beginner - chain replacement or change to single speed

Hello,

I'm wondering if anyone can give me some advice?
I'm looking to find out what the lightest chain would be that's reasonably priced for a 12speed bike.

I am considering changing it to a single speed though, but I've been previously advised not to do this as it's a peugeot racer and not really worth the investment.

I'm slightly torn, as I do love this bike. But it could be so much more. And def need to replace the chain & cassette urgently.

I'm just learning how to fix my bike up and do all the practical mending & maintaining. I don't want to be spending money now if it means that I should really go single speed to only spend more money...??

I guess this is more than just one question!

Many thanks in advance.

You want an 8-speed SHIMANO CHAIN ...

The 8-speed Shimano chain is a COPY of the SEDIS NARROW chain which revolutionized bicycle chain technology almost 30 years ago ... and, it can therefore be considered to be compatible with most older drivetrains ...

How is changing to a Single Speed an expensive investment?

Beyond the tools that you will need to remove derailleurs/shifters + extra chainring, you will need a BMX Freewheel ... most cost less than $20 ... some will cost a little more if you get them from a bike shop (if they even carry one). Danscomp is THE mail-order source for BMX 'stuff' (Danscomp.com, also).

The only thing you need to know is that BMX Freewheels come with cogs that are the same thickness as on ROAD bikes AND the thicker size which is used on some TRACK cogs ... you want the thinner size.

You WILL probably need to redish the rear wheel because you will want to re-arrange the spacers on the rear hub so that the Freewheel will be closer to the dropout and thus improve the chainline.

If your bike happens to have a Helicomatic rear hub, then sell the wheel(s) and buy a new rear wheel.

Your main, initial consideration is deciding what gear ratio you want ... and, that should be based on where you will be riding ...

Choose a chainring + a gear on the rear & leave it there for a day ... if it is too hard, choose the next largest cog for the next ride ... if it is too easy, then choose the next smallest cog.

Either the larger or smaller chainring will be better ...

When you figure out which cog is the 'best' for all your riding conditions, then buy a Freewheel with the same tooth count.

I beleive an 8-speed SRAM chain is an acceptable substitute for an 8-speed Shimano Chain. If it isn't, then I will have to tell my LBS that they sold me the wrong chain, and try to figure out why my 8-speed bike is shifting flawlessly with the SRAM chain on it.

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One life, one chance. Don't waste it!

Yes, a SRAM chain will work ... almost any SRAM chain.

An 11-speed Campagnolo chain will work, too ...

A TRACK chain could probably be used, too!

We can confuse the issue by listing all the chains which could be used on a 6-speed friction drivetrain -- few wouldn't work.

BTW. Of course, I'm suspicious of your LBS for having sold you Shimano 'Brifters'!

You know, it's not "who can you trust? ... it's "whom ...?!?"

Sorry, you can't accuse my LBS of selling me Shimano Brifters. I did that all by myself, and guess what, they are still working flawlessly!

__________________
One life, one chance. Don't waste it!

So, you did-bad-all-by-yourself and are proud of it!?! Well, no accounting for some people's behavior ...

I had a pair of 8-speed 105 shifters ... they worked well enough, and I presume they are still working as well as the Shimano design allows ... but, "flawlessly" ... I think not.

I had a couple of pairs of 9-speed Ultegra shifters + one pair of 9-speed 105 shifters (I 'love' Shimano), but when I finally figured out that I could use my Campagnolo shifters with Shimano derailleurs/etc. it was really a no-brainer to sell the Shimano shifters because the Campagnolo shifters just work better ...

AND (except for some Nuovo Record remnants), I sold my Campagnolo derailleurs because Shimano derailleurs just work better than Campagnolo's derailleurs!

Even so, I still plan to set up a bike with my now-archaic 10-speed Ultegra shifters + an XT Rapid Rise rear derailleur (which I have already set aside) to prove-or-disprove that the downshifting limitations which the Shimano shifters exhibit can be overcome (of course, THAT is a problem which SOME people like to say doesn't exist despite people other than myself asking how to overcome the problem at times) ... the 'project' has been delayed for several years because I just haven't had the inclination to dedicate the small amount of time required for the endeavor. I am certain that the 'boys-and-girls in Osaka' have already done the test ... and, I still predict that a future Shimano Dura Ace (and therefore, Ultegra & 105) group will have a Rapid Rise (and probably, Shadow-based) rear derailleur.

Unfortunately, resolving the perceived-by-some shifting "problem" doesn't eliminate the burdensome boat anchor weight which Shimano's shifters still have! THAT is something Shimano will have to resolve if-and-when they redesign their shifting mechanism.