Author Topic: Threaded hole in bottom bracket?  (Read 10412 times)

in4

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Re: Threaded hole in bottom bracket?
« Reply #15 on: December 17, 2015, 09:30:21 pm »
Below are a couple of zoomed photos of the bolt in my MK1 Nomad, as per previous post. Unfortunately my micrometer and vernier gauge are stored away so i can't give you any measurements. That said the top of the bolt appears to read FS and A2 70.
Additionally, there is also a small washer used between the frame and the bolt on mine.
Hope that helps.
« Last Edit: December 17, 2015, 09:56:55 pm by in4 »

Jonathan Hanson

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Re: Threaded hole in bottom bracket?
« Reply #16 on: December 17, 2015, 10:35:06 pm »
Thank you again Dan. I'm in Arizona, but I have a good hardware store nearby that carries a full selection of metric bolts.

mickeg

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Re: Threaded hole in bottom bracket?
« Reply #17 on: December 18, 2015, 02:01:15 am »
You will have to be extraordinarily lucky to find a hardware store in USA that stocks a 8X0.75mm bolt.

I looked for one some time back thinking it might be useful to have a spare in the event that one of mine (for my eccentric) fell out.

I am not saying don't go to the hardware store, I am saying I wish you a lot of luck.

If it was me, I would probably just try to plug it with something like a little wad of aluminum foil or a 5/16 wood dowel or something like that.  A wad of aluminum foil would probably allow leakage of any condensate out of it and could probably be removed easy enough with a long nose pliers.  A dowel would probably have to be tapered to be threaded in part way and cut off but would be harder to remove than the wad of foil.

Danneaux

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Re: Threaded hole in bottom bracket?
« Reply #18 on: December 18, 2015, 03:35:59 am »
Just thought of something...

The threads on male chainring bolts are M8 x 0.75. Again, assuming it will fit...(the threads on Ian's pictured bolt appear to have a much coarser pitch; the A2-70 indicates it is ASTM-302/18-8 stainless, so not marine grade/A4/316) this would extend the socket and allow continuous drainage while shielding the hole from water thrown up from the front wheel.

Best of both worlds.

A stainless one would fill the bill nicely. It would also allow a quick check on size to see if it matches the threads. A standard 5mm allen key will fit for easy installation,

Best,

Dan. (...who sends greetings from very wet and currently flooding Oregon)
« Last Edit: December 18, 2015, 06:44:43 pm by Danneaux »

Dave Whittle Thorn Workshop

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Re: Threaded hole in bottom bracket?
« Reply #19 on: December 18, 2015, 01:22:10 pm »
Some were M8x0.75 later ones went to M5x0.8mm, if the former you could use an inner chainring bolt and washer.

Hope this helps, Dave

Jonathan Hanson

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Re: Threaded hole in bottom bracket?
« Reply #20 on: December 18, 2015, 03:11:59 pm »
Thank you all! And thanks Ian for the photos. I'll report back when I've tried for fit.

jags

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Re: Threaded hole in bottom bracket?
« Reply #21 on: December 18, 2015, 03:56:50 pm »
so Jonathan whats the story are you stripping the  bike down  giving it a full service  ;)

Jonathan Hanson

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Re: Threaded hole in bottom bracket?
« Reply #22 on: December 18, 2015, 06:15:11 pm »
Quote
so Jonathan whats the story are you stripping the  bike down  giving it a full service

Sort of—I had a Shimano Hollowtech crankset on the bike originally, and I just didn't like it. The Q factor was too wide which resulted in a bad chain line. And . . . I didn't like the aesthetics. Meanwhile I'd been hearing great things about the SKF bottom bracket, and decided to switch to a Sugino crankset and the SKF (although I certainly gained some weight with the switch). I'm not sure why I didn't notice the open hole when I first built the bike, unless the bolt was there and subsequently walked its way out, which doesn't seem likely.

Here it is with the Shimano still installed:

« Last Edit: December 18, 2015, 08:07:48 pm by Jonathan Hanson »

Danneaux

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Re: Threaded hole in bottom bracket?
« Reply #23 on: December 19, 2015, 12:22:56 am »
Lovely bike, Jonathan, beautifully attired -- a stunner to my eyes!

Those derailleur Nomads are really something. AndyBG has one, and I had the chance to see and really appreciate it up close.

Best,

Dan.