Trail

Hi all.
I have a very nice old Trek 660 that I still ride now and then. Roughly 1989 vintage. Used to be my crit bike (many years and many pounds ago). It came with Shimano 7 speed Ultegra...I believe the 6400 series group.
I've toyed with the idea of picking up an 8 speed STI group. There are lots of Dura Ace 7402 parts out there. How difficult would the conversion be? Will the frame- rear hub spacing work to accommodate the 8 speed hub?
What other issues might I run into?

Thanks.

FYI...I still love this bike. Looks absolutely cool. Put a carbon fork on a few years ago and the rest is pretty much stock. Steel is real!

cb400bill

Thread moved from Mechanics to Classic & Vintage.

Duplicate threads merged.

easyupbug 

The '89 would be an Ultegra 600 2x7 so you may or will have to open up the rear to accept 130mm spacing. Lots of good info on "Cold Setting" on this site which I highly recommend even if your rear is a 128mm or so and you can stuff it in, cold setting is commonly done with great success.

Bianchigirll 

I am not a big fan of brifters. I have two bikes with them and if I could find an affordable SuperBee group I'd take them off one of the bikes.

Your best bet id to just find a good donor bike. Something that looks little used in a super big or small frame. Strip all the parts and rebuild your Trek

One often over look advantage to DT shifters is being able to use friction in a pinch. If heaven forbid you crash and bend something you can usually ride home in friction mode.

SJX426 

I have a full 720x group that came on my Pinarello. It is downtube sti, however. It is a great group to use. When shopping be careful when buying hubs. The cones are not available so if they are pitted, you are out of luck unless you get a second hub that has good cones. The second thing to watch for is the FD adjustment screw retainer. They fail and I haven't even looked for that part.
I am in the process of retiring my group because an Italian bike needs Italian parts. I may put it on another bike. I have thought about getting brifters but they are hard to find at a decent price and look good. Lots of road rash examples on the bay. I also don't care for the cable coming out the side of the brifter. Just a personal thing.
The replacement for the DA set is Campagnolo Chorus with Ergos. Like it just fine. I still am running the hubs while I build up new wheels. The spacing is different between Shimano and Campagnolo on 8 speeds. I found sprocket spacers that make up the difference that did the trick for me.
I happen to really like 8V drive train. I am building a 10 speed Record for the De Rosa. Should be interesting.

crank_addict

Its been awhile from doing a STI dual control but why not just install the levers and try it on the current 7 speed, see if it cleanly clicks through and spacing is confirmed?

Also, Sutherlands reference manual helps if you're shopping used parts.

Seven or eight speed... hmmm. When its time to cut the cheese, an extra grating of a gear doesnt mean anything. As if anyone is so dialed into maintaining exact cadence.

Bianchigirll 

Downtube sti?

Russ Roth

You can do 8speed sti on 7sp, did that for a while with a bike since I had the 7sp cassette and only switched to 8 when the chain and cassette wore out. Never had a problem with shifting. I don't understand why people love downtube shifting and really prefer sti. Groups of 8sp ultegra and dura ace sell cheap on eBay all the time.

miroslav kadlec

For example, I have Tiagra STI for 10sp cassette 11-36 (Deore derailleur) on my steel road bike.
Well, everything is possible.

RiddleOfSteel

Ok all you "no STI" dudes! Thank you for your opinion but, to the OP:

GO FOR IT!

You don't need to cold set. Going from 126mm rear spacing (your Trek) to 130mm (8+ speed era) is nothing, and requires just a touch of prying (the dropouts) with your thumbs as you use your fingers to pop in the rear wheel.

I have found that a modern groupset and modern wheelset can do a lot to reveal the "true nature" of a steel frame in some cases. I think, since your Trek has a lot in common with more modern racing bikes due to its geometry, it's not a thematic stretch. I've been doing this sort of thing to a lot of frames, and thoroughly enjoy it. Quill stem to 1 1/8" stem conversions to run modern 31.8mm compact handlebars is another thing I've done. Di2 conversion as well.

Get in on the madness, er, fun!

miroslav kadlec

Your Davidson is 60+ cm?

dedhed

If it's an 89 that trek is almost certainly spaced at 128mm to accommodate different drivetrains in the same frame.
After modding a few 1987 & up Trek's I've never had to cold set any to install 130mm wheels.

jdawginsc 

Personally, I actually like the snug fit of 130 on a 128 spaced frame. And I second the use of an 8 speed brifter on an 7 speed cluster.

plonz 

RiddleOfSteel nails it. No need to make it a bigger deal than it needs to be. If the current hub is a Shimano 7 speed hyperglide, I’m near certain it will accept an 8 speed cassette. 130 spaced hub drops into a 126 frame with little effort.

