Colnago V3RS 0mm seatpost poor engienering, issue and danger

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Belisarius
Posts: 79
Joined: Sun Jul 06, 2014 5:36 pm

by Belisarius

BLUF- Colnago shipped a V3RS with a badly (un)engineered 0mm seatpost, posing significant risk.

Bike ordered fall 2021. Painted June 2022, delivered/assembled end august 2022. 700 kms to date. We needed a 0mm seatpost as many saddles have shortened rails (a trend that started a few years ago). Run Selle San Marco Short-Fit Carbon FX, one of the longest Carbon or alloy saddles out there. The clamping mechanism is side clamp, metal on carbon
First ride the saddle tilted backwards. Torqued to 10, then 12 N.M. Kept tilting 1-2 degrees per ride, sliding 1mm.

It also sinks1-3 mm per ride, as the reinforced, thicker clamp grip texture part is too low as opposed to all other Colnago seatposts, the featured 15mm offsets or some odd custom Team UAE gets.

30 Sep 2022, close inspection reveals a serious issue: the metal clamp chews the carbon. Like arthritis eating a bone, the metal chews the carbon resin..Sideways, top… Another Aeroad type bad engineering? No engineering? No CAD no IP think on this? Told Hambini and asked for his input. But this seatpost is a write-off. As the carbon chews, it shrinks, reducing the clamping power and saddle effects as described. Each ride.

Added fiberglass tape, reduced the rate of change, but it is not stable, feels flexy and moving. And the seatpost cap moves, and evidently, the clamp area below.

Dealing with Colnago next week; but, after 20 or so rides, i should heed advice and stop riding... I think it will have to be a voluntary recall, or they will get the papers for a mandatory one. Maybe we get lucky and get a 15mm offset with a narrow top part, dual bolts, and thus be able to use my current saddles without going all the way to the rear (a No No for most saddle makers)…
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wickedstealthy
Posts: 427
Joined: Sat Jan 02, 2021 3:16 pm

by wickedstealthy

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Hi, I have the straight seatpost too. But contrary to you I have none of the issues you describe. Seatpost is nowhere moving and it is even difficult to put in the tube. I dont even have to torque the seatpost and it doesnt slip. The clamping ? Well not even slipping a tiny bit with only torqueing the bolt slightly.

The only difference I have with your is that I had the gloss version and had it resprayed in matt black. Solid as hell. The post is alos a lot more confortable then I have from Gelu on my Canyon.

I added some pictures of mine. Riding already 3000km and not issue on that part.

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justinn1234
Posts: 4
Joined: Sun May 07, 2023 7:15 pm

by justinn1234

Hello,

Does any one know what the thru axle torque specs are for the V3Rs? I can't find it online / manual. Colnago hasn't responded via email and it's not on my thru axle. Any help would be greatly appreciated. Thanks!

mike
Resident Pro
Posts: 2994
Joined: Tue Mar 18, 2003 9:42 pm

by mike

These are the new seatpost s that other brands also use. My issue was slipping but then I cleaned out the tube and made sure post was also clean. I then used carbon paste and torqued a little bit more each time until it stopped slipping into frame. I also put some frame saver tape on both edges of seatpost head and torqued it well so it would not move

bikeboy1tr
Posts: 1395
Joined: Thu Mar 21, 2013 3:19 am
Location: Southern Ontario Canada

by bikeboy1tr

justinn1234 wrote:
Mon May 08, 2023 3:19 pm
Hello,

Does any one know what the thru axle torque specs are for the V3Rs? I can't find it online / manual. Colnago hasn't responded via email and it's not on my thru axle. Any help would be greatly appreciated. Thanks!
They just need to be snug but I dont think too many ppl put a torque wrench on thru axles unless they are having issues and then its only for troubleshooting. Treat them the same as you QR, not too much and not too loose. I actually use a 8v Dewalt screwdriver on mine as the wheels are on and off the V2R frequently. With the 8V its spin it up until resistance and then off the trigger with a slight turn without power just to make sure its tight.
viewtopic.php?f=10&t=154188
2018 Colnago V2R Rim Brake
2019 Colnago V2R Disc Brake
2014 Norco Threshold Disc Brake
2006 Ridley Crosswind Rim Brake

robertbb
Posts: 2179
Joined: Thu Jul 23, 2009 3:35 am

by robertbb

I can't speak to the slipping issue, but the interface to the saddle rails is a copy of the Ritchey WCS one bolt posts. Right down to the little plastic wedge that sits atop the bolt as shown in the last pic on the kitchen bench. Provided you hit 12nm (as per spec on the ritchey version), the saddle shouldn't tilt at all.

