Changing sprocket on Brompton hub

[Yellow Fang]

I thought I might chain the sprocket on my Brompton as I'm changing the chain. Wish I'd never started now. It looks like you need a special tool to remove it. I can see three indentations where it looks like the tool would grip. Is this the case?

Also, anyone know where I can get a replacement nut for the hub axle? I've stripped the thread (then lost it in the hardware shop). It seems rather thinner than normal. I don't know if it has the same thread as those in the hardware shops neither.

 

[Yellow Fang]

My Brompton is still in bits. Apparently the sprocket is held in by a spring clip. I looked at it this morning and thought neh, you need some tool to twist it around. Apparently there is some spring clip. This video shows how to do it. The odd thing is that my sprocket doesn't look too worn, comparing it with the one in the video. However, I will probably have to buy a whole new kit from SJS Cycles just because I've stripped the thread on one of the nuts. The nut seems to be some odd size with a tight thread, and difficult to get hold of.

 

[tyred]

Is this a Sturmey hub?

If so, the clip which holds the sprocket on just pops out with a screwdriver. Pay attention to the shims and dish on the sprocket to keep the chainline correct.

Sturmey Archer axle nuts are notoriously easy to strip but any number of people sell them on Ebay for about £2 a set. I think the nut is deliberately soft steel so it doesn't damage the axle. It is a different thread from anything you are likely to find in a normal hardware shop.

 

[Yellow Fang]

No, I am pretty sure it is a Sachs 3-speed hub. I think Sturmey Archer had gone bust at the time. I read some thread on another cycling forum by someonw who had a similar problem. I think he had a Sachs hub too, and it was held in by a spring clip. However, I can't find the website now.

Thanks for the tip about the nut. I will look on ebay.

 

[mickle]

It's the same method attachement - and the same for coaster hubs too btw. A small sharp flathead screwdriver is all you need but the operation can be helped along with a large flat head or a pair of needle nosed pliers.

Just peel the spring clip away from its recess and the sprocket will slide off its splines.

That's easier to write than to do I should add, its a bit of a fiddle.

 

[SavageHoutkop]

No, I am pretty sure it is a Sachs 3-speed hub. I think Sturmey Archer had gone bust at the time. I read some thread on another cycling forum by someonw who had a similar problem. I think he had a Sachs hub too, and it was held in by a spring clip. However, I can't find the website now.

Thanks for the tip about the nut. I will look on ebay.

I'd suggest joining BromptonTalk for B specific Q's. I have a BWR and have changed my sprockets before even though I'm not a DIY person - it had a circlip. Needed husband's help to get the thing back on though.

There's also a wiki now, but a work in progress
http://bromptontalk.wikispaces.com/

From personal experience, if you've changed the chain you'll need to change the sprockets at the back as otherwise you'll skip.

 

[mickle]

I'd suggest joining BromptonTalk for B specific Q's. I have a BWR and have changed my sprockets before even though I'm not a DIY person - it had a circlip. Needed husband's help to get the thing back on though.

There's also a wiki now, but a work in progress
http://bromptontalk.wikispaces.com/

From personal experience, if you've changed the chain you'll need to change the sprockets at the back as otherwise you'll skip.

Thanks but Brompton Talk has no exclusivity on Brompton know-it-alls, general mechanical know how or knowledge of internal hub sprocket circlips. Indeed, I'm wondering if I should be offended that you'd suggest someone visit another forum. Especially after the OP's question was answered perfectly well.

And you only need to replace the sprocket if you've let your chain die on the bike. Replace the chain before it's completely shagged and your sprockets (and chainrings) will last forever.

 

[Yellow Fang]

I'd suggest joining BromptonTalk for B specific Q's. I have a BWR and have changed my sprockets before even though I'm not a DIY person - it had a circlip. Needed husband's help to get the thing back on though.

There's also a wiki now, but a work in progress
http://bromptontalk.wikispaces.com/

From personal experience, if you've changed the chain you'll need to change the sprockets at the back as otherwise you'll skip.

Is BromptonTalk the Yahoo group? I think I joined that. I asked them a question but didn't get any replies. All that happens is occasionally I receive an email containing a photo of someone's bike.

 

[buddha]

Those SA axle nuts are a bit overpriced IMO. I've just discovered that Petra Cycles (who are down south though) sell SA axle nuts for 35p each. However, they do charge for delivery. But still works out cheaper if you want to get more than one. I haven't tried them out yet, but may ride down there next week, as it's local.

Freemans cycles sell more Sturmey stuff at reasonable prices, including sprockets.

BTW: This is a good Sturmey Archer resource to bookmark. But, as others have said, the only tools you need are a spanner and screwdriver to remove the clip. And just remember the order in which bits come off.

 

[SavageHoutkop]

Is BromptonTalk the Yahoo group? I think I joined that. I asked them a question but didn't get any replies. All that happens is occasionally I receive an email containing a photo of someone's bike.

Yes. Sounds like your Yahoo group settings are wrong. You either need to set it so it emails you every time someone replies, or you need to visit the group to see the replies.
It's fairly active, I have 54 unread mails at the moment (!) from the last few days.

 

[Yellow Fang]

I thought I might clean and re-grease some of the bearings and cogs. That is what you're supposed to do, isn't it? Blimey, it needs a service. The jockey wheels hardly go around at all. Some of the bearings in the race kept falling out, which I presume means they're worn. Finally ordered a bunch of bits from SJS cycles. Hopefully it will all work again some day.

 

[Yellow Fang]

Some parts arrived yesterday - woohoo. One of the nuts seems to fit. Annoyingly, when I tightened up the hub, the sprocket wouldn't go around. It looks like the bearing retainers are f*****. It's taken me ages just to find out what they're called. There's a pdf with all the parts. Irritatingly, it doesn't look like anyone sells them over here, so I've order a couple from Germany. It's cost about £7 for two sets of those and a couple more axle nuts, and fifteen flipping quid for delivery. I wish I'd never started.

BTW, should these bearings be greased, or are they designed to work without?