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Discussion Starter · #1 ·
Yeah, I'll talk to the builder but I'd still like to consult with the brain trust on this forum.

So here's my issue: Ti frame with EBB used to tension a Rohloff hub linked to a Ritchey Logic crank using a square spindle Shimano bottom bracket. The crank/bb is important as it provides the narrowest Q-factor I can find (154 mm) that also matches up with the Rohloff chainline (54 mm). I've discovered that sufficient tension to prevent slipping using either of two Bushnell EBB's or a Carver EBB will bind the bearings of Phil Wood (severely) or Shimano (moderately) bottom brackets. Add to that the creaking that comes along with the first hint of moisture or a month or so of dust -- it's driving me batty! I notice that the EBBs need to be expanded pretty extensively to lock things in place and wonder if that could contribute to the binding and chronic creaking. Could the EBB be resized (shimmed?) to counter that effect?

I expect if I was willing to go to an external bearing bottom bracket, I could at least get rid of the issue of binding the bearings, but I need to keep the Q-factor where it is or (ideally) reduce it further -- and I have to be within at least 2 mm of 54 mm to keep the chain line with the Rohloff hub.

Love to hear some ideas!
 

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Got a Bushnell on my Salsa. Noticed the binding you mentioned right away. Got 6 months out of a new Tange BB, running square taper Middleburns. Just tore the BB down, the bearing are shot from water contamination.

I am going to use the new SKF bas 600 sq taper BB. It has a one piece shell out of stainless, and uses rollers on the drive side. It weighs 300 g, I don't care. The only issue will be grinding off a small section off the lock ring on the drive side so I can pull out the Bushnell for cleaning (if I need to) while leaving the BB in place and the drive side crank arm on. There is no way any binding will occur with the SKF, it just seems too beefy.http://www.skf.com/portal/skf/home/industries?contentId=517218&lang=en

As for the Bushnell, I've never had an issue with creaking. I use a torque wrench, and grease on the pivots and wedges, anti-seize where it sits in the frame. The bolt has to be very tight.

Drew
 

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EBBs just suck.

I hate to say it, but I'm guessing you'll have to deal with one or another of the problems you mentioned (creak, seize, slip, etc) for the life of the frame. That's the reason I stopped doing EBBs entirely - though I will say that I had better luck with the Phil Wood/set screw setups than the Bushnells.

Not that it helps you, but next time, get some sliders. EBBs are for tandems.

Good luck!

-Walt
 

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PeT said:
Yeah, I'll talk to the builder but I'd still like to consult with the brain trust on this forum.

So here's my issue: Ti frame with EBB used to tension a Rohloff hub linked to a Ritchey Logic crank using a square spindle Shimano bottom bracket. The crank/bb is important as it provides the narrowest Q-factor I can find (154 mm) that also matches up with the Rohloff chainline (54 mm). I've discovered that sufficient tension to prevent slipping using either of two Bushnell EBB's or a Carver EBB will bind the bearings of Phil Wood (severely) or Shimano (moderately) bottom brackets. Add to that the creaking that comes along with the first hint of moisture or a month or so of dust -- it's driving me batty! I notice that the EBBs need to be expanded pretty extensively to lock things in place and wonder if that could contribute to the binding and chronic creaking. Could the EBB be resized (shimmed?) to counter that effect?

I expect if I was willing to go to an external bearing bottom bracket, I could at least get rid of the issue of binding the bearings, but I need to keep the Q-factor where it is or (ideally) reduce it further -- and I have to be within at least 2 mm of 54 mm to keep the chain line with the Rohloff hub.

Love to hear some ideas!
Co-Motion Cycles makes a very good internal expander EBB insert of their own design. Very simple and secure.

The main reason an EBB creaks is the BB shell was not reamed after the frame was finished. You can not clamp properly with an out of round shell.
 

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I know...

Do a search for "slip + EBB" or "creak + EBB" on the singlespeed or 29er boards... you'll get hundreds of hits, I'm guessing.

Sorry I don't have any better ideas. I have had some luck converting Bushnell frames to pinch bolt (split the shell, install a couple of binder bolts) - that solution seems to mitigate problems a bit, but not eliminate them. Unfortunately all the EBBs out there seem to use different shells (ie, Phil Wood won't work in Bushnell, etc).

Best idea I've got: if you can find a solid insert (ie, non-expanding) that was bigger than the current shell ID, the OP could ask the builder to do a little lathe work to turn the insert down to size and install some set screws in the shell.

