RUST and Scale inside Brand New "Coated" bike frame | HAMBINI TI BSA30 | COTIC 

When someone emailed me this morning to say Hambini had done a Cotic episode, I have to admit I was thinking of trying to find some vasiline to ease the pain, but I'm overall pretty happy with that. I'm glad you picked up on the details we work hard on, and every Cotic frame is hand finished, faced and chased in the UK so every frame has our eyes on it before it goes to a customer. As for the corrosion, it looks alarming, but we have been doing bikes like this for nearly 20 years and I can't think of one that has corroded inside out. We have had a couple of our older Roadrat and Escapade frames die after years of being salt bathed on commutes without touching up paint chips, but that's it. It is worth noting that the internal corrosion protection is part of our workmanship and materials defects 5 year warranty, so if by some unlikely chance the frame did corrode through we would replace it. Ultimately our aim is try and be better than that and make long lasting frames that people don't put in the recycling bin (unlike carbon which breaks and then is landfill) and I would expect that frame to last a long, long time. I am not above criticism though, and I will be taking up with our frame vendor about the e-coat process again and the weld spatter. As for some of the comments: - Head tube concentricity: Big, relatively thin wall metal head tubes deform under weld heating. They just do. They key is understanding by how much and making sure than when you post-fab ream the frame there will always be enough material left. That's why you can occasionally see a couple of tenths of mm difference in wall thickness side-to-side and front-to-back. The facing and reaming process ensures the important thing, that the headset is concentric and square. - Chainstay clearance differences: Again, this is manufacturing pragmatism. The drive side stays are bent and crimped differently to the non-drive side for chainring clearance, and bending processing are relatively imprecise compared to moulding a carbon frame or CNC machining something. So, the stays around the crank ends are to a tolerance of +-2mm lateral location. Overall the tolerance is always within the minimum width required to fit the narrowest crank we're aware of (and I'll admit I haven't checked those Rotor cranks, but they're narrow) so cranks will always fit, even if there's a mm or so difference in cleareance side to side. In my opinion, that doesn't matter so long as it clearance, and so long as the critical items like chainring and tyre clearance and dropout spacing and alignment are spot on, which they should be. Those dimensions are much more tightly controlled from a tolerance point of view. This means our chainstay tubes can be bent to realistic tolerances and still provide the key dimensional requirements. Hope that's of interest. Cheers, Cy Turner Founder and Director Cotic Bikes

That’s an IS mount (International Standard) I believe. But it’s easy to get an IS to Post Mount adapter. Interestingly, I love these bikes and once had a job interview at Cotic and met the founder Cy, but missed out on the job. I’ve since had a lot more experience and still hope to join their team one day!

I would love to see more mountain bikes here.

The through axle is a system from Syntace called X12. There is an nut clamped on the drive side for wheel alignement, 3 version of the nut are available, 0, 0.5 and 1mm off eccentricity. meaning you an adjust the camber of your rearwheel by loosening the bolt and and axle, then turn the nur into the desired position to get it straight. Usually it is done by the manufacturer, check for a small mark on the nut, which should align with the gap. And the hanger bolt is a break away part in case of a bigger crash, so you dont have to buy an expensive hanger but a fairly cheap aluminium screw.

Internal humidity in the frame is why you always take the bike indoors and remove your seat post every so often to dry it out. A spot of grease at the back of the joint between seat tube and seat post will be sufficient to stop the majority of water ingress. Never go with internal cabling on a steel bike, just more holes to get water in

Super interesting! But as a roadie and an MTB rider I may be biased. Steel is popular off-road because of its general toughness and resistance to impact damage and scarring and scraping. An extra kilo of frame weight is really not relevant when the system weight i.e rider, backpack, bottle, clothing, is around 100Kg. Turns out that your comments regarding corrosion are well placed. I did some forum and manufacturer research and there are quite a few reports of internal corrosion damage slowly perforating right through the thin gauge (1mm or less wall) alloy steel tubing used in higher end steel frames. Seems to be between 12 and 25 years of age before perforation, unless drain holes are blocked and the bike is living in tropical climates. No mention of complete frame failure, most people have a patch welded in and a repaint. Obviously there are loads of vintage steel frames of great age and still riding around without obvious damage. Higher end frame makers definitely worry about internal corrosion. Their websites all have sections on how to reduce and contain internal corrosion, mostly by clearing drain holes and using specialised protection coatings, sprayed or rinsed in. Mostly paraffin wax-oil based, like car body coatings. They also recommend removing the seat pin occasionally and checking and re-coating.

