Great video! Very informative:) do you by any chance have the gpx of the connector road from Damyang Dam to Sunchang? I read some people ended up on a highway😮 and any guesthouse/motel recommendations for Sunchang? Thanks a lot!
@cathelijnvannisselroy6901 thank you so much! I just checked and Kakao Maps recommends the highway unfortunately so that's probably why. Here is the GPX to get from Metasequioa Road to Sunchang Bus Terminal: drive.google.com/file/d/1c8_xygoKJwxXmPKggkC3eyqWeYy2Ltgs/view?usp=share_link I've never stayed here, but this guest house looks pretty cool there (older traditional vibe with nice owners): maps.app.goo.gl/abarMrooWMpknAWL6 The motels in Sunchang are pretty old so if you want to stay in a motel instead just pick the cheapest one by using Google Maps in my opinion. Happy cycling and safe travels! (Pinned your comment for others to see as well!)
Excellent. A thoroughly comprehensive guide to korea's cycling paths is not just super informative, but also very comforting and pleasing to watch!. 👍👏
@ONCEbittenTWICEshyshyshy thanks so much for the nice comment! Really appreciate your kind words, and glad to hear it was fun to watch the nice sights to see in Korea! Hoping to explore a lot more this year too!
The Korean Tourism Organization should promote and sponsor your channel! Amazing job with all the planning, research, drone shots, and just the overall attention to detail you put into making this video 👍👍👍
Hey Denis! It's a tough call because the Seomjingang bike path is so nice and freeing, but also so far away from a lot of the other paths which can make it a bit inconvenient too. Where are you thinking of cycling?
Such beautiful footage of a beautiful country. I watched this twice. Looking forward to the second part. Is it difficult to purchase a bicycle as a tourist? What are the laws about where you can camp? Thank you for sharing your knowledge!
Thanks so much @Mudskipper9876! Really appreciate it! I'll go over in lots of detail about camping and how to get bikes in part 4, but to sum it up, you can buy a bike on Karrot Market app second hand for good prices, and there are Trek, Giant, and Specialized stores if you want to buy a nicer bike and take it back with you afterwards. For camping, it's a grey area that I don't know the exact laws for, but we have camped in the middle of cities, off the side of the bike path, etc, and people are almost always quite positive towards it as long as we are quiet and clean. You won't get in big trouble or anything, but if you want to avoid conflicts at all costs then it's best to use the paid campgrounds.
This is pure gold! I never tried 50K+ riding because I didn't know what's waiting for me, but this video might change that. Also, perfect timing to start this series!
Thank you so much @enamu! Really recommend you try long distance cycling if you haven't done it before. It's the best way to enjoy some new environments in my opinion, as everytime you see something new that's beautiful, you feel like you've "earned it" from cycling. Hope you give it a go!
@msj63님 감사합니다! 저는 한국에 오기 전에 이런 아름다운 풍경이 많을 줄 하나도 예상을 못 했는데 한국에 왔더니 너무 놀랐어요! 그리고 한국에서는 자전거나 대중교통으로 다니기가 진짜 편해서 캐나다 보다 더 많이 볼 수 있어서 좋아요! @msj63님도 행복하고 건강하세요~ ^^
thank you so much fo this video ! my family and i just relocated from PDX to Seoul and will be biking the 4 rivers this spring . i'll be trying these other bike paths myself for fun .
Oh that's great @kimyookyung thanks so much! Four Rivers is really fun, and I really recommend trying out the other bike paths as well if you get the opportunity!
Awesome video guys! After starting in 2017, We finally finished our passport in November 23 and your videos were so valuable for our more recent trips in Korea. We agree, the 섬진강 자전거길 is the best cycle path in all of Korea. Heading back to Korea later this year from Mid October-Mid November. Maybe hiking this time....or just eating way too much 소금빵 😂😂
Thanks so much Cheye! That's awesome that you guys finished your passports, congratulations on completing them! Also that's great you guys are heading back to explore more here! Hope all is well with you guys!
Hello hello! I was looking forward to more cycling videos. This series looks great! I've heard there's a bike-friendly train from Yangdungpo to Chunchon as well, although I've never tried it yet. I agree Somjingang is the best one. And autumn is the best time to do them. Weather is perfect and the landscapes are gorgeous. And you should mention the bike passport, It's so fun to stamp every few km, and link your previous videos for each of the paths.
