rothenfield1

I love working on bikes. But there are some aspects of bikes that are still mysterious to me. The biggest mystery is drivetrain compatability. Here's the problem. I bought a 2000 Specialized Allez frame hoping to build an everyday workhorse excersize bike using parts I already have. I was hoping to at least get it on the road using a 7-spd 105 hub. But, I don't want to buy a 7-spd brifter and it appears that 8 or 9 spd isn't compatible. What are my options without buying a new wheelset?

smiller

assuming it's a freehub and not a freewheel hub, you can just change out the freehub and cassette to go 8/9 speed. I've done it with my old 7sp DA wheels and was suprised how easy it is. Sheldon describes the process and parts aren't all that pricey.

rothenfield1

I'm going to expose my stupidity here; but by freehub, you mean that the splined section that the cassette slips onto can be replaced by a longer one to accept a 8 or 9 spd cassette? There does seem to be about a 3/8 inch space between the spokes and the large cog if one looked straight down over the cassette. This is an early 90's 105 hub. Is it possible that they had already made room for an 8 spd cassette? Bottom line; I have to buy brifters to build this bike. I was hoping not to have to buy another wheel. If I can get 8 spd to work, that's OK; 9 spd would be even better. I just don't understand the wheel dishing issue not to mention if a 7 spd RD will reach an 8/9 spd casset

Jeff Wills

Exactly so. More precisely, you're replacing the "cassette body" or "freehub body", the ratcheting mechanism that appears to be part of the hub. It requires disassembling the hub to get at the bolt that holds on the freehub body, but it's not tough for a decent mechanic. I've done this a number of times- here's an early Deore XT hub I converted to accept a 9-speed cassette:
https://home.comcast.net/~jeff_wills/...es/bike023.htm

rothenfield1

Thanks Jeff in Vancouver. Love your country; by-the-way, can I move there please! I'm sorry, my straight forward logical mind is not picturing this. There's only so much space between the chain stays, and that seems to be why they were spread at some point to accommodate more cogs. So, your saying that if I get a longer free-hub, I get another gear or two?

Oh; and is there any way I can get a pair of those socks in your photo. Awesome!!

HillRider

One other work-around is to use "8 of 9 on 7". In other words, get a 9-speed cassette and remove one cog and it's spacer. The remaining 8 cogs will then fit properly on a 7-speed width freehub body.

You will require 9-speed brifters and a 9-speed chain but it will give you 8-speeds and allow you to keep your current wheels.

rothenfield1

"Any 7-speed Shimano Hyperglide Freehub will actually work with 8 sprockets, without any modification! What you need to do is to use 8 of the sprockets from a 9-speed cassette, with the 9-speed spacers."

"To make this work, you'll also need to use a 9-speed chain and shifters. Your old 7-speed derailer should work OK if it isn't too badly worn. The limit stops on the derailer will cause the useless 9th position on the shifters to be locked out, so this will work as a perfectly normal 8-speed rig." - Sheldon Brown

Am I reading this correctly? To convert my Shimano 105 7-spd wheel to 8-spd, I need a 9-spd cassette minus one cog and a 9-spd shifter. Then redish the wheel to bring it to center. And, my 7-spd 105 RD should work. I don't understand what he means inthe second line, "a 9-speed cassette, with the 9-speed spacers." What spacer is he talking about?

Jeff Wills

Which country is that? Vancouver, Washington (the "other" Vancouver) is a suburb of Portland, Oregon. In fact, my morning ride was into downtown Portland to register for Bridge Pedal.

You can move here if you like- it's a great bicycling area, and just downstream of the Columbia Gorge: https://www.bikeforums.net/clydesdales-athenas-200-lb-91-kg/549422-bridge-gods-columbia-river-ride-many-photos.html

dabac

Yes.
Buy a perfectly bone-stock 9-spd cassette, then remove one cog (and spacer) yourself.

