Mountain Bike Reviews Forum banner

snapped 888 top crown bolt - can I still ride?

2K views 20 replies 10 participants last post by  wormvine 
#1 ·
The bolt on the 2007 888 RC2XVA top crown (one sort of in the center near the steer tube) has snapped in half.

Actually, I would say 3/4 of the bolt is still in the threads.
I'm going to take it to my LBS to see if they can drill it out...
but if they can't...would it be ok to ride DH this weekend?

I'm thinking ALL the bolts are there for a purpose...however, I don't see the top crown going anywhere considering the bolts around the legs are in tact and the stem is in place.

Should I chance it?
 
#4 ·
I am guessing you are using the integrated stem which has one bolt which is holding the headset tension, and the second one is broken. Personally I would let the shop extract the damaged one with an EZ out. Should be a piece of cake.

Riding without it could cause you to ovalize the headtube. That gets real expensive when you need to buy a new frame.

Take it to the shop. If they are 3/4 competent they will get it out.
 
#5 ·
stem

006_007 said:
I am guessing you are using the integrated stem which has one bolt which is holding the headset tension, and the second one is broken. Personally I would let the shop extract the damaged one with an EZ out. Should be a piece of cake.

Riding without it could cause you to ovalize the headtube. That gets real expensive when you need to buy a new frame.

Take it to the shop. If they are 3/4 competent they will get it out.
****
actually I am running the Easton Vice stem. It has a tall stack height and 2 side mounted bolts securing the stem to the steer tube.
I'm praying my shop can do it without messing with the threads.

I have a call into Marz for a replacement back up in case the LBS can't swing it.

Does the fact that 3/4 of the bolt is still in there add any strength to the area? Or are the "clamping" abilities completely negociated due to the head snapping off?

Thanks....
 
#6 · (Edited)
freeriderB said:
****

I have a call into Marz for a replacement back up in case the LBS can't swing it.

Does the fact that 3/4 of the bolt is still in there add any strength to the area? Or are the "clamping" abilities completely negociated due to the head snapping off?

Thanks....
seriously?? All bolts/screws/nails have heads for a reason....How do you think it is applying any force with no head?? That bolt is a simple 5mm (sorry, fat fingers) metric cap head screw available at any hardware store for a dime.

BTW, because you are NOT running the integrated stem, riding the bike would be a big no-no. Your top crown is not attached to the steerer in any way.....worse case scenario, your lower crown twists backwards and you loose you teeth.

So with the head sheered off, there is no load on the bolt. You shoud easily be able to back it out with some enginuity (ez-out. screwdriver, or simply supergluing something to the bolt stump and unthreading.

While you are at the hardware store, get a torque wrench!!!!!!!! You had to WAY overtighten that bolt to break it.
 
#7 · (Edited)
freeriderB said:
****
actually I am running the Easton Vice stem. It has a tall stack height and 2 side mounted bolts securing the stem to the steer tube.
I'm praying my shop can do it without messing with the threads.

I have a call into Marz for a replacement back up in case the LBS can't swing it.

Does the fact that 3/4 of the bolt is still in there add any strength to the area? Or are the "clamping" abilities completely negociated due to the head snapping off?

Thanks....
I have the same fork. Well an 06' but anyway. I doubt you would ovalize the headtube cause you should still have bearing load on the headset regardless of the steerer bolt..
I'd say you should be OK but take it easy but that one bolt won't make or break it. But it will not be 100%.

Look at it like a single crown fork with pinch bolts. Like the 2007 Marz DirtJumper. The lower crown has 2 pinch bolts but no upper crown. The 888 has a 2 pinch bolt lower crown and a single pinch bolt upper. Granted the 888 lower crown is not as beefy as a dedicated pinch bolt single crown but the upper crown adds to the stiffness and support regardless of the small single steerer bolt.
Still you ride it at your own risk.
 
#12 ·
Yeah not a good idea to ride it, I've seen top crowns ripped right off the steertube from a front impact. Not pretty.

Sometimes you can just take a hacksaw blade, stick it between the split in the crown and roll the broken piece right out. That is if there's enough of the broken end sticking out to get the blade to touch. Sometimes you can even just take a small flat head screw driver stick it in the hole and push on the end of the bolt and roll it out too. Of course if you fail with either of those methods the easy out is the next option.

