The SunTour freewheel page now covers Winner Pro, Winner and Alpha models in addition to Perfect, Pro Compe and New Winner.
SunTour freewheel page covers more models
Tag: bicycle
Addition to bolt-circle coverage
Campagnolo has come up with another new chainring bolt pattern (why?) and we have added it to our coverage. It’s the most complete you’ll find anywhere. Print out the template that corresponds to the kind of bolt pattern of your chainring, lay the chainring down on it and you get an instant readout of the bolt-circle diameter, brand and model of the original manufacturer’s version of this chainring. We cover classic brands as well as the newest and most confusing models with irregular bolt-circle patterns. Our coal here as with all of our cribsheets is to help you match parts, and to show cross-brand compatibility when it is not obvious and not promoted by the manufacturers. Thanks to Jacob Allen for the drawings in AutoCad!
Remembering Sheldon
Sheldon Brown would have been 77 years old today. We miss him very much.
In this picture his big brother Richard is reading to him. And at the right is the cover of the book Richard was reading.
“Run, run
As fast as you can,
You can’t catch me,
I’m the gingerbread man.”
Cable installation
John added photos and a quite a lot of additional information to our page about cables, and the page got too long — so we have split it into two pages. The original cables page now includes more background information — why use cables, the different types, and a video showing how they work. The cable installation page has many new photos, added details, and tricks and tips.
First cyclecomputer?
Our cyclecomputer database goes deep. We have found, scanned and posted a PDF of the manual for what is probably the first cyclecomputer, the Veltec Pacer 2000. We also have manuals for early Cateye, Avocet and Vetta computers, and rare brands.
On-Road Repairs update
We have added to our page about on-road repairs. There is now a quick list so you can check which particular tools you might need for your bicycle, and we have covered some additional tools.
The basic on-road repairs will get you home or to the next bike shop on your bike, almost every time. If you can’t find the time or inspiration to learn them yourself, you might ride with someone who did!
Derailer adjustment — and maintenance
We have added new sections on derailer maintenance to the derailer adjustment page, including how to cannibalize rear derailers, being careful about compatibility, and how to check cables, 
Modeling bicycle dynamics
We publish another paper by Osman Isvan. He uses a simplified model with only 3 degrees of freedom and simulates system frequency response under steady-state and transient conditions. He investigates the effects on vibration isolation of several key parameters including tire pressure, frame compliance and riding position. The graph below from his paper, one of several, shows results when tire pressure is changed.
Extensive revision of chainwheel bolt-circle information
A few months ago, a reader prompted us to make some updates to our chainwheel bolt circle cribsheet. But now we have followed up on that effort, greatly expanding our coverage, and we have added a set of templates which allow you quickly to identify the bolt circle of alnost every model of chainring, and the tooth count, without the need to measure or count by hand. It’s all here: https://sheldonbrown.com/cribsheet-bcd.html. Example template is at the right.
If you can correct any inaccurate information or you can identify a chainring that we do not cover, please let us know. We are not too proud to take corrections, and we’ll even credit you on the site for your contribution!
Update to Bolt Circle Diameter Cribsheet
We have reviewed the bolt circle diameter cribsheet, checked bolt-hole spacings using trigonometry and made some corrections. Apparently, the spacings were measured rather than calculated based on angles — and measurement is never exact! We have also added entries for several new patterns. Some of the new ones with uneven spacings had to be reverse-engineered from photos and, though we think that we have them right, we welcome feedback.
