Can't believe that Cervelo would use such a ridiculous method of retaining a rear brake caliper? Great work as work as always Mr. Hambini...

This is the video that originally brought me to your channel. Bought a PlanetX Pro Carbon 2 years ago, and almost immediately snapped the thread from a bottle cage boss, they wanted nothing to do with fixing it, even though it was under warranty, so i had to just deal with it. This video was in the related videos section on a GCN video a few weeks ago, so clicked it wondering how hard it would actually be. Turns out that it was a piece of piss to drill out and drop a new one in, and cost £8 for the tool with some rivinuts on ebay. Thank you 😁

You should have put some copper grease on the nut to mitigate the galvanic corrosion.

Although I do not have mechanical engineering background but I have just binge-watched almost all of your videos :) and I want to thank you for going into details to explain things. Please do go into technical details I do enjoy that. Your recent video about Shimano BB86 and Scott Bike Case Study was very insightful and one of my favorite videos.

Dude, wash your bike!

I still ❤ you hambini!

Comments are very helpful, 1. Copper grease can prevent that to happen again. 2. Very clean demonstration but you need to clean your bike man. 3. This Channel is good.

I love you showing every possible reason why people should stay away from carbon 💪🏻

I like to watch your video. It's nicer to work on your bike if is clean. I had the same problem on my road frame and I solved it in the same way.

Do you not use any anti-seize compound on your bolts to try and reduce the corrosion? I've always found that the Park Tool ASC-1 compound does a pretty good job at reducing corrosion between aluminum and titanium interfaces and if reapplied during a yearly overhaul can help reduce the acceleration that your bodies sweat can have on that corrosion.

I have used a little superglue "Cyanoacrylate adhesive" to stop a rivnut from turning, If you feed the glue in like you would soldering or brazing ( surface tension ) you can often remove the fixing bolt.

Thanks for shearing

Why no grease on the bolt? That's inviting the same problem again..

i like this kind of mechanics who do full on repais, not just some parts swap

dude you are the man...

FWIW, given the possible damage to the carbon, Cervelo might replace the frame for you. Last year Cervelo replaced my bike when a single tiny rivet broke off of one of the cable tensioners. Guess they couldn't rule out that the downtube was compromised and decided to give me a new frame.

You need a sacrificial anode to stop the corrosion, there is so much crap on your bike that you could place it anywhere and there would be an electrical connection ;) I cant believe a five thousand pound bike has such a rubish fixing for the brake. Rivnuts are utter crap, any vibration and they come loose or damage whatever they are fixed to. The fixing for the caliper should have been embedded in the matrix of the frame when the bike was made, not crimped on as an afterthought! Anyway keep up the good work.

Great informative video keep it up!

If you drill at a slight angle it helps stop the rivnut turning but will continue to cut even if the rivnut spins. I prefer the epoxy method, it helps secure it without stresses and also helps reduce galvanic corrosion.

Good to see carbon frame repairs, I bet there are many bridges jobs out there. Have you seen the UV setting adhesive? It's derived from dentisty. If you have, what's your take on this as an adhesive for repair or mounting bosses?

Thanks for sharing

loctite freeze on tire and rim, nice going m8

Hi Sir Hambini, any suggestion, how shud and can i prevent and care for my Aluminium Frame from corrosion? , i mean the inner tubes of the frame, by any chance, shud i spray the inner tubes in the frame with wd 40?

Thanks for the video i learned a lot from it. Would you think that a stainless steel or titanium frame would be more resistant to that kind of failure.

Do you have any plans to make 68mm english threaded bottom brackets? I am thinking of upgrading my track bike to a sram omnium or sugino 75 DD, and want to avoid press fit bottom brackets. Anyways, thank you for the epic content, keep it up!

How long would that last? That fix especially looks like it with break again the first time you brake.

"Job complete". Not sure I'd agree with that. Your part failed due to galvanic corrosion. My initial thought watching this video was surprise that a very smart engineer such as yourself who rides his bike in such wet hostile conditions would have allowed that to happen in the first place. I'm referring to the lack of any dielectric compound smeared on the threads prior to assembly to mitigate that corrosion. Clearly an issue evidenced by the corrosion that you pointed out on your handlebar clamp. Why not take all of those fasteners off, use a brass wire wheel and brush to get them back to bare metal (or just replace them...), smear well with grease, dielectric compound or anti-seize and keep it from happening again? Waterproof grease liberally applied is probably best in your climate. Your bike is a ticking time-bomb of part failure. How bad would it suck for your handlebar to snap off while you're riding due to fastener failure? Anyway, thanks for the #nerdporn.

