Vintage_Cyclist

You'd have to physically modify the mounts, as shown in this thread. Modification: Old style Shimano downtube shifter mounts to later style - Bike Forums

johnlink

Thank you for this information. I'm going to write to the seller and ask that he cancel the sale.

johnlink

The seller has graciously cancelled the sale.

johnlink

I presume the seller will relist the item so you'll have a chance to bid.

texaspandj

I would've already had it had it been a 54 or 52cm.

RobbieTunes

Not at all. They'll work fine. You'll need the 4.5mm bolts instead of 5mm, and I'd suggest something between the backing plate and the frame, because the convexity of the frame tube and the tightness of the bolt is all that holds the shifter plate from turning on the frame. If you file the notch into the backing plates, they work fine. Just take your time and avoid an ill fit.

Your luck will be better with cable stops, which simply bolt on and don't have any torque like indexed shifters might. I've managed both on those frames, with no ill effects. Just be sure to do it right, that's all.

If I wasn't moving, I'd be all over that '85. One of my favorites. I had the dark red one, beat to death, so I had to powdercoat it. I'd love me the grey ghost, and I have a pair of GPX groups/wheels I could slide right into place...

canklecat

Update since my 10/2/17 post...
Note: The following may be of interest only to Ironman owners with the Suntour GPX group. For anyone else these posts probably seem to belabor the issue.

I've ridden the '89 Ironman Expert with draggy drivetrain several times this month after some tweaks, around 100 miles in various conditions. Still not pleased with the drag. It's a bit lighter but some modifications resulted in too many chain drops with front derailleur shifts.

In the order of recent mods and tweaks:

1. I added an inch to the chain, which helped a bit.
2. I replaced the original Suntour 13-24 freewheel with a SunRace 13-25.
3. I replaced the original Suntour 42T inner chainring with a Vuelta SE Plus 39T.
4. I scooted the rear wheel forward a bit, from the rearmost position to as far forward as it'll go while still being safely retained in the dropouts. A difference of 1/4" at most.

The combination of gear mods and adjustment tweaks did loosen the drivetrain tension a bit, but still feels draggy. My times are no better over short segments or long rides. And the switch from a 42/24 to 39/25 gear hasn't helped much with climbing. I may be doing a bit less rocking and my legs may be very slightly less dead at the crest, but checking my times there are no measurable improvements and in some cases I'm slower. Part of the problem is that this is where the maximum drivetrain drag occurs -- in the small chainring and big rear cog. I'm burning power just trying to overcome drivetrain inefficiency.

And now the chain is dropping too often on front derailleur shifts. Adding slop to the chain through various mods and tweaks didn't solve the problem. I'll make a few more adjustments to the derailleur position and limit screws but it won't fix the draggy drivetrain issue.

Also, I don't like the gearing steps with the 39/52 chainring and 13-25 SunRace freewheel. Too much double shifting of both shifters to find the sweet spot, which hinders momentum on roller coaster hills. The original 42/52 chainring combo with the SunRace 13-25 freewheel felt pretty good, although it was a tougher grind on steep hills with dead legs. But I'm not sure the combination of the 39T chainring and 25T big cog is enough advantage to offset the awkward gear spacing.

I'll try putting back on the original Suntour 13-24 freewheel and see how it feels with the 39/52 chainring. The Suntour freewheel has tighter spacing, which may work out with the 39T chainring. But there will still be a challenge to reducing chain drops with that bigger jump between the 39 and 52 chainrings.

The only reason this matters, beyond being a bit of a perfectionist, is because I'd like to participate in local B group club rides (I'm a long way from A group speed), which average 16 mph over 50 miles with a single rest break (that's about the limit of my ability). And I don't want to hinder the group with mechanical issues such as chain drops and fumbling for the right gear. I'd be the only rider on an older road bike with downtube shifters, and I don't want the bike to become an issue.

To summarize the problem:
When I flick the pedal backward by hand or foot, such as when stopped to reset the pedal where I want it for takeoff, the pedal would rotate only half a turn, and even that took unusual effort. In contrast both of my hybrids will easily spin backward a full rotation and will over-rotate if I don't stop the pedal.