Hey @MrChaotio thank you so much! I'm not sure where Yangdungpu is, but it would be great to explore more bike paths near Seoul/Chuncheon too! Haha forgot to mention the stamps in this video (too busy thinking about the other info), but will include it in the next video and give a bigger overview in the general tips video at the end. Thanks for all the feedback, and happy cycling eh!
Hi, great informative video ! I am also Canadian touring Korea on my bike. I finished the 4 River path Incheon-Busan end of November 2023, to bad I didn't have all this precious information, but all went well, it was a great adventure ! I am planning do the East coast starting from Busan and can't wait to see your guide of the East coast bike path ! Great work ! 🤩
Hi @cyclingpilgrim thanks so much! Also great job completing the Four Rivers Bike Path! The Four Rivers is awesome, and I enjoyed the East Coast Bike Path even more, but it was a lot harder, especially if you link it up with Busan. Hope you have a great time doing it, and I'll try to share as much info as possible, especially if you plan on camping on the way as well.
Thank you for this very nice video. I cycled on the Ara and Hangang Path last year in November and it was so beautiful. I can't wait to return to Korea in September to do some more bike paths. Thank you once again.
Nice to see you guy on your bikes again! Thank you for the very useful information. I finished all the route except for Jeju. I did Yeongsangang Bike Path last fall but haven't edit the video yet, lost creative spark 😂 Ride safe guys!
Thanks so much @thoan71 it was great to go on a ride again! Jeju is a good one to save for last too! I'd recommend going in early June if you don't want it to be too hot but want to swim in the ocean a bit too. Haha sometimes editing gets tiring eh! It's tough to spend so much time on the computer all the time, but after you take a break it might be fun to return to some day! One thing I do is to set a timer for 1 hour, and I have to edit during that time (can't even look at my phone). Give it a try if you want! Haha. Ride safe out there, and hopefully the warmer weather comes soon! It was like 18 degrees a few weeks ago, and this week seems to be pretty cold again. 🥶
It's a lot of fun cycling here @johnkieffer5854! If you haven't been here before, it's definitely worth it to come for a longer trip and do some cycling as well to see the countryside!
Thank you for the video. Pretty good summary, short but rich in useful info. Looking forward to part 2. I'm planning on doing bikepacking for 5 weeks in Apr/May in Korea. I am going to mix hotel and camping. I am novice cyclist (occasional ebike rides), and I have never done bikepacking. I am however fit, avid hiker, and have done backpacking and have equipments. I have also reserched enough that I might be dealing with saddle sore, knee pain, and other body aches, and have prepared what I can. Doable to do grand slam? Which app do you use for lodging? Can you pitch tent anywhere reasonable or do I need to find paid campground? Also, I might have to use regular road for some parts. How dangerous it is to use regular HWY's rather than bike road? Thanks for your answers in advance.
Thanks so much @joshyi9228! I'll answer all of these questions in more depth in part 4 of this series, but to sum it up, 5 weeks is do-able for the Grand Slam, but it would be better to go slower if possible just to enjoy the sights and rest up when you get to cool spots that you want to spend a couple days at. You can use Google Maps or Air Bnb to find lodging on the English sites, or find places on Naver Maps and go there in person. We pitched a tent for free all over the country but avoided spots that said "no camping." No idea if it's "legal," but people didn't mind if we were quiet and clean. Highways are best to avoid whenever possible. Hope that helps a bit. That video will come out on April 7 just so you know, and thanks again!
Did you cycle in Geoje and nearby areas? It's on normal roads but the riding is great with mountains and seascapes creating dramatic views, and the cars haven't been a problem for me.
@@lostthenfoundthe southernmost part of the island is the best. Particularly the road section south of 망산 and 내봉산. I would link to Strava segments but it would get blocked by YT.
Great information. I look forward to seeing the rest! I plan to do the 4 Rivers this year & can choose either mid April or early October; from your experience which would be your preferred month? FYI if time permits I will also add on a trip from Busan…anything you can recommend do I can ride back to Seoul? Appreciate i will have to take a train/bus somewhere to do that. Many thanks in advance for any advice you can give on the above.
Hey @markmark5159 both seasons are great for cycling and you can't really choose wrong, but October will have better air quality overall, so that's the main advantage you will get riding then. To get back to Seoul, take the bus from the Busan Seobu Intercity Bus Terminal (naver.me/GjZMHGIo) to Seoul. It's really close to the end of the Four Rivers Path, so it's easy to ride from there.
