Heloise

Hi, I'm relatively new to road biking, living in Korea, and I just bought a second-hand road bike last weekend. It is a joy to ride, and I love it, but my daily commute to work is up a long, steep hill. I currently have 52 and 42T chainrings and a 8 speed cassette. And so, I was finding it difficult by the top of the hill this morning!
So, I think I would like to get a 30T chainring on... but I've never done that before. I think the existing ones are shimano, is it possible to just buy the 30T online one and pop it on myself??

Bob Dopolina 

Seoul may be pancake flat but I did a race in the north that was in a ski area and there were certainly hills.

Homebrew01

Each crankarm has a Bolt Circle Diameter (BCD) that determines the smallest chainring that will fit. If you have a 42, you may get lucky and be able to fit a 39 on there, or 42 might be the smallest. You have 3 basic options.
1) Get a crankset such as a compact style with 50-36 or 50-34
2) Get a cassette/freewheel with larger cogs on the rear wheel
3) Combination of 1 & 2

If you give specific details of your bike, preferably with closeup pictures, you might get more detailed answers.

krobinson103

237km with 1500m of climbing last Sat north of Seoul sayd there are. That really hurt.

Heloise

Here is a picture.. I've not got a clue what the BCD would be..

Does it help?

Bob Dopolina 

It's 130BCD which means the smallest you can go is 39T (or 38T if you can find one).

A less expensive option might be a rear cassette with a bigger cog but I think the largest you can go with your current rear der is 28T(?) which might not be enough.

Going to a triple on the front requires shifter changes and well as a new rear der. This could get expensive quite quickly.

Probably the simplest solution is a new compact crank but it will require a bit of a search as your BB is square taper.

Anyone else have any other ideas?

cruiserhead

Good suggestions Bob

Square taper bottom bracket- Shimano is JIS square taper. Avoid Campy/ISO square taper unless you have a crankset that is compatible.
If you buck up for a new shimano compact crank, I believe they come w/ the bb. But, that might be really expensive in Korea.

also, ask these guys-they are "local":
https://www.facebook.com/groups/HanRiverRiders/

krobinson103

Thats us. As local as you get. Check it out.

androidtt

With all the tight roads in Korea, I'd be a bit freaked out with the crazy bus drivers passing by! Heh. I haven't been back to Korea in a long time. Are there a lot of roadies and triathletes out there now?

Uncle partially got me into all this crazy stuff with his boxes of IM and other triathlon medals! Family and farm work have kept him too busy to keep up with the tri stuff~

krobinson103

Bikes everywhere... but mostly modded high end mtbs. Bus drivers are still crazy though.

escarpment

instead of going compact crank, could he just buy 2 smaller front rings? save the crank. take a few links out of the chain?

Bob Dopolina 

No.

With 130 BCD 39T is pretty much the limit (38T if you can find it).

kraftwerk 

Riding in Seoul seems similar to riding in LA. Snarling traffic in the urban grid, hills surrounding.
Would love to explore the Korean Countryside..enjoy!

Heloise

Thanks everyone, and fyi he is a she and for those living in Korea, I live on Jeju island, which is faabulous for cycling.
Hit me up if you ever fancy a trip down! I don't know many foreign cyclists here!

Vaio_s

Here are a few solutions: They are ranked in order of both price (low to high) and effectiveness (low to high). Go figure.

1. Cassette with a 28 tooth max.
2. Cassette with a 28 tooth max and new chainrings (53 and 39 tooth).
3. Cassette with a 28 tooth max and a new compact crank - provides 50 and 34 tooth chainrings.
4. Cassette with a 28 tooth max, a triple crank (30 tooth minimum I think), a front derailleur, and a front shifter.

Another silly idea you might want to consider (unsure of its feasibility) is to buy a mountain bike rear derailleur and slap on a large mountain-bike-geared cassette (32 tooth max or larger). Mix and match with the above solutions.

Heloise

So here is my rear cassette. Can anyone recommend a good shimano, or other popular brand cassette that would be suitable? Even if I have a link to a US seller, I can then find the same product on a Korean site.

spinerguy

Technically you don't have a cassette, what you have is a *freewheel* they may look similar but the guts inside are completely different.

You cannot put a cassette there as they are not compatible. It's not as easy as you may think, if you want a modern cassette you require a new hub (that's the wheel axle) or a new wheel, new rear derrailers and new rear shifter. Your frame may not have enough clearance for newer cassettes, as these are wider.

I'd agree with the poster above that suggested getting a new compact crankset, sometimes they come with the bottom bracket (set of bearings) included. Here in the US, a compact Shimano 105 or Ultegra can cost between $150-200 dlls, but to me it would be the simplest way to alleviate your problem.

Heloise

Ahh, I have a freewheel... I knew that. I'm learning. So buying a freewheel hub and changing it the same way isn't as easy?
I'll start having a look around for a compact crank, it would solve my problem.. If they aren't massively expensive here.

cruiserhead

Jeju is amazing! I would love to spend a few days and ride there, you're lucky.

FSA Vero crankset- square taper JIS- will fit your existing bottom bracket. Very affordable and quality crankset
https://www.fullspeedahead.com/produc...mpact-Crankset

Shimano Sora crankset - 50/34 chainrings (FC3450)
https://cycle.shimano.co.kr/publish/c...0.-type-..html

this is the required bottom bracket (*note the crankset may have the bb included. I'm not sure on Sora, please check before buying)
https://cycle.shimano.co.kr/publish/c...0.-type-..html

I don't have sources for 8 speed freewheels but there are several Shimano models like this
https://www.rei.com/product/769222/sh...speed-cassette

The HG50 I linked above is available in Korea as part of the 2300 group
https://cycle.shimano.co.kr/publish/c...road/2300.html

Note that you might need a longer chain if there is not enough slack.
Good luck!

Heloise

ooh, Mr. Cruiserhead, do you know of any online Korean sites that might sell the Vero?

cruiserhead

I don't but I bet those Han River Riders boys do.
Or maybe someone can help Ms. Heloise?

Good luck, I bet your knees will thank you after you change it up!

krobinson103

I would just look on

www.auction.kr
www.gmarket.co.kr

either are based in Korea and sell almost anything. I'd say they are the best bet beyond finding the best high end store you can get locally and seeing what they have in the parts bin. Most Korean riders upgrade so much stuff you can build whole bikes to a really nice standard from the stuff they just leave at the LBS.