Threaded Carbon Bottom Bracket Vs Press Fit. (Just Give Up And Buy A Metal Bike!)
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- čas přidán 29. 04. 2023
- In this video:
The bike industry continues to try to make carbon BB shells work, but will it be successful and is it worth it? Every “Innovation” comes with its own set of unique problems and the threaded carbon BB is no Different. I give my opinion on why this probably isn’t the solution and why the industry keeps failing to make the carbon BB reliable.
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Reg. - Auta a dopravní prostředky
i appreciate the existance of channels like yours, that don't just operate as advertisements for the industry, but rather speak their own mind, based on expirience.
Thank you, that means a lot. ❤️🙏🏻
I started following you because you called out the muppet but i have to say your wrong on a few things in this video. galvanic effect on bonded aluminium/carbon parts is easily avoided by wrapping a layer of fibreglass on the aluminium part. fibreglass is an insulator. Giant had an issue with wheel drop outs falling out because of galvanic effect and their solution was - a insulating layer of fibreglass. with regard to your comment that carbon fibre is soft that is a pretty sweeping generalisation. f1 have used carbon threads for a long time (along with gearbox casings etc etc) there are so many types of carbon/resin. I can't find the video at the moment but the way internal threads are (usually) manufactured is by wrapping a very thin strand of carbon around a mandrel in the direction of the threads. this along with very high strength non conductive resin will make a thread stronger than aluminium and resistive to galvanic effect. galvanic effect can and does happen in steel Titanium and aluminium threaded bottom brackets the aluminium of the BB and frame only has to be of a different type ie 6061 or 3003 etc for galvanic effect to happen. anodising helps massively as anodising is non conductive but i'm not sure who if any BB manufactures anodise their BB's
I've got a carbon fork where the caliper mount bolt has completely corroded itself in. I've tried putting an M6 bolt in from the front/fork on the floor and hitting it with a fairly big plastic mallet but it's not budging. Do you have any suggestions, I'm lead to believe penetrating oil won't have any affect?
Carbon fibre f1 parts aren't worked on by the average cycle mechanic/bike owner. It works very well for its intended purpose but as can be seen on f1 cars, when subject to unintended stress or impacts it is notoriously fragile.
@@Andy-co6pn I mentioned f1 as an example that it is possible to use carbon for a lot of things. Any material when exposed to stresses it's not designed for will fail
@@ap6584 in my experience (and I've had to deal with a few brake tube nuts siezed into carbon forks) if what you've tried doesn't get the tube nut out drilling it out is the only option but I wouldn't attempt this yourself with a hand drill it needs to be set up in a mill so it's absolutely accurate
@@garyfodden5034 aha, and remind us, please, how big F1 budgets are?
Great video Reginald.
Time and Look
would be my only carbon choices..
But steel is real.
Looking forward to your next video.
All the best!
Thank you so much!
Excellent presentation. Cant wait for Hambini2
Oh me too, it’s been a long project.
Glad I foresaw the problems that occur with plastic bike frames and stuck with Ti.
Smart move 🙂👍🏻
I've had four carbon fibre bikes; one with a threaded (aluminium insert) bottom bracket and the rest with press-fit. Zero problems with the frame on any of them. So although you describe the engineering problems that could occur, in practice there are very few issues. As a bike mechanic, people tend to bring you their problems and hence the problems may seem more prevalent than they really are.
Good point. 🙂👍🏻
Just a point of clarification, I was talking about press fit bottom brackets. I wholeheartedly agree about the threaded carbon BBs - one doesn't really need experience in order to know threads in carbon won't work. Your arch nemesis, Hambini, has clearly explained why.
I own two carbon bikes, a Giant gravel bike and a Norco mountain bike. Both have press fit bottom brackets. Both the frames and bottom brackets have given me zero problems. Have owned steel and aluminum framed bikes before but would not go back. The weight, stiffness and dampening are far better with a carbon frame.
All true , i use Bsa or press fit carbon frames , Even on press fit bottoms you can get two piece thread together bottom brackets that work perfect ...
