jpc2001

The rear wheel on my Watergate-era Schwinn has gotten wobbly with loose spokes. The nipples are mostly frozen. I'm thinking of replacing this wheel with a new one, instead of fighting with it to save a steel single-wall which I'm told is a lowly wheel. Though it's always been good to me.

To keep the project from growing in scope, my thought is to retain the 27" / ISO 630 rim size, and keep the existing tire and brakes. A freewheel-compatible wheel would allow retaining the freewheel that's on there, too. The goal isn't to upgrade, the goal is to repair.

There are wheels on ebay with descriptions like this:


BBS PART# J59-71621



Wheel Master 27" Alloy Fixed Gear/Freewheel Whl Rr 27x1 630x14 Wei Lp18 Sl 36 Form Fx/fw Loose Sl 120mm Dti2.0sl

• 27in (ISO 630)
• RR
• 14
• B/O 10mm
• Sil NMSW
• WEI LP18
• Form TH31
• 120
• Sil
• 1s FX/FW
• RIM
• DT-2.0 SS SL
• 36H
• Dbl
• PV

That's some alphabet soup. Here's my attempt to translate this into noob-ese, please tell me if I'm understanding this wrong. I don't want to spend $80 on something that doesn't fit due to not understanding the implications of one of these specs:

• 27in (ISO 630) - Matches the existing tire, tube, brakes. I know what this means.
• RR - ReaR wheel, I guess?
• 14 - Gauge of spokes?
• B/O 10mm - Diameter of the bolt in the dropout?
• Sil NMSW - Silver color? (and NMSW is ???)
• WEI LP18 - Weinmann LP18, the model of rim
• Form TH31 - Formula TH31, the model of the hub
• 120 - Rear dropout spacing, 120mm is correct for this Schwinn
• Sil - Silver color?
• 1s FX/FW - Fixed gear or free wheel, I guess?
• RIM - Purchase includes free Research-in-Motion BlackBerry phone. No really, what does this mean?
• DT-2.0 SS SL - DT is the brand of nipples? Apparently spokes are spec'd by wire gauge ("14") but nipples are spec'd by spoke diameter ("2.0mm")? Is that right? Y'all crazy.
• 36H - There are 36 spokes. Not sure about the "H"
• Dbl - Double wall (?)
• PV - Presta valve (?)

Thanks :-)

TimothyH

NMSW usually means Non-Machined Side Wall.

In plain language, no brake track on the rim, typical of fixed gear wheels for the velodrome where brakes are not used or more recently used to describe wheels for use with disk brakes.



H typically refers to "holes."

In this case, the rim and/or hub have 32 holes.


-Tim-

jpc2001

Thanks Tim.

Good catch on NMSW. This bike has a rim brake and will need a brake track.

Phil_gretz

Your Schwinn has a 5-speed freewheel on the rear? The wheel you've shown is a track wheel, for a single speed. You might need to buy a vintage wheelset, or string a new rim (like a Sun M13) to your existing freewheel hub.

jpc2001

Yeah, it's a five speed freewheel. Not OEM, the freewheel and derailer are new ~2016, they are both SunRace parts. Not a lot of options for five speed freewheels nowadays.

It's becoming the Schwinn of Theseus. A decent bike once you replace most of it.

rosefarts

Do you have a bike shop nearby? They often have loads of low end rims just for folks who need a new one. If not, they can get you one in a few days.

They aren't expensive and the shop can confirm that you are getting the right one.

Unca_Sam

You should be able to secure a new rim and spokes to keep your hub, though it's likely going to cost more than a prebuilt wheel with appropriate spacing and freewheel hub. It will definitely cost more if you ask the lbs to build it up for you with labor cost.

Are you up for learning a new skill?

jpc2001

Minor change of subject:

The old wheel has a failure mode which is new to me. All you real mechanics may not be surprised. I was a little surprised.

This wheel has a spoke protector disk ("dork disk.") Being a '70s Schwinn, the dork disk is steel and weighs eight pounds. Its rim is dished toward the spokes, and when mounted it makes contact with the spokes. Over 45 years it wore divots into the spokes. Those divots are corroding and now the spokes are breaking right at the divots. I was mistaken that the spokes were merely loose; one was broken and two more broke easily in my hand.