the reinforcements are also called gussets when we are talking velos the dropout is a Syntace X12 that uses a fine threat and also clamps the replaceable derailleur hanger that has a predetermined breaking position - quite useful with MTBs as well as Gravel bikes …

I am a steel frame fan, and I have seen corrosion like that on some bikes I've worked on over the years. For my personal bikes I treat the inside of the frame with ACF50 or car cavity wax when new which seems to prevent corrosion reasonably well.

PLEEEAAASSSEEEE do more Mountain Bike Frames. I have almost no idea which manufacturers provice quality frames and which don't.

The frame tubes are made of cromoly or possibly a similar HSLA steel from Reynolds. But it's usual to weld this with a mild-steel filler rod (cromoly rods are too brittle). Cromoly is more rust-resistant than mild steel which may be why the areas of weld-through, which contain a higher concentration of mild steel, are rusting first. Idk what those blobs are but unlikely to be spatter as TIG welding doesn't create any unless you're doing it seriously badly (but as you observed these Taiwanese frame builders are pretty accomplished). Maybe bits of swarf that fell in when reaming, facing or chasing things? Anyway the frame would benefit from some "framesaver" product or just oil on those inside surfaces.

Cotic have an almost cult like following, and are renowned for making really great bikes 👍🏻

That frame will probably last 45 years like my race bike. Getting the alignment and joints done right as in this case counts for a lot. Likely the safety margins are sufficient to tolerate some degradation due to corrosion. Corrosion also can be slowed significantly if treated properly.

2:19 This is a IS mount International Standard), the adapter you need is a IS to PM(International standard to post mount) These were common on old school MTB forks too, but it's no longer used on forks, but still common on frames. Post mounts are still the norm, but still many frames with IS mount.

I own a number of steel frames over 30yrs old, busy restoring a frame nearly 70yrs old. If they are looked after (not left outside) and some rust prevention done inside they will outlast aluminium and carbon

I've several steel bikes, all with BSA threaded BBs. I'd strongly recommend fitting any BB with an appropriate grease, and removing and refitting every couple of years. I've just had to resort to a 24inch spanner 🔧 encouraged with a brass hammer 🔨 to get the BB out of my old Kona MTB, to be fair, it's probably been in there nearly 20years, and the bike gets used in all weather for commuting, but it was nearly the end for the frame.

Looks like as well as allowing its polishing to add bling factor, there was a good reason for fully chrome platting steel frames. My 1990s Italian frames, all full chromed, are currently rust free after a fair few Welsh winters. I do spend time washing down after rides in shite weather with special care if any chance of road salting.

Weld splatter on a tigged frame usually indicates dissimilar base metal. I imagine they have worked out the materials to a safe level. Shoot some JP Weigle Frame Saver inside. Will be good for the next 20 years. Brakes are ISO. Drops are Syntace X-13..Great video..

I didn't watch the entire video yet. But in my opinion there should be a 3mm hole in the bottom of the bottom bracket housing. It makes sure that humidity can leave the frame so that water can drip out of it. Very important. It prevents rust. Cheers

The wishbone seat stays used to make sense with cantilever brakes. The shorter seat stays didn't bend as easy when the brake pushed them to the outside. With disc brakes, it's pointless, unless you want the classic look.

The stuff at the bottom of the seat tube is probably material from the frame finishing, like bottle hole drilling and seat tube reaming. There's probably not an extra step to make sure all that material is gone at the factory. It's fine. Nobody should get a steel frame without dosing the hell out of it with framesaver anyway, "coated" or not. It's like greasing a thread. Those are indeed vent holes. The seatstay configuration could be due to a welding robot needing access.