Nice comment. It’s down to experience and frame choice I guess. Steel bikes can definitely be nicer to ride if you get a good frame. (I have 2 steel bikes and the luged frame is significantly better) aluminium can as light but harsh, good for sprinting or young or if you are on a budget. And in my personal experience titanium wins at every level. Light, strong, reliable, Low maintenance, durable and comfortable. 🙂
@@reginaldscot165 I would go titanium also if i had too .
@@reginaldscot165 There are plenty of shoddy cheap as dirt steel frames out there. You should be comparing a good steel frame with a good carbon frame and not a very well made steel frame with some shoddy carbon one. As it turns out the carbon frame in this case will be just cheaper and actually provide a nicer ride. However I think as well that there is an upper limited to this "ride quality" think. At some level they both will be just fine and that's it. However when it comes to absolute high end steel frames they are certainly not more sturdy or durable than comparable carbon. The tubing will be so fine that it will dent quite easy for example. And there is a limit for usability on steel frames as well: some kind of corrosion will sooner or later eat them up.
Not true! I have been riding the hell out of the reynolds531 competition for the last 27 years, many thousands of miles and many tonnes of stuff hauled. Yes it dents easily but none of the 4 dents in the frame are in any way problematic
You are the best lowly expat bike mechanic in the world.
Ha ha, maybe? It’s not a very high standard then. 🤭
On my Sworks carbon frame i used an Sram pf30 to bsa adaptor. The bb shell appears to be up to spec and the cups pressed in nicely with a very light application of carbon safe grease. No locking compound. So far so good with my XT cranks.
Good news. 🙂👍🏻
After dealing with creaking from the bottom bracket on several bikes serviced by several shops, I'm staying with threaded brackets.
Yes it’s a sad situation that many shops don’t know how to fix it or simply can never find the sound. As long as your bike isn’t carbon you should have no problem. 👍🏻🙂
@Reginald Scot It will be hard to find press fitted bearings on an aluminium bicycle. It's interesting that it's that way. Only carbon fiber bicycles have PressFit and it is slowly going away.
@@jamesmckenzie3532 I'd be curious to see statistics about press-fit vs threaded including brands, material, sales...
On one hand metal is easier to machine for threads but also for a perfect press-fit fit, although welding might distort that fit, if machining is done before the assembly of the frame?
On the other hand press-fit is apparently the industrial rule, only the bike industry has gone back because creaking created a bad rep and customers want threaded...
@@DR_1_1 Actually, if you don't get bearings fitted perfectly, interesting wear patterns result. Pressfit cups can be set perfectly if the underlying materials are exact. Very hard to do with carbon fiber, but it is done with metals. Treaded brackets, like the Hambini ones, are exact but require attention to detail that most bike shops don't or can't do.
@@jamesmckenzie3532 Agree with that, but my aluminium bike comes with press-fit, that's why I was curious about statistics in relation to your 1st post saying that's rare...
Also Hambini's are really press-fits, "threaded" together, but not screwed to the frame, I believe, ie not what I was referring to by "threaded"...
So far I only had old style threaded BB screwed directly to a steel frame, and never replaced them (not even the bearings!) so they all started to become wobbly after a few years, at that point I just replaced the bike as maintenance was becoming expensive anyway (new wheels, gears, tools are never the same and shops want to be paid).
Now I'm on my first press-fit, Shimano plastic, aluminium frame, no creaking so far, I expect it will last for years since I'm not a very powerful biker!
I tend to build my bikes by myself. I really recommend buying a frame-set separately. I buy not the cheapest, but certainly not anything expensive at all. You have at least to give the manufacturer a chance to be honest and to do all that's required. If you go for the cheapest of all you have a guarantee that cost will be cut. If you go for a brand all costs will be cut too to make up for the overwhelming and obnoxious marketing. This is how they operate: make cheap products appeal by marketing.
When buying naked they will at least not be able to hide obvious manufacturing shortcomings by just somehow smashing it together during assembling.
If you maintain your bikes yourself assembling is no more difficult than what is maintenance. However if you are not really in to it. Well there are bike shops out there for that.
