Ask Nick: Cassettes specific to juniors

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,
What is the formula teams use to determine which wheelset to use for the day of a race. I am interested in purchasing a wheelset, but I would like it to cater to the races I take part in. I’m guessing factors such as average rider speed, elevation change and wind speed and direction can affect the decision.

I recently attempted use an “app” that HED made, but it was still has some major kinks to work out.
— Kevin Scott

A.Kevin,
That’s a really good question. I’m aware of several teams that have quite a bit of data compiled to help them with such decisions. They aren’t too public about it though as it’s an advantage that other teams lack.

Cycling is extremely dynamic out on the roads. Conditions can change quickly thanks to Mother Nature and what starts the day as the perfect wheelset can become a nightmare if a front blows in.

Because of that, there is no easy formula to help you choose a wheelset. My advice is to reflect on the races you do, what you rode in the past and think about where your equipment was possibly lacking. Try to compliment the wheels you already own.

Pros are riding deeper and deeper wheels all the time. It’s not just a trend either. Even on hilly days, an aero wheel may give up a little weight, but the energy savings on the kilometers leading up to the climbs often outstrips the advantage of a lighter wheel. Riders who are doing work for teammates on the front of the peloton often ride deeper wheels than protected riders do, as they see a lot of the wind.

The latest generation of aero wheels are wider and rims like Zipp’s Firecrest, HED’s Stinger and Bontrager’s newest Aeolus offering are all worth a look. What’s amazing is just how stable they are in crosswind situations. In the past I was never a fan of deep (50mm or more) wheels for everyday racing as I was almost blown off the road on several occasions. But the latest rim shapes are super fast and much easier to handle. I don’t think you can go wrong with a modern, high quality, 50mm aero wheel.

I too have used HED’s app with little success. But it’s a step in a great direction. It takes into account all the factors that teams look at: terrain, length of race, speed, race direction and wind direction. The app seems to recommend all of HED’s wheels for almost every application though. But it does get you thinking about the right factors.

Q.Nick,
Just a quick question about off-season bikes. I am curious about some of the bikes that pros ride in the off-season. I have heard about DZ’s fixie TT bike and recently saw some pics of Michael Barry’s Pinarello ‘cross bike that he rides on the dirt roads around Girona. But there doesn’t seem to be much info or photos of these “frankenbikes.” I guess I’m curious about what types of tires they’re using. Are most running fenders, ‘cross bikes, or fixies for training?
— Dave Cifelli

A.Dave,
Plenty of pros have a winter bike, but it’s usually the exact same bike they’ve trained on all season. They might throw on some tougher tires and clip-on fenders from SKS or Planet Bike are popular, but Michael Barry and Dave Zabriskie are more the exception than the rule.

Though I’ve spotted one Boulder-based pro on a Salsa Fargo that he has for really epic rides. I have one too and love it.

As far as getting more info, that’ll be tough. In some cases it’s difficult because a pro may be riding a bike that isn’t sponsor correct (though Barry’s is very well executed to keep sponsors happy). And no one wants to get them in trouble, especially not me.

Q.Nick,
I am a non-professional bike mechanic that is trying to help set up a new bike for a fully sponsored junior female rider.

Her team uses SRAM components and the bike will be using 700c wheels.
I have checked the USA Cycling regulations and found that juniors are limited in their tallest gear combination. The method used for measuring the tallest gear is called “roll back” in the USA Cycling documents (Sheldon Brown’s site calls it “Meters Development”). Bottom line, the measurement for one turn of the cranks can be up to 7.93 meters or 26 feet. With sponsorship in mind, I am trying to set up the drive train with 100% SRAM components.

With any stock combination of SRAM gearing (from any road group) the best I can get is 8 meters on a roll back measurement with a 700c x 23 or 25 tire. “Blocking” is allowed (using the derailleur limit screws to block gears) for all races except Nationals. I want to be sure anything I put together can be used, as is, for any race (just in case). I have used Sheldon’s Gear Calculator and found that if I use a 46t or 48t chainring, I can get by with a 13t cog as the smallest in the cassette and not need to “block” any gears.

I have found the Apex and Rival groups have 46t and 48t chainrings available in the stock groups. I have also found the 1050 and 1070 line of cassettes have cogs beginning at 12t and going through 32t.

I have four questions:

There is an absolute “tallest gear” allowed, but is there a limit on the easiest gear? i.e. would a 34t x 32t combination be allowed?

Can I safely combine cogs from a couple of different cassettes to create a 13t – 28t or 13t – 32t cassette?

Can I use the Apex or Rival chainrings on a Force or Red crankset (assuming they are both 130 or 110 spacing)?

Why doesn’t SRAM have factory sets available to help promote the use of their groups in the junior market? It appears as though Shimano has done this in the past. It also appears they have not continued this into the current versions of their groups. Does this indicate Shimano is discontinuing their support for junior racing?

Any help/advice will be greatly appreciated.
— Larry C.

A.Larry,
I raced as a junior and used a 45-tooth chainring for races that were gear-restricted. That allowed me to use my entire 12×23 freewheel (yep, no cassettes on my first bikes) as long as I didn’t run massive tires. The 45×12 is a 7.9-meter development, basically the largest possible. I think that is the best option as it allows the use of readily available cassettes.

I don’t think that SRAM or the team would be at all upset if you used a non-SRAM chainring, especially if it allowed the use of SRAM cassettes. And again, that’s what I would recommend. T.A. Specialites makes its Zephyr rings in 40-61 teeth for 110 bolt circle. Salsa also offers a 45-tooth ring in 130 and 110 bcd, though they don’t have ramps or pins to aid in shifting. Both of these options (as well as the 46- and 48-tooth rings you mention) are compatible with SRAM’s cranks, as long as the bolt circle match.

Alternatively, you can use the SRAM 46- or 48-tooth rings. But you’ll still have a tough time with the cassette. Shimano still produces 10-speed cassettes in 13×25 and 14×25 (Quality has them in stock, most shops should be able to order one). Again, I don’t think that SRAM or the team would mind the change, bearing in mind how tricky it is to achieve junior gears. You could pair a standard 50×34 compact crank with the 14×25 cassette (for a top gear development of 7.5 meters).

There is no restriction on the easiest gear. But I haven’t had a chance to play with taking off the 12-tooth cog on a 12×32 cassette. It’s bound to be possible to mix and match cassettes to come up with a custom 13×28 or 13×32 cassette. But pay special attention to the spacing between cogs. That’s the biggest problem to tackle if you go this route.

By far the simplest solution (and the one with largest legal gear) is finding a 45-tooth chainring. Installed on a compact crank with a 34-tooth small ring and a 12×32 cassette, your athlete would have a fantastically wide range of available gears.

The answer to your last question is a bit beyond me. I can’t answer for SRAM on that one. But in truth, junior gearing is a tiny niche in the sport. Producing a “junior” cassette wouldn’t make them enough money to justify the cost.

I did check with Quality Bicycle Products though and Shimano’s “junior” cassettes are still available. Campagnolo also produces several cassettes starting with 13-tooth cassettes.