Should be no need to redish, 8-of-9 will take up the same amount of space as 7-of-7, as they fit on the same body.

Most sprockets in a cassette are basically stamped out of sheet metal. To get the required clearance between them you use spacers, they look like thin slices of a pipe. If you decide to remove one of the bigger sprockets you take out the sprocket and its spacer. The smallest sprocket(s) is manufactured in one piece, so no need to remove a spacer if you decide to do w/o that one.
Do note that some cassettes use a carrier for the bigger sprockets. If you get one of those you'll have a merry old time trying to lose the biggest sprocket.

rothenfield1

Thanks everybody! That's exactly what I'm going to do. I like this idea because it allows me to get the bike riding now and when I get a 9-speed hub, I'll have everything I need.

Now, if I could just find a pair of the socks!

rothenfield1

I thought Washington was a country. That's what we're told down here in the Bay Area anyway.

Jeff Wills

Neener neener neener!

FWIW: I'm an "Invader from California" myself. Grew up around El Lay and moved here from Sandy Eggo. My parents still live in Pasadena and my brother lives in Martinez.

Sixty Fiver

The best route is to transplant an 8-9 speed hub body as then you can use stock 8-9 speed cassettes with no issues or screwing around with removing cogs.

Hub bodies sell for about $40.00 but can also be salvaged from wrecked wheels quite easily.

rothenfield1

Just when I thought I had this issue put to rest, leave it to Sixty Fiver to open up a whole new can-o-worms. Sixty; I'm standing in my garage, surrounded by all of these 6-7 spd steel bikes parts, looking at this modern alum frame, trying to figure out how I can get it on the road. What I have is a set of Wolber GTX rims on a 7 spd 105 hub. I'd like to end up with a 9-spd, I guess. How is there enough room on the hub to get 2 more sprockets if I get new hub body?

rothenfield1

Ironically, I'm working off San Fernando Blvd at the old UP rail yard. Do you want me to pick up some good mexican food for you while I'm here?

Sixty Fiver

From Sheldon We Sure Do Miss You Brown...

Upgrading From 6-/7-speed (126 mm) to 8-/9-speed (130 mm)

Most Shimano 6- or 7-speed cassette Freehubs can be upgraded to 8-/9-speed by replacing the Freehub body, as described above.

6- and 7-speed hubs generally use 126 mm spacing, while 8-/9-speed hubs use 130 mm (road) or 135 mm (MTB/Hybrid).

Many people will tell you that this requires a new axle, but if you're only going from 126 to 130, this is not true. The 137 mm long axles commonly supplied with 126 mm hubs are plenty long enough for use with 130 mm spacing. There is absolutely no risk to this.

If you do re-space your hub, you'll also need to re-dish your wheel, because the extra space will all be added on the right side by installing the wider Freehub body. You'll need to tighten spokes on the right, possibly also loosen some on the left, to move the rim 2 mm to the right so that it will once again be centered in the frame.

An 8-9 speed hub body is only 2mm wider than the 7 speed body but this difference is what makes it impossible to fit an 8-9 speed cassette on a 7 speed freehub.

The spacing between 9 speed cogs is narrower and this is why a 9 speed requires 9 speed specific chain.. the difference between 6-7-8 speed cassettes is not significant enough to warrant a difference in chain but this changes with a 9 speed.

8 and 9 speed cassettes use the same hub body and are the same width... this is because the cog spacing is different.

Sixty Fiver

Your 7 speed rear derailer will work with 9 speeds... it is the shifter that needs to be changed.

jland

I put 9 cogs of a 10-speed cassette onto a 7 speed freehub (it's a uniglide/hyperglide transition freehub with both internal and external threads - 126mm axle)... the last sprocket sticks a little beyond where the freehub splines end, but it's been working well so far. With a Shimano cassette, I needed a 1mm spacer behind the cassette, and with a SRAM OG-1070 cassette, no spacer was needed. I'm using 10-speed shifters, of course, and a 9-speed generation derailleur.