MRP

[Matthew Paterson]

Hi

I have recently acquired a World Cup System 1, bb mount, 36-44t 5 bolt
110mm chainguide. I also got a DMR 5 bolt spider (that can accept 3
chainrings) and a set of 24/7 3 piece cranks.

Now the spider fits on the cranks fine, but where the holes for the outer
ring are on the spider, they dont line up with the holes on the MRP chain
plates, they are all about 5mm short.

Will I require a new spider for this chainguide, or do I need new plates
for the MRP?

I havent tried fitting it to the bike yet.

Thanks.

--
Matt

Fear of a flat planet

[bomba]

On Fri, 31 Oct 2003 13:02:47 +0000, Matthew Paterson wrote:

> I have recently acquired a World Cup System 1, bb mount, 36-44t 5 bolt
> 110mm chainguide. I also got a DMR 5 bolt spider (that can accept 3
> chainrings) and a set of 24/7 3 piece cranks.
>
> Now the spider fits on the cranks fine, but where the holes for the outer
> ring are on the spider, they dont line up with the holes on the MRP chain
> plates, they are all about 5mm short.
>
> Will I require a new spider for this chainguide, or do I need new plates
> for the MRP?

I'm guessing you got the DMR spider which uses compact drive (94mm pcd)
which is incompatible with your standard drive (110mm pcd) MRP device.

Which part you change depends on your chainring. If it's standard drive,
change the spider. If it's compact drive, change the MRP plates.

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

a.bmx FAQ: http://www.t-online.de/~jharris/bmx_faq.htm

[Small Black Dog]

>
> I'm guessing you got the DMR spider which uses compact drive (94mm pcd)
> which is incompatible with your standard drive (110mm pcd) MRP device.
>
> Which part you change depends on your chainring. If it's standard drive,
> change the spider. If it's compact drive, change the MRP plates.
>

isnt it BCD, not pcd ?

Small Black Dog

[bomba]

On Fri, 31 Oct 2003 13:40:16 +0000, Small Black Dog wrote:

>> I'm guessing you got the DMR spider which uses compact drive (94mm pcd)
>> which is incompatible with your standard drive (110mm pcd) MRP device.
>>
>> Which part you change depends on your chainring. If it's standard drive,
>> change the spider. If it's compact drive, change the MRP plates.
>>
>
> isnt it BCD, not pcd ?

BCD (bolt circle diameter) is the distance between adjacent holes. PCD
(pitch circe diameter) is the diameter of the bolt circle:
http://www.chickencycles.com/products/chainrings/images/TA_chainring_tech.jpg

However, according to Sheldon, this is a British thing and we should all
be using BCD...

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

a.bmx FAQ: http://www.t-online.de/~jharris/bmx_faq.htm

[Matthew Paterson]

On Fri, 31 Oct 2003 13:25:24 +0000, bomba wrote:

> I'm guessing you got the DMR spider which uses compact drive (94mm pcd)
> which is incompatible with your standard drive (110mm pcd) MRP device.
>
> Which part you change depends on your chainring. If it's standard
> drive, change the spider. If it's compact drive, change the MRP plates.

Thanks bomba. That will be the problem. Cheers.

--
Matt

Fear of a flat planet

[Small Black Dog]

bomba wrote:

> On Fri, 31 Oct 2003 13:40:16 +0000, Small Black Dog wrote:
>
>
>>>I'm guessing you got the DMR spider which uses compact drive (94mm pcd)
>>>which is incompatible with your standard drive (110mm pcd) MRP device.
>>>
>>>Which part you change depends on your chainring. If it's standard drive,
>>>change the spider. If it's compact drive, change the MRP plates.
>>>
>>
>>isnt it BCD, not pcd ?
>
>
> BCD (bolt circle diameter) is the distance between adjacent holes. PCD
> (pitch circe diameter) is the diameter of the bolt circle:
> http://www.chickencycles.com/products/chainrings/images/TA_chainring_tech.jpg
>
> However, according to Sheldon, this is a British thing and we should all
> be using BCD...
>

cool, cheers for the info

Small Black Dog

[Andy Chequer]

> BCD (bolt circle diameter) is the distance between adjacent holes. PCD
> (pitch circe diameter) is the diameter of the bolt circle:

Factoid!

Andy Chequer, hey chaps