Gear change on an 8 speed
 

I've got an old Specialized Allez Pro (from 1993!!! :thumb:) with an original ultegra drivetrain. Love this bike... bought it about a year ago from a friend and it's now my commuting/touring/riding bike.

My question is... it's got the 8spd U cassette, 12-23. The 23 is killing me on hills, and want to go up to a higher flywheel. I've been considering getting a 9spd cassette and leaving off one of the rings. Would it be too much of a jump to change out the gears from 12,13,14,15,17,19,21,23 to 12,13,14,15,17,19,23,27? Unless it's a hill I don't guess I'm ever in the two biggest gears for any length so I don't think I'd miss the middle gears much.

Thoughts?

13-26.

You'd have to look up the specs, but a mountain cluster ending in a 28 is easy to find. SRAM or nashbar has them for around 20 bucks.

^

those have an 11. the OP doesn't even need a 12, let alone an 11.

I'd like to keep the 12, at least. I wouldn't mind going up to an 11, but read on Sheldon's site about 11's needing the hyperglide-c or something. I wasn't sure if that was still true on a '93 ultegra cassette or not.

My thought was get an ultegra 9spd (12-25 or 27) and just leave out one of the rings. I've seen a couple on ebay for $45, seems the easiest, best way to stay with a higher quality and get the gearing.

5233.3 %391227.120.38.3 % 1325.018.87.7 % 1423.217.47.1 % 1521.716.313.3 % 1719.114.311.8 % 1917.112.821.1 % 2314.110.617.4 % 2712.09.0

Pulled this off sheldonbrown.com/gear and it shows the large jumps on the last two gears, just wasn't sure how that would ride.

you don't need it.

No.

Go buy an 8 spd cassette. There are planty still available.

I have an 8-speed triple which was equipped originally with an 12-25 cassette. I bought an 11-28 cassette and loved the 28t cog but hated the 11t cog. I took the 12 and 13 cogs from my original cassette and replaced the two smallest cogs on 11-28. It works well and shifts well. Now I have a 12-28, which I like. This hybrid cassette has lasted for somewhere around 4,000 miles and is still going strong.

8 of 9 will not fit correctly on your bike and wheel's feehub. Both an 8 speed and 9 speed and 10 for that matter are designed for 130mm dropout spacing. 8 cogs out of 9 comes out to about 126 which is what some people with older 7 speed wheels do as 6/7 speed cassettes are designed for 126mm droupout spacing with matching hubs.

Maybe I missed it but what size chainrings do you have? You might be able to go smaller up front.

My 8-speed cassette is an 11-28. It's a Sram PG850.

You're welcome.

Buy/modify the new cassette. Whatever. But remember that you'll need to change the freehub or grind off a spline to make an HG cassette work with your UG hub.

8 speed Ultegra in 93, which I think was the first year it was called Ultegra, should be HG. I know my 600 tri-color hubs from 92 or so are 8/9/10 HG

^Oops, I guess I don't know my Shimano years.
I was going by the OP's description.
What does "8spd U cassette" mean, then?

Shimano designates ranges by letter

P 12 14 16 18 21 24 28 32
Q 12 13 14 16 18 21 24 28 Discontinued
R/ah 11 12 14 16 18 21 24 28
S 12 13 14 15 16 17 19 21
T 13 14 15 16 17 19 21 23
U 12 13 14 15 17 19 21 23
V 13 14 15 17 19 21 23 26
W 12 13 15 17 19 21 23 25

that it's time to buy a new group set.

You've still got 600 hanging on your dale right? What model was it, a 92 R800?

what's a "dale?"

NASCAR edition of the Denali bike.

:roflmao2:

Distant relative of the "Pinny".

very.

Thanks for all the replies! Very surprised when I get back to work and have 21 replies!

This is what I was basing the 9speed idea off of: "There is no problem mixing, say, 9-speed or 8-speed sprockets into 7- or 8-speed cassette. The smaller sizes (11, 12, 13) that feature built-in spacers should, ideally be matched, but even this isn't generally a problem in practice. (http://sheldonbrown.com/k7.html)"

Or would it be easier/better to just get a 27 tooth ring and swap out some of the cogs? Remove the 21, slide 23 over and add the 27?

I guess, what I'm asking is 19, 23, 27 too big of a jump? I've got a 52/39 upfront.

Go buy this from your LBS and be happy: http://aebike.com/page.cfm?PageID=30...ils&sku=FW6163

Still trying to figure out why you won't just buy an 8spd cassette....