Brilliant video, one question about rivnut’s, how strong are they? If I wanted to add disc brakes to an older carbon bike would I be able to attach them with rivnuts? Thanks

Hey great video, I just discovered this. I have the same problem with my seat post bottle cage rivnuts. Any help would be appreciated! Mine were loose so I tried pulling the rivnuts out, but I may have wiggled it a bit to get them out, causing a tiny chip on one hole (it's like a slight Q shape now). If I take the original expanded rivnuts that I took out, I am able to put them back in the holes without too much hassle. I'm thinking maybe the holes were enlarged a bit. Everything is out though. Just left with these holes. I think the rivnuts weren't corroded too badly as yours, but they must have come loose with vibration over time. I can't find anybody who seems confident in fixing this. I'm not experienced with epoxy but I can follow instructions quite well. Should I try (bigger) rivnuts or some epoxy? What type of epoxy should I go for? Or any other suggestions?

Just wonder. Wouldn't be possible to user steel rivnut with steel bolt? Finding adequate steel bolt shouldn't be a problem, and at the end would prevent corrosion, right?

Alternatively, if your a Cheap Skate like me, Slot the Riv Nut in the Hole, put a Nut on a Wheel Skewer, Screw the Wheel Skewer into the Riv Nut and then Tighten the Nut on the Skewer towards the Frame, worked a treat when i had a loose Riv Nut on my Merida. I use a Bit of Cloth so as not to mark the Frame in any way.

Curious to me your saddle possition!

Before gluing in the new nut you must clean out any penetrating oil that may have got in there. Use something like Methylated spirit on an ear bud.

What if the rivnut doesn't move, just the thread has been stripped? Would it be best to tap it out? Currently dealing with this problem at the bottom bracket cable guide. Thank you!

Preventive is the best medicine for any nut or bolt seizure on any bike parts. You're right rosomak. Copper grease from automotive place or if possible hardware store. It will also prevent the dreaded cold fusion of nuts and bolts or when there's contact between metal / aluminum / titanium or steel for seatposts and bottom brackets. Of course carbon grease for carbon to steel / aluminum contacts.

Nice video. I am skeptical, however, about the ability to effectively hold the round and minute protruding rivnut rim while drilling the core out. Of course, losing some depth of paint around it helps, but still....

Have you washed it yet?

I love your videos Hambini best technical vids on the web but bloody hell the clearance between your tyre and frame is miniscule. Don't go gravel riding !

Please tell me that they didn't use a rivnut on the front brake also...

Hambini you need to put your S5 in ISO.

If the set Rivnut pulled out the hole created was then bigger than the correct sized hole for a new Rivnut so that it is unlikely to be as secure (if at all) as originally. The best thing to do is to use a larger say, M6 Rivnut and bolt or fully coat the Rivnut and hole with epoxy, set the nut and leave the epoxy to set and hopefully there will be enough interference to stop the new Rivnut pulling out. Also, one of the complications here is that the titanium bolt is too long. The threads project too far through the set Rivnut and will clog with corrosion from the Rivnut or any crud floating about, when that happens the bolt will bind up and probably spin the Rivnut, never mind that its a waste of a bolt length and adds weight. Ideally, only 1 thread should be showing at the base of the Rivnut internally, which means that the bolt has maximum thread engagement without the possibility of clogged threads. Personally, I use Alusteel Rivnuts as they have greater mechanical strength and you can set them with higher torque for better holding power and there is less likelihood of galvanic corrosion. Also with steel threads the threads are less likely to strip or the bolt pull out after repetitive assemblies, a dab of anti-seize grease is sufficient to ensure no problem unscrewing the bolt.

Your commute looks brutal. I certainly hope the S5 isn't 'the good bike' :)

just a note on alignment for the rivnut might be good ? I would be concerned if the nut was off centre a touch and then affecting the calliper. Otherwise nice video please make more.

Just want to know what size of the rivnut need for cable guide under the bottom bracket? Thanks

Why not lightly clamp the rivnut in the vice an use a socket? just an idea love the channel

Many of the commentators here are missing one important point - this video is not about how the problem could have been avoided and what the guy should have done in the first place etc. It is simply about how you fix the problem, if and when it happens. It is not about "please advise me how not to get a broken rivnut in my bike". Those who want to say that should consider creating their own videos on the subject.