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wheelbuilder
Posts: 1193
Joined: Wed Feb 08, 2017 2:10 am

by wheelbuilder

As stated above it's identical to Ritchey WCS 1 bolt. I have 3 of them in use since 2012 with no problems at all. It can be tricky to install but certainly does not need a recall. Are you using the carbon rail specific one? Go to the Ritchey site and order one.
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TheBeautifulOne
Posts: 47
Joined: Tue Nov 24, 2020 7:53 pm

by TheBeautifulOne

Very weird. I have identical mechanism on my C64 and no issues at all. Did you use assembly paste for carbon parts?

justinn1234
Posts: 4
Joined: Sun May 07, 2023 7:15 pm

by justinn1234

bikeboy1tr wrote:
Tue May 09, 2023 12:23 am
justinn1234 wrote:
Mon May 08, 2023 3:19 pm
Hello,

Does any one know what the thru axle torque specs are for the V3Rs? I can't find it online / manual. Colnago hasn't responded via email and it's not on my thru axle. Any help would be greatly appreciated. Thanks!
They just need to be snug but I dont think too many ppl put a torque wrench on thru axles unless they are having issues and then its only for troubleshooting. Treat them the same as you QR, not too much and not too loose. I actually use a 8v Dewalt screwdriver on mine as the wheels are on and off the V2R frequently. With the 8V its spin it up until resistance and then off the trigger with a slight turn without power just to make sure its tight.
Thanks! I guess I'm just a bit parranoid I may have overdone it? I think I cranked it to about 8nm...I always have someone do my work, but I had to spring into action for this one and only after realized this.

Belisarius
Posts: 79
Joined: Sun Jul 06, 2014 5:36 pm

by Belisarius

Update. The 15mm seatpost resolved the saddle tilt. Different clamp. But the sliding seatpost is the same, after 20 rides it started sinking. Why? Paint scratches tell the story: the seat tube is too large in some spots especially concave at the flat D SPOT so the seatpost always drops until 9/9.5 N.M torque no matter what. Then the clamp stripped. The seatpost creaked twisting and tilting under load, sounded like a BB creak. Issue appears to be the oversized seat tube geometry. A manufacturing defect... so at 8 NM it sank. At 8.5 it sank. Creaked. Sort of stable and creaking at 9 NM. Sliding once paint stripped in a few contact spots which reveal the oversized aspect of the seat tube...

IvanZg
Posts: 280
Joined: Thu Jan 10, 2019 3:10 pm

by IvanZg

I had similar issue with my old v2r seat post slipping. Resolved it by striping down the paint and sticking some anti slip tape made by Tesa. This worked well for me as I wasn't readjusting or needed to remove seat post. But fit was definitely tighter then you'd like if you need to change height or remove seat post on regular basis. 5 Nm was enough after that.

by Weenie


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Belisarius
Posts: 79
Joined: Sun Jul 06, 2014 5:36 pm

by Belisarius

UPDATE- Seat Tube may be the issue

I am on my 2nd seapost, this one painted, 20 rides of BB creaking it was the seatpost banging inside. Never the BB. It anchors on the right side of the D and with each left foot downstroke the post moved. 8 nm just slips down. A careful examination tells us that the seat TUBE is too concave and wide for the seatpost, so after a few rides chewes the contact points etc. See pics.

The first seatpost, all carbon, also slipped each ride. Carbon paste and going over 8 slowed down the movement. So 45 rides on this frame, the seatpost does not stay put. Stu Kern from road cc is 250 lbs and he never slipped on his review Colnagos. I am 185 lbs. Also, working on it, when unscrewing (to re-raise it), the post just drops unless I hold it by hand or by the electrical tape (which would get deformed). Usually, any post with paste, if unscrewing a collar or clamp, just stays put with paste friction, unless tapping it up or down. Not this one.

The H cavity depth figure, from where the seatube contacts the seat post, appears to be nearly 1 mm wide! I thought it should be much smaller even allowing for room to push a post in. The cavity geometry gap varies, seems to get wider in depth versus entry point...

I still have time and room for warranty, but i admit this is quite unusual for a Colnago.
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