Go there try a bike to determine the geometry that fits you. Note the dimensions. When buying online buy only from a manufacturer, which is giving you the full dimensional specs in the product description. Just ask the shop about recommended group-sets for you and compatibility when you made your choice. If the bike-shop doesn't want to engage in this or is refusing to deal with anything but the monopolist brands take your business somewhere else. They are no-good. They should be happy to work on new parts.
For the bike assembly you should pay them something of about 4 work hours. This way they will really have time to do it nicely and precisely without a hurry. Remember: they have to make a living. You will still be on top those days by a huge margin or even a factor, compared to buying a brand package. And technically the bike will be of far better and assured quality.
I must be way to particular because it takes me a bit longer than 4 hours to put together… but you should see my bar tape. It’s wrapped nicer than a Japanese Geisha! 🤭
Enjoyed your comment. Some good advice here.
@@reginaldscot165 Of course it depends. I was mainly referring to a road bike. A general purpose bike I would buy stock on the cheap and just upgrade all the parts where corners have been cut one by one as they wear out.
There's a youtube video from a mechanic who was tasked at building up a Look frameset by the purchaser. It's his first Look bike that he's ever built and there's a very large hump on the fork where the resin sagged during the manufacturing process so that the disc brake bracket won't fit. It's so obvious that it would be impossible to miss during a QC check but Look shipped it anyway. Buying naked doesn't guarantee anything.
Can you and Hambini have a video chat regarding the bearing procedure. I find the video calls more useful, interesting, a better way to provide solutions and settling differences
Like a CZcams live chat 💬
I agree. That way it will also stay more gentleman like. We don't need more hate and arguing in the world.
@@Rusty-Metal Come on guys wake up , they dont have hate for each other , Both just making a buck ....
Yes maybe Look or Time with resin transfer moulding and accurately made and alignment.
I had 2 Litespeed frames back in the 90s, a road Classic and an Obed,both threaded bbs no problems.
My Colnago C40 has threaded alloy bb I think, no issues in 24 years fingers crossed.
Steel Bianchi,thr. bb,27 years no issues.Just needed facing.
Excellent! And a nice bike history. 🙂👍🏻
What about threaded synthetic resin/nylon/plastic cup ? This works with pressfit so it could also works well on threaded bb...
I have no idea! But I’m not a resin expert. 🙂
I totally agree
Boring!
🤭 Only joking, thank you. 🙏🏻
@@reginaldscot165 lol I could reword what you explained or simply agree 😊
Funny how experiences differ. 10 years + on carbon roadbikes, all with threaded bb´s, not one corroded or squeeked. The pressfit bb on my aluminum commuter, on the other hand, is a squeeking nightmare.
Are you using any type of retaining compound in your pressfit?
I have also never had any problems with my threaded BBs. (Well, minor instillation issues but nothing serious) But I have also never had any problems with my press fit.
On the other hand I have had customers with problems on both. And the main issue both work well when done right, except threaded shells into carbon?
I have several bikes carbon and aluminum. I have never had a BSA threaded BB creak or wear out the bearings. BB 30 bearings galled and wore out the aluminum BB 30 crank arm on two bikes. I’m going to keep watching to see if bridge have developed a working carbon threaded BB. If I had press fit your damn skippy I would have a Hambini BB installed as did several pro teams when press fit was standard on most tour level bikes
Yes we will see what happens. But you don’t need to spend 2x the price to get a BB that works well. 😉
I own a Pivot Switchblade(yes, it's a carbonfibre frame) which has pressfit standard from the factory. When the BB is ready to commit a relationship with the trashcan, I consider *_threadfit_* as a replacement.
I'll cross that bridge when I get there. All I know is I don't want to end up back and forth with some shop on something I mean is faulty, and all of a sudden they claim it is made that way. Spent months last year with one shop on a bashguard/chainguide that did not work with my bike, and I still feel the bike industry is lagging behind. Better just jump on a solution I have more faith in, even though there are no guarantees in life, it is better to aim for what we believe the most in.
Interesting thoughts. I hope it goes well for you! 🙏🏻
Can you please advise which is better for a titanium frame with Ultegra Di2, BSA threaded BB shell or T47 treaded BB shell? Is it worthy to "upgrade" for T47 BB shell when selecting titanium frame?
