3X8 to 1X8 old bike

[megachris]

Hey,
I finally got my Giant cold rock 99 fixed up. It's working fairly decently and I'm currently giving it a good clean, taking apart cranks and so on.
When using it, I find that I really only stay on the middle chain ring and the front derailleur shifts horribly, and it needs a new cable.
I don't really like using any of the other chain rings and find that the middle one suits my needs completely. So when I took the crank arms off, I went ahead and tried to remove the two unused chain rings, but disappointingly all the chain rings are welded together.
It's an old Shimano Alivio crank set.

I was wondering if perhaps I could find a single chain ring that could fit onto my old Shimano Alivio set, tossing away the old welded together chain rings.
I'm not sure if it's possible, I have also been looking at modern 1X10 crank sets, but they aren't cheap to say the least.
Any ideas?

Much appreciated,
megachris

 

[RickTheUncivil]

Re:

Can the rings be removed from the crank?

Measure / find the bolt centre diameter and go shopping. Just about any ring will work but narrow-wide should help stop the chain falling off.

Or just leave it as it is? Any harm in hauling around a few grams of chainring that you don't use?

 

[drcarlos]

Like Rick says if they unbolt you should be set. Have a look at snail rings on eBay, I fitted one on my fsa cranks. They seem well made and they don’t cost much. Make sure you get the bolts too as the current set will probably be too long.

Carl

 

[dyna-ti]

If youre putting the ring in the middle position, why not take an old outer, grind off the teeth, then run that as a sort of guard, plus means you dont need to buy any more bolts, ie shorter for a single ring.

Donkeys ago(about 97, i built a lightweight all alloy runabout, with a 1x8 set up. Did as above and used a ground down outer. All worked fine.

I think using the middle position helps run through more of the gears with a lesser chain angle than if placed on the outer position. Less chance if it picking up and chucking the chain off the ring.

 

[megachris]

Hey. Thanks for all the replies. I'll go through them all in detail tomorrow as it's getting late and my bed is calling my name.

I took it all apart earlier and my crank set is a dead end. It seems that this specific old Alivio crank set has a pretty obsolete BCD. It connects to the granny ring and every chain ring is welded on to it. This means that I'd have to find a single chain ring, 67 BCD, which is pretty much impossible. I'd have to do custom drilled holes. So I'm guessing my only opportunity is to find a crank set that would allow me to run 1X8 or just keep using the current setup and remove the front derailer cable and shifter, just keeping it on my middle ring.

 

[Timoth27]

Re:

I think I’ve got a few cranksets in the spares box you are welcome to a set for postage? Let me check what I have tomorrow and let you know.

 

[megachris]

If youre putting the ring in the middle position, why not take an old outer, grind off the teeth, then run that as a sort of guard, plus means you dont need to buy any more bolts, ie shorter for a single ring.

Donkeys ago(about 97, i built a lightweight all alloy runabout, with a 1x8 set up. Did as above and used a ground down outer. All worked fine.

I think using the middle position helps run through more of the gears with a lesser chain angle than if placed on the outer position. Less chance if it picking up and chucking the chain off the ring.

That is a pretty good idea. It already has a plastic guard on it, but I could remove that, grind the teeth and at least that would make it a bit more aesthetically pleasing. Obviously I'd still have the granny ring, but I guess I could just leave that. So I might well consider doing this unless I find a crankset that would allow me to do a simple conversion.
Perhaps I can find an older STX RC crank to upgrade it. Don't know what they go for.

I think I’ve got a few cranksets in the spares box you are welcome to a set for postage? Let me check what I have tomorrow and let you know.

That is very kind. I reside in Denmark and I don't want to hassle you if shipping to Denmark is complicated, and I'm not sure what the shipping prices are. I was currently looking around for older cranksets in my local area, but I am still interested in your offer.

 

[Timoth27]

Re:

Ok I will enquire about postage, never sent anything outside the uk but apart from cost I cannot see why it would be any different.

 

[megachris]

Hey everyone.

I've now cleaned up the crank and chain, it was covered in black gunk. I'm unsure of how these chainrings have been put together and was wondering if perhaps I could drill free the granny ring, leave the middle ring and grind down the first ring as a guard. I've outlined the areas I thought might allow me to drill free the granny ring. Just really wishing I was able to put on a new chain ring and call it a day. Quite like these old FC MC16 Alivios.

 

[mattr]

Yeah, drilling out the spotwelds will free the granny from the middle. At a guess the big ring is held to the middle with that ring of 5 single spots.

Only thing i can think off that might leave you unstuck is that your middle ring is ramped, so it may drop the chain more often/quite easily unless you are very careful with chain length.