bottom bracket for Timberwolf

Joined
Jul 29, 2021
Messages
57
Hello AZERs

I am now commencing the build of the adjustable bottom bracket (pages 139 to 147) in the manual. My choice for repurposing was an old Releigh but when I ground it down, I discovered big holes where the down tube and framing are welding into the bottom bracket tube. Really not a whole tube at all as shown in the manual.

Is there a certain type of bike frame I should be looking for that will yield a solid bottom bracket tube?

Dan

click to see image thanks
 
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Joined
Jul 29, 2021
Messages
57
Thanks Maddox I’ll do that if I have to but I wonder what kind of frame atomic Brad use when he originally did his
 
Joined
Oct 19, 2012
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2,008
Location
Wakefield, UK
Most bb shells will have those holes. Position them as best you can so the holes are covered by new tubes and weld in any left over.
 
Joined
Sep 18, 2022
Messages
7
Location
St. Louis Mo USA
Have you given any thought to mounting the bottom bracket under the beam instead of on top. I'm kind of considering this on my build if there is enough ground clearance.
 
Joined
May 31, 2013
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Location
South Benfleet, Essex, England, UK
The holes are there to let hot-air escape from the tubes that are being welded to the BB shell.
You can either have holes in the BB Shell or holes in the attached tubes to achieve this.
You can buy brand new BB shells with no holes from a frame supplies outlet. In the UK they are about £7.50 each.
 
Joined
Jul 29, 2021
Messages
57
Have you given any thought to mounting the bottom bracket under the beam instead of on top. I'm kind of considering this on my build if there is enough ground clearance.
Hi Steve:

I have not committed to the bracket being on top, and I can see some advantage to mounting it below. I am new to recombent biking and I have to say the initial "feet up" posture is a little off putting. I am trying for something more like you would see on an ELF where the feet are lower than your butt. So .....great suggestion.
 
Joined
Jul 29, 2021
Messages
57
The holes are there to let hot-air escape from the tubes that are being welded to the BB shell.
You can either have holes in the BB Shell or holes in the attached tubes to achieve this.
You can buy brand new BB shells with no holes from a frame supplies outlet. In the UK they are about £7.50 each.

Thanks Danny. Yes my neighbor suggested that as well, but I also need the cups and cranks etc for the drive train, so I am likely going to repair the holes of an existing Bottom bracket..
 
Joined
Jul 29, 2021
Messages
57
Hi Steve:

I have not committed to the bracket being on top, and I can see some advantage to mounting it below. I am new to recombent biking and I have to say the initial "feet up" posture is a little off putting. I am trying for something more like you would see on an ELF where the feet are lower than your butt. So .....great suggestion.
Probably going to put the bottom bracket on top as per the original design, and just make my seat higher.

as shown in HAPE 04's Fantom Project, the guy that inspired me to begin with
 
Joined
Oct 20, 2022
Messages
9
Hello AZERs

I am now commencing the build of the adjustable bottom bracket (pages 139 to 147) in the manual. My choice for repurposing was an old Releigh but when I ground it down, I discovered big holes where the down tube and framing are welding into the bottom bracket tube. Really not a whole tube at all as shown in the manual.

Is there a certain type of bike frame I should be looking for that will yield a solid bottom bracket tube?

Dan

click to see image thanks

AZ offered bottom brackets for sale which had heavy walls and no holes since they were new. All used bottom brackets have holes to insert frame tubes.
 
Joined
May 31, 2013
Messages
3,624
Location
South Benfleet, Essex, England, UK
All BB shells have holes in. It isn't to insert tubes though, it is to allow hot gasses from the welding to escape, else there is a loud "pop" and hot weld material sprays everywhere.
You can just puddle-weld them over if they are unsightly.
You can buy blank ones for about £7.50 each from frame suppliers.
Always insert cups in the threads when welding to ensure there is no distortions, and make sure you get the BB-Shell round the right way :D
 
Joined
Sep 17, 2020
Messages
159
Location
Ohio
All the donor bikes i used had holes as well, I used a piece of brass pipe and held it against the hole on the inside, and used it as a backing as i filled them in with weld then grinded them smooth. It kept the inside clean and I didn't have to worry about anything causing issues later in the build.
 
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