Whit51 

Other STI options - 7 speed Shimano RSX or Microshift - if you have 7 speed on it now you would not have to get a new rear wheel and cassette. Or consider Shimano 9 speed Ultegra or 105. Requires same size hub as 8 speed and maybe easier to find. You’ll need some down tube cable guides that fit over the over the shifter bosses.. I’ve never had to cold set a 126 frame to fit a 130 hub. I resisted brifters for many years, but once I tried them I’ve installed them on most of my keeper bikes.

Trail

Ok folks...I'm going to show my ignorance here....I may have used the wrong terminology. I have 7 speed STI, downtube shifters. I want to install the 8 speed integrated with the break levers.

dedhed

You can get brand new 7 speed STI shifters if you don't want to change the wheel to accomodate the 8 speed cassette. .
https://www.amazon.com/Shimano-Tourn.../dp/B00961NHA4

https://www.microshift.com/en/product/sb-r472/

RiddleOfSteel

Thank you, sir! I know we understand the convenience and "proper-ness" of a cold set. For the first time in what seemed like forever, I slotted in a 126mm rear wheel/axle into a 126mm-spaced frame and thought, "Oh, this is what it must feel like to have things made for each other." Felt really nice! So if you wish to have things cold set, by all means. And certainly if your frame had 120mm rear spacing (like many older frames), we all would be recommending you cold set.

I should note that you'll want to take note of the type of quick release skewers your 8-10 speed wheels possess. Since many if not all modern bikes have vertical rear dropouts (as opposed to the horizontal dropouts of your frame and other steel frames of this era), a number of wheelsets went to an 'external cam' QR skewer. 'Internal cam' QR skewers have higher clamping and holding power than external cam QRs, with Shimano (add in Campagnolo) possessing the best kind. Internal cam QRs, when tightened properly, ensure the rear wheel doesn't slip in the dropout--this is not needed for bikes with modern vertical dropouts that don't require as much clamping force.In the picture below, the top QR skewer is internal and the bottom is external.

RiddleOfSteel

64cm measured center-to-top! 59cm top tube. I've seen a size larger as well for these Impulses. Superb frame with superb components.

RiddleOfSteel

There is some misuse of terminology here in the thread overall.

What you have is SIS which in Shimano land stands for Shimano Indexed Shifting. This applies to any indexed shifter Shimano has or currently makes post-1985 introduction of it on the 7400-era Dura-Ace groupset.

What you are looking to go to is a gearshift system called STI or Shimano Total Integration. This setup integrates braking and shifting into one lever mechanism. They labeled certain MTB brake/shifter combos as STI as well, though we primarily know it as road.

eom 

Do it. 126 hub running 8 of 9 on 7 like St. Sheldon said.

• 7-speed hubs only accept 7-speed cassettes --though 8 or 9 sprockets can be installed on a 7-speed hub, using 9- or 10-speed spacing. It is also possible to transplant an 8- 9- 10-speed cassette body onto most 7-speed Freehubs.

Trail

Thank you...yes. I HAVE SIS. Looking to convert to STI. (guess I had it right the first time!)

Anyone here have any experience with Microshifters? Looks like I could just keep 7 speed.

RiddleOfSteel

You did have it right the first time. Other people misspoke. Shimano did have some first generation 7-speed STI stuff (RX100 and RSX if I remember correctly), so if you can source that then you won't have to worry about changing wheels. As for Microshift, plenty of people here and elsewhere have had decent experience with them, so on the merits of compatibility and functionality/reliability, they are worth consideration. They aren't too pricey either. They are, in my eyes, ugly. That's an immediate write off for me--they look bulky, clunky, and inelegant, and I'd rather Shimano components have a Shimano shifter. New 8-speed STI shifters are the Claris line. Inexpensive, with both shift and brake cables running under the tape, the new generation look and hood shape from Shimano (aka excellent), and they employ the same 7 through 10-speed-compatible cable pull so they will work with an old 600, 105, Light Action, RX100 etc rear derailleur.

Ultimately it's up to you what you want to do--the effort you want to put into it, the money you want to spend on it. 100%. A 1989 660 was a Shimano 600 (just below Dura-Ace) equipped bike. The tubing is team issue True Temper--great stuff. It's worthy of Ultegra today, so don't feel weird considering nice parts. And actually, as lower as Claris is in the ranks, it's painted the dark grey like old 600 and has very reliable, proven mechanicals. 'Slumming it' in name only. I've been looking for a frameset to put a full new Claris or Sora groupset on it to sell, I think that much of it. You have tons of options, but it's up to you. Hard to lose any way you go. You're starting with an excellent 'core' (the frame)!

R2000 generation Shimano Claris (2x8) shifters:

Trail

FYI....I took the easy (and cheap) route and bought some micronew shifters. They haven't arrived yet, so I'll report back once they're installed.

Thanks again to everyone who responded!

Trail

wrk101

Good move. Converting to Dura Ace 7400 8 speed can be an expensive move. I've done it on several bikes, but I had to find a deal on a donor bike first. And then you have shifters that are 25 years old. Meanwhile, brand new 7 speed STI shifters can be found at reasonable prices.