Diatech Headset Adjustment

DavidJL

Well-Known Member
I was getting frustrated with the Diatech headset adjustment until I took it apart. There is a little bitty set screw, which took a 1/16-inch Allen key. So I found out that preload is adjusted by turning the ring with 2 holes in it, and then locking the collar in place. An old notch spanner for bottom bracket seems to be a good tool for turning the ring with 2 holes. Not sure if it is necessary to tighten the little set screw.
 

Robert Holler

Administrator
Staff member
David,

I believe you are referring to the headset on the QX100, which is different than the Diatech on the Q559.

Robert
 

DavidJL

Well-Known Member
I just did a mod to the BI-3 headset, replacing the tiny set screw, which takes a 1/16-inch Allen wrench with 4-mm socket head cap screw, and added another 4-mm on the other side. Hopefully, this will hold the adjustment better. I had to raise the riser up to get room for the screws. DSCF0007.JPG
 

billyk

Guru
The confusing part for me has been the amount to press the pivot clamp down before tightening the headset. Press the clamp down too much, and the headset clamp has no room to rise on the beveled washer. Too little, and it won't keep the headset clamp from sliding up too much. I've pretty much learned to eyeball this, but it would be nice to hear what it's supposed to be.

I think this matters because we need to both have the setup be tight enough (no rocking) but also have the proper pressure on the bearings, to avoid wearing them out. I'm never sure if my eyeball method is optimal. Some specific guidance would be welcome.

BK
 

DavidJL

Well-Known Member
As I understand it, a DiaTech headset is used on the first model of the Q (the orange one), and on the QX100 a different design is used. On the BI-3 headset the white screw clamps the threaded piece on the the steering tube. There is a ring threaded onto this piece that is turned to adjust the preload on the bearings, and the set screw is supposed to lock the adjustment. One set screw doesn't seem adequate to hold the adjustment, and it takes a standard 1/16-inch Allen key. As I understand it, the DiaTech headset uses a screw, which looks like the white one in the picture to adjust the preload. I have been wondering if the theaded piece is slipping on the steering tube, causing the adjustment to go loose. Robert Holler should make a video on adjusting the IB-3 headset. Also, there should be a tool, along the lines of the old Park pin spanners to turn the preload ring. In the pic, you can see one of the holes. I will probably replace the socket head cap screws with set screws, but it is nice to be able to use a more commonly used size Allen wrench.
 

Emeljay

WiskersBlowinInTheWind
ISTM (it seems to me ) that for the DiaTech (on my Q) and the First BI3 (on my X) headsets to be effective they have to be tight enough not to rattle or shake around but not to tight to constrict turning, or damage the bearings and bearing races. This means they are just a tad (engineering term, OK not, but you know what it means ;)) loose. Tad loose is loose and loose things get looser when they roll, rattle, and go over bumps. So these things need to be checked often and adjusted as necessary assuming we know what to look for and how to make the adjustments.

As I understand it on the Q the DiaTech method to adjust the headset is used to allow the Q to be more easily and quickly folded and less weight than using a star nut with the long bolt needed for the long steering riser. I don't know what the advantage is for the BI3 on the X, but it gave me another puzzle to figure out that may keep my brain plastic (whatever that means, my doctor keeps saying that, and says change helps with this :rolleyes:, he also said change is good and to read book Who Moved My Cheese, and I took note since I like cheese! :D).

Anyway to make this short story longer the YouTube video on diatech adjustment helped me. That helped me to understand the dynamics for the First BI3 (did not find any instructions for it on First or CB), but the BI3 has needed fewer adjustments for me than the Diatech.:)
 

kdc

Member
So I'm new to the Q559 and I'm still learning about the bike (and how to ride it) but I've had a lot of issues lately with the DiaTech headset. No matter how I adjust it, there is significant play back and forth. Is there any other advice to firm it up?

Another note to the above issue, I removed the riser completely and there is a lot of play in the fork. Maybe the bearings are shot?

Any help is greatly appreciated. Thanks in advance!
 

benphyr

Guru-me-not
Hi @kdc
I used an extra long star nut bolt (as long as the steerer extension!) that I had from another bike directly to a star nut in the fork. It worked like a charm.
 

benphyr

Guru-me-not
Also, there are several threads which can be found by searching headset. Most are a mix of different versions. This is a frustrating topic because of the wide variety of possible answers and the finicky nature of headset adjustment.

Some good information and background can be found at http://www.sheldonbrown.com/headsets.html

Just farther than 3/4 down the lengthy page is a section called: Adjustment (Threadless)

I think the Diatech headset they are referring to is a little bit different model though.

Another way is to take off the steer tube extension, install a star nut into the fork (got one at the local bike co-op), use a locking clamp such as https://problemsolversbike.com/products/headset/locking_spacer_-_6788 and then spacers, cap and star nut bolt to adjust the headset, then clamp down the clamp, take off the other stuff and put the steerer extension complete with handlebars etc. back on and clamp it down. Once you have done this once you may be able to adjust the tension slightly by leaving the extension clamped, lostening the problem solvers (or similar) clamp and wiggling everything down tighter as described by Sheldon Brown (possibly on a different page) and re-tightening the clamp, and then removing any excess space in the steeer extension and clamping it down. I tried this before the option in the above post. It worked but was a little more difficult to adjust so I went with the other option from my old bike. Now the old bike has this slightly less easy option and seems to work fine so far.
 

kdc

Member
@benphyr - thanks for the helpful tips. I did read about your solution earlier (had to look up a few things, but got it...eventually!)