The drag is from excessive tension in the rear derailleur cage pivot spring. I've eliminated every other possibility: chain, bottom bracket, derailleur alignment, jockey wheels, etc.

I've already cleaned and regreased everything. There's no provision for modifying spring tension -- no choices of spring retention holes/slots -- although a replacement spring might work. The effect is like running a bottle generator on the tire, or a rubbing brake pad. It's robbing me of a few watts. I wouldn't worry about it with my errand bike, but I'd rather not lose power to drivetrain inefficiency on the road bike. It effectively overcomes any advantages to better tires, etc.

The effect is such that the only advantage to the Ironman over my 30 lb hybrid is the lower riding position -- more aerodynamic over distance -- and a small advantage in lighter weight on hill climbs. Many of my fastest short Strava segments are still on my hybrid. However my average speed over distance (10-30 miles or more) has improved from around 13-14 mph on the hybrid to 15-16 mph on the Ironman. But part of that is also due to focusing on high intensity interval training over the summer, and I'd have expected more results after four months of that. I'm plateaued at 16 mph average over distance and haven't improved. I'm at the point where the drivetrain drag is more a factor than the meatsack engine.

Anyway, I'm at the point where it probably makes better sense to replace the Suntour GPX rear derailleur. I'm not sure whether an inexpensive Shimano long cage derailleur would be suitable, at least with friction shifting, while I'm sorting out the drivetrain issue.

If replacement cage pivot springs were readily available in different tensions for the GPX, sure, I'd try that first. But in my area it's more cost effective to scan the used ads for an entire bike to scavenge for components and parts, than to buy individual good quality components or parts online.

ThermionicScott 

@canklecat, I don't have nearly the experience you folks do, but I find myself preferring a 42T over a 39T as well. You lose a low gear (half a gear?), but you have a little more room to run at the top end before you have to think about switching to the other ring.

The drivetrain drag is a bummer. I'd say that at this point, you've earned the right to drill that second hole to lighten the spring tension.

canklecat

Yeah, I might try drilling another spring retention hole for the rear derailleur cage pivot.

I'm going to try the original Suntour 13-24 freewheel with the 39T chainring, to see if I like the spacing. If not I may switch back to the original 42T chainring and the new 13-25 SunRace freewheel, which felt pretty good. The new Vuelta SE Plus 39T chainring cost only $7 via Amazon warehouse sale, so I'm not out much if I don't need it now. Might find a use for it later with another bike, since I may eventually add a touring bike to the herd.

RobbieTunes

If my GPX groups weren't intact, I'd send you an RD, but I simply can't break up the band, so to speak.

markwesti

If it were me (and please this is just me) I would restore that Ironman to close to stock as possible . I have seen a few stock restos' of these 85s' on this forum before and I really like them .
https://www.google.com/search?q=1985...VCT4kOblIJAqM:

texaspandj

No doubt that thing is sweet as it is. It's one of my favorite color schemes. I just like being contrary sometimes and putting the newest latest on the oldest Ironman is definitely putting a wrinkle in the norm. But I feel like centurion got it right with color schemes, components, and gear ratios for the Ironman line up so I totally get wanting to stay original.

canklecat

Heh! Thanks, but I can probably borrow a short cage RD from a friend locally. And I know a couple of mechanics, including one who's experienced with classic bikes. Next time I see 'em (which may be Wednesday night) I'll take the Ironman and ask 'em to check out the drivetrain and RD cage pivot tension.

And I may just buy an inexpensive Shimano Altus, Acera or Alivio RD as a backup for my hybrids (I've crashed on the drive side two or three times so eventually I may need a replacement RD). Meanwhile I can try it on the Ironman just to see how it feels. It'll probably work fine in friction mode and it'll give me an idea of whether the GPX really is the problem.

And I may even go with a 28 cog max freewheel, if I can find one with spacing I like for the original 52/42 chainring. I'm just not liking the way the shift flop-drops from the 52 to 39 chainring. I want to be worrying about the chain dropping on hill climbs in a group. It's already unnerving enough when it happens while I'm solo on a rural highway hill climb.

canklecat

Okey-dokey, I swapped the '89 Ironman Expert back to the original 13-24 Suntour freewheel, which is much better suited to the 52/39 chainring combo. The 39/24 combo gives me just enough oomph for our relatively modest climbs when my legs are dead. No weird gear spacing.