PF30 😁
Threaded is just another added step. A well made Ti PF30 gives you access to many options and is super simple to maintain and service. It’s literally just a metal tube.
I have built up 20 bikes with Ti PF30 BBs in the last 7 years and non have had any creaking or issue.
But if you absolutely positively have to have a threaded BB, go for the one that matches your cranks. If you want to run 24mm go BSA, if you want 30mm or Dub go T47. 🙂👍🏻 if you want to run both go T47.
Hello from Spain Reginald, i'm having problem with my new Giant Revolt Advanced, a creaking bottom bracket after upgrading the crankset. The mechanic had to put a new bottom bracket. The first FSA for 19 mm cranks was not creaking, but with the new BB from shimano, that is 24 mm for grx, the creaking is not stopping. I want to try to put again an FSA BB 24 that is aluminium, not plastic like the shimano, and see what happens. Also I have prepared retaining compound loctite 641, to try to stop the creaking. Next option, would be try that threaded bb that you show in the video (Could you recommend me one? My revolt has 86mm BB). And finally, the next step would be throw the bike from the bell tower of my village, and film that on video.
Thank you so much for this information. I wish I would have known this before to buy a fucking Giant.
(sorry about my english ;))
Hi, no problem. 🙂
Try one by BBB or Praxis, BBB is cheaper but excellent quality and Praxis offer a huge range of BB solutions for all crank and BB shell sizes. If you aren’t sure on the size you can ask them or ask a local bike shop to order for you for a small fee.
I wouldn’t use any “retaining compound” or any form of glue, only waterproof grease. First you need to check the BB shell is not misshapen, you can do that with the cups of the BB, see my video on “why I would never buy a Scott bike” to see the process.
Also be sure it is the BB that is causing the creaking, sometimes it’s actually the pedals or your shoes! 🙂
All the best!
Reg.
@@reginaldscot165 Thank you for your detailed answer. Today, after one month of investigation, a new mechanic tried something that has been the solution in my case. And yes, it was not the BB. (Sorry about my bad words, Giant. :_))
After showing videos and talk with this mechanic, he was almost sure that was a BB problem, but first, he wanted to try new cranks, new pedals... And in the end, he saw the little Flip Chip Hanger system from Giant revolt advance, where the axle is threaded. This system allows to change geometry, putting more or less distance between rear wheel and the frame. And it looks that can easily get dirty and without grease. He put some copper grease reinstalling the flip chip hanger, and the creaking totally disappeared!
I'm very happy, cause I wanted to sell the bike at some point.
So, for everyone reading this, and as you said before, Identify and isolate the noise origin. Sometimes it can have exactly the same sound. You will save money and time.🥲
Thank you again Reginald!
bruh this is what I thought while on a ride today. My most recent BB bearing change was a disaster. The inner bearing size was too small and the crankset shaft didn't fit through correctly. I live in a bike mechanic desert and the best guy I know is still not confidence inspiring. While I would have tried a different bearing to find one that fit ok, he forced the crankset through the too-small bearing by hammering MANY TIMES on the crankset with a mallet. Hammering hard. And the bearings aren't even working well. I live in an area that is horrible for bikes an BB bearings fail really often, so I really, really want to be able to do it myself, the right ways, at home. Problem might be that some of the reason the area is hard on bikes means it's also hard on steel frames. My friend noticed the other day that his one-year old steel frame has rust on the headset bearing mounting area.
I’m sorry to read your story, hopefully I can make a video to help you. I do plan to make more “how to” content. 🙂👍🏻
Im not so sure about the problems with mixing aluminum and cf, at least not when its bonded: i have a 1996 Giant cadex and there is no sign of any galvanic corrosion. Is that because the materials are effectively separated by the GLUE?🤔
It’s definitely a problem, I’ve seen it happen. There could be a number of reasons why you haven’t experienced it. 🙂👍🏻
Yep!
🙂🙏🏻
Do you recommend upgrading to the T47 bottom bracket for Litespeed titanium frames over their standard PF30?