I think the rust if near the welded joints was due to heat from the welding plus the humidity where it was made, purging with an inert gas would help this hot oxidization not normally done with the welding of steel. the weld spatter would also be solved with gas purging with an inert gas like argon, purging helps penetration of the weld too. If they did not wont to do this then sand blasting with a long sand blasting nozzle to get to the effected joint a very dusty prosses, better of done in a booth, if you can find one big enough, glass bead blasting is better because it distorts less, and you must protect all the thread, then air gun all the frame, then waxing it inside if the owner of the frame wants to do it

LOVED the conclusion. Really thought-provoking

glad to know hambini thinks cotics are well made, because im building an older one up right now, really hyped on it

Now that's the Ham we missed.... keep up the moisture in the tub of yours.

Never get bored of the intro 😂

I have a steel bike and I live near the sea, RH is invariably 60% plus. I've had the bike like for decades. Mind you I am a fair weather biker, but I don't have any corrosion in the tubes. It is Reynolds 531DB.

Not post mount but IS 2000. It’s a great standard because it puts the threading on a cheap replaceable adapter rather than on the fork or frame.

those are international standard 51mm brake mount. post mount is the more commonly used 74mm manatou style mount you see today. post mount kind of took over from IS mount due to being easier to make adapters for fittting larager rotors.

6:11 that could be down to the tyres, tyre make a huge difference how well the tyre transitions, how fast it transitions/changes direction, transitions from side knobs to mid thread. Problem with Bikeradar reviews is a lot of the miss crucial issues, talking points, like with the clothing, where they don't mention the measurements of the rider, the clothing, and to give an idea how it fits. But as they blocked links I can't post links to my own pictures, as the comment gets auto deleted. So at least I posted some critique, suggestions, and wrote my findings on the Endura gear. But a lot of the component reviews don't go that in-depth. There is a lack of proper reviews. I write reviews of stuff I use. I hope more people do the same.

Mic blast of mic blasts. Gonna have to sample that. I'd love to take you MTBing and we can film it. Don't know why OP wouldn't just use XT crank and bsa 24mm. No soft alu axle crap, a stronger bb, no spacers and bullshit.

Great video! would love to see more MTBs on here 🤙👌

My Cotic Solaris is 3y old and after watching this video curiosity got the better of me. BB and dropper removed with no obvious signs of rust.

There's not much I can say about it apart from BRILLIANT! ❤

The gap between the crank and the chainstay is a mm or two! The owner is a very brave man...

Hehehe I had very old bikes you would had nightmares for a moth if you look inside. Those rust spots are totally fine IMO,some places you can´t reach to clean the welds, Cotic response is spot on. Steel is real...but real heavy compared to any other material hehehe. I love steel bikes for commuting, love my steel dirt jump bike. I have rescued many many old bikes,mostly commuters and 1 or 2 road bikes. Those brake mounts are IS not post mount and the rear end I think is more for comfort,to soften the trails in your butt. Love to see MTB stuff, we need more!I bet some new enduro&trail bikes would bend your mind a little hehehehe.

I use steel frame gravel bike for everyday use and I wash it from time to time. Time for me to do some corrosion prevention and reduction since its been exposed to rain this winter.

This frame looks well finished. Not so often we see BB faces flattened. 👍 BTW, 30mm axle in a BSA frame doesn't leave a ton of room. (Especially with Rotor BSA30 cups) It can happen if some sand/dirty find it's way in the BB shell it is slowly "grinding" the aluminium shaft. So better take out the crankset a bit more often for inspection & cleaning.

Nice interesting video from a groovy manufacturer. Well done all round. Except the guy wanting a weird spec.

Cotic is like Time or Look in mtb, they did really creative stuff some 10 years ago with hardtail geometry (during the time when long low slack wasnt as widespread for mtb), maybe QR is not perfect but overall they are the good guys.

I’m a steel fan & a decade ago Cotic had quality and were cool. I think standards slip in many manufacturers of all different products all over the world from time to time. Sometimes it’s just a slight lapse & they get back on top, but I’ve seen factories just repeat their same mistakes over & over.

