Looks to me like that isn’t a tapered steerer on the forks. Therefore they have tried to bodge some sort of reducer lower headset.
If the spec list states a tapered fork, I would expect a tapered fork, not a straight steerer with a bodge.
Either way, this should not be your problem to solve. Since any fix would be a bodge in terms of the lack of a tapered steerer, and this can’t be the only bike that they have sold with this arrangement, unfortunately it needs to go back to Decathlon.
Just go back and tell them STW sent you.
That'll get it sorted quick smart.
The lower headset cup hasn't been fitted properly. That needs to be fully seated.
It's hard to see, but it looks like it's either a tapered steerer that they've tried to bodge to use a 1 1/8 lower headset, or they've put a 1.5" adapter onto a straight steerer fork, then tried to bodge it to fit a 1 1/8 headset on top of that.
I would remove the lower crown race from the fork to see what steerer it is. If it's a tapered steerer fork and a 44 mm internal head tube, I think you will need to fit an external cup 44 mm lower headset. If it's a straight steerer fork, I think you just need to remove the bits under the lower race and then fit the race back onto the steerer (and seat the headset cup too, obviously.)
As it's a safety critical part, I would just buy a new headset from CRC or someone for peace of mind and then try to claim the cost of that back from the shop. Whoever fitted that has no idea what they're doing or how unsafe it is. If it's a straight steerer fork, I think you need a headset like this:
https://www.chainreactioncycles.com/p/brand-x-semi-integrated-44iiss-sealed-headset
The lower headset cup hasn’t been fitted properly
the bike would not have been rideable with it at that angle. I wonder if it was loose and now isn't sitting right.
it's def a straight 1.125 steerer.
I'd be sending those photos to their customer service Twitter/X and see how they react. That's been bodged to get it sold...Very poor
That'd also be worth doing - as would going over the rest of the bike with a fine tooth comb...if you want a job doing right, etc.
To me it looks like the bottom lip of the lower cup has snapped off and is sitting on the top of the fork crown (the largest ring), the rest of the cup has pushed up in to the head tube.
Possibly pre-loaded again the friction in an incompletely pressed cup, with everything shifting (and breaking) on a big (or not so big) hit?
I still think that the bearing cage looks upside-down and eating its way through the cup. I've never seen a plastic headset cup either (which doesn't mean they don't exist).
What’s that jagged hole in this pic
Probably to allow hot air/gas to escape when the frame is being welded during manufacturing. If you weld an alloy tube at both ends without a vent hole the last bit of seam can blow through when the hot gas inside has nowhere else to go. It does look rough to say the least tho
a reducer isn’t necessarily a bodge, obviously.
It is if the sales description mentioned a tapered fork.....
This is definitely a case of taking it back. It really isn;t clear from the random looking collection of circular objects masquerading as a headset what order they should go in, and indeed whether they are even meant to work together!
It is if the sales description mentioned a tapered fork…..
Does it?
Even if so, it should/can work fine mechanically generally (obviously an issue in this case), so not necessarily a bodge, more a misdescription (if your assumption is correct).
All headtubes have holes where the down and top tubes attach, for the reason stated above. It looks rough because it’s a £1500 ebike i.e. it’s a £350 BSO with a motor and battery bolted on.
Agreed. Not cheap, but not really fit for purpose either. It's meant for occasional use at best IMO.
From the technical part of the description
Frame
ROCKRIDER COMFORT GEOMETRY FRAME in 6061 aluminium with hydroformed tubes
12x148 mm Boost
Seat tube diameter: 31.6 mm
Tapered head tube
1 bottle cage mounting point
Only says tapered headtube. Probably should have a tapered steerer but looks like they have bodged it
I'd bite the bullet and go buy myself a decent headset with cartridge bearings from the likes of Cane Creek or FSA (or Hope or Rideworks if you can stretch to it) and fit it myself, vs all the faff of at least 2 trips to the bike shop + no bike for a week, then still not being comfortable as to whether they got it right or ballsed it up again.
But that's me, and I know that when I do work on a bike or car, it's right. Because I know what I'm doing and I'm careful with my own stuff.
