Carrera Subway 8 chainring replacement

[Frank Jones]

Hi,

I've got a Carrera Subway 8 that I use for commuting to work. It's a
2006 model (when they were all matt black before the current grey
model). It has the Nexus 8-speed hub gear. I'm generally happy with it
but I'd like to take the gearing down a bit as it's a bit of a
struggle on some of the bigger hills on my work commute. It has a 44
tooth ring on the front and 20 at the back. It has 4-arm cranks. I
reckon my simplest option is to change out the front ring and, if I've
done my maths correctly, then I need to go for a 36 tooth chain ring
to get the gearing I want. Not being very clued up about bike
components I'm a bit bewildered by the range of replacement chain
rings available to me. Most of them seem to assume the bike will have
derailleur gears and I don't know how applicable they would be to my
hub set up. I'd be really grateful if anyone could recommend a
suitable replacement chain ring for me. Preferably one that doesn't
cost the earth and also has a chain ring bash guard (whatever they are
called); and ideally one that preserves the "none more black" look of
my bike!

Many thanks.

Frank

 

[Martin Dann]

Frank Jones wrote:
> Hi,
>
> I've got a Carrera Subway 8 that I use for commuting to work. It's a
> 2006 model (when they were all matt black before the current grey
> model). It has the Nexus 8-speed hub gear. I'm generally happy with it
> but I'd like to take the gearing down a bit as it's a bit of a
> struggle on some of the bigger hills on my work commute. It has a 44
> tooth ring on the front and 20 at the back. It has 4-arm cranks. I
> reckon my simplest option is to change out the front ring and, if I've
> done my maths correctly, then I need to go for a 36 tooth chain ring
> to get the gearing I want. Not being very clued up about bike
> components.

IMHO I think you would be better off replacing the sprocket on the rear
wheel (if possible), and the chain at the same time.
In >18 months the chain and sprocket will have worn, and if you want to
do some maintainence on the drive chain, replacing these could be
cheaper in the long run.

If you do as you suggest, and replace the chain ring, you will need to
measure the BCD of the bolt holes. (See Sheldon Brown's website for BCD
measurements).

 

[Frank Jones]

On Mar 30, 12:32 am, Martin Dann <[email protected]> wrote:
> Frank Jones wrote:
> > Hi,
>
> > I've got a Carrera Subway 8 that I use for commuting to work. It's a
> > 2006 model (when they were all matt black before the current grey
> > model). It has the Nexus 8-speed hub gear. I'm generally happy with it
> > but I'd like to take the gearing down a bit as it's a bit of a
> > struggle on some of the bigger hills on my work commute. It has a 44
> > tooth ring on the front and 20 at the back. It has 4-arm cranks. I
> > reckon my simplest option is to change out the front ring and, if I've
> > done my maths correctly, then I need to go for a 36 tooth chain ring
> > to get the gearing I want. Not being very clued up about bike
> > components.
>
> IMHO I think you would be better off replacing the sprocket on the rear
> wheel (if possible), and the chain at the same time.
> In >18 months the chain and sprocket will have worn, and if you want to
> do some maintainence on the drive chain, replacing these could be
> cheaper in the long run.
>
> If you do as you suggest, and replace the chain ring, you will need to
> measure the BCD of the bolt holes. (See Sheldon Brown's website for BCD
> measurements).

Thanks Martin, I'll give that some thought.

Regards, Frank

 

[Ivan Ardon]

Changing the rear sprocket is by far the easier job. Wheel out, ping off a
retaining ring, lift old sprocket off, put now one in it's place and snap
the retaining ring back on.

You'll be well served by replacing the chain at the same time.

Ivan

 

[Zog The Undeniable]

Frank Jones wrote:
> Hi,
>
> I've got a Carrera Subway 8 that I use for commuting to work. It's a
> 2006 model (when they were all matt black before the current grey
> model). It has the Nexus 8-speed hub gear. I'm generally happy with it
> but I'd like to take the gearing down a bit as it's a bit of a
> struggle on some of the bigger hills on my work commute. It has a 44
> tooth ring on the front and 20 at the back. It has 4-arm cranks. I
> reckon my simplest option is to change out the front ring and, if I've
> done my maths correctly, then I need to go for a 36 tooth chain ring
> to get the gearing I want. Not being very clued up about bike
> components I'm a bit bewildered by the range of replacement chain
> rings available to me. Most of them seem to assume the bike will have
> derailleur gears and I don't know how applicable they would be to my
> hub set up. I'd be really grateful if anyone could recommend a
> suitable replacement chain ring for me. Preferably one that doesn't
> cost the earth and also has a chain ring bash guard (whatever they are
> called); and ideally one that preserves the "none more black" look of
> my bike!

I got one from SJSC. Unlike the original, it is *designed* for
singlespeed/hub gear use and has no cutouts or shift ramps.

You need to measure the PCD (easy on a 4-bolt - just the distance
between opposite holes). I'd also get a ring designed for the 1/8"
chain, which will be 3mm thick. It will last a lot longer and run more
quietly.