Normally the manufacturer put a fibreglass piece in the frame to act as a barrier to stop the galvanic corrosion. I wonder if Cervelo did? I have a S5 and the rear brake is a bit of a poor design and the bracket acts like a lever when braking. I know it is about being aero. But I now don’t buy aero bikes as they have these special parts which can be a pain.

Does Titanium react with alu? i would imagine it does

How does one remove a m5 seat post Allen key bolt that is damaged and the allen key has no grip ? Thank you

Why don't they use the hexagonal rivnuts rather than the round ones with lines?

Now you can wash your bike ---please !!!

well done.. also yes, that Cervelo is filthy.. lol.. filthiness is for Felt's man, not Cervelo's...

Added Suggestions; - Remove RearWheel (to have more room to work, as it appears that the 'axis' of the RivNut was too close to tangent with the wheel, and the additional width of the tool making it appear to be simply added hassle and interference)... - Add a touch of Epoxy to RivNut/Frame (for less likelyhood of this situation occurring again, and 'fill in' the voids that occur when removing broken RivNut - additionally handy if you want to touch up the paint). (This may also make 'Removal of a previously Spinning RivNut' - unnecessary.) - Anti-Seize on Threads (for Better Initial Tension, Less Corrosion, Easier Removal)... - Steel or Titanium Bike Frames (are less likely to have these issues)...

thats the way cervelo attach a rear caliper??? crazy

The bike is begging to be cleaned. Sir Hambini, can you make a technical video shed light on various frame materials like steel (Fe) vs Ti vs Al vs composite in ride quality and damping capacities?

From what I see, there is no problem with the titanium screw and the aluminium rivnut. Here we have two problems: No.1) The aluminium rivnut is corroded away due to a galvanic reaction with the carbon. No.2) The bike is filthy as heck. This is no dirt from a week of commuting. This is solid patina, built up over months without any cleaning. The dirt together with moisture leads to corrosion like this. I always check if rivnuts on my bikes are properly sealed with paint. If not I just seal it with super glue. It's also a good idea to use weak loctite on screws, because it seals the thread. And yes, I am engineer.

grease all bolts will help stop galvanic corrosion

Odd that the Ti bolt is so long. That's the original presumably? I can't see why it's so long when the rivnut thread seems so short - surely a shorter (steel) bolt would be better?

What happened to all videos from last 2 years? Please upload them to Vimeo for example.

hi not to be to critical. you ride your bike in the winter and don't maintain it. I saw the one when you changed the rusted head set bearings. as an owner of any bike you have to clean and maintain on a regular basis and not wait until its rusted or broken. a simple clean and lube or grease its worth it in the end. its a bit of fussing around ; however for me it brings a certain amount of satisfaction. the rivnut would have lasted if you cleaned the bike . so my real point or question is if you ride in the winter and don't want to be bothered to clean and maintain your bike why on earth ride an expensive bicycle ? you could buy something nice as your winter bike and still be able to stay in shape and go 30 klm / hour . and finally I saw the comments and your answers to as why you do not put grease around the head set bearings. in my humble opinion grease keeps the moisture out even though it attracts dirt. that's why i do regular maintenance on my bikes. and yes i have one for the winter which is like your aero bike a project in the making which maybe i will finish by next winter. and does grease really hurt carbon fiber. they do paint the bikes for protection and yes I am careful not to get any grease on my carbon fork because i have heard its bad for the carbon fiber. you are dammed if you do and dammed if you don't. there must be something one could use thats not going to react with carbon fiber. other wise I do enjoy your videos thanks

I LOVE but why not to clean the bike when you inserting new bosses ore reinstall break calliper. The contact point between the frame and the break hanger filled with junk is gone damage you frame in that area and result in loose break calliper and less precise/string breaking.

Great video, but my case is slightly worse than yours. My water bottle rivnut has popped clean out from the downtube and taken a bit of cf with it - leaving a ragged 1cm diam hole. (Bottle cage now kept steady with zip-tie.) What I'd like to know (and how to do it) is whether to fill the hole with epoxy putty, or the trickier but maybe stronger solution of bonding layers of cf around the hole before drilling through them risking tearing, and then squeezing in a new rivnut. Obviously you shot this last year, but can i suggest that you treat yourself to a decent winter bike with mudguards and everything?! Even pro racers don't care what they look like when riding/training in shit conditions.

