Query: 1987 Triumph 3-speed: threading - Raleigh/BSC ?

[Anonymous]

Hi all

I am recently getting into more retro biking and I have bought a 1987 Gents 3-speed, made by Triumph under Raleigh ownership, in China. I'd post a pic but as a new user I can't , yet

Anyone wanting to see it before commenting might search the Flickr photography site for a user with the same name as I use here....

I want to put a new crankset on it and need advice regarding suitable parts.
Specifically, the issue of 24TPI BSC spacing versus 26TPI Raleigh threading on the Bottom Bracket

I have been reading up: Sheldon Brown's site makes certain claims that conflict in this case, specifically he states that all Asian-built Raleighs have 24TPI threading and have non-cottered cranks. He also states that any Raleigh with a rear fender/mudguard eyelet ABOVE the rear axle is likely to be 24TPI / BSC whereas any with the fender/mudguard eyelet behind the axle is probably Raleigh-specific 26TPI

Mine is an Asian Raleigh/Triumph with cottered cranks, but fender eyelets above not behind the rear axle.

Massive respect to the late Sheldon but this bike doesn't fit his summary of the situation.

the bottom-bracket ends (sorry, I dont know the terminology too well..) look identical to the example of a Raleigh 26TPI b/bracket shown on Sheldon's site.

the bottom bracket width is 68mm measured between the back of the chainguard and the back of the end-plate on the left side (which is wider than the BB shell, dont think it overlaps it though) suggesting 24TPI standard per Sheldon?

what I'd like to know is:

How can I find out whether the bottom bracket threading is 24 or 26 tpi?

if it IS 24TPI (BSC standard -), can I then use a cartridge bottom bracket and modern spindle to then use cotterless cranks or must I seek a specifically 3-speed bottom bracket set?

Thanks in advance for any help offered

Chris

I edited this to replace 26 with 24 in the last bit. My error. I know I need special parts if its 26TPI

 

[keithglos]

Chris, firstly Sheldon was mainly concerned with the US market.
Are you sure of the manufacturing date?
If you are removing the bottom bracket adjusting cup you should be able to measure the threads per inch. A standard hub spindle thread is 26 tpi, just compare by putting them together.
Put up some closeup pics when you can.

 

[Anonymous]

Thanks for the reply.

I take the date of the bike from the date on the Sturmey-Archer AW hub. the style of the transfers on the frame is very late-80s also.

(they're coming off, as are the black cables, grips and saddle - I'm shamelessly backdating the look of it..)

I'm very new to this and not yet equipped to remove the cups.... starting to look like I'll have to, though..

 

[DxMachina]

I posted this topic, and was hoping to make some more posts in order to then be able to post a photo

Then someone deleted my account. I have checked the board rules and found I didn't break any of them - so what gives?

 

[DxMachina]

Replying here for completeness to have my original query and the final outcome in one place (in case other people find this question by google, saves it being asked again)

A 1987 Raleigh/Triumph 3-speed with a 68mm bottom bracket shell CAN take a modern Shimano UN54 bottom bracket, the threading is compatible and that was the only hurdle.

Just waiting for my new crankset and the tool for tightening the bottom bracket to arrive from various eBay sellers.. can't wait to ride it without knackered bearings slowing me down.