Haha good question @Geeraffe! After living here for 10+ years, I've been to most places that I really want to go, but I'm still curious to explore more of Incheon, Pyeongtaek, and Chuncheon (cities outside of Seoul). We will probably start adding non-random trips into the series as well, as there are some really cool areas that we want to show on video.
@matth4397 best times are April 1 - June 15 and Sept 15 - November 30 in my opinion. I'll go into more detail with part 4 of this series on April 7th too!
Hi, that’s really helpful. I will start from Busan to Seoul tomorrow. Just one question: I can’t open the links in the doc, even when I copy them and fill in in Kakao App. What I’m doing wrong? Best Roman
@RomanMiserre thank you so much! I just checked and they are working again I think. I think Kakao made a change to their servers and they weren't working temporarily. Please let me know if you need a specific route and I will send it to you. Hope you have an amazing trip by the way! Enjoy the scenery to the fullest!
Hi @tansaypeng9772 if you use Kakao Maps, the stamp booths are all on there called "_________인증센터" (인증센터 means certification center), so if you just copy and paste 인증센터 into Kakao Maps you will find the location of the stamp booth. Luckily they are pretty easy to see most of the time!
@OfficeBlock as @MrChaotio said, the buses are the way to go, and the Busan West Bus Terminal naver.me/GjZMHGIo is the closest to the end of the Four Rivers Path between Seoul and Busan.
Haha the titles were a bit confusing I think! I just put a title everytime I showed our little ride in 2024 so people don't think it's the trail that I'm talking about.
@chongyu8706 do you mean riding every trail in Korea? This is how I would do that if you are curious (timestamped video): ua-cam.com/video/aVqj30tEbuM/v-deo.html
@chongyu8706 it would be very difficult to plan a tour to ride every path without taking a bus to be honest, as you will have to navigate a lot around the highways and country roads. You could cycle the Four Rivers Trail until Haengchon Crossroads, then cycle west on the Ocheon and Geumgang Bike Paths, continue south along the Korean West Coast, then cycle Yeongsangang and Seomjingang, take a ferry from Yeosu to Jeju, cycle around Jeju, take a ferry to Busan and cycle up the Four Rivers back to Seoul. You'd miss the East Coast and Bukhangang Bike Paths with this route though.
Great video! Very informative:) do you by any chance have the gpx of the connector road from Damyang Dam to Sunchang? I read some people ended up on a highway😮 and any guesthouse/motel recommendations for Sunchang? Thanks a lot!
@cathelijnvannisselroy6901 thank you so much! I just checked and Kakao Maps recommends the highway unfortunately so that's probably why. Here is the GPX to get from Metasequioa Road to Sunchang Bus Terminal: drive.google.com/file/d/1c8_xygoKJwxXmPKggkC3eyqWeYy2Ltgs/view?usp=share_link
I've never stayed here, but this guest house looks pretty cool there (older traditional vibe with nice owners): maps.app.goo.gl/abarMrooWMpknAWL6
The motels in Sunchang are pretty old so if you want to stay in a motel instead just pick the cheapest one by using Google Maps in my opinion.
Happy cycling and safe travels!
(Pinned your comment for others to see as well!)
Excellent. A thoroughly comprehensive guide to korea's cycling paths is not just super informative, but also very comforting and pleasing to watch!. 👍👏
@ONCEbittenTWICEshyshyshy thanks so much for the nice comment! Really appreciate your kind words, and glad to hear it was fun to watch the nice sights to see in Korea! Hoping to explore a lot more this year too!
Life is simple. I see Lost Then Found video I click…
Ahaha thanks so much for saying that @youtubeuser5768! You made our day!
The Korean Tourism Organization should promote and sponsor your channel!
Amazing job with all the planning, research, drone shots, and just the overall attention to detail you put into making this video 👍👍👍
Thanks so much for the nice message @ICDeadPeeps! Maybe some day we can collaborate with them! Haha
Thanks for the video. You two clearly put a lot of effort into making this.
Thanks so much @Douglas-vh5bb!
Looking forward to discover your favorites bike pathes n°2 to 5 :)
Thanks a lot @patrick.arnoux!