That seems like a very poor design, there are significant forces on the brake bolt. The frame should have an embedded piece of metal that is part of the carbon fiber construction, not a drilled-in afterthought.

i grease all my bolts before install. is that wrong? i also smear a light coating of grease into my booties for waterproofing. ugly, but it works in Canada in the winter

2:07 You were gonna what? Did I hear that correctly?

@Hambini Unreal that you use an S5 with Di2 as a commuter

Ok so its a commuter - we get that but breaking a boss on a filthy bike to clean one component is a bit naff. Why not leave it alone - happy and filthy. On my commuter I will wash the critical components at either end of the ride (often just with the water bottle and a rag) or the hose at home so that the drive parts work smoothly and last longer ( quality 60 - 90 seconds ).

why does everyone use round rivnuts... right right, round holes are easier to machine, but they make hex and square ones. That way even if things go sideways later you can at least get the fasteners out.

Ridiculous cost cutting by Cervelo going with rivnuts. They should have used a tapped piece of aluminum bonded into the carbon for that design.

Has a different electrical charge??

Could you point me towards a suitable epoxy? Everything I've tried hasn't been strong enough and I've always had to use the rivnut gun.

Those fuckin riv nuts give me anxiety, had a Cannondale in 05-07 and i must of replaced the waterbottle riv nuts half a dozen times on the bastard.

lol , grab the tool with a pair of old pliers , that will help make it really nice for future use.

Putting some thick lube on prevents or delays galvanic corrosion for some time...

A weeks worth of dirt?

I usually wrap around rivet simple nylon thread with some glue, that makes perfect insulation from carbon.

Aluminium and carbon don't mix either. A lot of carbon-wrapped aluminium products have a layer of tissue between them to prevent this.

Titanium screw on alloy part is not a good combo....

carbon is porous, why not coat with resin & paint the surface; Less moisture absorbson and less galvanic corrosion with AL. p.s. Great channel and info except for the issue I mentioned.

Seems to me that the rear caliper nut problem is due to poor maintenance

Isn't that classed as a crappy Engineering design in the first place? Normally on carbon fibre assemblies, mounting nuts or studs are welded to a perforated steel disk, the carbon fibre is then bonded to the disk making the nut or stud an integral part of the frame. Compression nuts are really for steel plates, where there is some mutual deformation to hold it in place.

borenco.nl/nl/artnr/10230100210a2/blindklinkmoer-vk-rvs-a2-m-10-x-21 These are stainless steel and they have groove's so it won't spin easy Also very important you have to apply a rivnut that krimps over the thickness of your material if its to long its loose if to short you wil damage the carbon

Did you buy a new bike yet ?

all you people whining about using grease you just dont get that its a small aluminum nut and very hard bolt, meaning you can only torque it very little, by feel generally, and it just must hold the caliper no matter what as brakes are important. Using grease you risk over torquing, stripping threads or that the bolt would come loose. I actually in such low torque application use special wax based clear paint which acts like a glue, but it melts from alcohol or heat, so no problem undoing the bolts.

And in a year or two you will have to repeat this procedure again? Why not use rivnut made from the same material as the bolt? That should prevent the galvanic corrosion.

I have some nuts, not sure if they are 'riv' though.. ..hehe

Note to self : Never buy a Cervelo.

Use a car - sorted.

JB Weld would sort that out

this bike looks so dirty and bad shape corrosion all over and the 1:21 stem in front can see it too.

I guess carbon aluminum potential difference is much bigger problem. This is totally unacceptable in aerospace industry.

Omg that seat is almost offensive lol.

Do they make titanium rivnuts? This may be a better solution. You may need a hydraulic gun. These things are expensive, try to find someone that will lend you one or do it for you. edit: I just found this item. RIVNUT SFC for CF material. www.boellhoff.com/gb-en/products-and-services/special-fasteners/blind-rivet-nuts-rivnut.php kzfaq.info/get/bejne/jpijrNZ52N25l30.html

I'm not a happy bunny.... there was clearly damage to the carbon composite around the failed rivnut, yet you failed to address this.... It's your brakes, man! (ok, so it's only the back, mostly useless, one). But FFS laminate in some new cloth to reinforce the hole!!!

i do not have that problems on my columbus slx frame

Squeeze your gun handle a lil’ when removing gun thread shank.

Strange looking mountain bike.

titanium bike with titanium bolts. problem solved

Just keep your bike clean.

Aluminum Seat Post Frozen inside steel frame...... You can destroy a seat tube taking it out!