riders can also take advantage of the benefits of the best tire choice

Dear Lennard,
Do the benefits of tubulars in cyclocross have a weight limit? Or is there any point to a 100-kilogram rider using set-up tubular set-up?

2010 Eurobike - new cyclocross bikes
Can bigger riders use these, too?

Dear Steffan,
I suppose that at some point a rider is so heavy that no glue job will hold their tires on. But 100kg is not there (look at all the track sprinters on tubulars that weigh that much). And certainly, while a 100kg rider would have to run higher tire pressure than would a 65kg rider on the same course (to avoid pinch flats and washing out), that applies to both tubulars and clinchers.

Like a lighter rider, a 100kg rider would still be able to run lower pressures on a tubular than a clincher, resulting in better grip on side hills and lower rolling resistance.

Dear Lennard,
My thumb and fingers get very numb when I am on the hoods riding hard. It is almost impossible to brake because of the numbness. Any suggestions?

Dear Bruce,
Wear gloves and change hand positions frequently. You might even try some of those handlebar tape sets that have gel pads in them.

You’re probably aware that it is inadvisable to let numbness, whether it’s in your crotch or your hands, to go on long for more reasons than just the discomfort, as damage to nerves and possibly blood vessels can occur. Your body is telling you something, and you should heed it. It may not be a simple solution, but you should start by at least padding your hands, changing your hand positions frequently, and shaking out your hands periodically. The same goes for crotch numbness. Stand up every five minutes or so when riding, whether you’re aware of numbness or not, just to restore blood flow and full nerve function.

If you find that this alone does not decrease the numbness to your satisfaction, then a professional bike fit may be in order. A visit to a neurologist may be, too. So might be reviewing what other things affect the nerves in your hands on a daily basis. I know that now, in my 50s, I notice a lot more hand numbness than I ever did when I was in my 20s, even though I spend less time on the bike and the bar tape is softer now. I also spend a heck of a lot more time at a computer keyboard than I did then, and computer mice and cell phones and other handheld computers, all of which affect nerves in the arms and hands, did not even exist 30 years ago. I’m sure all of those things have taken their toll, and my hand numbness issues can be partially attributed to those influences.

Dear Lennard,
I read with interest your recent response to the question of water getting into the frame and bottom bracket in wet rides.

I just completed a multiday ride and several mornings rode in the rain. The vent holes in my frame (a 1990 Tesch custom True Temper steel) had rust dribbling out of the seat stay vent holes. While it is going to the shop for an overhaul, my question is why manufacturers don’t put a drain hole in the bottom bracket, as you recommended? Also, if I do drill a hole, do you recommend plugging it, say with a plastic plug that can be removed when needed to drain, or leave it open?

Dear Stanley,
I don’t know why drain holes under the bottom bracket are so rare, other than it’s an extra expense perhaps.

I think the plug is a fine idea. I just leave my drain holes open, but as long as you remembered to open the plug after riding, your method is better.

Dear Lennard,
I have a Colnago E1 carbon frame and whenever I ride in the rain a great deal of water collects in the bottom bracket area. I have tried emptying the water by removing the seat and draining a 1/2 cup or more and then leaving the frame upside down for more than 24 hours. Unfortunately I have found out the hard way that water is staying behind and ruining my Campagnolo Chorus square taper bottom brackets (as evidenced by eroded and corroded sleeves).

My question is whether it would be advisable to drill a hole in the bottom of the E1’s bottom bracket shell to allow the water to drain? Can this be done safely as a Do It Yourself project by a novice? What diameter hole would you advise?

Dear Greg,
Absolutely. It’s a low-stress area, and you run no danger of causing the frame to crack by drilling a small hole. A 1/8-inch hole is fine.

Dear Lennard,
In regards to your answer about covering up vent holes in frames, I have a steel Dedacciai frame with carbon seat stays. Should I plug those holes? And if so what should I plug them with?

Dear Curt,
Yes, plug them with silicone tub and tile sealer.

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Technical writer Lennard Zinn is a frame builder (, a former U.S. national team rider and author of numerous books on bikes and bike maintenance including the pair of successful maintenance guides “Zinn and the Art of Mountain Bike Maintenance” – now available also on DVD, and “Zinn and the Art of Road Bike Maintenance,” as well as “Zinn and the Art of Triathlon Bikes” and “Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.”Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn. Zinn’s column appears here each Tuesday.