Kinesis 4S disc snapped dropout

The drive side dropout on my Kinesis 4S Disc has cracked / snapped through. The frame is broken. I purchased the frame back in October 2016 - and built the 4 season disc up myself. It has indeed - unlike previous winter bikes been a joy to commute on through the year... and stayed in great condition too - quite impressive paint.

Thursday night, and I was leaving the office, alarm, keys, pocket, lights, Garmin, clip up, push off, dull thunk, and something ... something is decidedly not right with the world. There is something rubbing, but something more... much more.

Stopped, checked, no broken spokes. Tried again. Wow. That's super wrong - maybe it's the axle (Hunt 4 season aero disc)? Nope. ..and there it was.

"Oh good god no... the rear triangle is flapping about like a fish!"

A snap through from top to bottom of the drive side aluminium drop out of the 4 season gave a surprisingly large amount of play to the rear wheel (sure its broken but there are two seat stays, and one chainstay still attached right - all held in place by the QR).

Closer inspection shows the crack travels around a surprisingly narrow section there and through the bolt hole for the rear mech hanger.

No limp home option here - this was time for the cavalry. Sitting on the bike opens that badboy up to about a centimeter. Hard winning right there.

Sad face and waiting in the cold for me with the prospect of grief, warranty claim, bikelessness, dismantling bike, ship frame, and do I want another one the same* (I will come back to this later)?

Come the morning - call the Kinesis UK and no - not interested - warranty claim through the vendor. Not even a "what happened mate?" or "where did it break?" - vendor/retailer - off you trot.

So I did. Chain Reaction Cycles - and form filled out, email off, and now the waiting begins.



* Why would I not want the same again? Well, I am super glad you asked. Especially as up to this point you had become really rather attached to its shiny shiny and bring it on attitude for the darker parts of the year. This is the 4S disc 2017. I happen to know a friend at the other end of the country. Fellow cyclist. Grew up together, now an engineer in the RAF - you know the type - very particular on torque, stress, mechanics....  as you would be. Well - he posted this picture to Strava last year.

While its probably a little distasteful to "Can you tell what it is yet?" in a bad Australian accent these days - however, I can clue you in - it's THE SAME. Now either there is some curious universal bond between these two frames made late on a Friday afternoon - or we are looking at a pattern, and what appears to be a DESIGN FLAW as opposed to manufacturing, or Quality Control, or similar. It's a thin little neck there riddled with retaining screw threads and sporting a beefy replaceable mech hanger (OH THE IRONY). His was replaced with a discounted GF Ti model. No aluminium issues there.

Here we are - waiting on a "we will get back to you in 72 hours" of the CRC Warranty department - and quite frankly bemused at the lack of interest from the Kinesis themselves.

I would be EXCEPTIONALLY interested to hear of anyone else who has had a failure with one of these frames. PLEASE do leave a comment below.

** Full disclosure: "Do you have frames break on you often?" - well, I thought initially no. Then I realised the answer was yes.

25 years ago a Raliegh DynaTech 7 something - screwed and glued with rolled and seam welded Titanium tubes plugged into alloy lugwork - cracked around the top tube - very visibly and very scarily midway along. I had JUST started riding again after breaking my back in two places - so this was FANTASTIC to discover. It held together by the grace of the weld of all things. Honouroubly handled by the fabulous people at Herberts Cycles (Whitstable) and warranty replaced by Raleigh with one of their custom titanium from their Special Products Division. Very happy boy.

15 years ago a hand-built Ron Cooper SL (Second repaint - old Raleigh colours) cracked and started to peel itself open (!) between the downtube shifter bosses (underneath and out of sight). It just felt wrong honking on the bars - something was not well with the thing. The lugwork was absolutely exquisite - and beautifully silver soldered. The frame hung on the wall in the garage for some time after the incident. Nothing less than a piece of history / art

- -- ----oOo----- -- -


Okay - so where did this go?

Well CRC are happy to refund. Yay.

They are also happy to replace but say they do not have stock.

Kinesis DO have stock and are happy to supply CRC - just not in the colour I had / liked (silver orange - just blue and silver / purple).

CRC confirm there was another similar failure locally to me (assuming my friend was local - is not - North Coast of Scotland) - so that is three failures.

