mlawranceowen

Hi, I have a 1997 Lemond Reno with a Sugino AC 130, 39/53 crankset that needs replacing (both threads nackered). I'm considering upgrading to a hollowtech crankset, probably a Shimano Ultegra 6600. Would this be compatible with my current 7 speed RSX set up?

Thanks, Mike

morri869 

Hi Mike,

You will have no issues upgrading to a 6600 crankset. I am currently running a 6600 crankset with 8-speed in the rear and friction shifting. Your current shifters will work fine with it. Happy upgrading!

mlawranceowen

Thanks a lot. Do you have an 8 speed chain or did you have to go up to a 9/10?

morri869 

You want to go with the chain that fits the rear cassette. I am using an 8-speed chain. I believe 7 and 8-speed clusters have the same cog spacing so you should also go with an 8-speed chain.

icemilkcoffee 

The problem is the RSX group uses STI shifting. The 8 speed crankset, although using the same width chain as the 7 speed, has different chain ring spacing than the 7 speed crankset if I recall. Furthermore the Ultegra 6600 crank is meant for a 10 speed drivetrain!

To the OP- to the best of my knowledge, there is no Hollowtech II crankset available for that 7 speed drivetrain. You could try a Claris crankset meant for an 8 speed drivetrain. You need to swap out the left brifter though to get the correct click spacing.

mlawranceowen

So you think it unlikely that the 6600 would work with my current 7 speed then?

icemilkcoffee 

In general you want to keep 7 speed drivetrains with 7 speed components and 8 speed drivetrain with 8 speed components, etc. Some people successfully mix 7 speed with 8 speed components etc, but mixing 7s with 10s seems to be pushing your luck too far.

RiddleOfSteel

Using a 6600 crankset with an 8-speed chain should be absolutely fine. Sure, the slightly wider 6/7/8-speed chain (over a 10-speed chain) may necessitate trimming the FD sooner and/or hopping onto the big ring sooner (chain rubbing against the inside of the big ring), but that's about it.

If the Sugino crankset is original to the Lemond, then I'd wager, as it was made in 1997, that it would work just fine with any number of 7- or 8-speed systems.

A 7800 and 6700 crankset both have ~7.5mm chain ring spacing (center to center). I measured my Dura-Ace 7402 crankset with no discernible deviation from that 7.5mm number. I've measured chain ring mounting flange widths as well, with nothing much different at all. Chain ring design can affect shifting performance, sure, but apart from that it's not going to matter.

I've run 10-speed chains on that 7402 crankset and...wait, I still do. On 2x10 setups, the narrower 10-speed chain would sometimes fall in between the big and little rings. That has yet to happen on my 3x10 setup using a newer ramped/pinned/gated version of the 7400 rings (when they went to the 7410 era and 8-speed STI shifting). A thicker chain will never have that problem.

Mix and match as you want. The 7-10-speed (and up) era stuff is all pretty forgiving save for a couple of exceptions when working within a specific company's offerings. There should be no 'click spacing' concerns as Shimano STI setups aren't super finicky in a 2x system. Slight cable tension adjustments go a long way to making easy work of things. 3x Shimano STI systems, however, are or can be finicky, even at the Dura-Ace level. Ask me how I know.

Dfrost 

I just measured chain ring spacing on the four cranksets installed on the household bikes: Shimano FC-6800 (11-speed Ultegra) with Shimano 4-bolt rings, Sugino XD600 with a variety of ring brands, Sugino AT, and Specialized “flag”. The last three are 8-speed setups all 110-74, the last two both use TA “9/10 speed rings”.

It’s not an easy measurement with installed cranks, but I could not find any consistent difference between them that would disagree with RiddleOfSteel ’s more accurate 7.5mm number above. If anything, the 11-speed might have been a touch wider, offset by the sloped inner face on the big ring.

This confirms to me that “N-speed” cranksets (insert any number for N, probably 5 and up) is largely marketing hoohah intended to separate you from your upgrade money. I’m not a fan of outboard bearing BB’s, either. Fixed something that wasn’t broken!

Cog spacing, however, has changed for Shimano: 5.0mm for 7-speed (and Campy 8-speed), 4.8mm for 8-speed, and I can’t remember after that (ask Sheldon Brown if you must know). Chain outside width has also changed to go along with the tighter-cog spacing. My several beloved Sachs Ergo shifters, apparently from both eras, certainly prefer different cog spacing. The Marinoni is lovely with 5.0mm, the Miyata shifts perfectly with 4.8mm, but they don’t like to use the other’s cassette. Good thing I have plenty of cog spacers for my custom 8-speed cassettes made from loose cogs.

RiddleOfSteel

Just so we're all clear on technology and terminology: Hollowtech I (the first kind) was Octalink with inboard bearings. 5500, 6500, 7700 for road. Hollowtech II is the outboard bearing kind. 5600, 6600, 7800 (first gen 10-speed) were all the first recipients of it. Shimano remains in this Hollowtech II era with its 24mm spindles, up to R9100 in Dura-Ace form and stretching all the way down the line to R2000 in Claris form. They work great and are easy to install. The BBs are easy to source online, Italian threading included. It's around $20.

icemilkcoffee 

I stand corrected gentlemen! And I should have known better because I happen to have a '96 Lemond with the exact same 7 speed RSX group as the OP, and a 10 speed 5700 Hollowtech II cranks on my parts bike!

Fivethumbs

Do like what i did. Put 7/8 speed chain rings on the 10 speed crank. The spider width is the same. The 9/10 speed chain rings have the teeth offset towards the center.