1983 Cannondale ST500 - Tires and ??

woof

Active Member
I came across a Craigslist ST500. Not beat by any means, but a little rough in the paint department. All original except for pedals and the rear mech. Missing the reflectors. It's red, which in this case is more like burgundy, maroon.

Going to disassemble it and refurbish it this winter. I'll add some clip ins, get some wider bars (the original brand is available in wider sizes) and may add some other small incidentals.

Looks like the hardest thing to source at the moment is proper 27" gum wall tires at a reasonable price. I am not paying 37.00 for Panaracers.

This bike is going to get used relatively seldom and almost never for fitness. For the most part I plan to make it my fishing rig and haul my Kayak behind it. (Anyone have a line on a Bugger?)

Sounds inglorious, but you should see where I kayak. Some decent tourer tires in gumwall would be nice as they will be negotiating crushed limestone/pea gravel.

Lovely bike. Already really like it. At 24 pounds it is already much lighter than many of the alternatives. Pictures forthcoming.
 

black lightning 1987

Moderator
Staff member
Nice find. I have one that's the same color. I bought it as a frameset and built it with mostly vintage SunTour components. I used tubular rims and 35? mm Tufo tires with diamond tread. I had some good pictures of it but lost them when hard drive died. As for 27" tires, there aren't many options. I put 1 3/8" Kendas on the last 27" build I did. They don't measure much more than 1 1/8" and aren't exactly supple, but they are cheap, durable, and available.
 

woof

Active Member
121141969_10221508475535071_3889046230481045220_o.jpg


The bike as found. I do now have the original Avocet touring saddle that belonged to this bike, and it is in 7/10 condition. Logos are clear and clean. Saddle was lad down on pavement along the way, but it is superficial. The seller contacted me today and gave me the original fluted, silver alloy seatpost which I very quickly traded for the one pictured. At this point the only thing not original is the rear mech and the pedals. Oh, and the Cat Eye reflectors are just plain missing. No rust anywhere, though a lot of paint chips, etc., and the brightwork is not the brightest.

My plans are to add a longer - 220mm - Nitto stem - probably in a 90mm; this will place the handlebars higher and further over the wheel - much closer to where I like them and am used to having them. It will also liven up what is a very, very neutral handling at the moment. I will probably also replace the bars with 42cm bars... I think they are currently 38cm and frankly not too terribly comfortable. I will likely replace the Saddle with a Selle San Marco Regal which has a nice vintage look to it... and add matching medium brown bar tape. Deda has a perforated that will match the saddle perfectly. That should be nicely set off by gumwalls. I'd also replace the brake hoods with the brown ones which seem plentiful and available on eBay.

I am mostly going to ride on road with some hard-packed gravel. Does it make sense to go to a 700C and perhaps a 28 or even 32mm tire? Would the brakes work as is with adjustment, or would it require additional fitting or further work? I'd love to go to 700c just because it is going to be easier to find proper touring/gravel slicks - overall the rig might be a little lighter. I could easily be convinced to leave well enough alone. These wheels seem bombproof. There is something to say about originality.

Hoping I did not overpay for this. I gave the guy $75.00 Bike is fully functional, and was tuned (well) last year. New tape on the bars, though that is no selling point really. Pretty clean, if a little chipped. I will disassemble it this winter and really clean the frame. I'll probably go ahead an polish it nicely and see if I can match the paint at all. Kind of think I won't be able to well, but maybe for some of the smaller stuff I can sand and paint. There are no dents anywhere. Overall, I could be happy with it just as it is.

Comments, feedback?
 

black lightning 1987

Moderator
Staff member
A great buy for $75. I paid twice that for a 1985 ST400 in great mechanical shape, but has paint scrapes.

I think these make great gravel bikes. Usually don't have low enough gearing but that's not too difficult to address.

You could probably go to 700C x 35 mm or possibly 38 mm depending on tire brand. Might involve a caliper change as your pads look pretty well down in the slots on the 27" rims. I would borrow a 700C front wheel and see if you can get the pads low enough if you are on the fence about changing wheel size and don't want to replace calipers.
 

woof

Active Member
Gravel bike makes sense given clearances. Just what I need for a kayak mule.

Calipers/brakes do fit on 700C, but only when the pads are adjusted all the way down - There is no more downward adjustment. That said, the pads are positioned about optimally when they are all the way down. So 700C is possible without a lot of additional work it would seem. The rims have to be 126mm, so a bit older. Interesting set here... campy hubs laced to a 700C close equivalence of the original rims.

https://www.ebay.com/itm/Campagnolo...737727?hash=item3dace5aaff:g:cNEAAOSwTNFfgRmk

That's likely the last thing I will do, so I'll think about this for a while. In the meantime,
 

woof

Active Member
Those Record/Wolber wheels would do the job nicely but I think they are a bit overpriced.