Kinesis also confirm their new version (6 months off) has a bolt through axle, and that area is beefed up. Hoorah! They don't really say "yeah - about that - sorry" - but the feeling is there. I am fortunate it failed when it did - the footer says no sharing - however, the phrasing was very much ' we are aware of failures to some dropouts and are addressing' - bravo number two.

Does that solve my issue? No - not really, as I cannot have one of those - even though my wheels would work just fine.

So my strategy is to replace, document, and hope if it does fail again it is at a similarly sedate moment. Local stockist closed, secondary local stockist not replying to email and phone rang out. Fail. So back to CRC it is.

After an hour of time parts in a box, looking sad. Frame in Dell R520 box ready to be sent back. Me... not riding as there is snow on the ground. All in all we are good here.

So - here are some pictures of the failure - location, nature of the fracture and so on. If you have any experience of metallurgy or fractures it would be FANTASTIC to hear your thoughts on what this is. To me it looks very dull indeed. Almost as if it had been cracked for quite some time and but was just waiting for the last part to go? Knowing is good - so please do comment / share. Moreover, when things go wrong on two wheels it tends to get exciting rapidly - engine or otherwise - if you have had a failure at light speed and are now nursing wounds - then yes - this is a thing - and this may be of use to you. Please do share experiences... I would really like to know.







7 Responses to “Kinesis 4S disc snapped dropout

  • Hi Anthony

    Really glad I saw this, I was looking for photos of the BB cable routing for the 4S before I bought one and linked to this through your build lessons post.

    This seems to be a very obvious design flaw – this area is under significant load and takes all of the shocks/bumps from the road so fatigue will build up quickly. The cross section through the break is shockingly small for Aluminium – this is a driveside dropout we’re talking about, not a Garmin mount!

    This has completely put me off buying one of these and I’m not waiting 6 months for the TA version.

    Anyway, thanks for your post – back to searching for a new frame for me!



  • anthony
    6 years ago

    Hello there Tom.

    I am glad this was useful to you. Around the bottom bracket is a little cluttered. but it works fine. As I had said previously this was replaced with a hydraulic hose which is a bit thinner, looks tidier.

    The finish was superb.

    The build quality was superb.

    Best winter bike I have had bar none – especially after the wheel + brake upgrade.

    However, the replaceable dropout really does nothing to reinforce that area. While it doubles the girth of the dropout – it does not also present a bunch of stress risers. I had notied the mech get pulled flat as the QR did up – less than optimal. I wonder if epoxying it in place would strengthen it as an interim measure?

    The warranty is only 3 years – something to keep in mind. My Cannondale, and hell, even my old Dynatech (Raleigh of the 90’s) are both lifetime warranty.

    I have taken the replacement option. I loved the bike. Alas, I liked it in the silver and orange – of which there are none left.

    Allegedly I am ‘just unfortunate one off’, with a friend with the same. Exactly the same. I can do no more than trust in that… otherwise, they would not continue to sell that model, would they? No. Or, if they were – that would be a very very different matter.

    Let me know what you chose – and I can have a “Look at what you could have won” tribute to Jim Bowen :D

  • Hi Anthony

    Well I sincerely hope that this was a 1-off for you, even the highest quality products will have bad examples – a “Friday afternoon bike”.

    If the mech is being pulled straight by doing up the QR then the dropout must be misaligned (I know, stating the obvious). From the pictures it also looks like the failure occurred right where the dropout would be under maximum stress – when you tighten the QR the whole chainstay will be trying to bow outwards to allow the dropout to align correctly and all of that stress will be concentrated on that spot, with a hole drilled through it for good measure!

    Have you got your replacement frame yet? If the mech clamps up straight on that one then it sounds like you have found the culprit.

    At least it looks like there is a contributory factor to the failure – a fractionally misaligned chainstay that was missed by quality control. Kinesis are aware of the issue so may well have changed the QC procedure to make sure these faults can’t occur in the future.

    I agree with your opinion on the colour too, not such a big fan of the grey/purple. Colour is generally the last consideration for me on a frame and it’s not too offensive so I could live with it.

    Having said that some colours are so repugnant that I’ve been completely put off buying the frame! Manufacturers should always offer a basic grey/black for those of us who don’t like this season’s latest colour/graphics scheme.