-Walt

dru said:
Not a vote of confidence, Walt............................... :-(
 

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I've measured at least 3 creaking EBB frames with a bore gauge. And found each one of them out of round or barrel shaped. I suspect that when they were welded that it distorted the shell. I fixed one of them by mounting it on a mill and used a boring bar to "kiss" the shell strait the other two were IMO way out and beyond repair.
On a side note one of the frames I rejected the owner welded the inside of the shell with line after line of weld then brought it back for me to bore I told him no cause it looked like he cooked the frame. Any ways he got a friend of his to bore it out on a mill. Not sure if it worked but I saw him ride it at least once.

Tim
 

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Would an external bearing compact drive road crank reduce your Q-factor? I have no idea... definitely would be able to fudge the small 34T ring to work with the right gear on the Rohloff.

I like EBB's, had trouble with binding on the bearings with Bushnell/ISIS combo, and would never do set screw on a ti frame EVER again.

Split shell was nice, but contamination (and then cleaning) was a pain.

I never had noise with my Bushnell set up w/anti-seize.

I'd look into the Niner Biocentric EBB, but I do not think they have a ti shell available to custom builders (pretty sure the steel (maybe alu) BB shell is available).

There's my half-assed two cents worth.
 

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Discussion Starter · #10 ·
teamdicky said:
Would an external bearing compact drive road crank reduce your Q-factor? I have no idea... definitely would be able to fudge the small 34T ring to work with the right gear on the Rohloff.
I would like this to work -- I could get use to the creak -- but the issue with compact road cranks is the chain line. For the Rohloff, the chainline is pretty far out (54 mm) and that works with most mountain triple cranks when the ring is bolted to the outside position, but a road double has about a 46 mm chainline for the big ring. A road triple might work, but the minimum front ring is about 38 teeth and that's too big for my application.
 

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pinch bolts, 5k miles, $5 BB is just now starting to wear out, no noise, ever. EBB's should be pinch bolt unless there is post process machining involved.

It sounds like the OP's problem might be ameliorated with soft (brass?) shim stock and lots of grease...
 

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SpoK Werks Handmade Goods
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I have a Black Sheep Ti with a Bushnell and a Curtlo with a pinch bolt. I was always afraid that the pinch bolt would give me problems. Never once have I had a problem with the pinch bolt EBB. With the Bushnell, it doesn't seem to matter what I do (grease, no grease, Ti prep) it always squeeks. I've even tried putting plumbers tape on the BB threads thinking that would stop it. Nothing works for more than a couple of rides. Aaaaarrrrgggghhhhh!

I despise the look and function of sliders but man... I am almost considering it on the next bike. If I didn't almost always ride with headphones, I think I'd have thrown my bike off the side of a mountain by now.

I'd love some semi-fullproof way of stopping the squeek. Even if it worked for a month, I'd be thrilled.
 

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1 Speed said:
I have a Black Sheep Ti with a Bushnell and a Curtlo with a pinch bolt. I was always afraid that the pinch bolt would give me problems. Never once have I had a problem with the pinch bolt EBB. With the Bushnell, it doesn't seem to matter what I do (grease, no grease, Ti prep) it always squeeks. I've even tried putting plumbers tape on the BB threads thinking that would stop it. Nothing works for more than a couple of rides. Aaaaarrrrgggghhhhh!

I despise the look and function of sliders but man... I am almost considering it on the next bike. If I didn't almost always ride with headphones, I think I'd have thrown my bike off the side of a mountain by now.

I'd love some semi-fullproof way of stopping the squeek. Even if it worked for a month, I'd be thrilled.
Ride the Curtlo. Problem solved!
 

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EBB can be noisy if not set up perfect from the OEM. There is little that end users can do in terms of correcting an out of round EBB. One thing I noticed on the black sheep is that it was quiet from the start then developed a ticking noise. As the tick is not constant and have swapped every part in the drivetrain and bike attempting to narrow the source it is the EBB. Last night I torqued it down quite a bit and the noise has been reduced. I’ve tried the plumbers tape, anti-seize, no anti-seize, grease and yet the noise is still there. Found some Teflon tape from the machine shop which is very thin that I’m considering applying to the EBB shell. Even going to strip the bushnell and apply near the pivots seeing if this will help. Thought is that if one could reduce the amount of metal on metal contact then it will help reduce the noise.
 
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