Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take Part in the March Giveaway: Coming Soon 3/24


Dura Ace CN-7801 stretch
#1
Just installed new Dura Ace chain and noticed when cutting to length<br />
it is just as stretched as old chain. Opened other 2nd box of chain and<br />
found same thing.<br />
Have used this chain for years and it always came tight and waxed,<br />
now Dura Ace CN-7801 is loose and oily.<br />
Checked with 2 chain gauges and found same thing, 75% stretch.
Does anyone have any word from Shimano on this?
Is this part of the switch to CN-7900?

  Reply
#2
10 speed chains have more side to side play than older chains might have. I think that is what you are seeing. "Stretch" usually refers to the length of the chain getting slightly longer. You can measure this by putting a ruler up against the chain. It should be exactly 12" between pins. If it is over 12 1/8", you need a new chain. I'm not sure what you mean when you say "75% stretch".
Side to side play on a worn chain will get looser, but that, in and of itself, is not an indication that the chain needs to be replaced.
I don't know that any chains came waxed, but they may have used a thicker grease in the past.

  Reply
#3
DaveM,<br />
Actually the Dura Ace chains came with a wax up to about 8 months ago.<br />
And yes I know what stretch is, the simplest way to check it is with a good<br />
gauge and most of them are calibrated in percent of wear. 100% would be<br />
the time to replace.
The looseness of these new CN 7801's is either a manufacturing error or<br />
for some reason intentional by Shimano. I believe it is an error at the factory.
I'm checking with a Shimano rep to find out more.

  Reply
#4
I didn't know Dura Ace came waxed. Neat. Sounds like you know what you're talking about. I haven't heard of many manufacturing errors by Shimano, but they should know the answer. Update us...

  Reply


Possibly Related Threads...
Thread
Author
Replies
Views
Last Post
 
13,414
02-24-2017, 02:15 AM
Last Post: LorindaCollins
 
28,219
03-23-2011, 11:00 AM
Last Post: dave_sd
 
12,758
03-03-2011, 04:03 PM
Last Post: colcazal
 
8,363
09-14-2009, 05:05 PM
Last Post: DaveM
 
8,335
04-07-2009, 08:34 PM
Last Post: DaveM

Forum Jump:

[-]
10 Latest Posts
Santini fluted frame
Today 01:52 AM
2010 Specialized Hardrock
03-26-2024 09:16 PM
1990 Specialized Rockhopper How to Fluff...
03-25-2024 07:05 PM
Thread busted on right pedal crank
03-24-2024 08:52 PM
Trek domane tyre
03-24-2024 05:48 PM
Modern rims crack at spoke holes
03-24-2024 05:32 PM
Cup & Cone — Simple & Durable or PITA & ...
03-24-2024 04:53 PM
Falling back
03-24-2024 04:45 PM
Derailluer Hanger Alignment Tool
03-24-2024 02:51 PM
Chain sits on top of chainring when shif...
03-24-2024 02:41 PM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. Painkiller
20 posts
no avatar 2. ReapThaWhirlwind
16 posts
no avatar 3. meamoantonio
15 posts
no avatar 4. GirishH
15 posts
no avatar 5. Jesper
15 posts