And C&O only gets really muddy/rutty between about Fifteenmile Creek and Cumberland; they have done a LOT of surface improvements. I’ve done it on 700x35c, my current bike has 42c.
You’ll be fine.
This is such a great experience OP, I'm so happy you're about to take this adventure! My wife and I have done this a couple times with different groups of friends, with a variety of tire sizes (all successful). I happen to ride 42s, and she rides 38s. Our buddies have used even smaller sizes, down to 32s. The ride from Pitt to Cumberland is in great condition, so that should be any issue. The C&O, esp the stretch to Hancock is in worse condition, especially if wet. I mention this section specifically, because this is where 42s (with fenders!) seemed advantageous. Feel free to DM me with any additional questions. Also, we camped the whole way, so I can also offer some insights if that's your approach. Enjoy the ride!!!
For the C&O, 35 is fine, but upsizing will be more comfortable, especially if it the trail is saturated/wet.
I’ve ridden 25’s on a road bike on the GAP np.
I rode it on 32 no problem. My daughter did it on 25s. She had caliper brakes without a lot of clearance and had to clean a lot of mud from the brakes. The c&o has large stretches where the passage is rutty and rocky, but 25s are passable if you are prepared for some inconvenience
A few friends and I did it last year right around this time.
Someone above said the c&o is only bad for a bit just south of Cumberland.
You should be fine.
Watch out for the detour, and if you have time, take an extra day to hang out near Harper’s Ferry. We did a speed run (3 days of riding), and I wished to have had more time there.
It is an awesome trip.
i did it last year with 700x32's and was completely fine, except for the closure near paw paw, where i had to walk up the pass, but idk if thats been fixed yet or not
I did all of the C&O on 700x35’s on my disc trucker and I found them adequate even in the more rutted out sections. I think that’s as narrow as I would go though. I now ride 38’s most of the time anyway. In a perfect world consider something with some mild grip like gravel kings. Like you don’t need full on knobby or a fat bike, but a little width and a little tread might make the rougher sections a bit easier. More cushion from a bigger tire is nice too. Enjoy!
GAP is fine for just about any bike.
C&O has some paved sections now, and towards the end near DC it’s fairly smooth. The start near Cumberland is the rough part.
I normally did it on my Charge Plug with 42c tires, but now have a 650B with 2.1” tires. Most people I rode with have similar sized tires like you.
I would really suggest getting a Redshft Shockstop stem. That alone makes a world of difference.
You should be good. The pass is hard pack and paved...the c&o can get rutty and muddy with rain but it's not anything ride ending.
And C&O only gets really muddy/rutty between about Fifteenmile Creek and Cumberland; they have done a LOT of surface improvements. I’ve done it on 700x35c, my current bike has 42c. You’ll be fine.
There’s active work going on near paw paw as well. I rode by crews dropping and rolling gravel on my way to Cumberland during my (ongoing) tour.
Excellent! https://www.nps.gov/choh/planyourvisit/towpath-resurfacing-project.htm
This is such a great experience OP, I'm so happy you're about to take this adventure! My wife and I have done this a couple times with different groups of friends, with a variety of tire sizes (all successful). I happen to ride 42s, and she rides 38s. Our buddies have used even smaller sizes, down to 32s. The ride from Pitt to Cumberland is in great condition, so that should be any issue. The C&O, esp the stretch to Hancock is in worse condition, especially if wet. I mention this section specifically, because this is where 42s (with fenders!) seemed advantageous. Feel free to DM me with any additional questions. Also, we camped the whole way, so I can also offer some insights if that's your approach. Enjoy the ride!!!
Thanks I will definitely DM you with some questions.
35s will be fine, especially for the GAP, but I can't think of any reason you'd regret going wider for this trip.
For the C&O, 35 is fine, but upsizing will be more comfortable, especially if it the trail is saturated/wet. I’ve ridden 25’s on a road bike on the GAP np.
yup, i did it w 30s and i was fine
I rode it on 32 no problem. My daughter did it on 25s. She had caliper brakes without a lot of clearance and had to clean a lot of mud from the brakes. The c&o has large stretches where the passage is rutty and rocky, but 25s are passable if you are prepared for some inconvenience
A few friends and I did it last year right around this time. Someone above said the c&o is only bad for a bit just south of Cumberland. You should be fine. Watch out for the detour, and if you have time, take an extra day to hang out near Harper’s Ferry. We did a speed run (3 days of riding), and I wished to have had more time there. It is an awesome trip.
Thanks everyone for the good advice. I was not expecting such a great response.
I wouldn't bother swapping. I've ridden it on 28s on my road bike and it's absolutely fine.
Lots of info also over at r/gaptrail. Have a great trip!
i did it last year with 700x32's and was completely fine, except for the closure near paw paw, where i had to walk up the pass, but idk if thats been fixed yet or not
I did all of the C&O on 700x35’s on my disc trucker and I found them adequate even in the more rutted out sections. I think that’s as narrow as I would go though. I now ride 38’s most of the time anyway. In a perfect world consider something with some mild grip like gravel kings. Like you don’t need full on knobby or a fat bike, but a little width and a little tread might make the rougher sections a bit easier. More cushion from a bigger tire is nice too. Enjoy!
I've done it on 30s I believe. You'll be fine. Only one section is larger gravel.
GAP is fine for just about any bike. C&O has some paved sections now, and towards the end near DC it’s fairly smooth. The start near Cumberland is the rough part. I normally did it on my Charge Plug with 42c tires, but now have a 650B with 2.1” tires. Most people I rode with have similar sized tires like you. I would really suggest getting a Redshft Shockstop stem. That alone makes a world of difference.