- This topic has 20 replies, 14 voices, and was last updated 5 years ago by DM52.
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2 crown races on my forks
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DM52Free MemberPosted 5 years ago
I have 2 crown races stacked on my forks to add an extra bit of clearance from the dials on the top of the fork legs and the cable stops on the down tube, 1 crown race means the stops hit the fork.
Everything seems to be all done up correctly and there is no play in the headset, test ride is going to be next weekend at Swinley. Recipe for disaster or a neat solution to the problem?
bigwattsFree MemberPosted 5 years agoSeems like a stupid thing to do. Most forks are a larger diameter locally where the crown race sits. Also, depending on the shape of the crown race the top of one may not sit nicely against the bottom of the one on top.
I wouldn’t do it.
one_happy_hippyFree MemberPosted 5 years agoWhat Bigwatts said.
Dependinv on the headset some manufacturers like king and Cane Creek make a +5mm race for this purpose.
I wouldn’t be surprised if you get some lateral play if the upper of the two lower races is sat on the steerer above the purposely larger diameter area.
scaredypantsFull MemberPosted 5 years agowot they ^ said
or, depending on the frame and what’s already in there, an external-bearing lower headset cup might be better
milky1980Free MemberPosted 5 years agoAs above, it’s not a good idea!
Even if there seems to be a large enough large flat area at the bottom of the steerer to take the two crown races before the taper starts there usually isn’t. That flat part usually has a slight taper to it too to help the crown race grip correctly when pushed on. If you take one of the split crown races you can get and slowly push it on square you can see the gap continues to open up ever so slightly just before it contacts the crown itself. The correct solution is one of the +5mm options mentioned above. This problem you’re having is why some newer bikes are coming with headsets that restrict the turning movement of the forks.
BearBackFree MemberPosted 5 years agoI just had to add a 2mm 30mm spindle spacer to my kids 1.125 steerer fork as when tightened the Durins crown binds on the lower cup.
Not my ideal scenario and he might not ride it as I’m not sure we have dental coverage to replace his teeth if it all goes horribly wrong.
He also might ride it as it<span style=”font-size: 0.8rem;”> works perfectly in the stand ;)</span>
DM52Free MemberPosted 5 years agoInteresting thoughts, I didn’t even know +5mm races even existed and will look into that, a cursory google has only revealed taller headset cups so far for the cane creek headset (think mine is an s8).
The frame is old – commencal absolute VIP 2006, the forks are older – Fox 36 2005 but it is all I currently have other than a DH bike.
With the current ‘setup’ both races seem to have hit the taper, the top race was a lot harder to seat than the bottom so I assumed there was enough taper for both. I am kinda thinking or hoping with everything done up correctly it is not going to fall apart like a clown car and at worst the headset will work loose as the stacked races are potentially squished together a bit more.
I acknowledge it is not ideal and a bit of a bodge.
hols2Free MemberPosted 5 years agoI think my worry would be that the second race doesn’t sit quite square on the steerer and you’ll end up damaging the headset or steerer. Unless the second race has a flat surface to seat on, it might tend to move around a bit.
wwaswasFull MemberPosted 5 years agothat’s my thought – the second race will slip down the taper of the first on one side and end up at an odd angle relative to the crown and bottom headset bearing.
DezBFree MemberPosted 5 years agothere is no play in the headset
I reckon if this is the case, then it should be ok (should). As soon as anything isn’t seated correctly you’ll feel the wobble in the forks and that would be the time to give it up as a bad job.
Trouble is, you’ll (well I would) be riding with it on your mind all the time. “Is this gonna hold up?” Especially now you’ve started a thread about it!
DezBFree MemberPosted 5 years agoJust a thought – what if the bottom one was upside down? Then they’d sit together nicely… (If they aren’t already)
wwaswasFull MemberPosted 5 years agoThen you’d have the ‘point’ of the lower race trying to dig it’s way into the steerer/crown joint every time there was any force applied?
hols2Free MemberPosted 5 years agoI’d feel a lot more comfortable with some large flat washers or something under there. I’m sure an engineering shop would be able to sort something out.
munrobikerFree MemberPosted 5 years agoWhy is the fork dials hitting the crown a problem? How many turns are you doing where you need over 70 degrees of bar turn? I’d fit a bit of rubber to the underside of the crown if I was concerned about them hitting during the one crash a decade where they actually touch and ride it with a much safer single crown race.
otsdrFree MemberPosted 5 years agoI have had a similar issue and a taller crown race was the correct fix: https://www.charliethebikemonger.com/cane-creek-3mm-40mm-lower-race-custom-for-salsa-7676-p.asp
hols2Free MemberPosted 5 years agoProduct Information
Cane Creek +3mm 40mm Lower Race custom for Salsa
Headset crown race that stacks up by around 3mm.
This is used to get a Bluto sus fork to clear the downtube on a Beargrease.
Apparently very rare.
Stock Status: Sold Out
DM52Free MemberPosted 5 years agoI don’t think a 1 1/8th steerer is compatible with a 40mm race anyway.
To answer Munrobikers question, I was trying to avoid damaging the forks rebound and travel dials in the event of an accident, I had not thought too hard about the potential ramifications of the crown race kludge.
cynic-alFree MemberPosted 5 years agoI agree with DezB, if the 2nd, higher crown race is a good press-fit on the crown, should be OK.
Certainly not going to be any catastrophic failure.
bigyanFree MemberPosted 5 years agoThe 2nd crown race will not seat properly on the taper of the first unless you machine them to match. It will “work” but it is point loading and will deform.
If you want a better bodge and the the crown race is tight further up the steerer a flat spacer would be a better solution.
DM52Free MemberPosted 5 years agoI am thinking maybe long term this is what I am after: https://www.ebay.co.uk/itm/41-8-52mm-Bike-Headset-Base-Spacer-Crown-Race-Bike-Headset-Washer-Bicycle-Parts-/152584218906
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