No definitely not. Total waste of money, Adds complexity, and limits your bb options.
the bb shell on their bikes is perfect, fit the PF30 BB right and you won’t have any problems. In 6 years non of my bikes or customers bikes have ever come back to the shop with creaky BBs . 🙂👍🏻
Have you bought Litespeed titanium eventually with PF30 or T47 bb shell? I have been considering upgrading for T47 when I have found you got the same headache :) Can you please share your experience?
I will try it with a T47 on my coming Litepseed Flint, let's see how it goes... :)
Do you think the proponents of threaded carbon BB shells are not aware of those issues you mention? Because they seem pretty obvious to me. Or they just ignore them for some reason? Or perhaps they have considered these issue and it actually works?
I think it’s the same old story, rather than admitting carbon is a poor material choice they will continue to try everything to fit a round peg in a square hole.
Yes, CF threads are at least a brow-raising concept. However, I think you were not accurate about the root cause of galvanic corrosion. I wonder why manufacturers are not using anodized bb inserts (or Ti)? Anyway, the biggest problem is the difference of the thermal expansion coefficients.
Many BB inserts are coated or Anodised in some way, especially threaded ones, but it doesn’t last and often installation does enough damage to let corrosion in.
imho they are machining metal parts and during molding its inserted to cf frame. so its glued in between cf layers
that should last a while
another idea is to sand material away then reapply thin layer of cf+resin.
with the help of machined die to be inserted before epoxy hardens, basically to stamp the new frame hole.
Are you saying they should do this or this is what they are doing?
@@reginaldscot165 i dont have insider info, but it should be doable to insert metal bb "holder" into cf.
years ago i had working experience with fibers on gliders.
some materials can be inserted during the manufacturing process.
I want a scott spark 950 aluminum. The 940 is carbon and i nearly ordered that instead 😅
👍🏻
10 years of press fit without issues for me. Every time I’ve had a creak the immediate reaction is to blame the press fit and without exception it has always been something other than the bottom bracket
Yes you are correct, I’d say a good 70% of people that come in complaining about the BB are actually mistaken and it is actually something else.
Hmm I have a more than 10 year old Storck Absolutist 0.9 carbon bike and a Shimano Ultegra 6700. Not the least problem at all. The BB says SM-BB6700. It looks like threaded. Will not dare to remove it 😨 🤷♂️
Cool 😎
I think it’s wrong to say carbon is soft. It may be brittle, but it isn’t soft.
When you consider what other things are made from carbon fiber such as aeroplane wings, F1 cars, even gears used in transmissions can be made of a carbon/steel hybrid. A bike frame is really low down on the list when it comes down to the loading and stress capabilities the material can be subjected to.
I personally do not think there is an issue with Carbon being used as a bicycle frame material. It is very strong and very light, that makes it an ideal choice. The issues I see on the internet lies with poor manufacturing techniques and poor QC in my eyes. Or poor handling of the material by the end user, such as over torquing bolts and such like.
I’d like to add that I have two carbon frame bikes, two aluminium bikes and one steel bike. My favourites from my fleet are my carbon bikes. They are the lightest of my bikes, the frames are more visually appealing to me with their more distinctive tube shapes and smooth lines and they are an absolute joy to ride with their zippy feel.
I have a pressfit Carbon BB in one carbon frame and an alloy sleeved BSA threaded in my other carbon frame. I’ve had zero issues with either of them. Replacing BBs has been very straight forward on both of them, no creaks, no poor fitment nothing at all.
I have nothing against other materials either and I’ve not experienced any structural or manufacturing tolerance issues with any bike I’ve owned. I don’t know anyone who’s had a poor carbon bike and I know a few keen cyclists, I have however known of aluminium welds failing.
I wonder what the true ratio is between defective carbon bikes vs those that aren’t. The ratio surely can’t be more carbon bikes are defective than are not, we just don’t get to hear about the many thousands of bikes that are absolutely fine.
Good topic, but I’m going to agree to disagree with you on this one 😊
I’d have to disagree, Carbon that I have experienced is very soft, it scratches easily and turns to powder if you rub it with something harder like metal or even the plastic cables on your bike! When compared with even aluminium it’s soft. It’s incredibly strong and has good flexibility but it also doesn’t like impact. If you made gears out of it without cladding it in metal first you would get a gear box full of dust! 🤭
You can’t directly thread carbon - it’s a threaded metal insert which in itself is press fitted (and glued) into the frame. Whichever system they use it’s always a form of press fit.
