Availability of Brompton 13T and 16T sprockets

[anim_al]

Hello all,

I have today emailed Brompton Support regarding their decision to sell the 13T and 16T sprockets only as a set with a chain disc, spacer and circlip. This seems a waste of resources as I don't need or want the three additional items each time I replace the sprockets.

Here is their response:
You can still purchase the 13T sprocket individually from a Brompton retailer, such as Balfe's Bikes, designed for a 3-speed hub.

Although if you have a two or six-speed Brompton, we recommend replacing both sprockets, so this is when the 12T/16T or 13T/16T sprocket set will be sold together.

We sell these as a set with other parts, as we recommend replacing everything as it could have wear and tear.

My question is:
Do any of you UK readers and riders have details of a source of 16T sprockets you would be willing to share?

Thanks

Andrew

 

[wafter]

I think this message corroborates my experience that Brompton CS sometimes struggle to locate their posterior; even if allocating their full compliment of both hands to the task.

Is yours a 6sp?

I think the individual 13T sprocket they refer to is the three-lug effort intended to fit SA hub gears on three speed models.

The later 2sp and 6sp models with the BWR hub use the standard Shimano pattern splined sprocket fitting so sprockets from road / mtb applications should fit in this regard; might want to keep an eye on the presence of integral spacers etc.

Not sure if there's a difference in sprocket thickness between the 6/7/8sp chain standard used by Brompton and the later 9sp+ chains; as IIRC the inner chain link width was reduced at 9sp.

I've looked into sourcing sprockets separately and this is hampered both by availability and cost. If you really wanted to wring out the last of the life from these bits you could buy the set and just replace whichever is worn. It would stand to reason that the 13T sprocket would wear out first; however usage would also play a part and in my case (with the older spec bits) the 13T is considerably thicker than the 16T.

Mine show detectable wear at about 3.8k miles but this doesn't look excessive / they don't look obvously knackered yet; I'm intrigued to see how long they continue to last.

The inclusion of the placcy disk seems like a bit of a waste however as I can't really see these failing in daily use.

 

[Fastpedaller]

I'm shortly going to attempt a 2 to 3 speed conversion using 10-speed sprockets, as I want to get the 'middle gear' because I'm either twiddling like mad or mashing. . I've found the HG500 10 speed cassette at Halfords is just around £27 and the 11-25 version offers 13/14/15 sprockets (alas no 16), The 11-32 version offers 12/14/16 (alas no 13). Quite frustrating to those of us seeking 13/16, but the cassette comes with spacers and it may be possible to sell other sprockets if you don't use 10 speed on other bikes. At the price for the complete cassette I concluded it was cheaper than buying all the parts (and I couldn't find them for sale anyway). I'll be using 13/14/15 for my setup.

 

[Chris S]

Hello all,

I have today emailed Brompton Support regarding their decision to sell the 13T and 16T sprockets only as a set with a chain disc, spacer and circlip. This seems a waste of resources as I don't need or want the three additional items each time I replace the sprockets.

Here is their response:
You can still purchase the 13T sprocket individually from a Brompton retailer, such as Balfe's Bikes, designed for a 3-speed hub.

Although if you have a two or six-speed Brompton, we recommend replacing both sprockets, so this is when the 12T/16T or 13T/16T sprocket set will be sold together.

We sell these as a set with other parts, as we recommend replacing everything as it could have wear and tear.

My question is:
Do any of you UK readers and riders have details of a source of 16T sprockets you would be willing to share?

Thanks

Andrew

There are plenty on ebay. Sturmey Archer, SRAM and Shimano 3-speed hub sprockets are interchangeable.
https://www.ebay.co.uk/itm/185333824086

 

[Fastpedaller]

All the above is relevant - It very much depends on what sprockets (spline and width) are on the existing set up.

 

[wafter]

There are plenty on ebay. Sturmey Archer, SRAM and Shimano 3-speed hub sprockets are interchangeable.
https://www.ebay.co.uk/itm/185333824086

I think it would help if @anim_al clarified the bike's spec - AFAIK those you list will only fit 3sp applications. If it's a 2 or 6sp (as use both 13 and 16T sprockets together) they're Shimano pattern:

 

[Fastpedaller]

I don't know if the spec has changed over the years, but my 2-speed (2007 Superlight) had 12/16. I changed the 12 to a 13, but I still need something in between

 

[Kell]

16T (£4.60)

14T (If you're looking to go 12-14-16) (£2.49)

It does look like you can buy the 13T on its own as a Brompton OEM part to fit the 6-speed.

 

[wafter]

I don't know if the spec has changed over the years, but my 2-speed (2007 Superlight) had 12/16. I changed the 12 to a 13, but I still need something in between

Now you mention it they might still be 12/16 - I always consider the 2sp as a 6sp without the hub (which in terms of shifters etc they are); however they might have a wider range to offset the lack of additional gearing from the hub in the 6sp version.

16T (£4.60)

View attachment 749451

14T (If you're looking to go 12-14-16) (£2.49)

View attachment 749452



It does look like you can buy the 13T on its own as a Brompton OEM part to fit the 6-speed.

View attachment 749453

Great work!

However..

The 16T item looks like an Ultegra part from the part number, so a bit posh (not that this is an issue)..

The spline pattern is wrong on the 14T sprocket; looks like microspline - probably confirmed by the fact it's M8100 which is 12sp.

The 13T item is the correct fitment but the older format and being out of stock I suspect is unlikely to be available again. This is as fitted to my 2021 C-line, however the current 13T sprocket has the same "multispeed" tooth profile as the 16T.

 

[Kell]

Do you know what - I completely missed the spline pattern on the 14T

 

[Punkawallah]

Note to self - ‘steer clear of Bromptons’.

 

[Kell]

13T Shimano. With Correct Splines. (I think)

https://www.sjscycles.co.uk/cassettes/shimano-deore-xt-csm77110-sprocket-13t-y1yr13010/

 

[wafter]

13T Shimano. With Correct Splines. (I think)

https://www.sjscycles.co.uk/cassettes/shimano-deore-xt-csm77110-sprocket-13t-y1yr13010/

Splines look right; not sure about spacers.

Personally this has just validated what I learned last time.. prices of individual sprokets aren't far off a pair from Brompton so might as well just buy the two and if I'm feeling tight change them one at a time.

 

[anim_al]

The hub is a 3 speed BWR with two sprockets.

 

[Fastpedaller]

I now have my 10-speed cassette and decided to see if the sprockets would fit the 'spare' brompton rear hub I bought on Ebay. I was surprised when I opened the box to find the smallest 3 sprockets had integral spacers and were not in the 'cluster' (I expected only one separate sprocket, being familiar with 7 speed cassettes). The other 7 were rivetted together, so with a little dremmel work they weren't any more! As I removed the rivets I noticed they looked a bit corroded and as I took each sprocket and spacer off there were 'rusty' marks on each sprocket. I've not yet attempted to remove said marks - they don't/won't affect the function (and may just wipe off) but may be a bother if I try to sell my unwanted sprockets. I guess the factory has washing processes which may leave residue when the parts are assembled? Anyway, the good news is that with 13/14/15 sprockets on the spare hub there looks to be a perfect space for the wire clip to be inserted - I'll not be able to try for sure until next week though.