Converting triple chainset with compact rings?

Discuss light weight issues concerning road bikes & parts.
deanh
Posts: 35
Joined: Sat Jun 15, 2013 9:50 am

by deanh

Is it possible to convert my fsa team issue carbon triple chainset to a compact by just changing the rings? If so can you guys recommend some reasonably priced rings?

by Weenie


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maddog 2
Posts: 348
Joined: Wed Feb 25, 2009 7:58 pm
Location: Lancaster, UK

by maddog 2

No.

FSA triples run a 130mm BCD for the middle and outer, so your smallest ring is 38t.

[I suppose you could run the rings in the inner and middle position, but that would just look silly]

deanh
Posts: 35
Joined: Sat Jun 15, 2013 9:50 am

by deanh

The fsa slk compacts run 130mm bcd also though?

SDP
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by SDP

Really....you 100% sure....?

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deanh
Posts: 35
Joined: Sat Jun 15, 2013 9:50 am

by deanh


SDP
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by SDP

Forgiven....;-)

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bikerjulio
Posts: 1901
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

deanh wrote:Sorry it wasnt the fsa slk.

http://pages.ebay.com/link/?nav=item.vi ... 0789130362" onclick="window.open(this.href);return false;


That's $228 for an unbranded Octalink crank with 130BCD. And you were asking about wanting a compact which has a 110mm BCD.

OP you need help.

To change to a compact crank, I'm guessing you will need a new BB as well. The spindle length is usually different between triple and double cranksets. Octalink was a good system, but now obsolete. So, if that's what you have, not only are compact cranks going to be hard to find, but the spindle's most likely wrong anyway.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

deanh
Posts: 35
Joined: Sat Jun 15, 2013 9:50 am

by deanh

I posted that up as proof id seen a compact with 130mm bcd. My current fsa team issue carbon use the isis bb.

sigismond0
Posts: 236
Joined: Tue Feb 05, 2013 8:29 pm

by sigismond0

Ahh, you're not understanding what compact means.

Compact is 50/34t chainrings, and is 110mm BCD. 53/39t is standard and has 130mm BCD. The smallest ring you can possibly put on 130mm is 38t, or 37t using proprietary chainring bolts.

If you just want to put a standard 53/39 on your 130mm BCD, you can absolutely do that. You'll need to put a double derailleur and shifter. I'd say just leave your old shifter/derailleur/smallest ring, put 53/39 on the big rings, and just don't use the littlest ring.

The only other option is to just switch your BB, crankset, shifter, and front derailleur.

deanh
Posts: 35
Joined: Sat Jun 15, 2013 9:50 am

by deanh

Thanks for that. Clears it up perfect.

I'll just use the current setup and limit the derailleur movement on the limit screws.

Next question is what rings to go for?

RussellS
Posts: 739
Joined: Wed Feb 03, 2010 1:31 am

by RussellS

deanh wrote:Next question is what rings to go for?


For fun you can remove the inner chainring. Maybe find a shorter bottom bracket. Octalink was mentioned. Find one in a double crank length instead of the triple length you have now. Adjust the front derailleur limit screws to fit the new double crankset. Probably no need to change the chainrings. Assume it came with 53-39-30 chainrings originally. Just take off the 30 tooth inner and leave the 53-39 outer and middle rings alone. That is what most double cranksets come with from the factory.

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bikerjulio
Posts: 1901
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

Just to be clear. Even though you said in the first post that you wanted compact, you really don't want compact. Is that right?
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

deanh
Posts: 35
Joined: Sat Jun 15, 2013 9:50 am

by deanh

For some strange reason I had in my head compact ratio was 53/39.

deanh
Posts: 35
Joined: Sat Jun 15, 2013 9:50 am

by deanh

Middle ring is currently 42t so ideally I need to drop to 39t

by Weenie


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LouisN
Posts: 2362
Joined: Mon Feb 19, 2007 3:44 am
Location: Canada

by LouisN

Yes, it is.
You can use only the two smallest rings.
Put any size smallest ring (104 BCD ?) and any size middle ring (130 BCD). If you want 34/50 = no problems.
Take biggest ring off, put washers instead to keep the same thickness for the bolts. Limit the FD so you don't drop the chain over the second ring.
Doesn't look silly at all. Just like a double.

I did this for both my daughters's bikes with a 34/42T setup on a triple.

Louis :)

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