New old Brompton - naive new owner questions

[newfhouse]

I have just become the custodian of an old Brompton. It has a five speed SA hub, M bars, and has a few bits damaged or missing. I have seen Bromptons being ridden, sometimes over long distances, but know very little about them.

Obvious problems:

The front brake cable has snapped. No bother, I can replace that.
The rear mudguard is damaged. I can cut the bent part off and/or buy a replacement.
What is the black part between the reflector and the mudguard for?

What stops the bike folding? I’m sure I’ve seen them being carried unfolded. There was a cable tie holding it all together, since removed.

Is there something other than the little castor wheels missing from this photo? It looks as if there should be something for the spike on the shock absorber (?) to mate with.

I’m sure I will be back for more advice but that will do for now.

 

[berlinonaut]

What is the black part between the reflector and the mudguard for?

That's the stopper disc. It blocks the bike from unfolding once it has been folded and the seat post has been lowered.

What stops the bike folding? I’m sure I’ve seen them being carried unfolded.

There is a little thingy to keep the rear frame in place when lifting the bike. It has only been invented in 2007 but is retrofittable. At a bike of the age of your's the rear frame is loose and collapses towards the ground when lifting the bike. That was the standard behaviour back then.
If you dislike it you can retrofit the rear frame clip: https://brilliantbikes.co.uk/brompton-folding-detail/340-brompton-rear-frame-clip-retrokit.html

Is there something other than the little castor wheels missing from this photo?

no.

 

[gom]

Do you know what year it was made? If not, the SA hub should have a year stamped on it. Or it can be looked up if you can read the frame number.
I have a 1999 5-speed, but with a rear rack (and originally a bottle dynamo). A “T5”, “T” for touring. I think yours must be an L5, if I remember correctly.
To stop mine folding I loop some elastic round the seat tube and castor wheels (which I still have). Not as snazzy as the later clip, but functional.
I think you must have the original brakes which I recall as being famously less-than-good. I bought the Brompton-branded dual pivots as soon as they became available, and more recently the modern brake levers.

 

[newfhouse]

Is there a look-up table for serial numbers freely available so I can find out the age and original spec for the bike?

 

[ExBrit]

I have just become the custodian of an old Brompton. It has a five speed SA hub, M bars, and has a few bits damaged or missing. I have seen Bromptons being ridden, sometimes over long distances, but know very little about them.

Obvious problems:

The front brake cable has snapped. No bother, I can replace that.
The rear mudguard is damaged. I can cut the bent part off and/or buy a replacement.
What is the black part between the reflector and the mudguard for?
View attachment 686770

What stops the bike folding? I’m sure I’ve seen them being carried unfolded. There was a cable tie holding it all together, since removed.

Is there something other than the little castor wheels missing from this photo? It looks as if there should be something for the spike on the shock absorber (?) to mate with.

View attachment 686771

I’m sure I will be back for more advice but that will do for now.

This might be what you're looking for to lock the rear triangle in place.
https://brilliantbikes.co.uk/brompton-folding-detail/340-brompton-rear-frame-clip-retrokit.html

 

[Kell]

I know very little about the older bikes, but is it not also missing a quick release for the seat post?

Or is the lever at the bottom on the side you can’t see?

 

[ExBrit]

I know very little about the older bikes, but is it not also missing a quick release for the seat post?

Or is the lever at the bottom on the side you can’t see?

I think it's almost completely hidden behind the frame

 

[newfhouse]

That's the stopper disc. It blocks the bike from unfolding once it has been folded and the seat post has been lowered.

Thanks, I see how that will work once the mudguard is cut back.

I know very little about the older bikes, but is it not also missing a quick release for the seat post?

Or is the lever at the bottom on the side you can’t see?

I think it's almost completely hidden behind the frame

Yes, it’s there.

 

[roley poley]

Is there a look-up table for serial numbers freely available so I can find out the age and original spec for the bike?

is this any good to you?

 

[newfhouse]

View attachment 686848


is this any good to you?

Thanks, I will see if I can decode it in the morning.

 

[newfhouse]

The date from the frame number matches the hub - mid 1995. Having replaced the brake cable I took it out for a brief spin, only for the left pedal crank to come adrift. I’ve refitted and torqued it up to ”pretty damn tight” so hopefully that will be that.

First gear slips under load. I don’t know if it’s in need of adjustment or a worn hub. It seems fine in all gears on the stand.

I found a couple of small castor wheels in my junk box that fit well enough so at least I can fold and stand the bike now. I’ve cut the bent part off the mudguard but the single castor seems to have pushed most of the way through so I will order a new guard in the near future.

Anyway, a couple of pics.

 

[berlinonaut]

First gear slips under load. I don’t know if it’s in need of adjustment or a worn hub. It seems fine in all gears on the stand.

The Sprinter is as sensitive as a teenager in a massive identity crisis. And adjustment is as stable as a completly drunken sailor with many examples of the Sprinter.

 

[Kell]

I’ve cut the bent part off the mudguard but the single castor seems to have pushed most of the way through so I will order a new guard in the near future.

I went through two mudguards in the past as I do a lot of folds and unfolds during a normal commute and I normally do it in a hurry so am not always gentle.

In the end, I ordered a metal strip that sits on top of the mudguard and prevents it cracking.

They need a bit of fettling to fit - that is you have to reuse your existing single wheel (or buy a new one) and drill it out to remove it.

Adds a little more weight, but it worked for me.

https://www.sjscycles.co.uk/frames/milian-plablo-mudguard-reinforcement-bar-for-folding-bike/

 

[Kell]

 

[404 Not Found Anywhere]

The Sprinter is as sensitive as a teenager in a massive identity crisis. And adjustment is as stable as a completly drunken sailor with many examples of the Sprinter.

my original Brompton L5 came with a Sprinter hub… I have little good to say of it other than top gave a useful overdrive above a standard 3 speed. First gear seemed to be useless, adding an amount of friction to exactly offset any reduction in gear ratio. None of the Sturmey FW 4 speed hubs on various Moultons have been quite as finicky.