Matt, you almost convinced me to build a route along the path that is number 1 on your list, thanks!🙂🤝
Hey Denis! It's a tough call because the Seomjingang bike path is so nice and freeing, but also so far away from a lot of the other paths which can make it a bit inconvenient too. Where are you thinking of cycling?
Such beautiful footage of a beautiful country. I watched this twice. Looking forward to the second part. Is it difficult to purchase a bicycle as a tourist? What are the laws about where you can camp? Thank you for sharing your knowledge!
Thanks so much @Mudskipper9876! Really appreciate it! I'll go over in lots of detail about camping and how to get bikes in part 4, but to sum it up, you can buy a bike on Karrot Market app second hand for good prices, and there are Trek, Giant, and Specialized stores if you want to buy a nicer bike and take it back with you afterwards. For camping, it's a grey area that I don't know the exact laws for, but we have camped in the middle of cities, off the side of the bike path, etc, and people are almost always quite positive towards it as long as we are quiet and clean. You won't get in big trouble or anything, but if you want to avoid conflicts at all costs then it's best to use the paid campgrounds.
This is amazing. Thank you for all the work.
Thanks so much for the kind words @bvergara!
This is pure gold! I never tried 50K+ riding because I didn't know what's waiting for me, but this video might change that. Also, perfect timing to start this series!
Thank you so much @enamu! Really recommend you try long distance cycling if you haven't done it before. It's the best way to enjoy some new environments in my opinion, as everytime you see something new that's beautiful, you feel like you've "earned it" from cycling. Hope you give it a go!
I left 2 bike paths to complete grand slam. Can’t wait to watch part 2-4. Great video
Oh very nice @cyberiansg and thanks a lot! What bike paths do you have left?
날씨가 추워보이는데....
열정이 정말 좋아요~
자전거로...........와 에너지를 너무 많이 쓰신것같요
경치가 정말 짱입니다.
항상 즐거운 여행이길 바래요^^~~~
@msj63님 감사합니다! 저는 한국에 오기 전에 이런 아름다운 풍경이 많을 줄 하나도 예상을 못 했는데 한국에 왔더니 너무 놀랐어요! 그리고 한국에서는 자전거나 대중교통으로 다니기가 진짜 편해서 캐나다 보다 더 많이 볼 수 있어서 좋아요! @msj63님도 행복하고 건강하세요~ ^^
thank you so much fo this video ! my family and i just relocated from PDX to Seoul and will be biking the 4 rivers this spring . i'll be trying these other bike paths myself for fun .
Oh that's great @kimyookyung thanks so much! Four Rivers is really fun, and I really recommend trying out the other bike paths as well if you get the opportunity!
Awesome video guys! After starting in 2017, We finally finished our passport in November 23 and your videos were so valuable for our more recent trips in Korea. We agree, the 섬진강 자전거길 is the best cycle path in all of Korea. Heading back to Korea later this year from Mid October-Mid November. Maybe hiking this time....or just eating way too much 소금빵 😂😂
Thanks so much Cheye! That's awesome that you guys finished your passports, congratulations on completing them! Also that's great you guys are heading back to explore more here! Hope all is well with you guys!
Hello hello! I was looking forward to more cycling videos. This series looks great!
I've heard there's a bike-friendly train from Yangdungpo to Chunchon as well, although I've never tried it yet.
I agree Somjingang is the best one. And autumn is the best time to do them. Weather is perfect and the landscapes are gorgeous.
And you should mention the bike passport, It's so fun to stamp every few km, and link your previous videos for each of the paths.
Hey @MrChaotio thank you so much!
I'm not sure where Yangdungpu is, but it would be great to explore more bike paths near Seoul/Chuncheon too!
Haha forgot to mention the stamps in this video (too busy thinking about the other info), but will include it in the next video and give a bigger overview in the general tips video at the end. Thanks for all the feedback, and happy cycling eh!
a ton of good information and beautiful footage. thank you for all the work you put into this!!
Thanks so much @blaaaaaaah2! Glad it was helpful!
