Replacing Brompton little chain wheels and sproket

[fimm]

Apparently I need a new chain on my Brompton, and the little chain tensioner wheels and sproket should be replaced as well. I think I've replaced the sproket myself before, but does anyone know if replacing the little wheels is fairly straightforward? I don't mind getting stuck in with a screwdriver, but if it is a bit fiddly I might leave it to the pros - on the other hand I'd quite like to avoid paying someone to do something I could do myself...

 

[TheDoctor]

Getting the tensioner wheels off isn't tricky., just a bit fiddly and messy.
Definately DIY in my book.

 

[Laurence Green]

I wouldn't change the tensioner (or jockey wheels) until you need to. The chain and sprocket wear together and should be changed at the same time (otherwise you'll find the chain jumping on hills). I've changed chain and sprocket at least 3 times and tensioner still working fine.

 

[fimm]

Thank you for the replies. I've had the bike at least 5 years, I think, and it has had regular use in all weathers, so I don't think it is totally unreasonable that the small wheels need replacing. I'm more surprised that the chain has worn out as it does not seem that long since I replaced it - but it may be that my habit of standing up on the pedals to start off is responsible for this...

 

[Brommyboy]

As the sprocket wears, it reduces the life of the chain. In effect, they wear out together. It may be that you will also need to replace the chain ring for the same reason. I have never replaced the tensioner wheels, although on my first Brompton I had to replace the tensioner itself when it warped, bringing the jockey wheels out of alignment. I found the life of the transmission on my 5-speed at about 4000 miles, but for the 6-speed with two sprockets, this extended to about 6000 miles. Using two chains and alternating them every 1000 miles will extend the life further. Even pressured pedalling will also reduce the wear on the transmission.