Today marked my third attempt at maintaining my own bike, specifically against the wishes of my former bike shop*.
Picked up a Shimano 10s Ultegra chain at the shop yesterday. It put me out around ¥3000, but was only ¥300 more than the Tiagra chain, so it seemed like a rare case of a good deal in bike parts. I learned that the reason chains have to match the number of speeds on your bike isn’t because of the length, which is usually designed to be shortened to fit your bike, but actually because of the width. Ten speed chains are narrower than nine speed, but fatter than eleven.
I was suspicious that my chain was stretched beyond what was safe for my sprocket and chain rings because even though I’ve quadrupled my efforts at cleaning and maintaining my bike (almost once a week at this point), three days in any weather and my chain would start to click and rattle over the cogs. I don’t have a chain measuring tool so I used the rule of 12″: I measured from the center of one rivet to the center of the rivet closest to 12″ away. Its dead center fell at about 3/16″ beyond the 12″ mark so it was clearly time for a new chain. I inspected my rings and while there is evidence (so very unfortunately) of asymmetric wear on my outer chain ring (the barely a year old Ultegra compact ring that I shelled out more than a few hundred for), it is ever so slight and I’m hoping I caught it in time.
I would like to say I’m really upset with the Giant store for not checking my chain for me when I went in to have the cables redone last month. I mean, sure, I didn’t ask them to look at the chain, but at the same time, whenever I ask them to teach me what I need to know to care for my bike, they brush me off as being too much trouble. This is one of the reasons I’m taking a break from them.
As with my brake replacement, I used the information from the Park Tools blog as my guide for the mechanical work and key points. Most of their information matched my situation, but I had a little trouble understanding some terms like “lead the plate into the rings”, which the Shimano replacement rivet apparently must do. I wonder if this means that the rivet that connects the two ends of the chain together must face a particular direction, but I was never able to find out for sure. I hope I did it right. It also is the case that my replacement rivet wasn’t shaped like the one they had pictured, but it was close enough that it seemed to work the same.
I took off the old chain and cleaned the sprocket and rings as best I could. Trying hard not to let the new chain touch anything, I held it up against the old chain to measure the length. This is what my MTB 先輩 taught me when he and I replaced my chain two years ago. With the new chain having the same number of links as the old, I went ahead and strung it through the rings.
The ultegra is a one-sided chain in that it has little slits on the outer plates on the side of the chain that faces the wheels. I think this is both for weight saving as well as for ease of shifting. My chain ring has little wedges on the inside that I believe help catch the chain and lift it over the edge of the ring when I shift into the outer gear. It’s nice. It’s also really sticky! This coating is supposedly good for something, but I don’t know what.
Anyway, after two fails at pushing the rivet (pin) out just enough so that the chain breaks but the pin doesn’t fall out, I managed on the third try to get it right. I lined up the replacement rivet and drove it in as evenly as I could. Park tools says that both sides of the rivet should stick out the same amount as the adjacent rivets or else the plates could slip off and the chain could break, but when I snapped off the excess piece of the rivet, it was still slightly longer than the adjacent ones. I decided to align the smooth end and allow the broken end to protrude beyond the other rivets. I feel like this is sensible. The only other option would be to perfectly center the rivet, but since they have a “peen,” which is a lip designed to keep them from slipping out, I figured lining up the lip was more important than being center.
I’ll have my new shop look at it tomorrow.
In any case, I now have one more maintenance skill to add to my list of things I can do:
- Align a rear derailleur
- Align a front derailleur (heheh, snuck that one in without telling you)
- Chain brake pads
- Align brakes
- Replace chain
I’m getting there. Slowly, but undeniably. I wish I had help, but I want this hard and I will do it whether or not I have help. I hope that one day I will get my break and soar, but in the meantime I’m enjoying each little step I can take alone.
*I don’t say former lightly. I loved that shop. We’re just taking a break.