[OGRipper]

Hey all, I'm running an evil drs with a 38 tooth "big" ring and an evil bashguard. My frame doesn't have ISCG mounts. Even though I tighten the piss out of the bb, when I top out on a log or rock, the guide gets knocked upwards, rotating around the bb and into my frame linkage. This sucks more than usual 'cuz I'm also running an e-type front der (mounts on the guide plate instead of the seat tube) so when the guide gets knocked, my front der gets knocked out of position too.

I wrote evil about it a while back and they didn't have much to say other than "tighten it real tight and use loctite." Tried that, didn't work.

I can't be the only one with this issue. I've got a few ideas but would like to know what you all tried, what works, etc. Thanks. I'll try to follow up and let you know what I do (and if it works).

And please don't tell me not to hit it any more.

 

[Fulton]

do you think a modified boomerang would work? One that placed the lower guide further up behind the bashring, instead of directly below it so you wouldn't hit it quite as much? you'd have to add some links to your chain, anyway, just a thought

 

[John P.]

Hey man-

Sorry to hear you're still having that problem. Honestly, though, if you're tightening the BB down as much as humanly possible, and you're hitting the guide hard enough to still move it, you would have long since ripped the ISCG mounts right off your frame - no doubt about it.

If everything is kosher on your frame/BB and you were tightening down your BB as much as you can, it would be nearly impossible for that boomerang to move except under some EXTREME scenario. I mean, I've installed guides before, realized the boomerang needed to be rotated more, and I couldn't get the thing to budge even when taking full swings at it with a hammer.

Is it possible your BB or BB cup threads are roached? I'm just really confused here, because with a proper install and good parts, it would be nearly impossible to move that boomerang.

Finally, if you have a chance to make it out to Big Bear, WV, VT, US Open, or Durango, I'd be happy to take a look at it personally and try to figure it out for you.

Let me know,

John
johnp@e13components.com
207-846-3355

 

[dw]

I want to add one line to wht John said here, check to make sure tht you aren't running ti-prep or grease between your cup flange, chainguide mount, and chainguide.

Also, it could be that your BB shell was never faced and you are bolting against an uneven surface. This would reduce contact area and therefore reduce holding power.


Dave

 

[OGRipper]

Thanks for the quick replies, props to John and Evil. BTW, I'm stoked on the guide, no other problems. And I'm actually really surprised more people aren't having this problem.

I'm about 200 lbs and pretty much put all my weight into it. Last time I did it, I cleaned all the surfaces with alcohol, put some red loctite between the cup and boomerang, then leaned on the bb tool with everything I've got. I figured it was in there permanently, but the problem persists.

I'm not even hitting it that hard, definitely nothing more than I used to hit without a guard, and I never really ate up too many rings. Honestly don't think I would rip the bolts out of ISCG tabs but I dunno, maybe.

DW may be onto something about facing the shell. It was factory faced but maybe it's uneven.

Just seems like I need to devise some kind of a stop, like a chainring bolt in one of the ISCG holes or something, but I'm a little worried about marring the frame and bending the boomerang if I do that.

So nobody else really has this problem?

 

[binary visions]

Originally posted by dw
Also, it could be that your BB shell was never faced and you are bolting against an uneven surface. This would reduce contact area and therefore reduce holding power.

I was just going to mention that.

If you're talking about whacking the boomerang with full force of your weight + bike's weight, though, there's really not a lot you can do. As John mentioned, you would have ripped out the ISCG tabs a long time ago (with the possible exception of, say, the quarter inch thick, one piece tabs on the Endless Lifetime or a similar setup), so be happy your boomerang is moving rather than destroying your frame.

edit: For what its worth, I have the problem too, but it's only 'cause I suck and case the boomerang on benches/rocks/whatever when trying to get up on them.. I would have destroyed ISCG tabs long ago. However, the Imperial's chainstays are formed in such a way that the boomerang just comes to rest on the bottom of a solid piece of Al., and stays there when I whack it.

