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NBD: 1990 Brompton Mk2
#1
Just picked up this little classic 1990 Brompton Mk2 with Sturmey-Archer 3-speed hub. Needs some TLC but all the important bits seem to be in reasonable condition with no signs of substantial rust on frame, rear triangle, or hubs. Not only do I look forward to learning The Way of The Brompton, but this means I'll probably be buying more tools. WINNING!
   
   
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#2
quite handy if you need one thats for sure.
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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#3
(05-12-2024, 09:17 PM)Painkiller Wrote:  quite handy if you need one thats for sure.

LOL, it would be handy if it worked.
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#4
SITREP: stripped the BB. Ugh!
   
Axle, NDS bearing cup, and bearings as they emerged from the BB shell. How many decades if non-servicing do you think this took?

   
After a few minutes of degreaser attention.

Let's examine the damage up-close and personal, shall we?
   
   
   

Dearie me, looks like FUBAR Saunders has been resident.

I'm not surprised. It would have been a miracle if the BB wasn't totally shagged. So, it's onto the great intarwebs to verify how to replace the BB on a 1990 Mk2 Brompton.
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#5
(05-14-2024, 04:46 PM)enkei Wrote:  SITREP: stripped the BB. Ugh!

Axle, NDS bearing cup, and bearings as they emerged from the BB shell. How many decades if non-servicing do you think this took?


After a few minutes of degreaser attention.

Let's examine the damage up-close and personal, shall we?




Dearie me, looks like FUBAR Saunders has been resident.

I'm not surprised. It would have been a miracle if the BB wasn't totally shagged. So, it's onto the great intarwebs to verify how to replace the BB on a 1990 Mk2 Brompton.

OUCH!! I do not know Mr. or Mrs. Saunders, but I do know FUBAR! Hope the hubs are not as bad. That BB should not be too hard to come by especially in your area. I would expect a local shop would be able to help you out. I would assume that the main issue will be its length and offset, cups should be standard threading (did Brompton make their own parts?).
My friend's family had a couple Bromptons from the mid 60s with the small front wheel and larger rear wheel. Cool bikes, but not something I could ride at the speeds I like to travel. I picked up an old "Nealeco" folder with Bianchi badging from a friend that gave it to me because it was just too odd to ride for someone who rode standard road bikes all his life. Sitting in my garage right now gathering dust.
Take care,
Jesper

"I am become Death, the destroyer of bicycles." NJS
  Reply
#6
(05-14-2024, 06:09 PM)Jesper Wrote:  OUCH!! I do not know Mr. or Mrs. Saunders, but I do know FUBAR! Hope the hubs are not as bad. That BB should not be too hard to come by especially in your area. I would expect a local shop would be able to help you out. I would assume that the main issue will be its length and offset, cups should be standard threading (did Brompton make their own parts?).
My friend's family had a couple Bromptons from the mid 60s with the small front wheel and larger rear wheel. Cool bikes, but not something I could ride at the speeds I like to travel. I picked up an old "Nealeco" folder with Bianchi badging from a friend that gave it to me because it was just too odd to ride for someone who rode standard road bikes all his life. Sitting in my garage right now gathering dust.

Yes, the cups should be standard. Axle length and protrusion on the drive side are critical, but due to differences between ISO and JIS taper, especially vs the fixed chainring cranks on the older Bromptons it becomes a bit of a dark art.

It appears the end of the taper on this axle is 12.7mm, which means it is JIS. A bit odd, perhaps, as a 1990 Mk2 should, I believe, have an ISO taper. Mixing them throws the chainlink out by 4.5mm one way or the other, which can play havoc with a Brompton. SJS Cycles says the ISO BB isn't available anymore...

Of course, it's highly possible (probable, even) that a previous owner or LBS has fitted a JIS axle. Next job is removing the other cup...

That Nealeco looks cool!

BTW, mid-60s wouldn't be Bromptons. Ritchie only designed it in 1975, and I think Bromptons have always had 2x 16" wheels. Possibly, those were Bickertons?
   
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#7
@enkei You may be correct about the Bickerton. I know he said they were English bikes from the mid 60s. Did Moulton's ever have different sized wheels?

