Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Blog NEW Galleries NEW FAQ Contact About Impressum
It is currently Mon Dec 18, 2017 6:44 am

All times are UTC+01:00





Post new topic  Reply to topic  [ 6 posts ] 
Author Message
PostPosted: Thu Mar 23, 2017 10:40 pm 
Offline

Joined: Thu Mar 23, 2017 10:32 pm
Posts: 3
Hi,

I recently ordered a r872 with full chorus group set with 50/34 chain rings from ribble. Today I got this email "Unfortunately we have come across a problem with your build, unfortunately the compact 34/50 does not fit efficiently onto the frame, the mechanics have tried to make it work but have had no luck, we can fit a standard 39/53 and this will run without any problems"

I found this odd so asked them if they could fit a mid compact which they told me they couldn't. Is there any reason why this could be? They even offer it here with mid compact ultegra... http://www.ribblecycles.co.uk/ribble-r8 ... l-edition/

Thanks


Top
   
Posted: Thu Mar 23, 2017 10:40 pm 


Top
   
 
PostPosted: Thu Mar 23, 2017 10:55 pm 
Offline

Joined: Sat Jan 19, 2013 1:17 am
Posts: 80
It might be something to do with the 110BCD (if 5 arm), hence they cant do mid compact or compact, and it must be something to do with the campag cranks, where the design differs to shimano.

Doing a quick google search it seems the bottom bracket area is wide and as it spreads out it keeps quite wide for some time. I assume the inside of the smaller BCD crank arm is fouling the frame or too close to be comfortable.

Is it one of the four arm campag cranksets or an older 5 arm?

If you asked them for a picture they would probably sort that for you.

Edit: It is very hard to find photos of the inside of campag drive side arms, however I did a search and it does seem that on both the 52-36 and 50-34 chainring combos for the 4 arms cranks, there is a small lip of metal extending beyond the hole for the chainring bolt towards the crank axle. On the 53-39 chainring combo that lip does not extend down as far. So i assume that that slightly longer metal lip is what is causing clearance issues on the frame.

Disclaimer here that I might be barking up the wrong tree.


Top
   
PostPosted: Thu Mar 23, 2017 11:12 pm 
Offline

Joined: Thu Mar 23, 2017 10:32 pm
Posts: 3
Ah I see cheers. That's a shame think a 53 will be a little too hard for me. I'll probably have to look for something else.


Top
   
PostPosted: Thu Mar 23, 2017 11:25 pm 
Offline
User avatar

Joined: Sun Nov 07, 2010 9:14 pm
Posts: 4782
It could also be that the brazeon for the front deraileur is too high and won't allow the front derailleur to sit low enough for the smaller front rings. I say this might be the reason because if it was chainring related it's usually the larger chain rings that might present clearance issues due to the chainstay angle towards the dropout, as opposed to the smaller ones. But if the derailleur cant go low enough, then that would certainly explain being able to use the larger rings but not the smaller. You should ask them specifically what it was. Would be interesting to know. I suspect it's one of those things they didn't really test out so well for All groupsets.

_________________
Colnago C60 - PR99
C59 Five Years Later
My Special Colnago EPQ
Trek Emonda SL Campagnolo SR


Top
   
PostPosted: Thu Mar 23, 2017 11:34 pm 
Offline

Joined: Thu Mar 23, 2017 10:32 pm
Posts: 3
I'll be sure to ask them tomorrow, thanks very much for your help. Now I'm just wondering whether I'll get away with the 53 with a 12-29 cassette.


Top
   
Posted: Thu Mar 23, 2017 11:34 pm 


Top
   
 
PostPosted: Thu Mar 23, 2017 11:40 pm 
Offline

Joined: Sat Jan 19, 2013 1:17 am
Posts: 80
I think Calnagos hypothesis is more likely!


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 6 posts ] 

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. Compact v semi compact

[ Go to page: 1 2 3 ]

in Road

wilwil

35

2296

Thu Jul 27, 2017 11:05 pm

shimmeD View the latest post

There are no new unread posts for this topic. "improving" Campy EPS switching. Anyone with a non-functional Campy shifter?

in Road

2old4this

2

314

Tue Sep 26, 2017 1:18 am

2old4this View the latest post

There are no new unread posts for this topic. Changing to compact?

in Road

Peedee

11

1144

Fri Mar 31, 2017 11:26 am

DJT21 View the latest post

There are no new unread posts for this topic. Compact Handlebar with Flat Top?

[ Go to page: 1 2 ]

in Road

daveydoo

24

2048

Thu Aug 17, 2017 2:47 pm

daveydoo View the latest post

There are no new unread posts for this topic. Looking for compact aluminum handlebar under ~260 grams

[ Go to page: 1 2 ]

in Road

mpulsiv

21

2171

Thu Feb 02, 2017 11:14 pm

DutchMountains View the latest post


All times are UTC+01:00


Who is online

Users browsing this forum: Baidu [Spider], DOUG, yjymb and 31 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited