A friend gave me his old bike which I'm fixing up to use. It has no chain and I've never replaced one before so I'm wondering what size I need to buy to replace it. The Bike is an Apollo Avio, it has 3 rings on the front chain ring and 5 on the rear cassette - from what I've read this seems to equate to a 15 gear speed bike, but I can't seem to find bike chains that would fit that spec... they seem to range through 7, 8, 9 and then 10 speed most commonly, am I missing something?
Looks identical to an early 90s MTB I ride. That too was 3x5 for 15 gears total.
I found that 6/7/8 speed chain worked well enough with the 5 gear freewheel.
But after decades of wear, the moving parts were a bit sloppy so when an opportunity arose, I fitted a 9 speed cassette and freehub wheel, with 9 speed chain/shifter/derailleur and its going nicely. The bike still uses the original triple chainring and shifter, so theres a 9 position deore right hand shifter under the bar, and a friction twist shifter over the left side of the bar.