Setting up "Modern" steering heads

Jim Lyon

Hi !
Back in the "good old days", after rebuilding your steering head it was quite simple, just wind a nut up & down the thread on the steering tube, & it was quite easy to get the precise tension/preload on the bearing to get good steering.. But ever since some "bright spark" in the bike industry worked out how to save a few pence per bike, we've had the nuts & thread deleted, & now we have a steering tube that is a "plain shank" & have a clamp on top to set the preload on head bearing.So, once we had some precision & now what we have is entirely "hit or miss".
The particular bike I'm dealing with here is a Marin "Mount Vision" with a taper roller bearing, & Pace RC36 front forks
( the softest spring out of the 3 is so soft, it's often difficult to tell what is excessive steering head play, or merely the softest spring compressing ! ) As my bike is a "Fair weather" bike, with low mileage & therefore little servicing, so my technique is not quite up to it as I'm either getting excessive play, or the bearing binding !
The technique i've used so far is to stand astride the bike, with handlebar stem & preloading clamp slackevec off, put the front brake on, lean over the front of the bike to push the handlebar down the steering stem, & tighten down the preload clamp, then reline the handlebars & front wheel, then tighten down the handlebar stem.
So, has anybody got enough experience to have developed a better technique that gets consistently good results with an optimum setting?

Cheers,
Jim

The Rookie

With the stem loose (round the steerer) tighten the preload down until the headset starts to feel tight, as you say, astride the bike pull on the front brake and push down on the forks a couple of times, check for play, if its OK then loosen the preload just a little until the headset feels free and then tighten up the stem clamp bolts.

Its EXACTLY the same as for a threaded steerer except the preload is set by the top cap bolt and not the big nut before you lock it in place using the stem and not the second big (lock) nut.

JGTR

Can't really see what your issue is, it's one of the simplest jobs to do and not really different from the old style bearing/cup setup with regard to pretensioning???? I was surprised when I first removed my forks of how easy it was compared to the old setup.

I grip the top bearing and head tube with my whole hand while holding front brake and rocking bike, I find it a better way to feel for excessive play especially if you have a bit of play in your fork, also lift bike up and make sure front turns freely on its own when tilted from side to side.

I think you may be over thinking/over worrying about it, it really is a simple job.

cooldad

Just tighten it until there is no obvious movement, go for a short ride and check for play if bits have settled.

keef66

I find todays threadless headsets a lot easier to work with than the old threaded ones with tabbed washers, locknuts and giant spanners.

Just tighten the top cap to remove play, then do up the stem clamp bolts. Maybe on a new build it will need tweaking after a shakedown ride has bedded the components in, but generally it's fit and forget.

Jim Lyon

<SNIPPED > see JL comments x 2

The Rookie wrote:

With the stem loose (round the steerer) tighten the preload down until the headset starts to feel tight, as you say, astride the bike pull on the front brake and push down on the forks a couple of times,

check for play, if its OK then loosen the preload just a little until the headset feels free

JL- You seem to be saying that so far this gets you into the "ball park" & then this slight reduction in preload by backing off slightly on the top cap preload clamp is roughly equivalent to helping the head bearing find it's own centre? How critical is that?

and then tighten up the stem clamp bolts.

JL - As I suspected it seems that I need to refine my technique a little - & then practice!
As for the nay sayers, while this system might be lighter, the old system was more precise. Which, being a sensitive rider allowed me to get more quickly the light neutral steering I look for.
Though I accept with this system, it's probably OK, AFTER I've developed a better feel for it.

supersonic

I find the threadless system (Aheadset) more precise and reliable - but it will come down to what you are used to. The thread on the top cap bolt is quite fine, and I find is quite a window of 'adequate' adjustment. I never have to push the steerer down the stem...

... but I did with some old DiaTech system, with locking collars. That system was a pain in the arse.

rockmonkeysc

The new system is exactly the same in principle as the old style. I prefer to adjust it in the work stand with the front wheel out to get a really good feel for it but it's perfectly easy to do in the woods, plastered in mud using a tired old multi tool.
The new style is not only lighter, it's also much stiffer to give much more precise steering on rocky or rooty trails. With the old style of stem enduro, downhill, dirt jump and even trail centre riding would be a lot less pleasant.

Jim Lyon

supersonic wrote:

I find the threadless system (Aheadset) more precise and reliable - but it will come down to what you are used to. The thread on the top cap bolt is quite fine, and I find is quite a window of 'adequate' adjustment. I never have to push the steerer down the stem...

... but I did with some old DiaTech system, with locking collars. That system was a pain in the ars*.

I understand that, being in transition from one type to the other, I'veyet to develop a feel for it, as I've been going from too slack to too tight. And while I occasionally hit the optimum, that hasn't been achieved consistently for my liking- sigh!


supersonic -" I never have to push the steerer down the stem..."

JL- You seem to imply that with the bike standing on both wheels. that gravity will set up the adjustment? Or @ least put it in the "ball park"?- My experience is that in that position, the set up can be too slack -though I've now found with the handlebar stem & locking clamp loose, then pushing down hard on the bars with the front brake on, I can get the bearing to start binding- which is NOT a good feeling in corners!.- Clearly the optimum is between these two extremes. It's just getting there -consistently !

Jim Lyon

SNIPPED> & see JL comments x2

RockmonkeySC wrote:

T I prefer to adjust it in the work stand with the front wheel out to get a really good feel for it


JL- Not only that, but the weight of the front wheel is likely to drag down on the steering head, tending to make the adjustment too slack. Also, you don't have to fight against the weight of the wheel. - I think I might try this method first, & once I consistently get a good set up, then try setting it up on the ground, so I can deal with it anywhere. though I doubt I'll need that, I prefer to hone my skills.