It’s my understanding that in this particular situation the technology allows the tapping of the carbon shell with no need for any threaded insert. That is what is new about this project.
@@reginaldscot165 Interesting. Let’s see how it plays out, if it’s all good then we may at last have a reliable solution to this frustrating problem that plagues the image of carbon frames.🤞
you mentioned that youve had no one with creaking BB in 6 years...could that be due to your climate where you are? Obviously in the UK, where I am.....climate can be very moist at anytime of they year and very much so in the late autumn/winter?
Well in south east Asia we have an extremely humid climate, it’s very hot and very damp. But does your PF30 titanium bb make sounds?
Maybe it’s because I’m a brilliant mechanic and my instillation is fantastic 😅
@@reginaldscot165 ah sorry I thought you were in the Middle East for some reason
I have family in Malaysia so know how incredibly humid it is there
From what I understand, the threaded area is a metal shell placed in the bottom bracket during the manufacturing process.
That is indeed a design of some BB shells, using an aluminium sleeve, but in this case it’s cut directly into carbon.
Or use a BBInfinite...
hello 1900 ,,ever heard of carbon chainrings , it's 2024 get with the program please
Bit of an odd comment. Sort of a mix of catchphrases? Yes I have heard of them. Very expensive and don’t last long… is that the “program?” You want me to get with?
Giant bikes have no issues with presfit bb.
Ha ha you are funny 😆 👍🏻
@@reginaldscot165 mine doesnt
@@ozgurinsan there are many bikes that have no issues. We just don’t get to hear about those.
Likewise not one bicycle I’ve owned has had a manufacturing defect.
Press fit is fine manufacturers just work on your circles and call it a day 🤦🏻♂️
🤭
In fairness to manufacturers, if they were to make a cfrp frame properly no one would be able to afford it.
Ha ha ha that made me laugh out loud! 😂 👍🏻
No. This is not true. You should know that western brands (and the one from Japan) with ridiculous pricing charge you mainly for their marketing and not the product.
Hi Reginald. A bit of contraversy then. I'll just through in a few thoughts, neither for or against.
First, I won't argue against your selection of press fit, though threaded BBs served the bike industry well for 150years or so. The point with the threads is that they are self tightening under the normal pedalling loads.
I've seen Roaul's video (I've almost certainly missplealt his name, sorry). I don't altogether agree with him about fibre direction. Not in the sense of whats best but in the sense of achievability. I have seen a process (in aerospace) which leads me to believe that it can be done. I have seen a vid clip in which one of the inventors (of this threaded carbon BB) speaks, and he makes a good case that as last resort a damage thread could be saved by boring out and bonding in a metal tube. Why not a Ti tube I wonder why Al? But thats off subject. One thing I will say is that engineers are clever (notice all the advances made) and we should trust they know something we don't up to a point. I would like to see the proof from lots of other customers not have troubles before I bought in.
You showed the "press the bearings directly in the BB shell" system of Canondale (I forget the spec). That would appear to be the lightest solution and it only then involves steel and carbon for corrosion. Steel and carbon have less electro potential difference and less expansion difference, so it seems more feasible. I wonder if there might be a process available to harden the surface of the composite recess (that ceramide?). There is no difference, in principle, to the bearings pressed in wheel hubs or even head tubes (which is well established) except frames cost more than wheel hubs.
When we talk of galvanic corrosion, the critical factor is the electro potential difference of the materials. Compared to carbon, aluminium, titanium, steel, roughly in order from worst to least. As a trip down memory lane, the first carbon bikes where made from plain carbon tube bonded into aluminium lugs. Corrosion was the problem. The solution is to isolate one from the other and in this case a single ply of E-glass over the carbon will do the trick.
I have no experience of ceramide, which the carbon thraeds are claimed to be coated with but guessing from the name (a trade name?) I would suppose that this is a ceramic. Most ceramics are insulators, as much of the electrical engineering of the late 19th and early 20th centuries display, so it has the POSSIBILITY of being an electo isolator in this BB application, maybe, maybe not. Ceramics also tend to be hard.
