Hello! I am trying to figure out what I will need to do to upgrade the componentry on my 1994 Cannondale R400. I am going from old broken rsx 2x7 stuff to 105 2x10. I believe I understand everything except the cranks and bottom bracket. My understanding is that they have changed the way bottom brackets are made and I cant get a modern crank that will fit on the old bracket. I am hoping there are some tricks or tips that you mech inclined folks can point me to that will make this process easier.

Thanks!

Are the stays steel? I think not-I don't believe a ten gear cassette will fit in there. Maybe on a steel frame/but not aluminum. I could and often have been wrong tho. Upgrading the crank I think can be done with a cartridge tho. If it ain't broke.....

If the old crank and BB are solid you should be able use them with most modern setups. To make things run really good you can buy new front chainrings in a 10spd variety for most common Shimmano cranks.

"Modern" Shimano (and many other) cranks have the spindle built into the crank arm and the bottom bracket is just a pair of cups with bearings built in. If you are willing to buy a new crank, the bottom bracket is a low cost part of the switch. Modern external cup bottom brackets will thread into your frame (which is English threaded) with no problems.

If your old crank/BB is RSX, I can't hardly see a modern 105 not just 'bolting in'. I would find out for sure what your rear wheel spacing is, 10sp road needs 130mm. Might think about new wheels, too -- lots of improvements in 18 years.

DX-Man makes a good point -- most 7-speed wheels/bikes are set up with 126mm dropout spacing.

Most 10-speed gear requires 130mm dropouts.

Some say you can just pull them apart and squeeze in the wider wheel, but you may run into problems doing that.

I believe that is an aluminum bike, which means you can't "cold-set" the chainstays to the larger dimension like you can with steel.

SO -- remove the wheel and measure the dropout spacing. If it isn't 130mm you may have problems with the 9- or 10-speed gear.

I'm not sure about 8-speed; hopefully somebody will chime in that does.

I feel your pain -- I have an older 7-speed bike that I'd love to upgrade to something more modern, but it gets pricey fast. Brifters, hubs, cog cluster, chain etc... and on it goes. Mine is steel so cold-setting is an option, but all the other expenses make that an expensive upgrade. A new bike is probably a better option.

-Tom in Ventura

I'd say you should run the serial against this-
https://www.vintagecannondale.com/info.html

and learn definitively if you have 130mm or 126mm rear hub spacing (rsx came in both sizes). From there, you'll know if you even CAN put an 8+ speed cassette in that frame.

Great info. Thanks. I will check that and find out if I am wasting my time on this endeavor.

From what I can see on the vintage site 1993-1999 serial codes do not give the dropout spacing. That is only included in the serial number before 1992. However, mine is FI 13855 106397 5bonsc if i am missing something

This is easy-peezy. As mentioned previously, a modern crankset- actually, an entire 2012 group- will fit without any problems whatsoever, except the impact to your wallet. Chances are the RSX is 126, but inserting a 130 hub into the 126 spacing is very easy, does NOT require cold setting and does NOT mis-align the rear dropouts. Done it dozens of times and those bikes have logged tens of thousands of miles without any trouble.

Looking for the current price/value sweet spot? Go for Ultegra 6500/6600 9 or 10 speed stuff, generally the same price as 105 5500/5600 but better made. Figure $400 +/- for the entire group including chain and cassette.

You will also either need new wheels or buy a 130mm freehub and have it installed on your (if it's in nice shape) wheelset along with (probably) a slightly longer axle, then have the shop re-dish the wheel for the new 130mm OLD width. That will fit any 7 (with spacer) or 8-9-10 cog gearset.

I just picked up a 105 10speed drivetrain for 140 so I am going to use that with the ultegra 6600 cranks and then look for the wheel. Thanks for the help!

Question the need for 10, vs 8 or 9..what ratios do you find lacking ?
8 is the beginning , of the 130 wide wheel,
the chains are $15 for 8 speed , they are $45+ for 10 speed .
so the parts you will wear out will cost a lot more ..

I found some 10 speed 105 stuff on craigslist for really cheap so I went with that. I really needed to upgrade the old RSX stuff, there were problems with the brifters so I decided to upgrade instead of spending a ton replacing them with ebay stuff. 8 or 9 might have been wiser in the long run but this is what I have now.

I bought the Ultegra 53/39 crank, 105 12-27 cassette, 105 brifters and derailleurs, KMC 10 speed chain, and vuelta corsa wheelset. Hopefully all will be good now w/o needing more parts.

Thanks everyone!

I'd be very surprised if the frame doesn't have either 130 mm or 128 mm spacing. By the early '90's many bike makers were fitting 7-speed or 8-speed components to the same frame at different price points and made the dropouts either 130 or a compromise 128 to take both. My '92 Trek 1420 bonded aluminum frame came with 7-speed 105 but the same frame was sold with 8-speed Ultegra and the dropouts were 128. Both width hubs fit easily.