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

New: Take part in the National Bike Safety Month giveaway for a RiderBag reflective backpack


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
 
9,131
02-24-2017, 02:15 AM
Last Post: LorindaCollins
 
21,728
03-23-2011, 11:00 AM
Last Post: dave_sd
 
6,295
09-14-2009, 05:05 PM
Last Post: DaveM
 
6,312
04-07-2009, 08:34 PM
Last Post: DaveM

Forum Jump:

[-]
10 Latest Posts
Clicking when pedaling on bike.
Yesterday 04:00 PM
Trouble Mounting Front Brake Calliper
Yesterday 03:40 PM
National Bike Safety Month | RiderBag Gi...
Yesterday 12:03 PM
CRESCENT PEPITA '72/'73
Yesterday 09:35 AM
Vintage Road Bike Restoration HELP
Yesterday 03:35 AM
COLNAGO NUOVO MEXICO 1986
05-28-2020 05:42 PM
Tires?
05-28-2020 11:29 AM
Saronni Colnago Critrium Frame set
05-28-2020 04:08 AM
Help me date this Rollfast
05-28-2020 03:11 AM
SmartHalo all-in-one biking accessory | ...
05-28-2020 02:25 AM

[-]
Top 5 Posters This Month
no avatar 1. Jesper
21 posts
no avatar 2. CharleyFarley
21 posts
no avatar 3. Criminal
15 posts
no avatar 4. Painkiller
13 posts
no avatar 5. Joe_W
11 posts