Composites (including carbon) are very process dependent. Get the cookery right and its great, get it wrong and well not so good. I have seen articles of frames made in the far east where the workers are laying up with bare hands. I'm horriified, all that grease compromising the resin matrix. Temperatures and pressures are fairly critical too. NDT is important but very difficult, if done, so dealing with someone else's carbon is guess work and trust.
The fit of press fit BB and the sanding out? The manufacturers should have made it undersize and sanded it correctly before it left the factory.
Your suggested solution of a shell BB in two parts which thread to each other, still need electro isolation in carbon, and al threads are soft too but sacrificial and cheap compared to a frame.
I am neutral on the subject of carbon BB and would like to see where it goes.
Keep up the good stuff.
No please argue away! My mind is not set in stone! I’m always open to a good well made argument. 🙂👍🏻
Lots to reflect on here, a very well thought out comment. It’s a privilege to have such people in the comments section.
One point would be about you questioning why not use Ti rather than aluminium as a tube to be Inserted into the frame? A few people have mentioned isolation of the frame and Aluminium tube with glass fiber to prevent corrosion, however nothing I can think of solves the expansion/contraction issue of the metal in the carbon. Whatever you bond in is going to de-bond eventually I would have thought, if you use Titanium it will just be more expensive when it does?
As for the magic of this new carbon technology, as someone with limited knowledge of resin composites (I have more experience in metallurgy) I checked out their website and as far as I can see it’s still moulded carbon (they are obviously staying tight lipped about the full process) with a Cerakote coating on it… if it’s not impregnated with anything I’m not confident they will have resolved the corrosion issue. But I didn’t see the interview people are talking about so I may have missed a lot of useful information.
I remain sceptical, for me its just another distraction from what people should be doing. Buying titanium bikes! 😂
I would say is the addition of yet more construction cost of more advanced/complex carbon bikes passed onto the consumer worth it? For me I will just stick with my super light, super reliable, super comfortable and environmentally friendly titanium bike. 😉
All the best and I hope I have the pleasure of seeing your comments again. 🙏🏻
@@reginaldscot165 Hi, I'm not against Ti, far from it I'm all in favour. If I buy another bike it will be Ti.
Most people want carbon because all the pros ride carbon. A fashion thing. It does have more potential for aero but more pitfalls for production.
I look forward to your reply to H's reply.
@@emmabird9745 The overpriced western brand crap which has been nowadays ballasted with disc brakes and batteries for derailleurs . However in a reasonable bike a carbon frame provides an unbeatable balance between cost performance durability and unbeatable weight.
Well, I was going to go look at a carbon fiber bike
I wouldn’t… but I’m crazy. Have been for years. “Crazy guy who rides metal bikes” they call me. 😁
Titanium bikes rule them all. Good as new 35+years later. All carbon bikes just one serious crash away from total loss.
Agreed 👍🏻
So don't crash them... :)
They said that if you destroy threads they will put metal insert in the frame.
Yes I heard from someone about that, I also heard they can’t repair the threads. And if you put a metal shell in are we not back to the same problems the other frames have? 🤷🏻♂️
Here's valid analogy to think about.
Communism is a really nice idea. You get what you want/need whenever you want/need that.
Anarchy is a really nice idea. You are in control of every connection, no government is there to create a tax and law barrier for you.
But the problem is that in practice these don't work at all. These systems have such a high human material requirements, that even small groups (up to 10 individuals, let alone giant nations) can't handle it due to how faulty human moral image truly is. Human is the problem, not the system.
Press-fit has the same kind of issue. It's a brilliant idea on paper and it works in automotive and aeronautical industry, in the heavy machinery, etc. But given how shitty manufacturing processes are in cycling industry and how giant corporations can't give a flying eff to improve the quality of their goods, you're asking for a problem by implementing press fit to loosely-made and badly QC'd product. In this case I will choose threaded BB any day of the week, disregarding how amazing and trouble-free press fit can be in the ideal world surrounded by little fairies and rainbow unicorns. We're living in the world of crooks, terrorists, burglars, liars, hypocrites and other pesky bastards trying to screw you left and right. I wanna ease my pain of living by choosing the product that doesn't add troubles instead of dreaming of the magic experience of engineering perfection that just can not be.
