Chain ring spacers?

[elspedo]

Hi guys, picked a new bike up last week and it's all perfect bar on the smallest cogs the chain seems to catch on the inside of the big cog, this is literally by <3mm and makes the chain want to jump up on to the big cog.

Having a bit of a read and have found some people put spacers in between the cogs to give that extra 3mm, can anyone point me in the right direction for these as my google fu is throwing up blanks.

It's an ultegra chain ring if that makes any difference?

Cheers

 

[Hillwalker]

Are you saying that you are having problems when using the small chainring combined with the smallest rear sprockets? This is a combination normally to be avoided because of poor chainline and increased sprocket and chain wear. How many rear sprockets are you running?

HW

 

[elspedo]

Yes exactly that, 2 on the front 7 on the back. Cheers

 

[Hillwalker]

You could use spacers to avoid the catching, but a simpler approach would be not to use the small chainring/small cogs combo. TA and Stronglight chainrings come with spacers (different design to Shimano/Campag sets) but adding spacers to the chainset will likely cause problems with your front shifter and/or chainline elsewhere. The little/little combo is potentially problematic from a wear perspective and shouldn't give you a gear that you couldn't get close to by using the large chainwheel and cog 3 or 4 instead.

Hope this helps

HW

 

[elspedo]

Cheers, ATM I am just staying off those but may give spacers a try if the time comes I need the little/little combo I would like the option.

Are these the things I need: http://www.sjscycles.co.uk/wheels-manuf ... prod17702/

 

[Hillwalker]

Looks like it, but for the same cost you could consider changing the large chainring to allow you to access the gear ratio you prefer but using the large chainring instead?

Just a thought...

HW

 

[elspedo]

Just been on the phone to my mate and he thinks it could be the chain being too wide?

Looking at it-it has an 8 speed chain on a 7 speed cassette would the 8 speed chain be sufficiently wider to cause it to rub?

 

[mattr]

No.

Only way to fix this properly is to get a frame with longer chainstays.
Certain combinations rub. It's as simple as that.

If you put spacers on, your front shifting will likely go to sh1t.

And using that combo is very bad planning. Most set ups are designed to do the big up shift (front and rear) just over half way down the cassette. Probably 4 or 5 on a 7 speed. And the big down shift on about 3 or 4.

 

[Ian Raleigh]

If you put spacers on, your front shifting will likely go to sh1t.

Agreed on that one mate! I had the same problem of the chain rubbing on the big rig-ring
whilst in the smallest sprocket, I fitted spacers thinking this is the cure but when it came
to shifting up on the big ring it was terrible and had to really push the gear lever down but
the worst was when I dropped the chain off the big ring to the little ring, the outer edge of
the chain fell on the to the tops of the teeth, thus allowing the ring to just spin and had to go
up a few cogs on the rear so the chain moved over and fell into the teeth! This was no fun at all
and decided to fit an axle which was 2mm longer on the drive side and this cured it for me.

 

[elspedo]

Cool, will give the spacers a miss then.

Will pop it into my LBS this weekend and see what he says as removing the bottom bracket maybe beyond my (as you can probably tell) limited bike experience.

Cheers