New chain needed.

[Kell]

Here's a quick one for you. My chain has started jumping under pressure. (Uphill etc).

Even by eye, I can see that it's not sitting on the front cog properly, so I'm assuming it's stretched. I'm going to order a new one, but with a normal bike, you often have to replace the cassette at the same time.

In your experience, do the rear cogs (6 sd) also need replacing?

I may as well order some at the same time if they do.

 

[raleighnut]

Here's a quick one for you. My chain has started jumping under pressure. (Uphill etc).

Even by eye, I can see that it's not sitting on the front cog properly, so I'm assuming it's stretched. I'm going to order a new one, but with a normal bike, you often have to replace the cassette at the same time.

In your experience, do the rear cogs (6 sd) also need replacing?

I may as well order some at the same time if they do.

Probably but with a 6spd it may be a screw on 'freewheel' not a cassette.

 

[Brommyboy]

Do you mean for a 6-speed Brompton? If so, the two rear sprockets will need replacing. There are two types, depending no your hub gear: Sram (Sachs) or BWR. These are secured with a circlip. The spacers are important, so be sure to keep in the same order. You may well need a new chain ring as well unless you have the demountable one fitted to the spider: for this you can rotate the ring so that the worn teeth no longer occupy the power stroke position.

 

[Kell]

Sorry, I did mean that yes it's a 6-speed and is a 2015 bike so does have the spider and it's the BWR hub.

I'll call my local store and see if they can get the bits in for this weekend.

Good tip about rotating the chain ring though, would probably never have thought of that.

 

[Kell]

Just looking at Strava and it seems that I've done at least 1,956 miles since getting it almost a year ago.

So I guess it's probably beyond time to replace. Think I might order a chain wear indicator at the same time.

Same chain? or 'upgrade' to a Shimano/SRAM version instead?

 

[12boy]

Since I cannot buy Sturmey parts here and the shipping costs a lot, I buy several cogs at one time since the shipping is about the same for several as one. If you do not replace worn cogs you will have some skipping. I have not heard of rotating the chain ring but have certainly reversed one since the wear is one way. A chain ring, even though aluminum,should last through a number of cogs. If you wish to avoid replacing the chain ring Surly sells a stainless steel ring in a variety of BCDs and sizes, a few grams more, of course. A 50 tooth 130 BCD will cost around $65 here in the US + shipping but you should not be replacing it as often. 50 is the largest 130 size.

 

[Kell]

In the end I just ordered all the bits.

£50 all in from our local shop. Pretty sure I could do a little better online, but then there's always the danger I order the wrong bits.

 

[Kell]

Ordered a park tools chain wear measurer. Just tried it on the chain and it's too far 'stretched' for the .75 to even drop in.

 

[Kell]

 

[Kell]

It was a joy riding it in to work this morning.

Shifts perfectly and no jumping. I'll have to remember to keep an eye on the chain a bit more frequently from now on.

 

[Brommyboy]

I use Brilliant Bikes for my spares: rapid service, free postage.
http://brilliantbikes.co.uk/