Super video!!👍 Great job!!👍
Thanks a lot Mom! 😊
Hi, great informative video ! I am also Canadian touring Korea on my bike. I finished the 4 River path Incheon-Busan end of November 2023, to bad I didn't have all this precious information, but all went well, it was a great adventure ! I am planning do the East coast starting from Busan and can't wait to see your guide of the East coast bike path ! Great work ! 🤩
Hi @cyclingpilgrim thanks so much! Also great job completing the Four Rivers Bike Path! The Four Rivers is awesome, and I enjoyed the East Coast Bike Path even more, but it was a lot harder, especially if you link it up with Busan. Hope you have a great time doing it, and I'll try to share as much info as possible, especially if you plan on camping on the way as well.
Thank you for this very nice video. I cycled on the Ara and Hangang Path last year in November and it was so beautiful. I can't wait to return to Korea in September to do some more bike paths. Thank you once again.
Thanks so much @TSaua067! That's awesome! Hangang is amazing for biking. Hope you can see some more paths in Korea next time too!
Thank you for another great video - so helpful!
Thanks so much @GMMras!
Learning so much from your videos. Thank you.
Thanks so much @marcomorales920! Glad it was helpful!
Yes, I did it last year. Seoul to Busan. One Round on Jeju. And 2 other bike paths.
Oh great @jasonloke2219! Did you have a good time cycling in Korea?
Yes,, 35 days of great cycling!@@lostthenfound
Thanks so much for your great videos. Looking forward to see the next ones ;)
Thanks a lot @MariusMustermann-rk2lb!
Nice to see you guy on your bikes again! Thank you for the very useful information. I finished all the route except for Jeju. I did Yeongsangang Bike Path last fall but haven't edit the video yet, lost creative spark 😂 Ride safe guys!
Thanks so much @thoan71 it was great to go on a ride again! Jeju is a good one to save for last too! I'd recommend going in early June if you don't want it to be too hot but want to swim in the ocean a bit too. Haha sometimes editing gets tiring eh! It's tough to spend so much time on the computer all the time, but after you take a break it might be fun to return to some day! One thing I do is to set a timer for 1 hour, and I have to edit during that time (can't even look at my phone). Give it a try if you want! Haha.
Ride safe out there, and hopefully the warmer weather comes soon! It was like 18 degrees a few weeks ago, and this week seems to be pretty cold again. 🥶
Gettin' psyched for this summer! great vid.
Thanks so much @ALEX-cs6vo! You must be getting stoked!
Great to see you on bikes again . Thanks for the show . Regards
Thanks a lot Howard! It has been quite a while since we biked together like this, so it felt really good to be back! Hope you have an amazing week!
Looks like fun! Thank you for all the useful biking info.
It's a lot of fun cycling here @johnkieffer5854! If you haven't been here before, it's definitely worth it to come for a longer trip and do some cycling as well to see the countryside!
Excellent tips and info. From a fellow Canuck.
Thanks so much for watching and for the kind words @terrencedeagle4429!
@@lostthenfound You bet.
Thank you for the video. Pretty good summary, short but rich in useful info. Looking forward to part 2. I'm planning on doing bikepacking for 5 weeks in Apr/May in Korea. I am going to mix hotel and camping. I am novice cyclist (occasional ebike rides), and I have never done bikepacking. I am however fit, avid hiker, and have done backpacking and have equipments. I have also reserched enough that I might be dealing with saddle sore, knee pain, and other body aches, and have prepared what I can. Doable to do grand slam? Which app do you use for lodging? Can you pitch tent anywhere reasonable or do I need to find paid campground? Also, I might have to use regular road for some parts. How dangerous it is to use regular HWY's rather than bike road? Thanks for your answers in advance.
Thanks so much @joshyi9228! I'll answer all of these questions in more depth in part 4 of this series, but to sum it up, 5 weeks is do-able for the Grand Slam, but it would be better to go slower if possible just to enjoy the sights and rest up when you get to cool spots that you want to spend a couple days at. You can use Google Maps or Air Bnb to find lodging on the English sites, or find places on Naver Maps and go there in person. We pitched a tent for free all over the country but avoided spots that said "no camping." No idea if it's "legal," but people didn't mind if we were quiet and clean. Highways are best to avoid whenever possible.
Hope that helps a bit. That video will come out on April 7 just so you know, and thanks again!
Very useful, thanks for the effort
Thank you very much! @gumdo
Did you cycle in Geoje and nearby areas? It's on normal roads but the riding is great with mountains and seascapes creating dramatic views, and the cars haven't been a problem for me.
@AntoineGrondin Haven't cycled in Geoje yet (haven't even been there), but will have to check it out some day for sure! It looks beautiful!