Seems like that is a great fix for the headset. But is the fact that my fork is loose by itself mean anything? I understand with a loose headset, the riser (etc) will have play, but shouldn't the fork be stable too?

Sorry if these are newbie questions.

Thanks!
 

benphyr

Guru-me-not
@kdc
A caveat before I share my limited knowledge - I am not a bike mechanic. I have learned a few things along the way of commuting by bike for many years. What is below is correct to the best of my knowledge from my experience.

The most common cause for a loose fork would be headset adjustment by a long ways. A distant second would be a worn out headset, then other causes.

Think of the head tube as a pipe, the headsets as cones with the points pointing into the pipe. The fork is attached to the flat end of one of cone #1, the handlebar riser/stem/handlebar sits on the flat end of cone #2. Gravity loosely holds the pipe against cone #1/fork. Cone #2/handlebar needs to be held tight against the pipe/head tube otherwise, if there is a gap then the handlebars can wiggle, and when they wiggle the fork pivots on the place where cone #1 and pipe touch.

It might be worth checking other things that could feel like the fork moving and/or often can be tricky diagnosis:
-quick release is tight - Don't need to be a hero but it should not be able to be opened by one finger of a five-year-old.
-wheel bearings tight - grab fork in one hand and top of wheel in the other hand and pull it back and forth, left and right with respect to sitting on the bike ie. perpendicular to the way the wheel turns
-brake play is not what you are feeling - grab the front brake strongly - mine when I pull the brake not very hard has a little slop in the mechanism (BB5 cable disc brake) which I at first thought was headset
-spokes sometimes make all kinds of noises. If you rub your fingernail across the spokes or pluck them like a guitar or harp then all the spokes should twang a note - not sound a dull thunk nor a really, really high pitched ping. Even with proper tension they often make all kinds of noises and I am not good enough to advise beyond recognizing some of the common issues to take to a mechanic.
-play in the rear suspension can feel like headset slop when you are on the bike - another thing I discovered by experience - The spring tension was so low that there was a lot of slop
-cables can rub on each other and wiggle in the end of the brake lever/ giving all kinds of weird feel through the handlebar if you are hyper sensitive like me.

Anyway there are some things to check out.

Hope that helps. You might have to do my solution several times before all play is removed from all of the many pieces that make up the headset as they settle into place following a ride. It can be really awkward adjusting things. :cool: Cruz-on! :cruzbike:
 

kdc

Member
@benphyr
Thanks for all the info and taking the time to explain it. I wrenched on the bike this morning for awhile and think I finally got it tuned in. The play is a lot less, but still there to a small degree and I'm more convinced that the DiaTech that is on there is either worn out, or simply a bad design. It just seems way too finicky and I should't have to be struggling to "dial it in" when all I really want to do is ride the damn thing! I will take it to a shop and have them see what can be done in terms of ordering a star nut to install, along with an extra long bolt.

Thanks again for all the useful information as well as encouragement! Hopefully it will hold together on my next ride. On to the other problems...
 

benphyr

Guru-me-not
If I can just help one person - mission accomplished. I agree, it is a poor design. It was probably a compromise of making it packable.
 

kdc

Member
Well, unfortunately, no dice on the ride today. As soon as I hit the front brakes, the stupid headset gets wobbly and loose again. Stopped three times during the ride to "adjust" it. Each time I would get it secure, then off to ride and the same thing would happen shortly after I started riding. I'm sure I must be doing something wrong but I'm fed up with having to mess with it. Going to take it to a shop tomorrow or the next day to make sure there isn't something more wrong with it. I really like riding it, but this problem has me wanting to toss the bike into the creek! :mad:

If it can't be fixed by a pro, you'll see the bike for sale here shortly...cheap. I took a video of what is happening, but I'm not sure how to post it. If I can, hopefully it will give you an idea of what's going on. Sure is frustrating.:(
 

billyk

Guru
A crucial point (not adequately explained in the Holler video) is that the boom (pivot) clamp must hold down the headset top ring. That's what keeps it from loosening. Namely, you push down and tighten the boom clamp so the top ring is "almost tight", then tighten the conical top ring to set the tension.

Otherwise, if the boom clamp leaves any room above the headset, there's nothing to keep it from riding up and loosening. I had similar problems as you describe until I figured this out.

Also note that the nuts on the boom clamp must be really, really tight! I switched out the stock quick-releases for bolts for this reason.

Don't give up on the bike for this problem. Once you figure this out it becomes straightforward.
 

kdc

Member
Thanks @billyk

I appreciate the encouragement, and I really do enjoy riding it, but the issues with getting this headset right is driving me crazy. But again, I'm probably doing something (or not doing something) to cause the issue since it seems not too many others are complaining about it.

I did try to use pressure to keep the boom pressed against the top ring as suggested in the video. I know what you're referring to. I tried pressure, tried my full body weight (don't ask how...it was ridiculous), then tried even hammering it down. The last way seemed the best as it was snug when I clamped down the boom clamp (also agree, bolts would be better than "quick release"), and then adjusted the DiaTech so it rose ever so slightly as portrayed in the video. Then, about 3 minutes later on when I braked, the whole thing was wobbling again. That's when I gave up. I've experienced lots of other "quirks" with bikes, but nothing this finicky to adjust preventing me from riding.

Hoping to take it to a shop tomorrow if there's time. I'll report back to let you know what, if anything, is suggested for a fix.

Thanks for all the help and support. I'd like to ride it if I can.
 

xjcampx

New Member
Is there a diagram of the complete Dia tech headset? My bearings are shot and I just broke the headset clamp. Are replacement parts available?
 
Top