MOT Failure Head Bearings

[Codey90]

Hi all,
My bike failed it's MOT yesterday due to movement in the forks caused by a faulty head bearing. This was due to the bike being stolen a while back and a hammer being taken to the yoke to get rid of the steering lock.. Lovely

Question being, look at the below part diagram
https://www.chinesemotorcyclepartsonline.co.uk/microfiche/8012/477

The issue is some parts the garage can't get hold of.
Parts 3, 5 and 7 (Upper Yoke Bearing Set) has been ordered but parts 4, 6 and 8 (Yoke Bearing Set) they cannot and the supplier has said they do not if they will be back in stock anytime soon.

After ringing my dealership where the bike was from, they said there is no lower yoke bearing, all it is is merely a plastic cup filled with grease and ball bearings.
Looking at the diagram, I can't tell what is what. Is the upper yoke bearing set likely to fix the issue? What is the difference between upper yoke bearing set and yoke bearing set? The last thing the garage wants is to take the bike to bits and then find out they can't get hold of the necessary part.

Any help will be much appreciated!
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Current: Lexmoto ZSX-F 125
Previous: Lexmoto FMS 125 (Blew Up)
Lesson: Don't Blast a Moped Down the A38 for 70 miles

[WD Forte]

This sounds fishy to me
How did a theif manage to just damage bearings yet leave the headstock/Yoke untouched?
Sounds like no one has bothered to assess actual damage and faults

Besides, if they do need replacing
Do you think they make one off special bearings just for one model of a budget chinese bike?
bollox they would
I bet they're common as muck if someone took the time to investigate and there's probably taper roller option too.
____________________
bikers smell of wee

[weasley]

And it may turn out they just need tightening up.
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Yamaha XJ600 | Yamaha YZF600R Thundercat | KTM 990 SMT | BMW F900XR TE

[steve the grease]

Measure up the outer diameter of the outer races , the inner diameter of the inner races, and the overall thickness of the bearings when assembled. Then armed with the dimensions maybe 43mm 25mm and 11mm go and look somewhere like simply bearings website

https://simplybearings.co.uk/shop/p43708/43Y/25M1-Narrow-Section-Steering-Head-Set-Taper-Roller-Bearing-25x43x11mm/product_info.html

sorted

[Codey90]

[Easy-X]

I was going to write a Tef-sized post about the generic nature of ball-bearings, their history, etc. but looking at the picture again I suspect the complication (for the hard of thinking garage mechanic seemingly) is they are caged ball races.

Still shouldn't be a problem. Ball races are common things you just need to know the size. If you have play in the steering then one would hope all the parts are still present to measure.

While I agree with my esteemed fellow member, weasley, that it may just need tightening up it seems rather lazy not to take the thing apart and assess the damage (if any) before ordering parts.

I suspect it's a case of "order all relevant parts, strip and replace, return unneeded parts to supplier." Wasteful but commonplace strategy in the spanner business.
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Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[steve the grease]

[stinkwheel]

Hitting the yoke with a hammer will not bother the actual bearings in the slightest. I've seen me whaling directly on a steering beraing race for half an hour with a lumphammer and drift trying to remove it and it just laughed at me. They are made from the hardest of hard steel.

So if there is play there, they either need tightening (most likely) or there is a more fundamental problem like missing ball bearings or damaged yoke.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[WD Forte]

We may all be going down the garden path here y'know
As Weasley says, they may just need nipping up.
I bet the OPs never checked the feckers and made a tenous link from
A
someone tried to nick his bike by breaking the steering lock
B
Then it fails the MOT for movement in the forks
( the MOT guy is only going to say it has excessive play
he isn't to going investigate why, not his job)
C
Therefore its 'broken' bearings due to the attempted theft not natural wear,tear and lack of checking/servicing

which all goes back to doing a proper investigation in the first place and not making assumptions
or believing some 'computer says no' spotty yoof in the parts department

On the off chance they are buggered.
I wouldn't be surprised if they're the same as YBR,CG or GN 125 head bearings anyway,
they've cloned just about everything else.

had a look out of curiosity my moneys on the GN 125

From Wemoto:

Suzuki GN 125 02-08 Tapered Headrace Lower Bearing
27x48x14. On RG 125 type NF12 you must re-use the original spacer on the lower bearing.

Suzuki GN 125 02-08 Tapered Headrace Top Bearing
25x45x14mm
____________________
bikers smell of wee

[jaffa90]

Maybe cheap and nasty like,
https://simplybearings.co.uk/shop/product_info.php?products_id=20027140&vat_inc=true&gclid=EAIaIQobChMIld7gr7iO5wIVCLrtCh29Jg_zEAQYAyABEgJJN_D_BwE

[Pete.]

[yen_powell]

That is exactly the same design as on my 2000 Africa Twin. The ball bearing sit in a plastic ring, you tap the metal cup all the way down the head stock, the shells get tapped into each end of the head stock tube and the plastic ring sits between them in a nice slathering of grease.

If you take the front wheel out it will give you room to undo the whole assembly and lower it with forks still attached to have a look and see if they really are damaged or if they just need a regrease and then readjustment.
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Blackmail is a nasty word........but not as nasty as phlegm!
XT1200Z and a DR350 in bits