Carbon FD clamp fitment and gap

[JerryLook]

I just switched my Orbea over from an alloy braze on FD adaptor to a carbon version from Omni Racer.
The alloy clamp had a pretty good gap between the two halves. Maybe 2-3mm. Since it is alloy and pretty beefy, the gap didn’t bother me. I looked at it like the gap on a stem, you don’t want the pieces to touch.
The Omni Racer clamp has a gap between the halves. About 1-1.5mm. This gap concerns me more because
A: the clamp is not as sturdy as the alloy clamp.
B: the pics on the Omni Racer site show the halves touching or very close to it.
Just want to make sure this is normal. The clamp is advertised as 34.9-35mm. Maybe my seat tube is slightly oversized. I have not measured it with a caliper yet.
I like the weight loss of the carbon clamp. It weighs 8.8 grams including the Ti screw. The stock clamp was 35.6 grams.

Top pic is the clamp on my bike. Torqued to 20 in lbs
Bottom pic is a stock photo of the clamp from their ad

[ms6073]

The Omni Racer clamp has a gap between the halves. About 1-1.5mm.

I did a similar process with my open mold CX bike, and while the clamp is from another vendor, it is the same design, and the gap is very minimal, so I am going to hazard that you were sent the incorrect diameter clamp.

[ghisallo2003]

That is wrong. Carbon clamps that I have used in the past have a very tight tolerance: even to the point of needing a layer or two of tape around the frame sometimes to get a tight fit. I would be wary of over-tightening that.

[RyanH]

Um, needing tape to get a tight fit != tight tolerance.

My experience with non-Parlee clamps is that they are hit or miss (mostly miss). Every Parlee clamp that I've had matched up perfectly with the frames I've used them on. Last non-Parlee clamp that I had was a similar issue, gap of similar size. Fairwheel tried to tell me it was normal and just torque to spec. I told them that I was pretty sure it'd crack if I did but they said to not worry and try anyway. I did and it cracked (and they accepted my return). Needless to say, don't waste your time with carbon clamps unless you're buying the Parlee one (IMO). Alloy ones are only 18g.

[ghisallo2003]

My experience is with both Parlee and with cheaper versions. Both very good and both a tight fit. The Parlee required the tape !

[RyanH]

All that means is that your frames are most likely undersized. I've had about a half dozen Parlee clamps on three Ti frames (no paint) and two Crumptons and they all fit as expected and did not require tape. I could go caliper my Litespeed but I'm fairly certain it will be very close to 34.9 whereas, based on the consistency of the Parlee clamps I've received, my money would be on your frame being less than 34.9 (or whatever nominal size it is).

[JerryLook]

Ok. I thought it should be tighter also.

I contacted the manufacturer and sent them the picture. I also told them what I torqued it to.

They said they are used to seeing them fit tighter than that, but it shouldn’t be a problem. And also told me maybe I should tighten it more. Lol.

The gap doesn’t bother me as far as asthetics. I just don’t want the clamp to break eventually and dump the FD into the crank or chain.

If I can get a better fitting carbon clamp (maybe just over 35mm?) I will buy one. Or maybe just go back to an alloy clamp. 18 grams isn’t bad.

I’m trying to save a few more grams off the bike for when I put a power meter on. I want to stay under 15 lbs.

[JerryLook]

One thought I had was to make a little shim that goes in the gap. I could use plastic or something that could match the curve.
It would be a lot easier if the gap was straight though.

Any reason not to just make a little shim?