I forgot that I had posted the Bianchi/Nealeco bike years back. I had done some researchh on it but only found other examples badged similarly on the identical frame design (Atala, Barbarella). I guess they were were made for others to add a folder into their line-ups to provide some variety. Mine is 100% Italian regarding parts. Amazingly, I have seen them sell up near $100 so I guess folks collect them. I have always heard goid thing about Bromptons. Thanks for the history lesson regarding when the Bromptons and Bickertons first arrived on the scene. It says early 70s for the Bickerton also so I am going to talk to my mate and see if I can jog his memory (he is a bit older than me and may be mistaken as to what time period he rode it).
Take care,
Jesper

"I am become Death, the destroyer of bicycles." NJS
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#8
@enkei Just checked ebay and they are showing a few JIS BBs so possibly Brompton went to a different design. If so, then the cranks would have to JIS taper also. The listing shows 3 available at $18.50 OBO (free shipping in US) so probably not a large demand in the US.
If you think that might work for you let me know. I have no problem ordering it and shipping to you. I would try to find the best shipping cost to reduce your overall price. Let me know. I did not review all listings, but this one caught my eye since it specifically stated Brompton JIS. I am going to inquire on an English site I use where I know they are knowledgeable regarding your bike and see if the JIS design can be verified as OE.
Listing says JIJ, but that's a typo. I guess the length would be the main issue if all else is good, but I cannot imagine that they used too many different sizes.

Brompton Bottom Bracket Sealed JIJ 68x119mm NEW Best eBay Deal FREE SHPPING USA!
https://www.ebay.com/itm/285806312754?itmmeta=01HXYF2PEEEDWHASEZ9Z8RZASZ&hash=item428b623d32:g:MWIAAOSw5qxloPAm&itmprp=enc%3AAQAJAAAA0GyeAr0n9tA7CX1Sljdnm3YnqoPnJP8%2Fn1v%2BBxHAf58tCJhProA​cdgo8ZNbtvOzWoM%2BzlYMo34BFMPeyyHf7L84IjQ6oj1ZwYzbdMDD3CRfX4IWlhVcgo7%2F%2BKk2rN​MhyI6s8xDg3A26%2F1DEIOiKwdDknZUewgAc1v6OYwlDNfhF5gAY%2FGXZ28CyDps%2FdAbeMSPxH74d​q1rZWb8fqUOSUMsPgfqGRXULyrELIdXc8zDh0569D%2B29vHWJ%2BAMGLzPKef3Oxg0WINXHvLLCqcPz​XwE0%3D%7Ctkp%3ABk9SR6bnis_vYw

You could have the spindle machined and polished, but probably not cost effective unless you cannot find a replacement. It shortens the distance between the bearing races about 1 to 2mm, but that would not affect you since it only causes the spindle to protrude a little more on the fixed cup side. I do not think the left crank would be close enough to interfere with the frame since it will move inboard slightly in the process.

How does the crank seat on the spindle when installed. Is is close to "bottoming out" or does the crank seem to stick out with a fair amount of gap between the flange of the crank and the end of the spindle. I am not familiar with these so looking at your photo I do not know if that cranks are original. Perhaps the whole crankset/BB was replaced with all JIS taper parts??
Take care,
Jesper

"I am become Death, the destroyer of bicycles." NJS
  Reply
#9
(05-15-2024, 03:54 AM)Jesper Wrote:  @enkei You may be correct about the Bickerton. I know he said they were English bikes from the mid 60s. Did Moulton's ever have different sized wheels?

I forgot that I had posted the Bianchi/Nealeco bike years back. I had done some researchh on it but only found other examples badged similarly on the identical frame design (Atala, Barbarella). I guess they were were made for others to add a folder into their line-ups to provide some variety. Mine is 100% Italian regarding parts. Amazingly, I have seen them sell up near $100 so I guess folks collect them. I have always heard goid thing about Bromptons. Thanks for the history lesson regarding when the Bromptons and Bickertons first arrived on the scene. It says early 70s for the Bickerton also so I am going to talk to my mate and see if I can jog his memory (he is a bit older than me and may be mistaken as to what time period he rode it).

