mkadam68

Alright...I have an older Cannondale Black Lightning, all beefy aluminum, frame I'd like to upgrade to a few newer components for my son. Currently, it has a 6-sp freewheel married w/Campy downtube shifters (which may actually be 7-sp indexed shifters ). I'd like to get it up to some brifters with 8-, 9-, or even 10-speeds (if I can afford it).

1st:
Do you think I can force open the rear 126mm spread (I measured it at actual 127mm) to accomodate a 130mm rear wheel, or am I risking damaging something, given the older, stiff aluminum rear triangle?

If not,
What's the maximum # of gears for 126mm spacing? 7, 8, or 9? And would I look for certain parts numbers (say like off eBay), or just grab them if they say 7-, 8-, or 9-speed?

vpiuva

https://sheldonbrown.com/k7.html#up7

https://sheldonbrown.com/frame-spacing.html

good places to start. you didn't mention what kind of RD you have, but you may have to change it out, too. If you have Campy syncro shifters and RD, it's really not going to match up with much else if you want indexed.

well biked

Note that the OP's bike is a Cannondale, though. Aluminum. No cold setting for this one. Flexing the stays apart a few millimeters by hand each time the wheel is installed, yes; permanent bending, no-

Scooper

+1

It's an aluminum frame, so the dropout spacing cannot be widened by cold setting as could be done if it were a steel frame.

mkadam68

So it could be flexed enough to get a 130 wheel in there, just have to do it each time?

well biked

Should work, yes. You'll have to try it and see how difficult it is to flex those stiff aluminum stays-

redirekib

Pretty damned difficult to spread the stays on my Schwinn (1991). Just do an 8 of 9 conversion.

well biked

How is that related to the hub spacing question? Please elaborate-

barba

Shimano Sora can be had in a seven speed configuration. I would be inclined to try that.

redirekib

7sp spacing is 126mm. 8 sprockets from a 9sp cassette fit very nicely on a 7sp hub.

well biked

Interesting, thanks-

mkadam68

Well..I didn't know that either. So I can just put 8 sprockets on a 7-sp hub (126 spacing), use Sora/Tiagra 8-speed brifters & rear der. and that should work? What about clearing the drive-side seat stay?

well biked

I doubt it, but I haven't tried it so I can't say for sure. Even if it works, it seems like a lot of trouble and expense. I think I'd either go with barba's suggestion of seven speed with seven speed brifters, or see if you can flex the frame apart and put a modern hub in there. If you go with a modern hub, your options are limited only by your budget-

vpiuva

You use 8 out of 9 of the 9s cogs with 9s spacers, so you need a 9s shifter, not 8s. Covered in the Sheldon link I referenced earlier.

well biked

I just read that link, that is interesting. But still, you've got to cannibalize a nine speed cassette (or buy the cogs and spacers separately?) to build the new eight speed unit on the seven speed hub. I say if it's more cogs you want and the frame can be flexed apart, go the modern hub route-

redirekib

It's modern brifters the op wants, on an AL frame. It is really the best option. 9sp stuff can be had rather cheaply. The expense of 10 sp makes no sense, why not just buy a newbike then? Plus if you had to change a flat on the road, by yourself, you would have to lower the wheel into the dropouts with your teeth while spreading the stays with your hands.

well biked

The flexing of the frame isn't that big a deal to most folks, I've done it myself and it's an inconvenience at most. Certainly not something I'd need a second person to help me with. But then agan, this is a Cannondale, presumably a very stiff frame, so I don't know for sure about this one. I do know that I've seen folks report doing this with old Cannondales here, it apparently isn't a big deal for some. In fact, new Cannondale touring frames may very well be spaced at 132.5mm, to accomadate road or mtb hubs. I'm not positive about that, maybe someone else knows for sure.

My point to the OP is to try it and see before trying this other method. And if it's just brifters the OP wants, why not just go with barba's suggestion. For eight speeds, it will be a LOT less trouble and expense to just get a 130mm hub and put on there with an eight speed cassette and eight speed shifters than to do the "eight of nine on seven" thing UNLESS it's just too difficult to flex the stays apart. For road componentry, nine speed stuff probably isn't terribly expensive these days either, another easy option with a modern hub. After reading Sheldon's link, he seems to imply the "eight of nine on seven" thing is really a last resort, like if you have an old glued, carbon frame-

Volfy

If the OP's C'dale is already at 127mm, even the AL stays can tolerate being spring apart 1.5mm on each side, each time you install the rear wheel (how often do you do that anyway?).

The main question to the OP is:

1. How much money are you willing to spend vs. how much time/effort are you willing to invest in order to save some money.

2. How much is keeping that C'dale frame worth to you?

I recently went through the same process with my 20yr old lugged steel Pinarello with 7sp SIS. Finally decided to ditch the whole drivetrain & wheels and upgrade everything to 10sp. Yes, it's expensive, but my time is even more so. And the Pinarello carries a boat load of sentimental value to me personally.