 

[Transcend]

Originally posted by binary visions
I was just going to mention that.

If you're talking about whacking the boomerang with full force of your weight + bike's weight, though, there's really not a lot you can do. As John mentioned, you would have ripped out the ISCG tabs a long time ago (with the possible exception of, say, the quarter inch thick, one piece tabs on the Endless Lifetime or a similar setup), so be happy your boomerang is moving rather than destroying your frame.

edit: For what its worth, I have the problem too, but it's only 'cause I suck and case the boomerang on benches/rocks/whatever when trying to get up on them.. I would have destroyed ISCG tabs long ago. However, the Imperial's chainstays are formed in such a way that the boomerang just comes to rest on the bottom of a solid piece of Al., and stays there when I whack it.

Just as an example, bromont this weekend, one of my guys slammed his idler into a rock and snapped all 3 bolts off the iscg tabs. Frame is ok, but bolts are gone.

Definetly try facing it, mine was a little slack in my 223 until i got it faced, now it is rock solid. I am not using the tabs, as I like to use my guide setup properly ( ). The 223 iscg tabs are about 20 degs off, but hey, no one listens to me...

 

[-dustin]

what are you using on the BB threads?

i had a similar problem with my SRS. dw said something about using anti-seize instead of grease (or was it the other way around...i can't remember now) then tightening it real good. that solved my problem.

 

[Fulton]

What about a larger diameter bashring?? Correct me if I'm wrong, but I think the DRS guides come with the 36-40 tooth sized bashring. I believe they make one that will cover up to a 44. Since the lower guide sits behind the bashring, this will provide some additional coverage, Maybe then trim off any additional materail at the bottom of the boomerang if possible.

 

[OGRipper]

Fulton, you're right, a bigger bashring would help but one of the reasons I wanted a smaller one was for more clearance so I'm reluctant to get something bigger. And I've already, er, "trimmed" some of the guide material - pieces of the plastic chain guide have broken off, so there is more room than usual.

I'l try to face the bb and tighten it real good again. If that doesn't work I'm just gonna weld that bi-otch to my frame!!!

 

[vitox]

Originally posted by OGRipper
Fulton, you're right, a bigger bashring would help but one of the reasons I wanted a smaller one was for more clearance so I'm reluctant to get something bigger. And I've already, er, "trimmed" some of the guide material - pieces of the plastic chain guide have broken off, so there is more room than usual.

I'l try to face the bb and tighten it real good again. If that doesn't work I'm just gonna weld that bi-otch to my frame!!!

please do face it before welding!

sometimes just filing the paint off (some frames come that way!) and manually seeing to that the surface is flatter helps a lot.

 

[Threepointtwo]

I don't have tabs either. I just run the roller up behind the bash guard and have had good luck.

 

[Threepointtwo]

Originally posted by Threepointtwo
I don't have tabs either. I just run the roller up behind the bash guard and have had good luck.

I meant to add a little picture.

 

[OGRipper]

Thanks for the comments, I thought it would prove to be a common problem and all you monkeys would bury me with creative ideas, but I guess not, maybe I just need to lean on it a bit more.

Vitox, the frame was faced when I got it, so there is no paint to file. It could be uneven but not to the nekkid eye.

And 3.2, you've got (a) a bigger bashguard; and (b) a less obstrusive roller setup, so your rolller is tucked out of the way. I want to keep the smaller guard for more clearance, and I really like the way the drs works (except this issue, of course) and want to keep it too.

All I'm talking about is the occasional smack that occurs when I go over logs or rocks. It's not like I'm expecting it to hold up to cased landings from 15 feet or something, and I don't use this rig for street or urban, so it's not about coping grinds or sprocket stalls. And with the guide rotating on me, I find myself avoiding contact more than ever (so I don't even really need the bashguard). Anyway, I'll deal, thanks for listening....

 

[prophet6]

I had issues like this on an older frame of mine, and found that the route cause was an ovalized BB shell. Thus me now owning an Imperial.



p6