I tightened handlebar stem before top bolt - risk of damage?

[20130814]

Hi,

As I said on this post:

Loose forks on Ridley Kanzo

I am a clueless eejit - because I realise I have been tightening the stem before tightening the top bolt on my bike.

As per this video:

Don't Touch This Bolt, Before You Release The Stem! How Not To Adjust Headset Bearings On Your Bike.

That is definitely the wrong thing to do.

I have sorted the issue now and there is no play in the headset, the steering is smooth and all seems okay.

However, I am concerned that by doing things wrong, I might have damaged something - though as I say, all seems to be okay.

I am being paranoid I suppose - is there a risk I might have caused damage, or is the fact the handlebar stem now has no play in it, and the steering is smooth, a sign that I haven't caused damage?

Sorry, I realise this is a vague question.

Thanks

Jim

[cyclop]

So,if i,m right,you clamped the stem first then tried to tighten the topmost bolt.I don,t reckon it would have caused a problem, however ,you may have damaged the star nut inside the stem which might be worth replacing if you did overtighten it.Indeed ,you may have damaged the stem itself.Is the fork stem alloy or carbon?Any doubts at all ,get the bike shop to have a look .

[Cugel]

Hi,

As I said on this post:

Loose forks on Ridley Kanzo

I am a clueless eejit - because I realise I have been tightening the stem before tightening the top bolt on my bike.

As per this video:

Don't Touch This Bolt, Before You Release The Stem! How Not To Adjust Headset Bearings On Your Bike.

That is definitely the wrong thing to do.

I have sorted the issue now and there is no play in the headset, the steering is smooth and all seems okay.

However, I am concerned that by doing things wrong, I might have damaged something - though as I say, all seems to be okay.

I am being paranoid I suppose - is there a risk I might have caused damage, or is the fact the handlebar stem now has no play in it, and the steering is smooth, a sign that I haven't caused damage?

Sorry, I realise this is a vague question.

Thanks

Jim

It all depends on how tight you tightened what.

The top cap is meant as the pre-loader of "tight" to keep the fork column properly seated for the correct headset bearing operation in the head tube. The stem column is part of the spacer column on the fork/head tube arrangement that transfers top cap press throughout the whole assembly to create this bearing pre-load.

Therefore the stem needs to be loose on the fork column until the top cap is tightened (usually to 2Nm and no more). Once the top cap is so-tightened and the headset is operating as it should (smooth but no play) you can tighten the stem bolts of the aligned stem (usually to 4-5Nm) so that the stem grips the fork column enabling you to use the handlebars as they're intended to be used.

Did you, when tightening things in the wrong order, greatly over-tighten any of them? If so, you might have done damage or perhaps just displaced something like that star nut that the top cap screws into.

In short, do assembly in the right order and use a torque wrench. Oh, and make sure that the top cap is pressing on the spacers and/or stem column, not the top of the fork column, which should be below the height of the spacers/stem column stack.

[20130814]

Thanks both for your reply.

There's no carbon anywhere on the bars / stem etc.

There was a good gap between the top of the spacers and the top of the steerer tube - I bought some new spacers to make sure that was the case.

I did tighten the top bolt quite tight, as I only have regular allen keys.

Hopefully I've not done any damage, all feels solid and secure. I suppose I was seeking long distance online reassurance which when dealing with a bike is quite tricky!

Thanks again

Jim

[Cyclothesist]

If it's an alloy stem and steerer tube it's highly unlikely you've broken anything. You learn by doing, and often learn more by making a few mistakes on the way. Hopefully avoiding any expensive ones.
Just a suggestion: maybe add Lennard Zinn's Zin and The Art of Mountain Bike Maintenance to your Christmas wish list. I have his road bike version and it's a brilliant guide.

[jb]

The only likely damage is if you rode it any distance before rectifying it. this could damage the bearing races due to it being loose and moving about on rough road surfaces.

[Cugel]

The only likely damage is if you rode it any distance before rectifying it. this could damage the bearing races due to it being loose and moving about on rough road surfaces.

I once fixed a friend's bike on which he'd performed such an installation incorrectly, by tightening the top cap to the point that the headset bearing became far too stiff - but he rode the bike anyway, for many miles. (He was lucky the thing didn't seize and throw him into the road). This seemed to produce a permanent brinelling effect and so the headset bearing needed replacement despite doing well under a hundred miles since new, in all likelihood.

That top cap pre-load tightness is a critical thing, really. Even with tougher (than carbon fibre) alloy components, it's worth using a torque wrench to tighten it. 2Nm is quite hard to judge "by hand" so overtightening is easy to do.

[Brucey]

if you are sufficiently ham-fisted it is possible to damage headset bearings by overtightening the top cap whilst the stem bolts are loose. However most headsets are wrecked by being ridden on while the preload is still much too high, but set to a lower value than that. If you increase the bearing preload slightly above normal and there is still no notchiness, this is a good sign that there is no damage. It isn't a bad idea to regrease the headset bearings using a good quality grease, removing/replacing seals if needs be.