    Good luck with the new build, I think I might have a bike building addiction – do you know of a help group (bike builders anonymous?) who might be able to help me?!


  • anthony
    6 years ago

    Yes yes, I can not stress enough build, finish, QC all very good indeed. Just design – possibly could be a little heavier through there.

    As for rear mech – I am forever bending them – however, this – was the hangar and the dropout I believe. Had slightly different ideas of ‘forwards’. Certainly not structural, and as I dont ride my bike without the wheels in it – not a functional issue either.

    I had Silver/Orange. In now have Grey/Purple.

    I was prepared to be disappointed and press on – but it turns out that ‘Grey’ and ‘Silver’ are apparently THE SAME – huzzah! I did like that silver.

    Furthermore – its no longer the 90’s when EVERYTHING was anodized purple – so its socially acceptable to do 20 years on ; D

    Alas now getting around to:

    1 – fitting some wider bars I had;
    2 – replacing old cables;
    3 – that chain is due a change – and Shimano asymmetric chains don’t make that funny noise my preferred ones do on Shimano chainrings;
    4 – Shoes need changing;
    5 – I need to learn how to bleed hydraulics quickly.

    ….this is a very expensive effort all of a sudden : /

    Ahh well once its done – I will leave the mudguards off and get on with getting back to riding.

    Currently, I am rocking a Raleigh DynaTech Ti with 753 forks from the early 90’s with Campag… you really do not appreciate how far things have come on in the world until you have cause to look back.

    Thank you for the candour it has been good.

    I promise to document the rebuild and DO let me know what you went with (the Mason looked good – then I saw the price, and it’s designed by the same guy!!).

    *I too like building and fixing. However, like my day job changing X usually means that Y and Z now need addressing… why-o-why cannot it just be a case of “fix and work” sometimes, Have a great weekend.

  • Good luck with it all. The Mason does look fantastic but it’s seriously pricey even for a European made alloy frameset – the Kinesis 4S is such a similar frame for half the money I would find it hard to justify.

    I’ve built a couple of bikes with Shimano hydraulics and I can recommend a bleed kit from these people:

    They have some quite good tips on their website as well.

    Bleeding the Shimanos is quite easy but getting a firm short lever pull less so, I found initially that the lever would pull almost to the bars before full braking power and when braking with 2 fingers from the hoods the brake levers would squash my lower 2 fingers.

    The best tips I’ve got are:

    Once you’ve bled the system and with the reservoir still attached to the lever “flick” the lever several times. i.e pull the lever back and then slide your fingers off allowing it to spring back. This seems to draw slightly more fluid into the system before the caliper pistons have had a chance to push back into the caliper. It also seems to shake stubborn bubbles out.

    Having bled a lot of car brakes as well – bleed, bleed and bleed again!! Just when you think the job is done another little bubble will appear! If it’s a new system you can pour the bled fluid back into your bottle and re-use it.

    Also if you’re using the syringe in the bleed kit make sure you draw the plunger back slowly when filling it or tiny air bubbles can draw in through past the plunger seal without you noticing.

    Lastly I would recommend spreading a small amount of grease between the captive washer and the bolt head on the caliper bolts – I used a cable tie like a little spatula. It seemed to me that the friction between the washer and bolt head was enough to twist the washer and would easily torque the caliper out of alignment when tightening the bolts even with the brakes on hard.

    Once they’re done properly though they are incredible – no rubbing, 1 or 2 finger braking to the point of lockup and amazing modulation.

    Hope it all goes well!

  • Chris Bikie
    4 years ago

    I had the exact same thing happen . A crack started at same point in my Cx race frame . Lucky Chain reaction refunded me after 6 weeks if returning frame to them . I I spotted it just before frame snapped and 3 year warranty expired . I think later models might ( should ) have a beefier drop out . Certainly other makers do. From what I’ve seen here, I’d expect this to happen again In a similar time frame until the drive side dropout design is changed or reinforced somehow to eliminate what seem to me like a weak point at a critical stress point . I like Kinesis bikes , and am very grateful they approved my claim .

  • tim seddon
    8 months ago

    same happened to me same age same place .kenisis no longer produce frameset or the later through bolt they offered me 25% of any other frameset, I searched the Web and found the kenisis r2 frameset which has 5 year warranty . just waiting now for frameset to be delivered

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