Jim’s Tech Talk
By Jim Langley
Today is Stage 6 of the Tour de France. I hope you’re enjoying the race so far. To prep for this year I watched the Netflix 8-part documentary “Tour de France Unchained” on last year’s race and enjoyed it a lot. Here’s a link if you haven’t seen it and you subscribe to the service: https://www.netflix.com/title/81153133.
Since I imagine you’re glued to the race on TV today I want to share a quick tip from regular contributor “Fixieguy” and then ask for your help answering a question that came in from “Chuck.” He rode the TransAm Express tour across the country in 2021. As he prepares for more epic rides he’s looking for input on choosing between the different inner tube types available today.
NOTE: As is appropriate for a roadie who goes by “Fixieguy,” this tip is about setting up a one-speed drivetrain. But keep reading because the tip could come in helpful on any chain to prevent a stiff link or possible annoying squeak.
Fixieguy says, “Jim, you wrote a piece a while ago on stiff chain links installed using a chain tool rather than a “power-link” (AKA “quick link”). I think I may have a tip of limited utility. However, I’ve only used it once so it may be more correlation than causation.
On fixed gear bikes, it is often necessary to install a half-link (photo) to use a gear choice (chainring plus cog) that does not fit the dropouts because a full chain link takes up ½” of chain distance in the dropouts and a particular gear choice may leave the axle too far back in the dropouts but if a link is removed, the axle could be too far forward. A half-link takes up only ¼”.
Given that a tooth takes up 1/8”, using a half-link in the chain will make even the shorter horizontal dropouts of the 80’s and 90’s work. Alas, half-links must be installed using a chain tool. In your article about stiff links, you had suggested that just pushing the pin in or out a little should loosen the link. On half-links, my experience is, that does not work quite well enough. And having a stiff link makes setting the chain tension more difficult.
I was installing a new half-link today and it was stiff and would not loosen enough no matter how much I tried to move the pin. I took the half-link out, intending to try it at a different spot on the chain. I noted that there was no lube on the half-link (which is always the case with new half-links, but I’d never thought about it). I decided to put chain lube on the half-link, being certain both to drip some into the hole in the narrow portion of the link and onto the pin at the wide portion. I installed it and, to my surprise, it worked satisfactorily after just one minor adjustment with the chain tool.
As I said, even assuming it is causation and not mere correlation, its limited utility would be only to fixed gear and perhaps single speed riders. However, it might be useful for persons still attaching chains with chain tools to squirt some chain lube on the two pins that will engage the chain. I can’t see how it would hurt.”
Thanks Fixieguy! I’d like to add that I recommend always lubricating quick links the way you are before installation too. That’s applicable to most modern bikes these days now that most groups use them.
Chuck’s Question That I Hope You Can Help With
He writes: “The topic I’m interested in is butyl vs latex vs TPU inner tubes. I would be interested in all the usual issues as well as if TPU tubes can accept sealant without issue.”
In response I told Chuck that sealant is supposed to be problematic with TPU tubes according to Schwalbe. Also, that mostly sealant is used in tubeless tires not inside inner tubes because it adds weight and most riders choose lightweight tubes to have light tubes i.e. less not more weight.
I have a review of Schwalbe’s Aerothan TPU tubes here:
Chuck’s already heard from me. He would appreciate what you choose in the way of tubes for your road riding and why you choose them. If you use tubes with sealant, please share your setup. Thanks!
Jim Langley is RBR’s Technical Editor. A pro mechanic & cycling writer for more than 40 years, he’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Tune in to Jim’s popular YouTube channel for wheel building & bike repair how-to’s. Jim’s also known for his cycling streak that ended in February 2022 with a total of 10,269 consecutive daily rides (28 years, 1 month and 11 days of never missing a ride). Click to read Jim’s full bio.