Quite a few budget bikes have moved onto a better tapered headtube frame but on the cheaper models still run a straight steerer budget fork (mostly Suntour).
On the basis that (a) that is a very cheap headset and (b) something has been fitted incorrectly - I’d just buy a headset to fit that has better quality metal parts and cartridge bearings. You may need to take the bike to a decent bike shop to identify the exact parts you need and get them bought or ordered in.
That frame looks like it is a zs style one - so using press in internal cups. The Decathlon website is terrible for giving full detail of bike specs though, so hard to say if zs 44/56 etc or something else. Either way, the lower cup needs to have a reducer in it so that it fits in the bigger tapered frame lower cup position, but can go round a 1/18th” straight steerer.
The alternative might be weeks waiting for Decathlon to sort their life out.
I still think that the bearing cage looks upside-down and eating its way through the cup. I’ve never seen a plastic headset cup either (which doesn’t mean they don’t exist).
With caged bearing headsets, the solid ring points down on the bottom race and up on the top race. The inner bearing surface (crown race in this case) should be stepped to ensure the cage doesn't bind on anything. If you had the ring at the top, the race in the head tube would just crush it. It's an angular bearing, you just need to consider the cross section of the assembly to see this.
Though, to be frank, i don't think it'd matter in the slightest on this particular set up, looks like they've dropped a box of random headsets and picked up bits they think might work.
Measured the head tube today and it is a 44mm upper 56mm lower. I think the suggestions to just replace the thing with a proper headset myself are sensible rather than deal with Decathlon...
Any idea what a shop would charge to fit a headset if i supplied it? Am i better off investing in a headset press so i can do it myself in future?
NB. the third image in the OP seems to show the crown race for a cartridge bearing headset as well…
So it really is a random mismatch of headsets, and adaptors.
Yes, they seem to have just stuffed random stuff in there. I suspect it's because the lower cup was crooked and they couldn't get the play out of it so they just tried to shim it out thinking that would take care of the play.
Any idea what a shop would charge to fit a headset if i supplied it? Am i better off investing in a headset press so i can do it myself in future?
It's a five minute job with the correct tool, so depends on how well you know your LBS and how much Decathlon tax they charge you?
If you've got cycling buddies, then it's likely that one of them will already own a headset press that you could borrow?
Looks to me like the lower heasdset cup has failed.
Any idea what a shop would charge to fit a headset if i supplied it? Am i better off investing in a headset press so i can do it myself in future?
Why not get the LBS to supply and fit then all responsibility for work lies with them?
Drift the old one out with screwdriver carefully and new headset should drop in. No tools needed. Crown race on forks possibly if not a split race
If it’s pressed in cups they won’t just drop in - you’ll need to press them in.
Burton tools do a cheap headset press - I’ve got one and it does the job.
With caged bearing headsets, the solid ring points down on the bottom race and up on the top race. The inner bearing surface (crown race in this case) should be stepped to ensure the cage doesn’t bind on anything.
Thanks for taking the time to correct me (I've only ever used cartridge headsets). I like to try and join in these 'helping out' threads but am rather limited in experience I'm afraid. 🫤
That bottom caged bearing has been fitted upsidedown - if that first photo is as it was disassembled.
If you remove the caged bearing and turn it over you'll notice the 'non bearing side' has a flat surface - this should sit against the corresponding flat face within the lower cup (thats pressed in the frame).
As it's been fitted incorrectly the flat bearing face has instead been grinding on the 'radius ball race' of the lower crown race. If you turn the bearing over you'll notice the 'balls' fit in the radius ball race surface correctly, however the whole headset is damaged and needs replacing
It's the cheapest type of headset available normally found in 1980's Raleigh's and general BSO's whichis why non of the above bling bike STWers have got the correct answer!
Just waking this one up again, finally got round to trying to fit the Nukeproof ZS56 with reducer race someone linked earlier but with the old lower cup removed the headtube actually measures 54mm so I take it I need to find a ZS54 with a suitable reducer crown race?
I also notched the frame slightly when tapping the old cup out so will have to file the burr down a bit I guess.
Should have accepted my lack of expertise and took it straight to shop to sort but you live and learn!
