abecedar

Hi guys, i am partially rebuilding my very old highschooler road bike battaglin(or that's what the old paint said before stripping it down) on a budget because i don't feel like putting car budget into the bike.
I have bought a set of shimano 105 1055 8 speed shifters(bought them for 50 bucks since the previous owner said the left one was broke because it wasn't indexing anymore but only needed a inside clean) wich i am using with the same era rear derailleur(8 speed aswell) but i have a 9 speed casette and a 9 speed chain.
Is there any point to try and make it work on the first 8 sprockets or just buy new 8 speed cassette? I don't wanna throw away the 9 speed cassette as it's almost new and i hate throwing away things that are still in good shape.
And no, i am not willing to get anything newer because budget and parts are hard to find in this country.

Bill Kapaun

Scroll down to the second chart-
https://www.sheldonbrown.com/cribsheet-spacing.html

You'll see the cog to cog spacing is different.
IF you had everything aligned in gear 5, 4 shifts would put you nearly 2mm off. Almost 1/2 cog.
Just get an 8 speed and avoid the noise & poor shifting.

ShannonM

The cog-to-cog spacing is different, so the 8 speed shifter is unlikely to index the 9 speed cassette. (7/8 is close enough that I've never had it not work, in either direction. 8/9 ,not so much.)
At a minimum you'll need an 8 speed cassette, which are cheap and easy to find. The chain will probably work, but if not, 8 speed chains are cheap and easy to find.
That said, I'd give it a shot, why not? You might get lucky, and you've already got the parts. Adjust out the high-side click, not the low-side one. A slack cable is better than a bent derailleur hanger.

--Shannon

alcjphil

Save your 9 speed cassette and chain for a future build. They won't work with an 8 speed shifter

maddog34

you won't be happy with the shifting......

Get the 8sp. cassette.

The slightly narrower chain will work, but may be a bit less quick to shift.... internal bushing width(the part that actually rides on the gear teeth) remains the same, but the outer plates are narrower, and the pins can be shorter too.

KCT1986

If your rear derailleur is the 8 speed version with the 'tabbed' cable clamp plate (either 1 or 2 tabs see arrow on the attached), or you can salvage a plate from another RD, you could try the cable routing per the diagram.


Clamping the cable over the tab will decrease the movement of the RD per 'click' from the shifter. This may get you acceptable shifting for most of the sprockets.

rccardr 

Or take your nice 9 speed cassette apart and rebuild it using eight cogs with 8 speed spacers. Local Coop would help with that.

abecedar

After a few days of tinkering around with the derailleur still couldn't get it to run properly without going over 7 sprockets wich at this point is pretty pointless the have the 8 speed shifters so i suppose i will get a new chain and a new set of sprockets.

shelbyfv

Sometimes you just have to see something for yourself.

mitchmellow62

The cheapest but most unorthodox solution would be to use a friction thumb shifter mounted on the drop bars near the brifter. The right brifter would only be used for brakes. I've done it and it worked well. Of course, you've given up indexing. I'd suggest the Sunrace SLM10 for about $15. You need to experiment with mounting for the easiest reach.

abecedar

Just wanted to update my post. Eventually i ended up replacing many more parts and it turned into a frankestein of a road bike. I replaced chain and cassette, then i ended up replacing the chain rings because it was too worn, the teeth became spikes with no top flat, bearing hubs, headset, pedals. Oh well what can i say, it's a frankestein because the chainring is 34T-50T (finally climbing is easy)