[rob moree]

Hi, I am new here. I am Rob from the Netherlands and just bought a standard frame completely striped. So I want to get some advise on what kind of bottom bracket would be the best to start with.
What kind of alignment is the best?

Thanks

[kenneth buttterfield]

rob…it all depends on the way you want the bike….perhaps you want to go original, which you need to source cottered axle, bearings, cups etc?

or you may want to upgrade to sealed BB unit with cotterless cranks fitted of your choice?
Alignment comes after you decide on rear wheel gearing ie block, cassette or any hub gear….there are many options…ken

[Matthew Dunn]

If I take your question literally then the best is considered to be Phil Wood which can also be adjusted side to side to fine tune the chain line. You’re looking at around £100 for a new one though.
Axle length would need to be around 103mm depending on components used as Ken said.
Hope this helps!
Matt

[Morten Engel]

Hi,
I am also looking to replace my BB with something new, sealed and modern.
Any cheaper options than Phil Wood?

Cheers.

[Gavin Clark]

I’ve been using a Shimano UN26 on my Series 2 for the last two years with no problems. IIRC it cost less than £10. Highly recommended.

regards

Gavin

[Morten Engel]

Thanks Gavin,

Will it mount directly to an old F-Frame?
Or does it need some kind of modification?

Cheers.

Morten

[Gavin Clark]

Hi Morten

Assuming you have a Series 1 or 2 F-frame, AFAIK any standard 68mm BSC thread bottom bracket will fit without modification. Apparemtly the bottom bracket shell on these F-frames is offset to the left, so I added two 1.5mm Sturmey Archer sprocket spacer washers onto the drive side bottom bracket cup before fitting. However, I’m not sure how critical this is.

I used a 113mm BB which was fine for the old SR Chainset I used.

I don’t have one myself but I understand that Mark 3 Moulton’s have a much wider bottom bracket shell (76mm?) and used Raleigh’s proprietary threading, so they do need modification in order to fit a standard BB.

Hope this helps

Gavin

[Morten Engel]

Hi Gavin,

Cheers.
This is great news. It sounds like replacement is fairly painless.

As far as I gather it’s a series 2.
I will get to work now on my restoration project.

Happy New year.

m

[joerg Maltzan]

Hi Folks, hi Gavin!
Very interesting reading about BB-conversions. I am in the process in fitting my Moulton Speed with a modern SA 5speed hub plus new sealed BB. How do I figure out the correct chain line? Which bottom bracket axle lenght is the best using a modern chainring and crank? Thanks for any advise.

[Author]

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