14 April, 2017

Cross Buns and Cross Chaining

By Scott

When I started riding, one of the "rules" of cycling that was passed down from more experienced cyclists was never to have the chain in big and big or small and small. This meant you did not want the chain aligned with the largest cog in the back and the largest ring in the front  or the smallest size cog in the back and the small ring in the front.

(big and big)

There are certainly some good reasons not to do this:
  • This combination puts more strain on the chain. Chains run best when they are as straight as possible.
  • It also puts more stress/wear on the chain rings and cassette.
  • Some rear derailleurs can't handle the range of the cog and the front chain ring, and if the chain is short, putting it in big and big could do damage to the rear derailleur
  • When using small and small with a compact double, the chain can strike/rub against the large ring due to the angle that the chain is at as well as the size difference between the small and large ring.
  • It can make a hideous noise due to the chain being at an extreme angle
So instead of being in big and big, you should be in a small and mid range cog. The big and big gear combination (46T x 28T) works out to a gear inch of 42.7 inches. If I use the inner ring and a middle cog (30T x 18T), I get a gear inch of 43.3 and a much straighter chain line.

(small and mid- better chain line)
Now while chains have certainly become stronger over the years, some things have stayed the same. More folks seem to use the larger cogs while being in the big ring. This might be a reaction to the increasing popularity of 1 X systems. Just make sure your chain is long enough and most drive trains can handle it for a short period of time.

(small and small)

Small and small is still something we don't recommend. The chain can get caught on the pins on the inside of the large chain ring (they are there to help shifting on 10 speed set ups, due to the narrowness of those chains). Typically the gear ratio that is the small and small is replicated by using the large ring and a middle cog in the back, similar to our earlier example of big and big.

If you want to learn about gear inches/ratios the late Sheldon Brown's site has the best set up for figuring out the gear ratios on your bike. You can find it here.

Owing that it is Good Friday, our resident baker Clint, took it upon himself to bake some hot cross buns. We'll be enjoying these today at the office with a coffee or tea.

Recipe can be found here


Coline said...

Just logged on after a coffee and bun break with the spicy taste of the buns still tingling in my mouth. Now time to go out and screw some of your bits to my half rebuilt bike. Yes it is a good Friday.

Unknown said...

Forget the chain, the hot cross buns are more interesting. You guys look like you have fun. Cheers, Rod

John Duval said...

The old chains used to pop links pretty easy, so it was good advice. These days? Unfortunately modern drive systems have very little overlap in the ratios, and the range you need most forces you to front shift constantly and/or be in a serious cross chain situation. That is where the 46-30 crank is so wonderful. Minimal front shifts, always in the middle of the cassette.

Anonymous said...

What does the new Polyvalent fork look like?

VeloOrange said...

The ones we have now use a bi-plane fork crown and triple braze-ons down the fork blades. We're changing to a new crown design, but that will take some time for samples to be made and ready. Here's a teaser: https://www.instagram.com/p/BS8qHerjWqb/?taken-by=eccentricvelo


C said...

Any ETA update on the new Polyvalent?

VeloOrange said...


We're planning on having them in stock by spring '18.