Double0757

Hi everyone, I think this is my first post here in this forum ever!

I've been a crazy mad biker for over 43 years, (10 years old to 53), touring, commuter, racer want to be, worked with a bike (literally pedaling donuts). In other words I have used bikes in most of their capacities.

Presently I want to convert my 27 year old touring Cannondale 27" into a 700c tourer/commuter. Why 700c? Well, all my other bikes, from my backup commuter to my tandem they are all 700c, and I'm getting a 700c dynamo front hub wheel to fit both commuters and the tandem. I was going to wait a little to change the rear wheel but the gears are starting to slip, tooth on the rear cogs are worn ( to cause concern). This is the fourth time I have changed the rears cogs on this bike.

Being stuck in 80's and early 90's technology, I'm here for some education and advice.

The rear spacing on the frame is 125mm. I know I can fit a new hub with an 8 speed HD cassette to run an 8 speed Shimano's Deore XT integrated 8 SIS rear derailur (127mm maybe?), which I have on hand. I would like to run it with a Shimano's Dura Ace 2x9 brake shifters, also on hand, with an Shimano's STI HG new narrow chain/9-speed HG compatible, also on hand. My question is, besides loosing my grany gear in the front and having one phantom gear on the shifter lever, would the setup work?



My concern is that the movement (spacing) for the 9 speed is different than for an 8 speed and they would not work together, or the chain would not be compatible with the 8 speed deore XT derailure and cassette hub gearing. Thanks in advanced Double O

Bill Kapaun

The cog spacing is different.

demoncyclist

8 and 9 speed cassettes should fit in the same space. If you can fit an 8 speed hub in your dropouts, the OLD measurement of that wheel is generally 130mm not the 126mm of a 7 speed setup. That being the case, i would just slap on a 9 speed cassette for now. The triple to double in front may be the bigger issue in terms of spending at this point.

Double0757

Thats what I have at this time, a 7 speed setup, it's a 1984 bicycle, second year production. Maybe my best (economical) scenario is to keep all the same and just change the rim to 700c and a new cassette. I just thought of upgrading the bike with available parts that I have been collecting with time. Double O

FastJake

If you are using 9S shifters and a 9S cassette you are good to go. The RD (assuming it is a 'normal' Shimano unit) doesn't care how many speeds you run.

You'll need an 8/9/10S freehub body, or a wheel with that body spaced out to 130mm. Is this bike aluminum? You might not want to stretch it to 130mm. If it's steel you don't have to worry.

Jeff Wills

I wouldn't ignore the frame spacing. You can't go to an 8/9/10 speed cassette since the extra width of the cassette creates a wheel with too much dish. You might be able to wedge in a 130mm width hub (8/9/10-speed standard) but that would be tough on your Cannondale's aluminum frame. (The first couple years of Cannondales had very stout rear triangles. I had a first-year bike- the shop where I worked sold them.)

If you want to run the Dura-Ace brifters, you could create a custom 7-speed cassette using 9-speed cog spacers and have it work, but then you'd have 2 phantom gears on the lever. Also, finding all of the correct cogs (some cogs have built-in spacers) might be difficult.

It's possible, but something I'd only attempt on a dare.

Double0757

Thanks Jeff! I thought the 7 and 8 speed cassettes fit on the same hub cassette lenth and spacing of 125mm (or close), but then again I was wrong once! LOL! No, I wouldn't try to wedge anything more than 1 or 2mm on that rear triangle. Any way, I'm just thinking to go with the 7 cassette on a new hub and 700c rim, then slapping the Deore XT and not using the Dura Ace brifters, and just keep the end bar shifters I presently have, to make it easy on my self.

But then, I love a good dare!!! Thanks. Double O

Jeff Wills

Yeah... 7-speed is as far as you can go with 126mm spacing. When Shimano introduced 8-speed, they also went to 130mm spacing on the rear hub. That's been the road standard ever since.

Aside: the first Dura-Ace 8-speed hubs had a conical left locknut. This made it easier to cram a 130mm width hub in a 126mm width frame. I don't know how well it work on an early Cannondale- like I said, they were stout. The seatstays were laterally ovalized to reduce sideways flex.

Here's an early Dura-Ace 8-speed cassette hub. Rare as hen's teeth now:

Kimmo

Unless you use an off-centre rim.

Double0757

OH! Now you done it! Just checked it out on google! still reading on it! Double O

fr_walnut

Hello,

I went through this a few years ago, this is a very common problem when converting older bikes to modern brifters, the safest and simplest method is the "8 of 9 on 7" approach

https://www.bikeforums.net/showthread...acing-question

You just need to get a Shimano HG-9 11-25, or a SRAM PG-950 11-26, remove the 11 and you're good... Note that you'll need a lockring for 12-start cassettes, which you probably already have

(These cassettes are all steel, last forever and shift as well as any high-end cassette)

Kimmo

If you use an off-centre rim, you can have 9 of 9 or whatever your brifters go up to.