The new style is not only lighter, it's also much stiffer to give much more precise steering

JL- Now we're getting into situationalism, & different ways to get to better riding. You're talking about a stiffer steering head, which I feel I've got with my Pace front end. And I'm now seeking precision through correct adjustment of the steering head.

on rocky or rooty trails. With the old style of stem enduro, downhill, dirt jump and even trail centre riding would be a lot less pleasant.

veronese68

Jim Lyon wrote:

supersonic wrote:

I never have to push the steerer down the stem...

I understand that, being in transition from one type to the other, I'veyet to develop a feel for it, as I've been going from too slack to too tight. And while I occasionally hit the optimum, that hasn't been achieved consistently for my liking- sigh!


supersonic -" I never have to push the steerer down the stem..."

JL- You seem to imply that with the bike standing on both wheels. that gravity will set up the adjustment?

No, gravity does nothing. Screwing down the top cap tensions the bearing in the same way screwing the big nut did on the old threaded steerers. On the picture below loosen the stem bolts then adjust the bearing by tightening (or loosening) the top cap. Once you have the correct feel tighten the stem bolts.

The only thing I would add is that there must be room for the top cap above the steerer, you may need a spacer above the stem as in the picture below.

It's actually good practice as it allows the whole of the stem to grip the steerer.

supersonic

As above, the top cap does the adjusting, with Aheadset. Which system of threadless do you have? The aforementioned Diatech (and GeForce) have somewhat different approaches. But with aheadset, there is no pushing down needed at all in the adjustment, no other technique - obviously when fitting the stem and spacers you don't leave any gaps except right at the top, as mentioned in the above post.

supersonic

You can even remove the top cap after you have tightened the side stem bolts (though no real reason to do so, bar save a few grams).

The Rookie

supersonic wrote:

though no real reason to do so, bar save a few grams

That sounds like a very good real reason to me!

I use a MtZoom lightweight topcap and bolt assembly, I use a normal top cap and bolt until the stem is tight and then fit the MtZoom so if anything happens on the trail I can still fix it but without risking excessive wear on the alloy 'bolt head'.

Jim Lyon

After early input from others on this thread, I had a play with it on a work stand yesterday, mainly so that I'd have both hand free & could see what I was doing. But, on a work stand, with the front wheel removed even heaving fully up with one hand on the fork bridge, I couldn't get the bottom bearing to fully seat in the bottom of the head set. So, I refitted the front wheel & did it on the ground with the front brake on & leaning over the handlebars to put some weight on them ( but not so much as last time when I ended up with the steering bearings binding ). After a couple of goes & quick test rides, I got the "sweet spot" I was looking for, so I'm happy now. And though by the next time I have to do it, I'll probably have 1/2 forgotten, @ leat I now know what I'm trying to do.
While I know that taper rollers cn be preloaded, previously, I've used them on an old Trek 720 Antelope, which was the old type with a thread & lock nuts system, so I simply would tighten it down without giving any thought to whether I was preloading the taper roller bearings or not. All I was bothered about was finding the "sweet spot".
The one I've had this problem with is a Marin "Mount Vision" with Pace R36 forks. Handlebar & stem are by Marin. The taper roller headset is a NC17 "Imperator" & though that comes with a top cap, I have nothing to wind the top cap screw into, as there's just a dirty deep hole inside the Pacesteering tube . So, my top cap is actually a rubber plug saying Diatech to plug up the hole in the top of the Pace steering tube.
So, with no screw to wind in any preload, I'm forced to apply the front brake & lean over the front end to apply the necessary preload. So, though I'm still using the same technique as before, I'm now doing it with some better understanding. Btw, instead of a top cap screw what I've got is a wedge shaped metal ring that sits immediately above the bearing cap, & a clamp on top of that which you are, in effect pushing down the ramp created by the wedge. Get that where you want it & tighten down with a single pinch bolt. so that's what I use for applying preload directly to the bearings & for locking them in place. Above that sits my spacers & handlebar stem.
Thanks for the input guys, it helped to guide me to where I needed to be !

veronese68

Jim Lyon wrote:

The one I've had this problem with is a Marin "Mount Vision" ...So, my top cap is actually a rubber plug saying Diatech to plug up the hole in the top of the Pace steering tube.
...Btw, instead of a top cap screw what I've got is a wedge shaped metal ring that sits immediately above the bearing cap, & a clamp on top of that which you are, in effect pushing down the ramp created by the wedge. Get that where you want it & tighten down with a single pinch bolt. so that's what I use for applying preload directly to the bearings & for locking them in place.

Aah, you have the evil Diatech that Supersonic mentioned above. That doesn't work in the manner I have detailed, it's evil. I did mine on my Marin by pressing gently on the stem and tightening it, then got final adjustment by tightening the tapered collar. Make sure the collar and it's opposite are clean and apply a thin smear of grease to help it along. Thankfully the bottom bearing in mine went and I replaced the headset with an Aheadset set up as in the pictures, much easier.
So, yes they are a complete pain in the aris.

Giraffoto

Threaded headsets were devices of the Devil too. When my youngest grows out of his current bike I'm glad to say my forty year battle with them will be over!

rockmonkeysc

There's the problem. You said "modern" so everyone assumes aheadset because that's what the modern standard is. Fortunately Diatech is not a modern standard, it was a mistake from the past.

cooldad

A decent Orbit XLII can be had for less than £20. I'd just change the headset.

rockmonkeysc

cooldad wrote:

A decent Orbit XLII can be had for less than £20. I'd just change the headset.

I've just got an FSA Pig headset from CRC for £12.49
Reasonable quality and dirt cheap.