QUESTION: I recently bought a Giant TCX cyclocross bike with tubeless tires. I really enjoy the bike and would like to ride it as a road bike as well. Is it better to buy another wheelset with 25s on it, or buy a new bike for the road? My TCX currently has 33s. – Jeff K
RBR ANSWER: There’s a formula in cycling for the correct number of bicycles to own, which N + 1. The N variable is the current number of bicycles that you already have. So according to that formula, we’d never discourage you from buying a road bike too.
In all seriousness though, it’s perfectly acceptable to ride your cyclocross bike as a road bike and just use a spare set of wheels with narrower road tires. We’ve covered this before with a similar question about whether it’s ok to use a gravel bike as your road bike.
The only issue I see with your TCX cyclocross bike setup is that with the single chainring upfront, you might be a little bit under-geared when the going gets fast in a group. I noticed that some of the TCX bikes have a 42 tooth ring. So you’d run into trouble if you tried to race on it, because it’s likely you’ll run out of gears and spin out once you get faster than 25 mph, unless you’re very good at riding with a high cadence.
You could always put a bigger chainring in the front to get the higher gears, but that might lead to also needing a wider range cassette in the back, if you still wanted to have the same low gears for steep cyclocross climbs.
One final option. It’s also perfectly fine to just ride on the road with the wider cyclocross tires and wheels that you already have. Sure, they’ll slow you down a little bit with the extra tire width and the knobbies. But the larger air volume of the tire combined with more rubber on the road gives you a very comfortable ride, with lots of braking power. If you’re just road riding casually and not trying to break any speed records, then you’re ok to use it as-is.
John Lye says
I regularly ride my Scott gravel bike (basically a cyclocross frame set up for road) with road wheels. I would recommend 28s. The main difference is that the frame is designed for quicker starts and turns,, so it’s a bit tender in stiff crosswinds, takes a bit of practice to weather the gusts comfortably.
There is an alternate to the N + 1 maxim for the correct number of bikes to own. That alternate is S – 1 where S equals the number of bikes that will cause your spouse or significant other to leave you.
John Lye says
When I mentioned this to my wife, she wondered If the spouse would leave on the new bike.
Jeff vdD says
Agree, 28s or even 30s. The idea riding 25s is simply barbaric. Uncomfortable AND slow.
Unless you are competing, why would you care? I’ve been riding my modified TCX for many years. A tripple and a flat bar etc., sacrilege, I know. My Motorcycle is a Supermoto with a 12L tank and I ride the BRP with no fuel for 700K so I fuel up every 2 hours and lean like a Sport bike while sitting erect without my knees in my chest and able to see what’s happening unlike the Sport bike or road bicycle. It’s your $$$
Dave Minden says
I agree with Jeff on the antiquated view of riding skinny tires. Testing has shown up to 35’s have no speed deficit over skinny tires (see Bicycle Quarterly, Jan Heine on tire testing) and are much more comfortable and better at gripping the road. Get a good tire with a supple sidewall. You’ll never go back! Also, I switched last season to a FD 46/30, and find I still spin out at about 35mph. So I don’t get the idea that you need bigger chainrings with a fast group. I love the climbing with the 30!
Jeff vdD says
Per this calculator …
… I would spin out (95-100 cadence) at about 30 mph on my 46/11
FYI, I’m geared 46-30f/11-34r and love that combo for gravel … but it can be a bit light for slightly downhill sections of a fast group ride on the road.
Your current 33mm tires are fine for road biking. Play around with the pressures to get the most comfort; that size won’t hurt your speed. (Again, see Jan Heine’s Bicycle Quarterly for more on this.)
The roads are so bad where I live I finally went to a bike that can handle 32 mm tires with a tubeless set up. My average times are a little slower than my old bike on 20 mile rides but faster on my 30 plus miles rides.
Jeff vdD says
If the 33s are file treads, they’ll be okay (but only okay) for road. If they’re more aggressive, they’ll give up too mch IMHO.
I’ve put over 11K miles on my TCX in under 3 years and finally put 28s on it about midway through those miles. I rode it 100 miles in the fall of ‘19 and had no trouble keeping up with the group, and the slightly shorter reach and upright position made it a comfortable ride.
donald ostertag says
Daaaaah, Is it ok to ride my road bike as a cyclocross bike?
Jeff vdD says
Yes, absolutely it’s okay to ride a road bike in a CX race. That dramatically eases the burden on the spectators to come up with heckles, as the road bike will make the heckles obvious.
Make sure that it’s a rim brake road bike, preferably with 23mm or narrower tires. Slick is good, shoot for 120 psi.
Also, please let me know the location of the race, as I would like to come and photograph it. [grin]
I ride tubeless 28s on my latest road bike, it will take 35s easily. My gravel and winter (CX) bikes currently have 37s and 35s respectively. My older road bike will take 25s but its relegated to the trainer. Ride what you have and then decide what you want or need to do. One rider in our club rides 23s only because they can’t find 18s anymore.
Bruce Miller says
Road surface is also a factor. I ride a Trek XC1 cross bike with 35mm tires as a road bike where the road surface is poor or in light snow.
Joy Ahearn says
Five years ago I got a new Kona Jake the Snake cross bike. A friend of mine told me I could get a spare set of wheels to use it with 25’s for winter riding on the road. So I did. He recommended a wheel builder and also ordered the brake discs to match the ones on my bike. He put it all together, but it didn’t work. He said that the reason was that the original wheels on the bike had a tiny difference in the axle width, so the new wheels didn’t match the brakes exactly. He said that every time I wanted to switch the wheels, I could go through the process of adjusting the brake pads. I watched him demonstrate and it was a painful process that I would never want to do myself. Not easy at all. So I decided to keep the newer wheels and just gave away the original wheels. The next time I brought my bike into the shop to complain about the brakes rubbing, the guy said it looked like the pads had learned one wheelset, and then I changed to a different wheelset. Very smart mechanic. He was right. He said I needed new brake pads, and that I should never think I can just switch wheels, because the pads need to exactly match the discs, and not some alternate wheelset. I know that I will have to swap out the tires now if I want to convert my cross bike to a road bike, but since the other method you have recommended did not work at all for me, I see no other option.
Jeff vdD says
I run 3 different wheelsets on my adventure bike and 2 different wheelsets on my CX bike. It’s a total of 4 wheelsets: sets 1, 2, and 3 are for my adventure bike, and sets 3 and 4 are for my CX bike.
As such, I have different hub/rotor combos interacting with a single adventure caliper and CX caliper. The rotors are the same diameter (of course) and thickness, but not necessarily the same make/model or even mount type (centerlock vs. 6-bolt).
Everything works together via shims (thin washers). Basically, I find the hub/rotor combo that has the rotor the farthest outboard (away from the hub). I align the calipers to that rotor/hub (call this wheel A). Then, on the other wheelsets, I add shims between the rotor and hub to move the rotor outboard until it has the same position/alignment as wheel A.
Ilan Vardi says
Thomas Frischknecht rode the 1996 Olympic road race (the first one with professionals) on his cyclocross bike and finished with the main group which included Indurain, who won the Olympic TT. Frischknecht won the silver medal in the mountain bike race. He was allowed to participate in the road race because Swiss team mate Tony Rominger decided not to do the road race, so there was an opening for him, and he rode his cyclocross bike as there wasn’t a road bike available. A Swiss rider won that road race, by the way. So cyclocross bikes are adequate even in professional road racing.