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NC35 Fork Top Bolt Too tight

Posted: Thu Jul 28, 2011 12:31 am
by Steve910
Hi all,

I've got a '94 RVF400 which i'm restoring to its former glory. While going to change the fork oil yesterday, with the forks off the bike, I found myself unable to get the top bolt undone on the fork. I managed to get the bottom allen bolt loosened as per the haynes manual, but I'm not sure if I'm strong enough to get the top bolt undone.

It's the first time I've done it with the bike so i'm not sure what the previous owner has torqued it to, but whatever it is, it's stronger than my mate and I are capable of getting undone. The main problem we're having is holding the fork while trying to turn the top bolt. We've tried putting the fork in a soft vice with a grip pad on it but it's just not enough. Should i put the fork back in the triples and use those to hold it in place while we try and undo it ?

I was somewhat nervous about dousing the whole thing in WD40, not wanting to contaminate the fork oil so I've held off on using anything like that. Any suggestions as to how to get the prick undone so i can get on with my rebuild?

Thanks !

Steve

Re: NC35 Fork Top Bolt Too tight

Posted: Thu Jul 28, 2011 12:44 am
by magg
Yes put the fork back in the triple clamps & slide it through so that the top of the fork tube is poking a few cms through. If the fork tub is flush with the top of the top triple clamp when you tighten the pinch bolt you will also be clamping the top fork bolt in the tub. Tighten the triple clamp binch bolts & you should be able to undo the top bolt of the fork tube.

Re: NC35 Fork Top Bolt Too tight

Posted: Thu Jul 28, 2011 12:57 am
by Steve910
Thanks very much! I'll give that a shot as soon as i get some alone time with the bike!!

I thought that may have been the best way to do it!

Steve

Re: NC35 Fork Top Bolt Too tight

Posted: Thu Jul 28, 2011 1:16 am
by RoninZX-10R
The fork caps are virtually impossible to undo unless they're in the triple clamps. When I was young and stupid (the only difference now is I'm older!!!) I tried so hard to undo the top cap that I nearly busted my knuckles when the spanner slipped, so I cracked the sh*ts and whacked the fork with the spanner...what an idiot! Can't remember what it cost me.

I wouldn't be too worried about contaminating the fork oil with WD-40 if you're changing the oil anyway.

Re: NC35 Fork Top Bolt Too tight

Posted: Thu Jul 28, 2011 1:28 am
by Steve910
I can understand how you would have done that. I couldn't believe how hard it was. It was a pretty frustrating afternoon !

Re: NC35 Fork Top Bolt Too tight

Posted: Thu Jul 28, 2011 10:54 am
by amorti
Best way is an air gun with deep socket. Click-click-click-whirrrrrr as it submits to air pressure.

Other than that the common error is using spanners instead of sockets, or not undoing the top triple clamp before attempting to undo the cap. Of you wind off the preload it'll be easier, but then you probably need a deep socket which not everyone has. Swings and roundabouts if you don't have all the tools.

Re: NC35 Fork Top Bolt Too tight

Posted: Thu Jul 28, 2011 11:17 pm
by Lane
Isn't the top bolt alloy?

I would be very careful of using pneumatic tools on soft alloy.

Re: NC35 Fork Top Bolt Too tight

Posted: Fri Jul 29, 2011 12:37 am
by lizard821000
a simple job off the bike, just need a soft,rubber pipe wrench to grip the stanchion. machine mart sell them for a fiver.

Re: NC35 Fork Top Bolt Too tight

Posted: Fri Jul 29, 2011 9:10 am
by amorti
Lane wrote:Isn't the top bolt alloy?

I would be very careful of using pneumatic tools on soft alloy.
I would never advocate using air tools to put them in, but taking them out - why not? At least you can use all your concentration and weight to push down and ensure the socket doesn't slip. The damage comes from either using ill-fitting spanners, or slipping off when trying to lean against the extension bar.