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Technical Q&A with Lennard Zinn - Packing for the trip
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Dear Lennard,
I just re-read your review of the Dura-Ace wheels in the May VeloNews Buyer's Guide. It sounds like you did exactly what I have in mind - packed these wheels in a 26x26x10" hard travel case for a bike with S&S couplers, and then re-inflated them with a hand pump.
Did this work well, or is it asking for trouble? Was your bike covered in sealant? Will tires other than the Hutchinson inflate easily with a hand pump? Can I just use a tube if necessary?
Basically, is it worth using the Dura-Ace wheels for a travel bike, or should I stick with a light but durable wheel like the Ksyriums? I love my XTR tubeless wheels and want the same on the road.
Tom
Dear Tom,
It works fine for me. I’ve done a lot of transoceanic trips with it that way. I deflate the tires (something you must do for an S&S case), and only a little latex comes out around the edges of the tire bead. There are no drips on anything else, and hand pumping has not been a problem.
Yes, you can use a tube with them. I've only tried the Hutchinsons in this capacity (I’ve ridden the Specialized road tubeless tires but have never deflated or inflated them).
Lennard
Dear Lennard,
How much space, if any, should be left between the top of the stem and the steerer tube on a carbon fork? Some shops cut it just below the steerer tube, other let steerer tube protrude 1cm - what do you say? Also, how does it change for aluminum or steel?
Marcus
Dear Marcus,
You should always leave some length of the steering tube above the stem and put a spacer above the stem so that the entire stem clamp is clamped around a cylinder of constant diameter. The extension above the stem clamp can be as little as 1mm. Obviously, you need to put a spacer above the stem clamp that extends above it by at least 3mm to allow the top cap to push down on the stem via the spacer; otherwise, the top cap would bottom out on the steerer.
As you can see on the photo of my travel bike above, I have a thin (5mm) silver spacer above the stem.
If you do not extend the steerer out of the top of the stem clamp, the fibers will be damaged at the top, because the stem clamp will pull down tighter at the top bolt, forcing the top of the steerer to curve inward, thus delaminating some of those fibers at the top.
With an aluminum or steel steering tube, it is less critical, but still, the stem clamp works better if its slot is a constant gap, indicating that it is fully wrapped around a constant-diameter cylinder.
Lennard
Dear Lennard,
I am planning to travel to Europe to do some traveling, cycling, and catch a bit of the tour. I am big guy, and struggle going uphill. At home I ride a Devinci Leo with full Dura-Ace 7800, 53x39, with a 12-27, which is OK for Northern Ontario.
Is there a way to economically put a 105 compact crankset on my bike to help in the hills of Europe? Or should I bring my winter bike with a triple and 105 / Sora mix. I would really prefer to ride my good bike as it is lighter, more comfortable and more reliable, but I really am not interested in walking up the hills. No matter what bike setup I choose, I know the high passes are not for me.
Guy
Dear Guy,
Sure there is! You can just slap a 105 compact crank right into your existing bottom bracket; there is no reason to change anything other than the height and cable tension of the front derailleur.
Lennard
Dear Lennard,
On the cover of a recent VeloNews, it appears that Taylor Phinney is riding a Madone seatcap not offered by Trek. The seatcap has a bulge and more setback than models currently available. Any insider info on the post? Will it be offered to the general public? I ask, because of my weird body shape I need more setback than the current 10mm.
Tom
Answer from Trek
We have made a few 30mm offset caps for athletes, but will not be offering to public at this time. Standard options are 10mm forward, 5mm and 20mm back.
Tyler Pilger
Trek Bicycles
Dear Lennard,
I am 6-feet-5-inches tall and weigh about 250 pounds. Do you have any recommendations on what type of road wheels to get?
My questions must include:
- • How many spokes?
- • What size spokes?
- • What type of rims?
- • Any places to look up information concerning this subject?
- • What type of hubs to get?
John
Dear John,
I'd do DT TK 7.1 rims, 36-hole, with 14/15-gauge butted spokes and brass nipples with any of a number of hubs. Chris King, Campy Record, Dura-Ace, and many others are all nice.
You could also do 36-spoke Mavic CXP30 rims. It isn't as strong, but it is lighter. In prebuilt wheels, the most reliable road wheel we've found for a rider your size is the Mavic Ksyrium Elite.
You might find information on some of the Clydesdale forums online, but rarely is there a mention of road wheels on them. My own site – www.zinncycles.com – of course, always has information on equipment for big and tall riders.
Lennard
Dear Lennard,
Do you have an opinion on whether one should re-glue tubulars annually? I glued my racing tubulars to their rims last year and the glue job still seems strong, but I’m worried about the risk of rolling a tire due to an old glue job. I’d appreciate your thoughts.
Mark
Dear Mark,
Yours is an interesting question and I decided to pose it to Donn Kellogg, the president of Challenge USA, located just down the road from me in Highlands Ranch, Colorado.
Answer from Donn Kellogg:
It would be our recommendation to re-glue tubulars tires on an annual basis, as the following points should be considered:
If the rider is located in a mountainous region and is racing full time, the tires should be re-glued at least on an annual basis. The heat generated from the brake pad on the rim can evaporate the glue over time.
It is always a good practice to do a thorough maintenance check of the bicycle at the start of a new season. This is the best time to re-glue tires.
Care should be given when removing the tire from the rim, so the base tape of the tubular tire stays on the tire.
Donn Kellogg
Dear Lennard,
I will be “competing” in the Mt. Washington Hill climb this August, and had a compatibility question about what I will run for a drivetrain.
I have a Specialized Tarmac with SRAM RED shifters and rear derailleur, Force Front derailleur, Specialized carbon Compact Crank (50/34), and Mavic Wheels.
I am trying to achieve the “perfect” 1-to-1 ratio as far as gearing, and would like to keep my standard compact crank on the bike (specifically because it is an integrated bottom bracket also).
To achieve that, I need a cassette in the 11-34 or so range, and a derailleur to work with. In the ideal world, I would keep my SRAM Red shifters on and work with something that will work with that (the new SRAM XX Mountain cassette and derailleur will do so, but from the sounds of it there is no way I will get my hands on that before August).
So, do you know if a SRAM mountain derailleur (9-speed XO per say) will work with the Red Shifters and something like an IRD Wide Range 10 Speed cassette (11-34)??
And/or, do you have any other suggestion (or, a good contact at SRAM that will make my problems go away with availability of the XX group sooner).
Matt
Answer from Ron Ritzler, SRAM MTB Product Manager and the product manager for Rival, Force, and RED:
The combination of XO and Red Shifters will not work – the cable pull number differences would result in terrible shifting.
He could try the IRD cassette (I would push him to the 11-32) but it may not clear the RD upper pulley and since the Red RD is short cage it would not have the capacity to take up the chain in the small ring and the smaller cogs- therefore he’d need to stay out of these combinations.
If he wants a less expensive way to try the 32 or 34 – tell him to grab a 9-speed MTB cassette- put it on the bike and see if it clears.
But there is no guarantee that these would work until you try them, which may be cost-prohibitive.
Ron Ritzler
Technical writer Lennard Zinn is a frame builder (www.zinncycles.com), 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.
