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FOX 40's LOWER CROWN FOULING FRAME

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FOX 40's LOWER CROWN FOULING FRAME
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flag neally
Posted: Feb 21, 2010 at 10:56 Quote
After the first weekend riding with my brand new new cove shocker and Fox 40's I now have two identical dents on each side of the bottom tube where it meets the steerer tube, this is being caused by the pinch bolts area of the lower crown on the 40's fouling the frame when handlebars are turned 'full lock'.

I have the rubber guards fitted to the upper stanchions but they are not doing the job as they don't protrude far enough - ie the lower crown is hitting the frame before the guards get a chance to guard!

Does anybody else have this issue? I think it may just be a compatibility thing between the shocker frame and the 40's but it might happen with other frame and fork combo's too.

I wonder is it possible to run the forks with the lower crown facing the other way - ie with the pinch bolts facing to the front? I reckon this will solve the issue?
flag oceen246
Posted: Feb 21, 2010 at 22:11 Quote
I've noticed this problem when i put the 40's on my 951. To solve the issue, i've used double-sided tape to stick thick rubber on my down tube where the pinch bolt are suppose to make contact. In the process I've lost a bit in turning radius.
flag craigdhboy
Posted: Feb 22, 2010 at 2:13 Quote
contact fox and cove and see what they suggest, i wouldn't advise in turning the lowers crowns around the other way though
flag neally
Posted: Feb 22, 2010 at 5:15 Quote
I had rubber stickers on it. The bike shop that built my bike up noticed this would likely be a problem and put some on.

But they didn't really help as the area around the pinch bolts on the lower stem is so angular that it went right through the stickers and still dented the frame. You see I tend to come off and crash quite regularly and the force of the bars 'snapping' to full lock on any sort of impact is enough for the crown edge to cut through these stickers. If pressure = force / area then it's a fair force over a very concentrated/angular edge resulting in a large pressure.

Anyway, I currently have some old inner tube wrapped round the frame area as a temporary measure and I'll probably replace it with some rubber tape or something similar this week. But the point is, I don't really want to have to be wrapping large sections of black inner tube or rubber protection around my brand new frame - especially somewhere so prominent. Call me vain but...
flag jessejones
Posted: Feb 22, 2010 at 5:35 Quote
Not sure if it would work but you could try getting a headset with a bigger stack height on the bottom cup.... this might sit your crown a bit further from the frame?!

Obviously if its catching the frame fairly high up it wont work but if its just clipping then it may do the trick.
flag demostug
FL
Posted: Feb 22, 2010 at 5:35 Quote
neally wrote:
I had rubber stickers on it. The bike shop that built my bike up noticed this would likely be a problem and put some on.

But they didn't really help as the area around the pinch bolts on the lower stem is so angular that it went right through the stickers and still dented the frame. You see I tend to come off and crash quite regularly and the force of the bars 'snapping' to full lock on any sort of impact is enough for the crown edge to cut through these stickers. If pressure = force / area then it's a fair force over a very concentrated/angular edge resulting in a large pressure.

Anyway, I currently have some old inner tube wrapped round the frame area as a temporary measure and I'll probably replace it with some rubber tape or something similar this week. But the point is, I don't really want to have to be wrapping large sections of black inner tube or rubber protection around my brand new frame - especially somewhere so prominent. Call me vain but...

hey neal, m8 paul has the same problem with his yeti rdh, cut an old tyre and use it as a bump stop on the down tube. the other solution i saw is you can buy a lower headset extension piece that makes the lower crown sit lower. dont ask me where from tho.
flag jessejones
Posted: Feb 22, 2010 at 5:36 Quote
demostug wrote:
hey neal, m8 paul has the same problem with his yeti rdh, cut an old tyre and use it as a bump stop on the down tube. the other solution i saw is you can buy a lower headset extension piece that makes the lower crown sit lower. dont ask me where from tho.

Great minds!
flag pbuser102331
Posted: Feb 22, 2010 at 6:21 Quote
neally wrote:
I had rubber stickers on it. The bike shop that built my bike up noticed this would likely be a problem and put some on.

But they didn't really help as the area around the pinch bolts on the lower stem is so angular that it went right through the stickers and still dented the frame. You see I tend to come off and crash quite regularly and the force of the bars 'snapping' to full lock on any sort of impact is enough for the crown edge to cut through these stickers. If pressure = force / area then it's a fair force over a very concentrated/angular edge resulting in a large pressure.

Anyway, I currently have some old inner tube wrapped round the frame area as a temporary measure and I'll probably replace it with some rubber tape or something similar this week. But the point is, I don't really want to have to be wrapping large sections of black inner tube or rubber protection around my brand new frame - especially somewhere so prominent. Call me vain but...

Vain lol just wait until you bin it.
flag cloverleaf
Posted: Feb 23, 2010 at 3:28 Quote
I can't remember off hand if the Shocker uses a 1.5" headset but either way, that would only exacerbate the issue. The 40 crown is upturned slightly towards the stantion clamp whereas most are slightly downward (allowing extra clearance to the downtube on full lock). When I was running the RL9 Rotec we ran it with a zero stack upper and a normal cup down below to give the necessary clearance. If you have a full zero stack in there this may well be an alternative for you. If you're running a low stack 1 1/8" headset you can either try to source an aftermarket crown race that provides extra height between the crown and the bottom of the headtube (dependant on who the manufacturer is really on that one) or alternatively just try to source a headset with a greater stack height to provide the additional clearance.

If none of that is really an option then you can source some sticky back door stops which are made of hard rubber, usually about 10mm thick and 15mm in diameter. In the UK you can get them from B&Q, Homebase etc but stateside I guess somewhere like Home Depot will be the alternative. We used to use these on Yeti's when we were running the original Dorado's and they lasted a reasonable amount of time before needing replaced and were cheap to boot. Place these on the most prominent point of contact on the frame and then position the actual 40 fork bumpers to hit these stops. If necessary you can run a zip tie round the proper bump stop to help hold it in place on the stantion.

Hopefully some of that'll be of some use...
flag neally
Posted: Feb 23, 2010 at 12:40 Quote
photo
photo

Thanks for the advice demostug, thanks Cloverleaf.
See photos of what I've done - section of inner tube cut to a slimmer size and wrapped round area in question, secured with a single tie-wrap. Not the best looks-wise on teh white frame but will definitely work, which is the main thing.

Thanks again to all.
flag bikerboywill
FL
Posted: Feb 23, 2010 at 12:47 Quote
couldnt you put a headset spacer under the cup?
flag iggzdaloc
Posted: Feb 23, 2010 at 13:07 Quote
bikerboywill wrote:
couldnt you put a headset spacer under the cup?
Are you f*cking serious?
flag
Posted: Feb 23, 2010 at 17:57 Quote
JBDirtJumper wrote:
bikerboywill wrote:
couldnt you put a headset spacer under the cup?
Are you f*cking serious?

$1 says he meant under the crown race
flag riggadon
Posted: Feb 23, 2010 at 18:20 Quote
i have an idea- buy another set of 40 bumpers and put them on, problem solved
flag neally
Posted: Feb 23, 2010 at 22:16 Quote
fall0ut wrote:
i have an idea- buy another set of 40 bumpers and put them on, problem solved

That won't work. They won't protrude any further than the bumpers I have on - and they don't protrude far enough to prevent the pinch bolts hitting the frame. So unless Fox do a set of thicker bumpers that's not an option.
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