Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 05-03-10, 03:53 PM   #1
georgegeorge
Member
Thread Starter
 
Join Date: Nov 2009
Bikes:
Posts: 37
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Running chainrings the other way round, flipping them over

Hi,

I've tried searching around but can't find a definitive answer as to the pros and cons of running a chainring the other way round.

Obviously if it's offset/dished then it'll affect chainline. And if it's ramped and pinned then it'll not help shifting.

The bike I'm interested in this for is fixed however, though I sometimes set it up with a freewheel block at the back. Either way, the front chainring is not offset and definitely not ramped or pinned. It comes from a time before that existed. Its got an obsolete Stronglight BCD actually (122) which is why I'm interested in seeing if I can make it last longer.

Assuming, for a moment, that it was running a freewheel at the back and therefore the only wearing effect on the chainring was forwards, what would flipping the chainring over do? Is it as simple as increasing its usable life? Surely it makes a difference that the other side of the tooth is mis-shaped?

Does it make a difference if you're going to run the flipped chainring on a fixed drivetrain? I imagine not because however much you resist forward motion through the pedals it can't be as wearing as forward cos you spend most of the time going forward.

Aye, so any experience or technical wisdom would be great
Thanks
georgegeorge is offline   Reply With Quote
Old 05-03-10, 04:06 PM   #2
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 29,671
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 223 Post(s)
Yes, running the chainring flipped will improve it's life as it brings fresh correctly profiled teeth to the loaded side of the chain. It doesn't help as far side wear at the points, but that should be a non-issue in SS, since there'll never be chains feeding from angles.

Either way, the one best thing you can do to prolong chainring life is to replace chains before they wear too much, and even consider rotating multiple chains every 500-1,000 miles, so you're not running stretched chains until the very end of the total life cycle. I rotate 5 chains trying to eek every last mile out of an old and not replaceable freewheel on my vintage bike. I'm about half way through, or on my 3rd pass through the chains and the freewheel looks almost new. Had I been on my third chain, each used to the end, there's no way it would be this good.

BTW- your chainring bolt head will stick out a bit because chainrings are only counter-bored on one side.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline   Reply With Quote
Old 05-03-10, 04:24 PM   #3
AEO
Senior Member
 
AEO's Avatar
 
Join Date: Jun 2007
Location: A Coffin Called Earth. or Toronto, ON
Bikes: Bianchi, Miyata, Dahon, Rossin
Posts: 12,258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
you might need longer chainring bolts and nuts, because the other side no longer has any counter sunk holes...
then again, some chainrings don't have counter sunk holes at all.
__________________
Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
http://sanfrancisco.ibtimes.com/arti...ger-photos.htm
AEO is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 02:41 AM.