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One for the techy boffins


Mark O
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Hopefully an easy one for those far more adept at these matters than me.

 

I'm replacing the headset (integrated) on my winter bike. After a few false starts as to which size etc., I reverted to the original supplier of bike and HS in order to ensure the correct fit. I spent yesterday fitting the HS. I removed the various parts, carefully setting them out in the order they were removed and in the correct orientation, then matched the new HS parts with these before reassembling everything. All going well - no left over parts and various parts inserted in correct order etc.

 

The HS appears to have been fitted correctly - it looks right to my untrained eye. However there is, in my opinion, excessive movement in the HS/front fork when I apply the front brake and rock the bike, - probably 2-3 mm, with the top bearing cover visibly moving. This is more than there was previously and more, by comparison, with my summer bike. The upper most bearing is sitting about 2mm proud of headtube. Is this correct, or should in sit flush? Gentle persuasion did not suggest this bearing wanted go be inserted further into the frame. Is there anything fundamental that I am missing? 

 

Any constructive advice or tips welcome. (the winner might attract a bottle of red recovery fluid)

 

Cheers

 

Mark

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Any chance of a photo?

 

To eliminate play, I'd want to check that:

 

- The plug/bung (if there is one) in the steerer tube is fully tightened down and secure.

- That the top edge of any spacer above the stem sits a couple of millimetres proud of the steerer tube, so the headset top cap has something to press down on.

- That you tighten the headset bolt before the stem bolts and that the stem bolts are well backed off at the outset.

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Gents,

 

Did not touch or adjust plug/bung - still insitu and assumed to be doing its job. Top most spacer is proud of steerer tube (I put everything back exactly as it was taken off). I may have mistakenly put pressure on the frame rather that the head cap prior to tightening stem bolts. 

 

Richard, I'll follow your advice to tighten up the head cap bolt before the stem bolts and see if this works. I'm afraid the subtleties of extreme fettling are lost on me. Very much the case of monkey see, monkey do, monkey redo ad finitum until correct or penny drops when it comes to mechanical side of stuff. 

 

Cheers

 

M

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Mark

 

Suggest you straddle your bike and push it against a wall as you gently nip up the steerer bung to eliminate play. Or hold front brake on which is a bit more fiddly. Did you make sure you inserted the top bearing same way up, there will likely be a chamfer on the outside diameter for the underside and a chamfer on the inside diameter for the top side.

 

Cheers

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Ok, firstly thank you to all that had something useful to offer and took the time to do so. I have had another bash at this one and have eliminated the play in the HS hurrah........but now the front forks are very stiff to turn. Seems that in my unquestionable mechanical ignorance I’m still missing something. Any further constructive thoughts.

 

Chung - will give you a call in the morning.

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would love photos.

 

I once got some recommended HS bearings but they were wrong cos the model had changed so I always compare old with new.

 

The top of top bearing would usually be level with top of frame, I wouldn't expect them to sit proud of the frame, that would look v odd. I certainly would not expect a 2mm gap between top bearing cover and frame. Can you measure OD and height of bearing with callipers or even just compare old with new. Even 0.1mm difference in diameter might mean you have to ease the greased up bearings v. gently into the frame if the tolerances are tight.

 

I don't suppose you have tapered HS with different top and bottom bearing? Apologies if you are already miles ahead of me

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You have compressed the top and possibly btm bearing by overtightening the top cap bolt , back it off a couple of turns

 

Bearing should have been put in with a press , should be flush or even slightly counter sunk , but not proud , though some older ones can be.

 

But who am I to comment when not asked , but have both city and guild and Gold Citec in Bike mechanics to underpin my guesstimate, however not seeing it it is just a guess apart from the overtighten part

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The aim of the game here is to tighten the headset bolt to the point where play disappears - no further. If the forks aren't turning properly, as Billy says, you've overtightened the headset bolt. Loosen the stem bolts and headset bolt completely and have another go. Failure to achieve the proper adjustment at the first or second attempt is not unusual.

 

Obviously the above advice will be useless if you've got the wrong headset or you've installed it incorrectly. It's hard to tell for sure without being able to see the bike, but I think it sounds like you're on the right track and guessing's half the fun on threads like this!

 

(PS I think the top bearing of an integrated headset may sit a teeny-tiny bit higher than the top of the head tube without there being a problem. The question is, what does it look like when the headset top cover goes on? Does it feel like it all fits together properly? No conspicuous gaps?)

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All pointers, advice and guidance duly welcomed and noted. For those following this cliff hanger of a thread, there are no discernible gaps between the crown of the forks and the lower extent of the headtube, nor is there a discernible gap between the upper extent of the headtube and the cap (now), albeit the top bearing still is sitting a mm or so proud, which does look wrong and isn't what I was expecting.

 

Will fettle some more this evening based on the comments above and report back. I am working on the premise Ribble have sent me the correct HS, as I specifically asked for the HS for the 365 frame and forks. To be honest they all look pretty much the same to my untrained eye, and if Mr Bain can call it wrong them I'min good company by default. I reckon I have over tightened the HS bolt and compressed the bearings. I didn't use a press to install the HS when I put the bike together originally, although Ginty was on hand to steer me in the right direction.

 

Currently looks like a 3 way share of a bottle of Lidl Chiraz or Merlot among Richard, Doc McL and MacBagel making a late charge on the rails. If I capitulate and revert to the LBS all bets are off.

 

Photos are all too horrible for a forum where youngsters might lurk. 

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My titanium frame the top cap sits about 1 mm above the head tube If it’s right it would be the same take the top bearing back out and measure against the old, do the same with the btm in case the are different sizes , they can and do need a bit of pressure to get seated in the head tube ,

 

Try btm bearing in top and vice versa in case you have put them in the wrong place

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I concede defeat on this one. A 3 way share of a bottle of merlot for Richard, Doc McL., and Billy. All partly correct in assessing my folly without the aid of diagrams. I have failed to find the sweet spot where the play disappears but the steering is not stiff. The bike shop beckons alas.

 

Tune in next week to the Skinny Workshop for another nail biting episode of bike maintenance for the uninitiated, where we’ll be looking at how not to lube your chain!!

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