Chainring spacers and bolts
 

I have an FSA double (44/32) which has threaded holes ready to accept a granny ring. However, I have no bolts or spacers. Do I need specific FSA bolts and spacers, or can I use anything that will fit? Also, do spacers need to be specifically made for chainrings, or can I just rig something up with washers (metal/plastic) from a DIY store? The reason I ask is that all my LBS have plenty of complete cranksets for sale, but no spare parts like bolts and spacers.

Thanks.

That's odd that your bike shop doesn't carry chainring bolts. For 99.999% of the cranksets you'll encounter, all teh chainring bolts are the same size (diameter wise). The washers dont' need to be "chainring bolt specific" as long as they fit.

Finding an LBS which has both items for you saves you the hassle of looking for it yourself. But if you do need to do it, it's not rocket science.

I just checked a bunch of chainring bolts I have in my collection liberated from various Shimano, Sun Tour, Suguino and SR cranks. They all seem to be M8 in diameter but have neither of the two common M8 thread pitches of 1.0 or 1.25 mm so I'm not sure what the threading is.

The Shimano triple cranks I'm familiar with don't require spacers for the granny ring as the mounting bosses are long enough to position the ring properly. The SR and Suguino cranks do need them.

Bike tools Etc has chainring bolt sets and spacers avaialble. Look here:

http://www.biketoolsetc.com/index.cg...s&sc=Chainring

BTW, have you contacted FSA? They will certainly have the required parts available.

Thanks for the link. Unfortunately, I'm not in the US or Canada, but this at least shows me what I'm looking for. I notice that there are a whole range of spacer widths available for the Granny ring ranging from 2.2mm up to 8.3mm How does one know which width to choose? Is there a formula, or do you just have to eyeball it?

[QUOTE=BTW, have you contacted FSA? They will certainly have the required parts available.[/QUOTE]

Yes, about ten days ago, but no reply so far.

The spacer thickness will vary from maker to maker and model to model. As I mentioned current Shimano road triples don't require any spacers. My new Campy Chorus triple crank also has no spacers and the granny ring bolts flat to the mounting bosses. An old SR crank I have uses 3.8 mm spacers so there is no general rule.

Do the mounting bosses on your FSA crank stick out beyond the middle chainring line a fair bit? If so it may also need no extra spacers.

If you are trying to get good indexing, the spacing has to be right so either the manufacturer makes the mounting bosses the right length or you will have to experiment with washer stacks.


That's unfortunate. Where are you located and is there a local distributor for FSA that might be more responsive?

No, they are flush with the middle chainring, so spacers are definitely required. The middle to outer chainring spacer is 3mm. I don't know if this is relevant?

So, perhaps a pile of thin washers and trial and error is the safest way to go?

I'd start with 3mm since there is some indication that's the spacing for the other two rings. Then try the shifting to see which way, if any, you need to go.

Why not put your location in your profile so we can see it?

Good idea. Done!

By the way, thanks for all the advice concerning the problem in hand. To update you, I found that 3mm (3 x 1) spacers leave the Granny too close to the middle chainring, but that the bolts are too short to handle 4mm! So now I need to search out longer bolts. Also, I'm beginning to consider what length of spindle I need - 68 x ???

Now that I know you are in Taiwan, I'm surprised you are having problems contacting FSA. My two recent FSA headsets say "Made in Taiwan" as are all their other components I'm familiar with.

As far as I know they are a Taiwan-based company and I expect they would be a local phone call for you.