For a 125mm OLD, the rim only needs a 2.5mm offset to produce a wheel with the same dish as a normal rim on a 130mm hub.

I gather most OCRs have an offset more like 3-4mm, which will give you a wheel that fits an old frame with less dish than a normal one, or you could run standard dish as narrow as say 123mm, depending on the rim.

Double0757

Being reading and learning, my question is: If I need a rear hub for 125mm spacing with the OCR to fit the 9 speed cassette, do they make does, or are they as rare as hen's teeth? And do I need a rear mech for 9 speed or can I use the 8 sis Deore XT I have? And if I understand correctly, the pitch of a shimano 9 speed is the same for mountain (one I be using) and the road one (ie. Dura Ace brifters [road] with rear mech Deore XT [mouintain] correct? Thanks! I hope to bring this old friend to the XXI century! Double O

pierce

never seen 9 speed fit on anything other than 130mm (road) or 135mm (mountain) hubs.

Double0757

Ok, so I'm back to my old 126mm hub with 7 speed, and if I want to run the brifters, find 7 cogs with 9 speed shimano spacing.

I decided to leave it as is. Have the 700 rim build on the old hub with new 7 speed cassette and use the existing components on the bike.

I'll save the 9 speed brifters for my sons (my backup commuter) 1986 Brigstone 700 with a cromoly frame. Then I could use 130mm hubb (stretching the frame), OCR and use appropriate road components for the Dura Ace 9 speed brifters! Thanks everybody! An education on XXI century bicycling! Double O

Bill Kapaun

I've "stuffed" a 9 speed on into 86 RockHopper.
The dish isn't pretty and sometimes I "think" I've felt the rear end act weird on a left turn. Kind of like hitting a 2-3" dia. spot of ice.

I have a freshly built wheel with a Velocity Synergy OC rim waiting for it.
I think I'm going to take the "plunge" and respace the rear. Need a few more days to heal from my broken leg (see avatar) to have a little more mobility. Have to remove rack, baskets & fender first, then get my friend to come over & bend while I measure via Sheldon's method.
https://sheldonbrown.com/frame-spacing.html

Doing some additional calculations, IF I were to respace to 135MM AND revert back to my 7 speed FH body (8 of 9 on 7) I'd have a wheel with only about 1-2MM of dish. Hmmmmm

Kimmo

With Shimano hubs, you can usually swap the old 6 or 7s cassette body for a later one, lose the 4mm spacer on the NDS, lace the hub into an OCR and have an 8/9/10s wheel @126mm OLD with less dish than a plain 8/9/10s wheel @130mm.



This example is the Ritchey Trekking 700 Comp.

I believe the Velocity A23 OCR has 4mm of offset. Only 2mm is required to make an 8/9/10s wheel @126mm have the same dish as an 8/9/10s wheel @130mm.

Double0757

What is NDS? And if I'm building a new wheel, which hub and OCR combo do you recommend for a 9s touring setup? Thanks Double O

pierce

NDS == non-drive-side, eg, the left side of the bike, if you're facing forward.

cyclotoine

Indeed, or you could just use a new hub (cut axle down 4mm, remove 4mm of spacer from NDS) instead of swapping, but either way we are in agreement, but yeah if the OP wants to keep the old hub, but that is probably more of a pain than just getting another hub.

pierce

or cold set the steel frame to 135 and use a modern mountain/hybrid wheel with a 135mm OCD hub and run any gearing you want, like 9 speed...

Jeff Wills

Not relevant. The original poster specifically mentioned modifying an old Cannondale with 125mm spacing. There's no way they'll be spread.

pierce

oh, i should have reread the whole thread. yeah, C-dale (or any other alloy/composite/etc/nonsteel bike), fergit it. you're stuck with what you got.

hmm, and it just occured to me, playing games with axle spacers to put a wider cassette on there by offsetting the rim and axle... that will mess with the chain line, no? probably not enough to really throw it off, but still...

Jeff Wills

Not enough to matter. Kimmo's correct: a narrowed 9-speed hub and an off-center rim is the same as a 130mm (standard) width hub and a non-offset rim. It's a bit of a kludge, but if it's what you want, it can be made to work.

Kimmo

I think you mean, it's a wonderfully elegant solution.

OCRs are a free lunch; they cost no metal to improve the spoke angle and make the NDS spokes work, making a normal wheel much stronger, OR a 8/9/10 126mm wheel so feasible, it's a bit stronger than a normal 130mm wheel.