[JohnR]

My method for tightening the top cap is to first tighten the stem bolts sufficiently that it grips the steerer then tighten the top cap bolt a bit, then move the handlebars backwards and forwards with the front brake on to check if there is forwards/backwards slack in the headset bearings. If there is slack, then tighten the top cap bolt a bit more then check the slack again, repeat as necessary. Once there's no slack in the bearings I lift the front of the bike by holding the top tube and check if the front wheel flops from side to side when I tip the frame a bit. Then I do the final tightening of the stem bolts.

[slowster]

I prefer to use a long handled L shaped allen key on the top cap bolt to pre-load the bearings, as opposed to an allen key on a multi-tool or a ratchet handle (especially a relatively large/heavy 1/4" ratchet) etc. The long handle and light weight of the basic allen key makes it easier to judge and feel the tightness, and thus to tighten just enough and no more. I would not use a torque wrench, because I doubt that the torque wrenches typically bought by cyclists are sufficiently accurate and reliable, and I also doubt that one stated amount of torque is a sufficiently reliable and precise universal measurement for the tightness required to remove headset play and no more. Park Tool do not suggest using a torque wrench, and advise tightening the top cap bolt in increments of 1/8th of a turn. With a long handled allen key it's easy to fine tune the adjustment even more precisely than that.

I usually begin tightening the bolt with the wheel and bars pointing forward, and then turn the bars and wheel close to 90 degrees when finishing, in order not to mistake any slight play or movement in the brake for play in the headset when rocking the bike back and forth with the front brake on.

Edit - '3/4" ratchet' corrected to 1/4".

[Nearholmer]

^^^

Completely agree.

I’ll also confess that when I first encountered an ahead stem setup and adjusted bar height by moving spacers, I too misunderstood how to preload the bearings. I thought the top cap was purely a dust cap, so loaded the bearings by a three handed process that involved lifting the fork and pressing down on the yet-to-be-tightened stem. Fortunately it didn’t take me long to spot that I wasn’t getting a “feels right” setting, so I didn’t actually ride the bike until I’d looked-up how to do it properly!

[toontra]

Another long-handled allen key and "feel" merchant here. I use that method on most components and most materials, only occasionally double-checking with a torque wrench if carbon is involved.

Tighten the top cap until there's no fore/aft play in the headset (tested by applying the front brake and pushing/pulling on the bars) but still turns smoothly, then tighten the stem bolts. I've yet to wear out a headset on any bike and some are 15+ years old and done big mileages.

[jb]

Fatter tyres at lower pressures will increase headset life considerably.

[Cugel]

I prefer to use a long handled L shaped allen key on the top cap bolt to pre-load the bearings, as opposed to an allen key on a multi-tool or a ratchet handle (especially a relatively large/heavy 1/4" ratchet) etc. The long handle and light weight of the basic allen key makes it easier to judge and feel the tightness, and thus to tighten just enough and no more. I would not use a torque wrench, because I doubt that the torque wrenches typically bought by cyclists are sufficiently accurate and reliable, and I also doubt that one stated amount of torque is a sufficiently reliable and precise universal measurement for the tightness required to remove headset play and no more. Park Tool do not suggest using a torque wrench, and advise tightening the top cap bolt in increments of 1/8th of a turn. With a long handled allen key it's easy to fine tune the adjustment even more precisely than that.

I usually begin tightening the bolt with the wheel and bars pointing forward, and then turn the bars and wheel close to 90 degrees when finishing, in order not to mistake any slight play or movement in the brake for play in the headset when rocking the bike back and forth with the front brake on.

Edit - '3/4" ratchet' corrected to 1/4".

If one understands the full mechanics and forces involved in getting the headset bearing "right" then working without a torque wrench is certainly possible, via the trial and error process you describe. On the other hand, its all too easy to misjudge how much force you apply by hand ..... especially with a long lever such as a lengthy allen key. And especially if you're a brawny bloke beast; or even a savagely forceful lady!

Its also true that bog standard torque wrenches of the less expensive kind, as sold for cycling by many places, are not very good for applying the small torques. I spoilt myself (and also the bikes of the household) by buying this:

https://products.wera.de/en/torque_tool ... 40_41.html

Its a good fail-safe for tightening all sorts of small screws or bolts in relatively delicate fixings. I use it mostly to put teeny brass screws into small woodworking stuff such as jewellery or tea boxes, as these strip tiny wooden threads very easily.

But its also very useful for tightening the smaller stuff on bicycles as it stops you applying that last bit of turn "just to be sure" that mangles a small thread or breaks the area housing the thread. Its also useful for the small fixings of computers and some other household gubbins where thread stripping is all too easy to accomplish when doing it by guess-turn.

[Nearholmer]

Possibly also an investment, in payback sense, simply for bikes, to buy a “professional quality” torque wrench.

I managed to snap the clamp that holds the saddle rails at the top of a seat post by over-tightening one of the bolts, while using a very carefully set “ordinary bike type” torque wrench, which I’ve now binned because there is obviously something very wrong with its calibration.