Carbon Fiber Saddle Rails
12-15-10, 08:34 AM
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Carbon Fiber Saddle Rails
I ordered a Selle Italia SLR Fibra saddle with carbon fiber rails. I have a Specialized Pave carbon fiber single bolt seat post. I understand this seat post may not be compatible with the carbon fiber rails. Do they make an adapter for this type seat post? Do I need to use a 2 bolt seat post. I actually have a Specialized Pave carbon fiber seat post with 2 bolts.
12-15-10, 08:59 AM
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It's not an issue of one bolt versus two bolt seat posts. The issue with some carbon fiber railed saddles is that the rails have a larger diameter than the "old" standard size rails. Thus, for you current post, check the Specialized website to see whether they sell a replacement clamp for carbon rails. While I do not use a carbon railed saddle, I know that the maker of my seatpost, Ritchey, makes substitute clamp parts for use with carbon railed saddles. Maybe Specialized does the same thing.
12-15-10, 09:55 AM
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+1. It's the design of the rail clamp itself, not whether it's clamped with one or two bolts. You have to find a post, or replacement rail supports for yours, that is made for carbon rail saddles.
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12-15-10, 05:03 PM
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I found the Ritchey Clamp. I couldn't find a comparable clamp for the Specialized Seat Post.
https://www.ritcheylogic.com/dyn_prodfamily.php?k=98383
https://www.specialized.com/us/en/bc/...jsp?spid=57222
https://www.ritcheylogic.com/dyn_prodfamily.php?k=98383
https://www.specialized.com/us/en/bc/...jsp?spid=57222
12-20-10, 09:04 PM
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I received the saddle.The carbon rails are oval. 9 mm tall and 7 mm wide. A 2 bolt seat post works and is the only style post condoned by Selle Italia after reading the instructions that came with the saddle. The vendors don't provide adequate information when ordering it.
12-20-10, 09:49 PM
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I'd say the two bolt recommendation is based on the likelihood that some single-bolt designs won't open far enough.
12-20-10, 11:23 PM
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One bolt seatclamps have to be tightened hard enough to keep the seat angle from slipping in addition to just clamping the saddle rails; a two bolt clamp can be gentler on the rails.
12-21-10, 06:50 AM
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The shape of the one bolt clamps aren't compatible because the rails are oval. zzyzz_xyzzy also has a good point about clamping torque. The torque recommendation for the SLR is 6 ft lb. If I tightened my one bolt clamp to 6 ft lb the saddle would tilt after a short ride.
12-21-10, 07:15 AM
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Oh yeah, that would totally be it.