It's an M5 bolt not a M6 bolt.
4 millimeter thread, 5mm x .8 thread
 
#13 ·
instead of showing your girlfriend feets of strength by over torgueing your bolts on your bike you should do one arm pushups.....she'll love that


oh and get a torque wrench.....snapped bolts are caused by over tightening
 
#14 ·
update

SHIVER ME TIMBERS said:
instead of showing your girlfriend feets of strength by over torgueing your bolts on your bike you should do one arm pushups.....she'll love that

oh and get a torque wrench.....snapped bolts are caused by over tightening
*****
good idea...but my wife isn't impressed by anything that I do! Especially if it has to do with my biking obsession....

LBS just called and advised they backed it out no prob.
I also ordered a new top crown this morning from Marz (who had excellent cust service by the way).

So I should be good to go for the weekend since I had them ship it 2 days (assuming I decide to switch the old with the new)...either way, now I'll have a spare.
 
#16 ·
wormvine said:
I have the same fork. Well an 06' but anyway. You already have the 2 pinch bolts on the 2 stanchions and you have a standard stem. Which is the only means of connection to a single crown fork. I would say since you have a regular stem with pinch bolts, you should be OK. I doubt you would ovalize the headtube cause you should still have bearing load on the headset.
I'd say you should be OK but take it easy but that one bolt won't make or break it since you have a regular stem.

If you look at it like a single crown fork. The lower crown has 2 pinch bolts, the upper only has one.
You are failing to understand that a single crown fork is designed to not have a top crown. A dual crown fork is NOT. THe crowns are not the same design, size, mass or strength.
 
#18 ·
wormvine said:
I understand completely how they work. I have both and have installed both myself.
Riiiiiiiight....

What you wrote above makes absolutely no sense what so ever. If you did actually understand the forces involved in a fork, you would have not posted that. An integrated stem (marz type) would actually connect the crown to the steerer as the stem bolts to the crown AND clamps to the steer tube. A non-integrated stem does NOTHING.
 
#19 ·
davep said:
riiiiiiiight....

What you wrote above makes absolutely no sense what so ever. If you did actually
understand the forces involved in a fork, you would have not posted that.
It'll be fine, don't you worry. I agree the last line of my first post is a bit convoluted. I will fix it so you can stop worrying. But that one small bolt will not catastophically fail the fork under nominal riding conditions IMO.
 
#20 ·
wormvine said:
It'll be fine, don't you worry. I agree the last line of my first post is a bit convoluted. I will fix it so you can stop worrying. But that one small bolt will not catastophically fail the fork under nominal riding conditions IMO.
I am not worried at all. I just dont like when people give an opinion on something they dont know anything about, especially when it could endanger someone if they chose to take your advice.

It is OK to not post in a thread if you are not familiar with the topic.

Riding a MTB for less than 3 years and installing a fork 'all by yourself' does not qualify you to determine the stress loading and possibility of failure of a mis-installed MTB product. Read what Marztech posted again, and see if that jives with your recomendation...
 
#21 ·
davep said:
I am not worried at all. I just dont like when people give an opinion on something they dont know anything about, especially when it could endanger someone if they chose to take your advice.

It is OK to not post in a thread if you are not familiar with the topic.

Riding a MTB for less than 3 years and installing a fork 'all by yourself' does not qualify you to determine the stress loading and possibility of failure of a mis-installed MTB product. Read what Marztech posted again, and see if that jives with your recomendation...
Dude, get over yourself... My profile is not even correct but laughable that you even looked at it. Should I have mentioned that I have been a motocross mechanic for 15 years in my profile? Or that i was a triple clamp fatigue tester at Pro-Circuit for 2 years. I don't like when people like you claim to have all the answers. You have no idea what training I have in anything. So STFU.
I gave him many disclaimers. He is a big boy. I stand by my evaluation. He wisely said he wouldn't ride it! You haven't qualified your knowledge whatsoever. If you want to post up force vectors and stress/fatigue tests. Do it. How bout catastrophic failure tests? GO for it! Flex your nahledge...
But do yourself a favor and let it go!:thumbsup:
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top