Yep. Let em go for that reason. Will keep watching.

Have some other things I want to do first really. An idea where to source the braze on cable guides that would be needed if going with bar end shifters? Eventaully a whole series of Cannondales employed these, but I never see them come up for sale anywhere. Do I need flat-mount of will the concave do?
 

black lightning 1987

Moderator
Staff member
That's a good question. I have 7 speed Shimano bar end shifters on my 1985 ST400 but I don't remember what I used for down tube cable adjusters. I'm sure that they aren't anything Cannondale specific. I am guessing that they are standard Shimano. I believe the Shimano ones are made with the inner surfaces flattened off so that they will mount on either round steel down tubes or the flat shifter bosses that Cannondale used. I will try to remember to check but don't hesitate to remind me.
 

woof

Active Member
Yep, those looks good. There seem also to be plenty of Shimano STI cable guides that have the flat back as well. I probably will go with a pair of the flat-backed ones. They are pretty reasonable. In looking at the Bar End shifter, should I stick with the 6/7 Suntour or is it worth looking at the SHimanos as well. Typically the shimano go a little higher, perhaps as much as ten gears... any issues getting these to work with a six-speed drivetrain?
 

black lightning 1987

Moderator
Staff member
Generally speaking, I think it would be cheaper to go with Shimano for a bar end indexed shifter build. It's probably best to stick with 7 speed unless your rear dropout width is at least 128 mm. To go to 8/9/10 you would need a 130 mm rear hub and it's not recommended to spread 126 mm spaced aluminum frames to 130. You would also likely need to change/modify the rear hub to go beyond 7 speed. There are lots of things to consider but let's start with the dropout spacing.
 

woof

Active Member
Change of plans really. I do not think I am going to go with bar ends. It turns out I do not mind down-tube shifters at all. Probably because I put 15K on a Peugeot in my teen years. If I do this right, I should be able to convert to indexed bar ends in the final analysis.

I am thinking about doing an Accushift rear derailleur.

I think you found in the past here: http://community.vintagecannondale.com/threads/84-st500-rear-derailleur-what-model-works-well.187/ that there were some issues with the 30T and might have been additional small cog issues.

While the technical bulletins for Suntour http://www.yellowjersey.org/Suntour21.pdf seem to imply that any rear will work with any regular freewheel assuming correct shifters, I have seen in multiple places that the RD-4050 and some others are really only index compatible to 24T. See: http://velobase.com/ViewComponent.aspx?ID=bb2c5b9b-740a-4b8b-8b18-3c604d8d6114&Enum=108

The seller's description here is helpful for this 4050: https://www.ebay.com/itm/New-Old-St...271361?hash=item5b3997c401:g:1mcAAOSwNOFc-nbN

  • Index shifting compatibility: 6/7 speed (with Suntour branded or compatible index shifters and freewheels/cassettes)
  • Friction shifting compatibility: Several options (most 5/6/7 speed freewheels/cassettes)
  • Front capacity: Double chainring w/14T (max) difference
  • Rear capacity: Index/Friction...24T/28T
  • Total capacity: 28T (combined front chainring and rear sprocket difference...also known as chain wrap)
  • Weight: 257 grams (per our digital postal scale)
So I am a little confused between the technical bulleting from Suntour and all of the collateral that seems to indicate 24T for the 4050 and similar. In the end, I actually believe the limit of 24T, and sort of think that is why you saw issues mounting the 30 tooth ring. I am thinking that a Long Cage is going to be required. Still, hard to find... perhaps a Suntour XC long cage? Here is the description:

  • Index shifting compatibility: 6/7 speed (with Suntour branded or compatible index shifters and freewheel/cassette)
  • Friction shifting compatibility: Several options (most 5/6/7 speed freewheels/cassettes)
  • Front capacity: Triple chainring w/20T (max) difference
  • Rear sprocket: 32T (max size)
  • Total capacity: 40T (combined front chainring and rear sprocket difference...also known as chain wrap
The long cage does seem to get me in the ballpark. Some math... the ST500 has a triple on the front... 48/44/28; the rear is a 13-30T

For total Capacity - Chain Wrap I think this is (48-28 = 20) + (30-13 = 17) = 37T

The example of XC Long Cage above fits perfectly... Triple with max of 20T difference in the front (48-28) with less than 40T total capacity (actually 37T). The FD-4050 seems to be short cage. i do not see a long cage option for that Mech. I am wondering if a SUNTOUR A-2000 LONG CAGE might not work... Or just cut and run and get one of the long cage mountain mechs that support Accushift. It can't be worse than what is on the bike now.

Thoughts?
 

black lightning 1987

Moderator
Staff member
I think the 4050 was rated for 24T in index mode. You might push it to 26 large cog but it's not going to have the total capacity you need to run a triple. I have several of them on the shelf and they are all short cage.

