Modern chainrings on 6 speed bike?

RadNomad

Senior Retro Guru
All original 1986 Carlton with 6 speed Shimano golden arrow groupset, friction shifters (see my sig).

Want to fit compact chainset so i can better use the bike around hilly terrain (will keep original parts for later return to originality). I just bought a new Sugino Mighty Tour 901D compact chainset direct from Sugino Japan which is beautifully made and looks quite retro, similar style to the Shimano. Somehow only now i realised the Sugino is 10/11 speed compatible which means narrower chainring widths than old 6 speed. I need to run 6 speed chain to work with the rest of the transmission.

Question is, will the wide 6 speed chain work OK on modern narrow front chainrings (shifting etc)? Thx!
 
Re:

Thanks LGF.
Rear cassette is UG though, you know, the ones with slightly twisted teeth and i want to use it because it’s a NOS 28T UG climbing cassette and fits my hub. I’m guessing the UG twisted teeth may demand greater internal chain link width than the straight teeth HG cassettes? With that in mind do you still think a 9 speed chain will work?

Is there any reason why i should avoid using 6 speed chain? Thx.

Why use spacers on the rings? I’m not worried about chainring spacing, but the actual chainring thickness. Chain rub at extreme chainline perhaps?
 
The old 6spd chains are big buggers, whereas 8/9spd are a lot narrower on the outside. I dont think wear would be an issue, rubbing on the rings can happen but with a 1mm spacer on the rings, you'd widen things enough.

Hows about using an 8spd chain instead? Thicker plates, nice and bevelled for shifting and reasonably sturdy.
 
Re:

In my case i did also source an original NOS UG 6 speed chain as i thought i had to use UG chain with UG cassette, but i have no objection to using a narrower HG chain if it might work better with the thinner 10/11 speed Sugino chainrings. I may go with LGF's suggestion of 8/9 speed chain and have some chainring spacers on standby to fix/reduce chainring rub. Thanks all for your advice.
 
Re:

in pure definition terms there are no 8/9 speed chains

there are pure 5/6 speed chains which, if they are decent will be new 30 years old stock. If they are modern, they are far east crappy ones that won't index properly as I found out on my pub bike

there are modern 5/6/7/8 speed chains - decent enough quality, SRAM is most common. This is what I would buy (doesn't have to be SRAM, other decent makers do them)

there are dedicated 9 speed chains, dedicated 10 speeders and dedicated 11 speeders - all would work for you, but why spend more a for a weaker chain.

if you have a wide chain on narrow rings, it will function perfectly, but you will get the odd tinkling sound as the chain can move laterally on the ring. More noticeable when on the small ring.
 
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