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Heya,
When using my hardtail with rigid forks, by the time I've finished a normal ride (10-15 miles) the headset always has play.
All snugged up nicely before. Bearings preloaded so that there is no play without being tight. Finish every ride with loosening off the stem, tighten the top-cap bolt and re-tighten the stem because of the play.
I don't have this problem when I have suspension on the front, just with the rigid forks.
Does anyone have any idea how I might solve this?
Stem feels tightened up plenty - it's a thomson with quite small bolts so I don't want to risk over tightening them.
Oh, and:
456 carbon frame
exotic carbon forks (straight alu steerer) with star nut
Hope headset (pretty new)
Thomson elite stem
star fangled wadget slipping up steerer?
it's a thomson with quite small bolts so I don't want to risk over tightening them.
how tight are you doing them? using a torque wrench?
I had this with my rigid bike. Salsa El Mariachi and Salsa Firestart forks. No matter what I tried, it always worked loose.
In the end I binned the lightweight superstar stem and replaced it with a stem out of the parts box and that cured it. For whatever reason, the stem wasn't clamping enough and there is only so tight you can safely torque the bolts up.
So I recommend trying another stem, preferably quite a chunky one, and seeing how it goes.
Edit: in my case I had a star fangled nut installed, it doesn't stop things working loose if the stem can't clamp enough. 5Nm torque is not a lot, very unlikely most people have stem bolts done up to this!
Sounds like the stem is the problem. Thomson are pretty poor IMO. Try a cheap one and see if it fixes it.
If you find the solution, please let me know.
I've had the same thing from a brand new fully built 456 from On-One and I've checked pretty much everything:
Steerer tube not lifting out of crown assembly,
spacer under top cap and small gap between top of spacer and steerer,
stem bolts done up to required torque, then tighter, then tighter still,
load up top cap after tightening stem,
grease the steerer, de-grease the steerer,
The only thing left is replacing the headset, but it was brand new and did it FFS!
It's almost a year old now so perhaps I should as it's the only thing that lets the bike down.
edit ^^^ no one mentioned trying a different stem.
star fangled wadget slipping up steerer?
It probably would have popped out by now if that was the case! But I will check to make sure.
Have used a torque wrench, can't remember what torque off the top of my head but it's not a lot on the Thomson stems.
So I recommend trying another stem, preferably quite a chunky one, and seeing how it goes.
I'll swap it over with the chunky funn stem from the other bike and see how it goes. I have been wanting a shiny new CNC'd stem for a while so hopefully this will fix it! 🙂 The thomson one is nice, but the bolts do seem unnecessarily tiny
I've got a long ride planned tomorrow, so I'll swap the stem over and update tomorrow evening on if it worked
Is there a torque setting marked on the stem for the bolts?
I think the Thomson stems might suffer the same problem as the superstar one I had. There is a lot of material cut away around the clamping area to save weight. So there isn't as much surface area in contact with the steerer, which might not grip well enough (I know with more material cut away the clamping pressure will be greater but that's not the only factor to consider)
Is there a torque setting marked on the stem for the bolts?
There is. Can't remember what it is (bike is locked away at the moment!) but I was adhering to this. I probably ended up tightening it more with a normal allen key after it came loose anyway.
Ensure the stem bolts are nicely greased and are threadlock free.
Could you try a some carbon assembly paste on the steerer/stem interface?
I know there wont be carbon involved but it would maybe add a bit to the clamping force of the stem on the steerer?
Maybe worth a try before ditching the stem?
Ensure the stem bolts are nicely greased and are threadlock free.
I could be having a mental blank- but surely I want threadlock on the stem bolts? No threadlock = bolts potentially loosening = stem movement. ?
try a some carbon assembly paste
good shout. I will give it a try with the thomson stem after trying the other one tomorrow.
I had exectly same problem with my BMX. Bicycle mechanic friend explained that well greased bolts with tighten tighter / torque tighter as less friction. Give it a go.
So the update, is that a beefier stem worked. 38 miles on the xc bike (nice event evans!) and no play throughout or after the ride. Will update if it does work loose.
Previous stem = thomson elite
Working stem = funn rippa
Much bigger bolts on the funn stem, and more clamping area.
Now to find a nice stem which still clamps as tightly (this dh one isnt the right look for a carbon rigid!) 😉
After looking at the thomson one which was slipping, I was overtightening the bolts as well. Did them up to the 5nm reccomended, then tested with an allen key and it felt fine to go a fair bit past that.
Carbon paste if a carbon steerer, rough the steerer with sand paper if metal. Perhaps.
Had the same problem on my bike with a Thomson stem, switched over to an Easton and the problem went. Put the Thomson on the commuter and that started slipping!!
Sold the stem in the end, problem solved.
Hey Monkeyfiend
load up top cap after tightening stem
Noone? really?
Your issue is that you're doing that the wrong way round. Load up the top-cap to take the play out of the bearings BEFORE tightening the stem onto the steerer.
^ I think he means he preloaded bearings, tightened stem and then nipped up the top cap a bit more to try and stop the stem slipping up the steerer.
Previous stem = thomson elite
Working stem = [s]funn rippa[/s] Any other stem
I just opened this thread and thought exactly what Retrodirect said - no point in nipping up the top cap after tightening the stem; it should have been loaded before, so all this would achieve is snapping or stripping the threads in SFN/expander/cap bolt
It's a technique more commonly called 'clutching at straws'
I have been living with a constantly loose headset for far too long, so began to lose common sense.
Good to hear a stem chamge can hopefully cure it though.
Ha ha, my road cycling buddy is a very clever bloke but when he and I first began riding together his bike was in a shocking state and his headeset completely loose. He is a mechanical numpty and has no sense at all of what's wrong or right or how to fix it.
Little update....
the thomson is also coming loose on my full sus- it just takes a bit longer to happen!
Not very impressed Mr Thomson!
Still. Just in time for xmas! 😀
I would guess star but in a carbon fork steerer is the culprit. Probably has worn grooves up the inside of the steerer. I'm pretty sure that all carbon steerer forks need to be used with an expansion wedge (22-23mm)
I would recommend you have a very good look down there or get a reputable bike mechanic to check for you...
eh ?
Ok, well it's good news from me.
Changed stem from a forged On-One one to a Ragley CNC'd one and it seems to have cured it for me.
It only took 12 months for you guys to bloody tell me though!!!