I'm not aware of any Moulton bicycles with mullet (lol) wheel sizes.

Brompton bikes' strength is the innovative folding design, their ubiquity, and their resale values/brand strength. Apart from that, they're heavy, overpriced, and overall rather unremarkable. And parts supply isn't even as good as one might expect. Despite those failings, it's not without reason that they're popular.

If I wasn't so attracted to the idea of having such a compact/practical folder, I would probably get a Tern.

(05-15-2024, 11:47 AM)Jesper Wrote:  @enkei Just checked ebay and they are showing a few JIS BBs so possibly Nrompton wrnt to a different design. If so, then the cranks would have to JIS taper also. The listing shows 3 available at $18.50 OBO (free shipping in US) so probably not a large demand in the US.
If you think that might work for you let me know. I have no problem ordering it and shipping to you. I would try to find the best shipoing cost to reduce your overall price. Let me know. I did not review all listings, but this one caught my eye since it specifically stated Brompton JIS. I am going to inquire on an English site I use where I know they are knowledgeable regarding your bike and see if the JIS design can be verified as OE.
Listing says JIJ, but that's a typo. I guess the lenght would be the main issue if all else is good, but I cannot imagine that they used too many different sizes.

Brompton Bottom Bracket Sealed JIJ 68x119mm NEW Best eBay Deal FREE SHPPING USA!
https://www.ebay.com/itm/285806312754?itmmeta=01HXYF2PEEEDWHASEZ9Z8RZASZ&hash=item428b623d32:g:MWIAAOSw5qxloPAm&itmprp=enc%3AAQAJAAAA0GyeAr0n9tA7CX1Sljdnm3YnqoPnJP8%2Fn1v%2BBxHAf58tCJhProA​cdgo8ZNbtvOzWoM%2BzlYMo34BFMPeyyHf7L84IjQ6oj1ZwYzbdMDD3CRfX4IWlhVcgo7%2F%2BKk2rN​MhyI6s8xDg3A26%2F1DEIOiKwdDknZUewgAc1v6OYwlDNfhF5gAY%2FGXZ28CyDps%2FdAbeMSPxH74d​q1rZWb8fqUOSUMsPgfqGRXULyrELIdXc8zDh0569D%2B29vHWJ%2BAMGLzPKef3Oxg0WINXHvLLCqcPz​XwE0%3D%7Ctkp%3ABk9SR6bnis_vYw

You could have the spindle machined and polished, but probably not codt effective unless you cannot find a replacement. It shortens the distance between the bearing races about 1 to 2mm, but that would not affect you since it only causes the spindle to protrude a little more on the fixed cup side. I do not think the left crank would be close enpugh to interfere eith the frame since it will move inboard slightly in the process.

How does the crank seat on the spindle when installed. Is is close to "bottoming out" or does tje crank seenm to stick out with a fair amount of gap between the flange of the crank and the end of the spindle. I am not familiar with these so looking at your photo I do not know if that cranks are original. Perhaps the whole crankset/BB was replaced with all JIS taper parts??

100% certain that someone replaced the original BB with the JIS item. Brompton themselves say that the older one-piece ISO cranks can be fitted to JIS taper spindles. These cranks have plenty of life left in them, they're not sitting too far down the JIS taper. Well, saying that, the drive side of these old Solida cranks is a fixed chainring that's swaged onto the crank arm. It's not unknown for them to shear...

In any case, I've bought a super-cheap used bb on eBay and will see if that gets the bike up and running for now. I just want to get it operable, and then I'll decide whether to just get the hinge pin/bushing replaced only, or send the frame to someone to have the whole fork/frame and triangle assembly restored. It's badly in need of paint.
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#10
Great! Hope you get it roadworthy again. Thanks for the info regarding the bike; never seen one in the flesh.

Please pardon my typos on previous post! I had just awakened after a long night in the OR (working, not getting worked on!). Surprised anyone could read it.
Take care,
Jesper

"I am become Death, the destroyer of bicycles." NJS
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