Bicycle Mechanics - chainring BC size

Giant Cypress


Anybody know what the second (middle) chain ring bolt circle and # of bolts is?

Thanks

You sayin' you can't count up to five? Or jus' missin' a few fingers?

Nice,

A friend of mine stopped by on a bike ride and asked me to take a quick look. His chain was slipping under load in second gear. I noticed the teeth were worn.
I counted the teeth but did not find any info on the bolt circle. I figured it was standard but when I looked them up I found many options.

Needless to say, the bike is not here right now.

So if anybody has any info.....

I'm afraid it's a little too broad to answer. Giant's been making a Cypress in some form or another since 1998, and the spec has changed over time. If you had a year and type of crank, it would narrow it down considerably.

You sayin' you can't count up to five? Or jus' missin' a few fingers?
From the pictures on the Giant web site, you only need to count to four. The crank is a no-name 4-bolt geared 28/38/48 so I expect the BCD is 104/64.

Better contact Giant first if you are trying to buy replacements as that's only an estimate.

how many teeth on the rings?
how many bolts? 4? 5?

42 teeth
not sure of bolts.
I noticed he had a 53 or bigger on the big ring so maybe it not stock.

Thanks for the help, I'll just have to measure it next time he is around.

Most modern chainring teeth are not uniform in shape or length. The special shapes aid in quick smooth shifting. These are often mistaken as worn teeth. Compare with some new bike chainrings.

Al

Most modern chainring teeth are not uniform in shape or length. The special shapes aid in quick smooth shifting. These are often mistaken as worn teeth. Compare with some new bike chainrings.

Al

Hi, Al-

+1.

My first MTB and experience with ramped and relieved-tooth chainrings was back in '93. I was SURE that I needed to take the bike back to get the rings replaced. :P

I understand the geomety, but this was the only chainring that had not been replaced in the last 15-20,000 miles.

I'd be very surprised if the chainring was the cause of the skipping. Those teeth would have to be broken/damaged, not worn, to cause the chain to slip. Most likely, your friend uses a particular cog on the cassette when in the middle ring and a different cog when using the big ring. You will get slipping when the cogs on the cassette are worn, which also means the chain is worn and needs replacing too.

New cassette

The other issue is whether the Cypress is low enough in the line to have a riveted crank.