chainring bcd



M

Matthew Paterso

Guest
Quick question

How do I measure the bcd of a chainring. I have one which is
94 mm, and this wont fit my MRP, I need one which is 110 mm.
But what do these numbers relate to?

Thanks

--
Matt

Fear of a flat planet
 
"Matthew Paterson" <[email protected]> wrote in message
news:p[email protected]...
> Quick question
>
> How do I measure the bcd of a chainring. I have one which
> is 94 mm, and this wont fit my MRP, I need one which is
> 110 mm. But what do these numbers relate to?

> Matt

BCD = Bolt Circle Diameter, 94mm = Compact drive, 110mm =
standard drive. Take a chainring you know fits and use it to
compare to one you want to buy, make sure the bolt holes
align all the way round. Another clue is the tooth count,
compact drive chainrings are usually 22/32/42T wheras
standard drive are 26/36/46.

Steve.
 
On Fri, 16 Apr 2004 11:46:27 +0100, Matthew Paterson wrote:

> How do I measure the bcd of a chainring. I have one which
> is 94 mm, and this wont fit my MRP, I need one which is
> 110 mm. But what do these numbers relate to?

BCD is the distance between chainring bolt holes (literally
the diameter of the circle made by the bolts).

94mm is compact drive, 110mm is old standard size, IIRC.
Sounds like you've got the wrong MRP device.

--
a.m-b FAQ: http://www.j-harris.net/bike/ambfaq.htm

b.bmx FAQ: http://www.t-online.de/~jharris/bmx_faq.htm
 
On Fri, 16 Apr 2004 11:47:29 +0200, bomba wrote:

> 94mm is compact drive, 110mm is old standard size, IIRC.
> Sounds like you've got the wrong MRP device.

Or wrong chainring ;)

I have a 110 MRP and a 110 DMR spider, and a 94 chainring.

--
Matt

Fear of a flat planet
 
To all,

Do you know of any standard BCD bolt diameter chainring with
a granny of 22T?

regards "spademan o---[) *"
<[email protected]> wrote in message
news:[email protected]...
>
> "Matthew Paterson" <[email protected]> wrote in
> message
> news:p[email protected]...
> > Quick question
> >
> > How do I measure the bcd of a chainring. I have one
> > which is 94 mm, and this wont fit my MRP, I need one
> > which is 110 mm. But what do these numbers relate to?
>
> > Matt
>
>
> BCD = Bolt Circle Diameter, 94mm = Compact drive, 110mm =
> standard drive. Take a chainring you know fits and use it
> to compare to one you want to
buy,
> make sure the bolt holes align all the way round. Another
> clue is the
tooth
> count, compact drive chainrings are usually 22/32/42T
> wheras standard
drive
> are 26/36/46.
>
> Steve.
 
On Sat, 17 Apr 2004 08:48:52 +0800, Jansen A. Danganan wrote:

> Do you know of any standard BCD bolt diameter chainring
> with a granny of 22T?

The smallest size available for standard drive is 24t.
 

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