So. I can probably throw spokes at this wheel and save it. They don't seem to make 120mm multi-speed hubs in the 21st century so fixing the old wheel is maybe the best bet. And I guess leave the dork disk off.

WizardOfBoz

I just went through this process.

So first, check the rim to ensure that it's not "dented" (out of round). If the rim took a curb or pothole too hard, the dent is a weak point and is hard to true out of the wheel if you relace. Once you've checked this, remove the freewheel. You may have to find a specific tool (or a vintage LBS) if the freewheel is the Normandy splined version on some Schwinns (and not the notched key) style. Once the FW is removed, I'd take out the bearings and clean and inspect the bearing races and cones. If they are in good shape then I'd save the hub and relace. After you remove the FW, you can then cut and remove the spokes and inspect the rim. Check that the rim is flat. If the rim is not dented, and flat, why not keep the vintage rim?

If you have a good hub and need a new rim, the Sun CR-18 gets some good reviews (but quality is apparently spotty). Also may want to consider a Weinmann RM-19.

I just did this for an old Schwinn superior with Weinmann rims. Kept both the hub and the rims and relaced. Measure your spokes and check length before you order new ones if you can: my rear wheel was improperly dished from the factory!

If this is too much, or if your hub bearings and/or rim is kaput you may want to get new 700c (if your brake pads are easily adjusted and long enough to handle the extr 4mm) or 27 inch rims. If you want to remain vintage and use 27 inchers, Harris has some inexpensive replacment wheels. Frankly, I spent almost as much on new front and rear spokes and nipples as the cost of these wheels, so new wheels may be cost effective. Especially so if you don't have the tools (truing stand, dishing gauge, nipple drivers, very expensive spoke nipple treatments like Spoke-Prep) to do the job. I wanted vintage, and wanted to build my own wheels after decades of riding and wrenching on bikes. So for me, the rebuild was the best path. If I just wanted a great riding bike I'd buy the new wheels in a heartbeat.

Very interesting note about the novel failure mode. I'm gonna check my old spokes for this.

On re-reading your original post, I note that you have steel rims. I'd DEFINITELY replace steel rims. And you likely have steel hubs, too. I'd just get the new prebuilt rim/hub combination. If your brakes have enough length to extend 4mm more, you could buy 700c rims ,giving you more choices for wheels, rims, and tires. If there's not 4mm of extra adjustment space I think that the Harris 27" wheels would be an excellent upgrade. There are plenty of tires available for 27" wheels.

Anybody know if the OP would need a spacer in place of the thickness of the dork disk if he installs the FW without the disk?

Gresp15C

In my view, the sidewall doesn't need to be machined if it's a silver (natural aluminum color) rim. The brakes work fine on natural aluminum, and machining simply exposes a fresh metal surface by removing a small amount of material.

I've built wheels from both Sun CR-18 and Weinmann RM-19, and was happy with both. The RM19's have lasted for well over a decade of daily commuting despite being lower tech. Braking has been fine without machined brake tracks, and in any event, whatever surface is on the sidewalls will be gone after a few hundred miles. Here's a thread comparing them:

https://www.bikeforums.net/classic-v...8-vs-rm19.html

These days if I'm putting the effort into building a wheel, I'd spend a few more bucks for the CR18s.

02Giant 

Classic 27'' x 1 1/8 - 1 1/4 Road Wheel Set

I just bought a set to install on a 79-80 Schwinn.

JohnDThompson 

Machined sidewalls are a recent fashion preference, not necessarily a requirement for braking. Machining sidewalls became common when hard-anodized rims in various colors became popular; the anodizing made for poor brake performance until the anodized wore through, and machining the sidewalls eliminated this break-in period and made for a brake track with uniform color instead of a stripe where the pads wore through the anodizing.

Prior to hard-anodized rims, no brake tracks were machined and rim brakes work just fine with those rims.

N.B. some special purpose rims lack enough sidewall for a brake pad to engage. As long as you avoid those, rim brakes will be fine regardless of machining or the lack thereof.

Homebrew01

What he said. Machined brake tracks always looked to me as though they used too much metal, so removed some.