Note: I recently replaced the original 42T chainring with a new Vuelta SE Plus 39T and hated it with the 13-25 SunRace freewheel -- although I liked the SunRace 13-25 with the original 52/42 chainring. The gear spacing was all wrong with the 52/39 combo and I was double shifting constantly to stay in the zone, which meant losing momentum on hills.

If my climbing strengthens enough I may go back to the 52/42 Suntour chainring combo and the SunRace 13-25 freewheel, which worked well together. Good spacing, better for me than the 52/42 and 13-24 original. But for now the 42/25 combo doesn't give me quite enough oomph for climbs on days when my legs are dead.

Main problem switching between the freewheels is the thickness of the built in shim or spacer at the back of the freewheels. It's thinner on the Suntour, and needs the dork disc to minimize tweaking the rear derailleur barrel adjuster. The SunRace has a thicker spacer so the dork disc must be removed -- there isn't enough adjustment in the barrel adjuster to compensate.

And I repositioned the front derailleur to minimize chain drops and smooth out shifting. It's not quite perfect yet. Apparently it really needs to be at a very slight angle relative to the chainrings, rather than perfectly aligned as most tutorials recommend. Without the slight angle I need to tweak the friction shifter slightly to dial out chain rub at the extremes. So it was actually set up better when I bought it, although I don't know whether that was the factory setting or the seller's influence.

RobbieTunes

A lot of people set up their FD's visually by aligning the cages parallel to the chain rings. Most FD's have channeled and shaped inner plates, and the outer plate often has an insert in it. These two factors effectively angle the true "parallel" chain path of the FD cage. One can be well served to blink a few times, then visualize this path when aligning an FD, resulting in an angled FD cage when viewed down towards the chain rings, but fewer shifting/trim challenges once dialed in.

I came across this while setting up an Ironman for Thunder Ridge in VA. I needed a friction FD setup that allowed me to slam the L shifter fore and aft, on demand, for the rapidly changing terrain one can encounter there. One throw, no trim, either way. Through trial and aching error, I arrived at it, then I looked at the angle of the FD cage re: the chain rings and realized there is "outer parallel" and "inner parallel" on those FD's. One must also consider the chain line across the cassette, as well as the limited area of the FD cage that actually touches the chain to move it. Then it has to settle in and stay out of the way.

Of course, SRAM seems to have fixed this on theirs, and Shimano, years later, has followed suit. Go figure.

Let's just say, previously, it was in the adjustment, and now it's in the design. In the niche we are in, it's the adjustment, but we must avoid appearances and go with what our grandfathers used: practical application of common sense, by looking for the intended result and managing the device to achieve it.

Then again, I just put DA 9000 on an Ironman, and wham bam, thank you ma'am, that was good to me.

seypat

Robbie,

I was just looking at the 17lb Carbon bike again. That is such a good looking bike! Never before have I seen a wheelset and a bike frame color scheme that goes so well together.

Anyway.......As always you are giving really good advice here. I've always had good results aligning the cage plates to the opposite chainrings. (outer plate to the smallest chainring and inner plate to the big chainring)

canklecat

@RobbieTunes -- Hey, thanks for the tip! I'll definitely try that. (And thanks, @seypat as well.)

I want to use the front derailleur/shifter exactly as you've described -- for those roller coasters. That's one reason I'm so picky about gear spacing between the chainrings and freewheel. Usually it's easier to slam the front derailleur shifter back and forth with my left hand. My balance is better with my right hand on the bar, which is crucial in group rides where I don't want to wobble or drift off my line even slightly. Everyone else has brifters and they'd get impatient with that one guy who insists on old school downtube shifters if he (I) can't hold a line perfectly.

And everything was working just about perfectly before I began messing with stuff. Offhand I can't recall any chain drops before installing a new chain, then swapping in the 13-25 SunRace freewheel, then the 39T Vuelta inner chainring.

But it's just as likely to be due to some cable stretch. The bike hadn't been used much before I got it, despite the age, so effectively I was breaking it in over the summer.

