jssf

Sorry if this belongs in Vintage..


Hi All

About 5 years ago I took on my first bike project: taking the Miami Vice Dave Scott down to the bearings, cleaning and building it back up. I learned a lot along the way and had a ton of fun. I'm not a serious cyclist, but I do like to deep dive into hobbies (bike maintenance in this case). I kept it mostly stock except for tires and changing to city (upright) bars as my back doesn't like drops at all. With that came brake levers too, obviously.


Unfortunately, I've forgotten a great deal about that effort, but I do have a vision of what I'd like to do next. The big thing I'm concerned about it making sure any parts I buy are compatible with the current frame.


I'd like to try to turn it into a 1x and maybe swap in some new wheels. I'm not overly concerned with obsessing over covering gear ratios/gaps. As I say, I'm a casual cyclist and my biking is mostly consistent: slow speeds, residential flat streets. I'm just having fun making this an evolving project.


I'm open to replacing the bottom bracket and actually want to change the crank arms. Would love to keep it all below $500.


So, here's what stuff I need:

BB (I assume? Unless you have a crankset recommendation that works. I have a square taper 68x113mm there now)

crankset, 1x narrow-wide chainring dealio that more or less mimics the size of the small Biopace ring

cassette/freewheel

I would guess from the beginnings of research I've done so far I might need something that changes the position of the rear derailleur?

wheels (for 700x25 gatorskins), this is decidedly optional, but would enjoy it for aesthetic reasons and the delusion that doing so would "feel" faster.

If you have a good recommendation for appropriate levers that fit 23.8mm bars (other than the cheapo Velo city ones), I'd love to hear


Thank you for reading this far!

bluehills3149

Although I have this same frame with a similar conversion (flat bars, new wheels with cassette) there is nothing special about this frame and it takes the same parts as most other steel frames from this era and the parts are still easy to get and cheap.
But I'm not sure what you want to change everything as that bike's parts (Shimano 105 6spd?) are very good, even today. The wheels (Araya?) are also decent wheels so unless they are shot, I would just keep them. If the gearing is not not "easy" enough, get a new freewheel with lower gearing (14-28 perhaps), new chain and if you want to convert to 1x then remove the large chainring and mount the small ring on the outside tabs of the crank (or get a new 39tooth chainring if you want to ditch biopace). To do this you will need to grind down the 5 chainring bolts or get new shorter ones. A new shorter bottom bracket (probably 68x107) will bring the chainline back to center.
For brake levers, Shimano BL-R550 Road Brake Levers are nice and come with cables and come in black or silver. If the brake calipers are single-pivot, putting more modern dual-pivot one (on the front at least) will greatly improve braking. Look for Shimano 105 br-5500 or Ultegra 6500 brake calipers on Ebay.

jssf

I totally get that it's a pretty pointless exercise. But part of this is the journey, to be the one responsible for evolving the bike, to learn along the way and complete a task. Even if it's unnecessary.

70sSanO

This is pretty easy and makes a lot of sense. Here is what I would do...

First thing you need to do is cold set your frame to fit a 130mm dropout width. This is the easiest way to get a wheelset that lets you run a 1x with enough range. Despite you not caring about ratios or gaps, since it is a 1x, it will make the bike more useful overall.

Any decent 8-10 speed freehub wheelset will handle a 25c wide tire. There is nothing special about tire widths, especially for the riding you are doing.

You can hunt for older brake levers or shifters, but if you go to a Claris 8 speed setup, you can get the right shifter and brake levers for a flat handle bike that will work with your brakes.

The bottom bracket is a little tricky, as you might want to go with a longer spindle than 113mm for a 1x with a 130mm dropout width. Hopefully someone will have a knowledgeable suggestion that will put your inner, and only, chainring in the best chainline position. You want it to line up in the center of your cassette. As an example, your DS is going to be 2mm further out and your inner chainring needs to go out 2.5mm; and an 8 speed cassette is 35.4mm wide and a 6 speed freewheel is 29.5mm wide.

Personally, I would run a 39t to an 11-34 8 speed cassette so I could fully utilize a 1x anywhere. You will need to get a rear derailleur that can handle a 34t max cog.

Then just find mountain bike handlebars, maybe around 600mm, a rise quill stem, or a quill steerer extender and and threadless type stem.

Put it all together and go ride.

John

dedhed

https://www.bikeforums.net/classic-v...i-s-ergos.html

grayEZrider

I upgraded my '84 Ironman to full Ultegra (except tor an FSA compact crank) and did no frame adjustments. Just removed a spacer on the cassette side of the axel and both fit and clearance were OK.

texaspandj

Uhhh, that's a '86 Ironman.

ramzilla

Yeah. Do this:

bluehills3149

Note the OP wants a 1x flat bar conversion - not STI.

Here is a pic of a bike I converted from 12 spd (2x6) to a cassette based 1x 7spd with new cassette based wheels. Note small chainring has been moved to outer position. Shifters are Shimano downtube 7spd (right side only). Bars are 75mm riser with Shimano BR500 levers.



here is another I did with 2x9spd using thumb shifters (Deore XT) but you could just omit the left shifter for 1x9 spd. Brake levers are generic but the Shimano BL-550 would work too. Note you need Shift-barrel stops to replace the old downtube levers. The thumb shifters are definitely easier to ride with as the shifter is right there and thumb shifters for 8,9 or 10 spd are easy and fairly cheap - just use a MTB right side shifter (the left side can be finicky anyway when used on a road bike). Keep your old rear derailleur as is.



And here is my Centurion with flat bars and 2x9 spd with downtube shifters. I would not recommend this as downtube shifters above 8 spd are not common and so are expensive (~$100).

grayEZrider

I also have an '86 Lemans. But I agree the dual grey/silver paint job seems to be '86. I always assumed it was an '84 frame left over and painted later. I will check both in the morning. Maybe I've got my records on the dates crossed up.?

ramzilla

Suntour thumb shifters

jssf

This one is a beauty. Nice job. I'm going for something a little different but I love it.

grayEZrider

You're right. SNs show the Ironman to be an '86 and the Lemans to be an '87. I got both numbers wrong. Now if I can figure out how to change them on the listing at the left. I do remember it was on a new years day that I got the Ironman!

jssf

Not necessarily getting these specific components, but I want to verify I'm looking at the right specs/data when considering stuff.
Because these cranks are also JIS, I could potentially mount to the existing BB?
https://www.fullcyclebikes.com/produc...t-263048-1.htm

And because this is a 110 BCD chainring, I could potentially mount it to the crank arms?
https://www.wolftoothcomponents.com/c...14782347083811
Thanks!