We don't have any road worthiness inspections here in the US. But if a coper pulls you over he/she/it can give you a fix-it ticket for any deviations he/she/it notices during the traffic stop. Then you have to fix it and get it inspected. I'm amazed at the junk driving on our streets.

...also, that rear axle clamp thing... The clamp tightens down on the aluminum insert with the threads, Fox does it on nicer forks, you tighten down the wheel the first time to load the bearings (set the axle spacing) then clamp down the frame so the aluminum threded insert stays in place.

I've been thinking of getting a steel gravel/light touring bike similar to (say) Kona Sutra SE Bombtrack, Trek 520 Disk etc. As I hope to return to living in Vietnam on Mekong Delta, rust is a significant concern. A few people have recommended stripping a new bike down to the frame them carefully and thoroughly spraying the insides with Boeshield T9 then reassembling. Note, temps wet season 22-30C, humidity 90-100%. Dry season, temps 27-35, humidity 65-80%.

0:06 mopping up the blood from my ear drums

Get a litre of oil, and pour it into the frame, slosh it around and pour out the rest.. helps with rust buildup

I ride steel exclusivity on road and gravel. I just treat the frame with framesaver every so often, no issues with corrosion. Takes a little more maintenance, can't just hang it up wet. Not a good rain bike.

It takes a LOT of rust to structurally compromise a frame. Some Boeshield T-9 on the interior deals with the problem.

i have much more rust on my custom made steel frame. It is from columbus spririt tubes and only 8 month old. The good thing is you can sort things out and don't have to e-mail x times before getting a new frame that isn't better

In Taichung, if that frame is not made there it will be nearby, average relative humidity is 74.5% So, there you go.

I've got a special coating solution, it's called smegseal, shake the applicator vigorously to dispense the pre mixed batch correctly.

Oh I missed new episodes from you ;)

It is called IS2000 Brakemount

now that was a proper intro.

I don’t know hambini, I think you are grasping to ream this one. Frame looks built really well. You are right about the salt. In Wisconsin they salt the roads in winter, cars rust out bad. Out west some areas do not salt and they have just as much snow and ice as here, their cars done rust nearly as bad. I don’t think the level of corrosion in that frame is concerning. There will not be any basalt water exposure. Is there a history of steel bikes failing from corrosion? Also, can 2 steels be dissimilar metals?

The little bit of rust is probably not going to cause big issues if you spray the frame with some internal wax now. These types of frame steels wont immediately turn into a pile of rust. It likely has some overdimensioned tubes anyway. Its more likely to get damaged in a crash in its service life than from corrosion. But its worth keeping an eye on it and keeping things clean.

quite interesting! I was looking on getting a custom steel fat bike frame from a local builder with awesome more modern geo and was wondering about rustproofing after welding on the frame, especially since I live in such a cold climate that has potential salt intrusion here in Calgary Alberta. Some good comments on how to spray the inside of the frame to inhebit oxidation.

Not a bad looking frame. Reinforced in area's. Rust is gonna happen on a steel bike. I always thought that they should coat the internals somehow by submerging it in some sort of liquid that coasts and protects the inners. I am not a weight weenie so that little extra weight from the internal coating is not a big deal to me. Not ridden on steel since the 70's. I have ridden aluminum mostly, barring one of the early carbon tube bonded specialized allez from the early 90's. I have a full carbon kuota now and riding a carbon to me at first was like riding on a cloud, very shock abosrbing. I rode an alu vitus and that was the most flexible bike frame i have ever been on. I got rid of that really quick. The ending to this clip intentional? "other than............."

I have had a steel frame 531 frame for over 30 years notice a bit of rust inside the bottom bracket a spray of wd40 no more rust since that was 28 years ago bike and frame going strong ok

Blocked off the exits and filled all my steel race frames with rustolium, then drained. That was 40 years ago, and still no rust. A little precaution will last your lifetime.

I'm old and used to race on steel frames until the 1990s. I never looked inside, apart from the bottom bracket, when I built a frame into a bike. So, maybe they had those problems ? Those steel frames were all Renolds double butted tubes.