@@lostthenfoundthe southernmost part of the island is the best. Particularly the road section south of 망산 and 내봉산. I would link to Strava segments but it would get blocked by YT.
@AntoineGrondin oh thanks so much! I saved this info for later. Will check it out when we can get down there some day!
Great information. I look forward to seeing the rest! I plan to do the 4 Rivers this year & can choose either mid April or early October; from your experience which would be your preferred month? FYI if time permits I will also add on a trip from Busan…anything you can recommend do I can ride back to Seoul? Appreciate i will have to take a train/bus somewhere to do that.
Many thanks in advance for any advice you can give on the above.
FYI I will be on my Brompton & plan on camping wherever possible
Hey @markmark5159 both seasons are great for cycling and you can't really choose wrong, but October will have better air quality overall, so that's the main advantage you will get riding then. To get back to Seoul, take the bus from the Busan Seobu Intercity Bus Terminal (naver.me/GjZMHGIo) to Seoul. It's really close to the end of the Four Rivers Path, so it's easy to ride from there.
Where would you like to explore in Seoul that you have yet to go to if the randomizer wheel was rigged?
Haha good question @Geeraffe! After living here for 10+ years, I've been to most places that I really want to go, but I'm still curious to explore more of Incheon, Pyeongtaek, and Chuncheon (cities outside of Seoul). We will probably start adding non-random trips into the series as well, as there are some really cool areas that we want to show on video.
How were the quads after that "little" excursion? 😃
Ahah definitely feeling the burn most days cycling, but always worth it for the reward of getting to eat lots afterwards! 😁
Which months of the year would you say are most suitable for bike touring in Korea?
@matth4397 best times are April 1 - June 15 and Sept 15 - November 30 in my opinion. I'll go into more detail with part 4 of this series on April 7th too!
Hi, that’s really helpful. I will start from Busan to Seoul tomorrow. Just one question: I can’t open the links in the doc, even when I copy them and fill in in Kakao App. What I’m doing wrong? Best Roman
@RomanMiserre thank you so much! I just checked and they are working again I think. I think Kakao made a change to their servers and they weren't working temporarily. Please let me know if you need a specific route and I will send it to you. Hope you have an amazing trip by the way! Enjoy the scenery to the fullest!
Hi, is there a map to show your position n nearest stamp station(red phone booth) best in english. Reason you reach there but cannot find the booth
Hi @tansaypeng9772 if you use Kakao Maps, the stamp booths are all on there called "_________인증센터" (인증센터 means certification center), so if you just copy and paste 인증센터 into Kakao Maps you will find the location of the stamp booth. Luckily they are pretty easy to see most of the time!
I am cycling from Seoul to Busan in May. Do you have any tips on the best way of getting me and my bike back to Seoul on either train or bus?
Bus. Trains don't allow bikes afaik.
@@MrChaotio thank you 😊
@OfficeBlock as @MrChaotio said, the buses are the way to go, and the Busan West Bus Terminal naver.me/GjZMHGIo is the closest to the end of the Four Rivers Path between Seoul and Busan.
@@lostthenfound thank you so much! Very excited to be doing this ride, your videos have been inspiring.
Good info just on time😅
Glad it was helpful @prashantbisht6384! Hoping to do a lot more exploring around Korea this year too!
@@lostthenfound all the best and keep posting 😃
Back in 2024?
Haha the titles were a bit confusing I think! I just put a title everytime I showed our little ride in 2024 so people don't think it's the trail that I'm talking about.
I am planning on riding only even the transfer to other bikepaths. Is it possible?
@chongyu8706 do you mean riding every trail in Korea? This is how I would do that if you are curious (timestamped video): ua-cam.com/video/aVqj30tEbuM/v-deo.html
I meant without getting on the bus.
@chongyu8706 it would be very difficult to plan a tour to ride every path without taking a bus to be honest, as you will have to navigate a lot around the highways and country roads. You could cycle the Four Rivers Trail until Haengchon Crossroads, then cycle west on the Ocheon and Geumgang Bike Paths, continue south along the Korean West Coast, then cycle Yeongsangang and Seomjingang, take a ferry from Yeosu to Jeju, cycle around Jeju, take a ferry to Busan and cycle up the Four Rivers back to Seoul. You'd miss the East Coast and Bukhangang Bike Paths with this route though.