Are you sticking with 6 speed? There are a number of long cage derailleurs that are 6/7 speed compatible: XCT, XCM, XCE, X-1, XCD, XC Comp, XC Pro. Those are all Accushift Plus models. I also like the earlier XC Sport, which I believe was a 6 speed Accushift model. It looks like a long cage version of the Sprint 9000.

http://velobase.com/ViewComponent.aspx?ID=E0FA65EA-0433-4725-921F-1CF39F2B9F7B&Enum=108&AbsPos=0

I might be able to spare an XCD. There were two cage lengths, with total capacity of 34 and 40 teeth. Not sure which I have. You can sometimes exceed total capacity by using a long enough chain to safely use the big ring and big cog, and avoiding using the small cogs when in the small ring.

http://velobase.com/ViewComponent.aspx?ID=7C2E3966-D524-41DE-BC0C-FDD9B9E561E5&Enum=108&AbsPos=22
 

black lightning 1987

Moderator
Staff member
I found a used long cage XCD. Some scuffs in the usual places on a used MTB RD but in good shape other than that. I have a can of touch up paint somewhere that would make this one look fairly presentable.
XCD 6000 long cage.jpg
 

black lightning 1987

Moderator
Staff member
I was mistaken about the long cage 4050. I'd forgotten that in addition to the road group the 4050 designation was also used for XCE. Found a NOS long cage XCE in the SunTour MTB parts box.
XCE 4050 long cage.jpg
XCE 4050 long cage.jpg
XCE 4050 long cage.jpg
XCE 4050 long cage box label.jpg
XCE 4050 long cage specs.jpg
 

woof

Active Member
Your XCD 6000 is covered in that last document as RD-XD00-GX; by capacities alone it seems compatible. My understanding is that my freewheel is a New Winner, the WP parts in that document are for Winner Pro. The AL part number is for an Alpha, which was a down- market Winner Pro. So I am not 100% sold on the compatibility with my freewheel.

That XCE 4050 is in fact basically a 4050 Long cage. It does appear to be a seven speed; Using that I assume I would need to go to a 7-speed freewheel. Not hard. Just more expense. The Suntour freewheels seem to fetch pretty high prices on eBay - or at least they are priced high.

Meanwhile... most of the forums state that Accushift gets less so - less "accu" - as time goes by, and that they are problematic at best. I can see why. There are so many limitations despite technical bulletins that state otherwise...

Honestly, I am very tempted to pick a spec in a later catalog and match it. For example, the 1987 ST600 has Shimano Deore on seven speed with SIS shifters. I can easily find these bits... you don't happen to have any of this, with a preference for seven speed?

RD - Shimano Deore MT60 Rear Derailleur Long Cage (6/7 speed)
FD - Shimano Deore FD MT60 Triple
FW - Cannot find the exact 13-30 but there is a 6 speed 14-16-18-21-24-28T There is also a Shimano MF-TZ500 7 Speed Both are screw-on type
SH - Shimano 105 Downtube Shifters - SIS Index Or Friction - SL-1050

This would give me an upgrade path to: Shimano SL-BS50 3x7 Bar-End shifters.

I think this might be a more sensible way to go... I want a little time to research these. The math looks like

(48-28 = 20) + (28-14 = 14) = 34T which seems very doable, even for a shorter cage. I'd probably still get the long cage. The only thing I am not 100% on would be the freewheel. Need to spend a little more time looking at manuals for these parts.
 

black lightning 1987

Moderator
Staff member
The 1990 XCD RD was compatible with indexed 6 or 7 speed use. The 1989 XCD 6000 was 6 speed, but I don't know for a fact that the geometry of the RD changed from 1989 to 1990. So the XCD 6000 might well work for 7 speed. Same goes for the XCE 4050: it was 6 speed when introduced but may work fine with 7 speed.

As far as freewheels go, all you have to worry about is spacing. There were regular and Ultra freewheels for both 6 and 7 speed, and Sheldon Brown's chart shows a third spacing for MicroDrive, but that may only apply to cassettes.

https://www.sheldonbrown.com/cribsheet-spacing.html

I'm using the cheap Chinese made Shimano freewheels with SunTour on a couple of bikes. They work fine, probably shift better than NOS SunTour cassettes but the cogs are much thinner, presumably softer steel, and can't be expected to last like the SunTour freewheels did. But dirt cheap and they work. I probably have a dozen of the 6 speed 13(14?)-28 freewheels on hand, less of the 7 speed ones that are roughly the same tooth range.

I would have to look around for the Shimano parts you mentioned. If you are not focused on period correctness you have a lot of leeway with Shimano. All the long cage 7-9 speed derailleurs have the same geometry, and the front derailleurs in that era need only match the chainring range and mount type.
 
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