Then, last week, I looked down at the front derailleur while riding and noticed the outer cage *seemed* to be slightly angled. So I "fixed" it during a rest break, aligning it according to the many tutorials. I should have left it alone and confined my tweaks to the cable and trimmers. Although it's possible switching from the original 42T inner chainring to the 39T necessitated some adjustments -- it's a pretty big drop, with a sloppy sounding clunk, compared with the 42.

Now I've got it back pretty close to where it was originally, but there's some slight rubbing in the extreme gears -- 52/13, 39/24 -- that wasn't there before. But so far the chain drop problem is fixed, so I may live with the compromise for awhile. If I have to choose, I'd rather fiddle with dialing out chain rub than the hassle of a chain drop on a climb or, worse, in a group ride.

Now I can see why some pro tour mechanics consider the front derailleur a necessary evil.

rccardr 

I've always thought, all things being equal (all things being chainline, correct chain length, FD tension, etc.) that a 52-42 chainring combo was smoother shifting than a 53-39 because of the drop difference (10 teeth vs. 14). Then I tried a compact 50-34, which is 16 teeth, and it was even better than the 52-42.

Which led me to the conclusion that the FD being used has a LOT to do with big ring friction shifting. Experimented a bunch with different Shimano FD's and believe that the geometry used on the Dura Ace 740X design (also found on 1050, 1051, 1055, 640X, 5500, 5600, 5700, 6500, 6600, 6700, 7700 and 7800) seems to do the best job. Second: Shimano 600 6207-8 FD's, which have a completely different design but are very tolerant of anything thrown at them, including triples with big rear cogs. And yeah, any of the ones mentioned work well with 6 through 10 speed applications.

Lately have been messing around with CX70 FD's, which I believe was originally a CX derailleur, and like it a bunch. Used that on the yet-to-be-revealed Merckx Century build that is likely going to Eroica CA in 2018. On a 50-34 with 12-34 cogs, it's just...perfect.

Wish I could offer some assistance on the GXP stuff, but have no data points there.

seypat

I went back and read the thread so I could get a handle on canklecat's problem. People are bringing the info! The first thing I would do is to swap out the RD to isolate the problem. Any other working RD of the general type would do. If the problem goes away then it is indeed the RD. I (I'm sure everyone does) have the same happen after I loosen the derailleur cables to do something to the drivetrain. The derailleurs tension springs return to their natural position and cause the chain to bind on the rings and the rear cogs. The RD is a lot worse. It sounds like something similar might be happening in this case, or not. You might loosen the RD cable and see if the feeling is the same but magnified. If it is, the problem has something to do with the RD moving in and out. Maybe your cable/spring does not have enough tension to hold the RD in a fixed position. It could be the shifter as well. I have a set of old Simplex barcons on one bike. Whenever I ride that bike, I have to carry a small screwdriver. One of the shifters will lose its ability to hold its position. After I tighten it up, it is good for the rest of the ride.

One other thing on derailleur adjustment: For me, it is a lot easier to initially adjust the derailleurs without the cables attached or the chain on. (especially the rear) The chain goes on last. Hopefully only minor adjustments are needed then.

RobbieTunes

I agree on the cable-less/chain-less visual setup. It's generally pretty close. More so on the RD, in my experience.


I'm seeing some redundancy here, but maybe it's just put in there twice, instead...

seypat

Dang!
Corrected.

seypat

Here is a question for the highly knowledgeable IM thread. Some the fabric covers on my saddles are starting to come unglued from the frame/base/last. I used to have a leather/upholstery customer that would repair/redo them. He now works at the upholstery shop in the sky. Can anyone recommend a modern saddle that looks/rides like the Vettas, Avocets, Kashimaxes, etc. of yesteryear? Thanks in advance.

norcalmike

ive bought a few NOS Vetta and Avocet saddles off the Bay. Most the time the NOS stuff is high priced but of the 3 i bought they were all between 25 and 35 shipped.

seypat

Thanks for the info.

diomekes

Merlin Cycles has the Selle Turbo 1980 reissue on sale for less than $40 right now. I'd post a link, but I can't yet due to low post count.