But aren't the bearings in threaded bottom bracket cups pressed in?...........
@@garyfodden5034 Do you understand that cups are machined from aluminum? Machining is very precise. Molding carbon fiber parts is not. During epoxy curing period, the material distorts, leaving your meant-to-be-round bottom bracket an ovalized misplaced mess. QC staff in the cycling industry lets that shit slide and then badly misaligned, mangled BB shell goes to the shop for customer to experience all kinds of creaking, drag and premature bearings wear.
@@garyfodden5034 That's why the old style BB's with loose bearings are still the best operating parts.
@@tweed0929 do you understand that carbon fibre can be machined to very tight tolerances?
This comment is a work of art… I loved your Analogy and when I got to the end and read the bit about “we’re living in a world of crooks, Terrorist… I was thinking “yeah and that’s just the British government!” 😅
Excellent, 10/10 must read! 👍🏻🙂
For some reason most bike brands can't machine a round hole into carbon.
Funny isn’t it… 🤔
You can't machine carbon on the production line, because the dust gets into the tools and destroys them quickly. You have to mold CF to precise tolerances, and most manufacturers seem unable to do that. Time does a great job with their resin transfer molding, but their process is expensive and probably won't trickle down to lower end frames.
The BB68 threads where designed to fit high tensile strength steel. Even for aluminium they are technically far too fine. Almost always when changing the BB you run the danger of cross threading it in aluminium. And BTW galvanic corrosion is not something unknown to the interface between the different metals in the BB. Always apply grease in interfaces between different metals. Copper grease is cheap, ready available and just fits the task. And of course I have never ever seen a new bike with properly greased bottom brackets before assembly.
And then they propose threaded carbon?! People should RUN from this engineering wankering.
When you have a press fit BB for the threaded together variants. I even did go for some ceramic bearings just for the pace of mind when it comes to corrosion and thus logevity.
Good points, copper grease is my favourite! 🤭 and yes you are correct the threads were designed for steel not softer material. It’s something nobody has mentioned yet! 👍🏻
@@reginaldscot165 Who never cross threaded an aluminium BB please throw the first stone! However another point you forget about is that more frequently than not those thready will not be executed properly at all:
1. Cut by absolutely worn tools.
2. Cut without proper alignment left to right.
3. Cut before welding the frame which in esp. in aluminium will guarantee some distortion.
The only advantage for threading is the assembly: you can almost always somehow force the BB in no matter what. Good luck customer for trying to prove that the BB was already cross threaded during initial assembly.
In short poor engineering. Every bottom bracket should be reamed to a final size but costs savings preclude this process - hence a bunch of frames not made to tollerance. This is where hambini has jumped in on. For rhat reason is why I always go for BSA thread where you can easily screw in a square tapered bearing unit in 5 mins and at a reasonable cost. Im a mech tech mtber and I would not touch carbon, not saying it doesnt have it benefits but if i had a preference Ti for frame material.
Good comment. 👍🏻
I have heard machinists say that it isn't feasible to ream carbon bb shells because the resulting carbon fiber dust gets into the tools and destroys them quickly. Also, whenever you grind through the carbon fibers after molding, you risk significantly weakening the material. The good option seems to be resin transfer molding of carbon fiber, which allows much more precise molding of the bottom bracket shell than molding with pre-preg. Time uses resin transfer molding, and their tolerances are consistently excellent.
Raoul was the reason that I ditched my one carbon frame, lol. I'm at 3X Ti, 2X steel, and 5X Al for the fleet. No desire for carbon.
Good choice 👍🏻
Nah. Just don't go for the western brands where you pay overwhelmingly for marketing.
That’s often true. 👍🏻
@@reginaldscot165 It is always true. Pushing a brand isn't for free. I know the actual hard numbers from the phone industry. The cost of marketing is 70% - 80% for the so called high end. It sounds ridiculous, but that is how the degenerated oligopolies work. It is a safe bet to assume the same for other industries as well.