Galvanic corrosion can occur between any dissimilar materials, even between different steels or even welding material/spatter

Nice to see a mtb

Logan is a wolverine, those are IS (international standard brake mounts), the extra tube from my experience is not needed for the brake.

I owned a cotic roadrat, cotic are very solid bikes

Does the BB thread require copper slip to stop the titanium and steel galling or suffering galvanic corrosion?

Coincidently, I just acquired a mid-2000's Soul. It does have some paint chips and surface rust on it, but I've patched it up. I'll report back if the frame snaps on me.

Is that (or near to) the backside of a hole at 8:55? Because that looks like swarf (That's the twisty corkscrew type stuff that comes out of a hole being drilled for the uninitiated) you can see the metal curls. If its not a hole it could just be that it was loose in the frame and then got caught in the joint, Not a big deal if it is but it will probably break off at some point and go rattling around the frame.

I had btr ranger I use put acf 50 down the seat tube and on down tube,and acf 50 grease on bottom bracket

Other than.... What? Don't leave us hangin man!

Another fantastic video again telling us all. Bring on the hoodies!!!!!!!

Enduro has a bsa30 BB called Maxhit. Its steel, and it doesn't have a separate cup and bearing, it seems like the outer race is the cup and the threaded part all in one. Pretty slick design.

Excellent video as always.

1:44 non PC Hambini makes me lol every time

Got to be honest looks a really nice frame I'd be well happy with it with the bit of rust sorted out.

15:43 🤣👍 Much Love for this hurtingly true words

actually looking for a cotic soul 26

I've got a 2012 cotic full suss and it's still going strong

That BB 😍

What kind of anti-corrosion treatment do you use inside the frame? On airplanes we spray Corrosion-X inside the wings & inner fuselage areas, works well. You could do something similar with a bike frame.

Hi Hambini, where can I find that Kingdom Vendetta video? I considering buying such frame and wonder how bad is it ;) also, how about Planet X and Titus Ti? Prices are great

On thw welds, you've not mentioned if they tig or mig,, on the backside of the welds could be from the penetration, mig with flux wire and gas or tig with bronze silicon , is what you might be seeing the welding material, and the steel weled too hot, you can get rust form quicker on weld beads . mill scale is oily in nature and heat burns it off when welded

The question is: do you really need that massive diameter shaft to have better stiffness when it is coupled with a frame that is likely much more flexy ? It is a MTB with large and ¨spongy" tyres so when you stroke on the pedals they will also deflect and I guess there will be a front suspension too.

Nice KuruToga mechanical pencil!

When I descale coffee machine, I pour a shot of solution also into bike frame. ☕

I have a steel frame road bike from 1952. Reynolds 531 tubes, a Viking Servern Valley. still ride it, no idea if it’s rusty inside.

The Surly Straggler has a strut to support the the rear brake.

@hambini. Ever consider using a Wacom board for your ppt?

IS mount if on the side. Post mount if directly on the frame or fork

For the corrosion, why not spray some oil in there to slow things down?

did you serously just mounted bb cups and a crank without grease copper paste or any other paste?

Hambini time !!!

I've had to fiddle with spacers of different sizes on each side of the spindle before and it got me wondering if it is possible to end up with a symmetrical left/right crank position after doing so? Also, how is the pinned comment 4 weeks old but the video was posted yesterday?

Nice looking frame and a pleasure to see Steel still has a place on the world market stage!!!! How much is the RRP for a frame like this?

If you’ve seen a mountain biker ride, you’ll know that a small amount of corrosion inside a frame is the least of their concerns. Full disclosure, I do own a Cotic and tend to ride it into trees at high speeds often 😂

That seat stay configuration is known as wishbone stays

I allways add anti corrosion sealant into new steel frames (Salsa, Surly) and no problems so far.

Don’t you ever ask your customers: why? Why do you want this? 😂

Is the lack of penetration on the welds surprising? From the inside all we see is a little spatter.

how about columbus and reynolds ?

I've got a 16 year old steel tourer... I really must look inside it! (I live by the sea). I did give it a good spray internally of ACF50 shortly after purchase so fingers crossed. Love the look of the hambini BB - what's the weight saving with the Ti model? I'd like one for my steel road bike one day.