dgsca

I am going to retire my 8 speed Dura Ace down tube shifters and replace them with combo brake/shifter levers.

If I am reading the Sheldon Brown compatability table correctly, I can use either DA 8 speed shifters OR any other Shimano (Ulterga or 105) 9 speed shifters. True?

Thanks all.
dgsca

Al1943

Yes you can use any Shimano 9-speed shifter with a Dura-Ace 8-speed rear derailleur and any 8-speed Shimano compatible cassette. Here is a helpful chart: https://www.ctc.org.uk/DesktopDefault...D=3946#Shimano. Coincidentally this combination is compatible with Shimano 8-speed cassette cog spacing. The 8-speed Dura-Ace rear derailleur has a unique actuation ratio.

But if you are going to buy new shifters why not go with 10-speed Shimano shifters, new rear derailleur, new 10-speed cassette, and new 10-speed chain.

Or you could do the same with all 9-speed components. Either a 10-speed or a 9-speed cassette will fit the same hub as an 8-speed cassette.

Al

TallRider

Apparently 9-speed indexing has the cable-pull ratio to work with 8-speed dura-ace.
Although if I had the classic Dura-Ace group that you have, I'd just keep the DT shifters.
I assume (since you didn't mention it) that you're keeping the 8-speed cassette?

I second Al's recommendation of, if you're going to make this switch, just move up to 9-speed or 10-speed stuff. The brake/shift levers are the biggest upgrade cost already.

strop

Don't think so. I'm running an eight speed cassette (HG-90 12-23) on a ten speed Shimano hub (Mavic KSyrium Elite) and I needed a spacer, so going the other way it won't fit.

I tend to agree that if you're going to do this you'd be better off doing it properly and going ten speed but it's a pretty major overhaul at that point. The problem with buying 8 speed brifters now is the only upgrade path to ten speed is to replace them again.

TallRider

strop is wrong about this, at least as applied to the OP's case. Mavic Ksyrium may use a slightly wider freehub body than Shimano and it works for 9- and 10-speed and only works for 8-speed in modified format. But this isn't the case with Shimano freehubs, which is presumably what the OP has. 8/9/10 speed Shimano freehubs have all been the same width.
Given this, a new hub (or a spacer) is not necessary for the OP to upgrade to 9- or 10-speed.

Options and requirements:
1. stay as-is; presumably the down-tube shifters work fine.
cost: nothing
2. find 8-speed Dura-Ace STI shifters to use with present drivetrain
cost: unknown, these may be VERY difficult to find
3. use 9-speed STI shifters on present 8-speed Dura-Ace drivetrain
cost: probably around $80 used on eBay
4. update to 9-speed or 10-speed by buying new shifters, cassette, rear derailer and chain
cost: doable for $150 with 9-speed used stuff, more with 10-speed and/or new stuff

Al1943

The problem you've got is the MAVIC hub that requires a MAVIC spacer to work with any Shimano compatible cassette. This is because MAVIC cassettes are wider overall than Shimano cassettes. Shimano 10-speed cassettes are actually narrower overall than either the Shimano 8-speed or Shimano 9-speed cassettes. Shimano 10-speed cassettes require a special 10-speed spacer to work with most 8, 9, and 10-speed hubs. Shimano 8, 9, and 10-speed cassettes are cross-compatible with Shimano 8, 9, and 10-speed hubs with the exception of certain D-A and Ultegra 10-speed hubs used on certain Shimano wheels.
Shimano 10-speed cassettes on most MAVIC hubs require both spacers.

Al