burgerk84

Hi,

I have a '71 Nishiki with a stem labeled ".833". I would like to upgrade my headset and possibly my stem, and i'm guessing forks may have to be upgraded too, but I would rather not. What options do I have? I'm pretty new to bikes, so I know very little about these parts. Also, I'm on a fairly limited budget (of course).

Thanks!

rykoala

That's a "standard" 21.15mm stem. You won't need anything special for the headset, but you'll need a properly sized stem. Most are 22.2 mm.

TimJ

You're probably screwed.

I went looking in to finding a new headset for a schwinn with a .833 stem and gave up because it was like quantum mechanics, it was. I don't know if aftermarket .833 locknut headsets were ever made, and switching to a regular "1 inch" headset would require a new fork unless you're lucky enough to have a fork that isn't actually .833 inside diameter but that's very unlikely. I think it's basically all or none, and that's not the cheap way out.

TimJ

Huh? What he's saying is he has a bike with a .833 stem. He'd only have a .833 stem if the fork's inside diameter required it, and what he wants to do is upgrade the headset.

TimJ

Oh! Something I never thought of before- I suppose it might be possible to use a standard 1 inch headset and use the old forks if you just use the old .833 headset's locknut.

carpediemracing 

It's a 7/8" stem I think. I have a Schwinn like that too (exercise bike - a fixed gear spin bike). I think a BMX stem will work. Otherwise I haven't been able to find one.

If you're thinking of upgrading it might be worth it (unless you're looking to keep a classic) to simply get another bike and scavenge it.

cdr

burgerk84

Being new and all, I'm kind of confused on which parts are which on a headset (threaded) Is there a diagram I can refer to in order to reference the parts that are referenced? (that sounds funny)

This sounds like an interesting idea.

well biked

The .833" size was also used on some Schwinn road bikes through the mid-'80's. I can tell you what I know about the Schwinns I've worked on with this issue. To change out the headset, you'll need to re-use your old locknut so that it fits snugly around the .833" quill. The Schwinns I've worked on with the odd-sized stems have had ISO headsets, so other than the locknut everything about the headset is commonly available. Your Nishiki might use a JIS headset, those are available but not as common these days. Again, it will be the inside diameter of the locknut, where it fits snugly around the stem, that is odd sized. Go to Park Tool's site and check out the chart of the different headset standards to determine the type of headset your bike uses. You will probably need calipers or just take it to a bike shop to determine this.

As for the stem, unless you get a different fork, you'll probably need to stick with the .833" size. I've heard of people sanding down a standard stem to fit the .833" (21.15mm) steerer tube, but there is usually a disclaimer stating something like "I'll never try that again!" 1.05mm may not sound like much, but it's quite a bit of material to sand off. I had success finding a different stem for my Schwinn on ebay, most of the nice ones in .833" are SR branded, and marked .833" on the lower portion of the stem. They can sometimes be found, but they're not terribly common. There are some .833" stems still made, but the ones I've seen are for steel handlebars (22.2mm clamp diameter). The old SR's will be 25.4mm clamp diameter and can be used with most older aluminum drop-style handlebars, and some of the current Nitto drop bars are also available in the 25.4mm size if you want new bars. Good luck-

Here's the link to the Park site showing the headset standards. Scroll to the bottom for the chart: https://www.parktool.com/repair/readhowto.asp?id=68

TimJ

Alright I feel like a weirdo with 4 posts in this thread, but anyway...

Here's the deal, burgerking, your stem is .833 inches (21.5mm) most likely because the inside diameter of your fork requires it. A standard "1 inch" (22.2) stem will not fit.

You can't buy a new headset that is sized for a .833 stem. But, the only thing size-specific on the headset is the lower crown race and the top lock nut. If you found a standard 1 inch headset that had a fork crown race that fit properly on your fork (someone else would have to figure that out for you) you could use the new headset with the old headset's locknut and still use your old fork and old stem and have yourself an upgraded headset.

But if you wanted to upgrade your stem you'd either have to find an .833 stem or get a new fork and headset in order to accomodate a standard "1 inch" stem. Forks for 27" wheeled bikes are actually really easy to get. Dimension makes a chrome hi-ten fork for 27" wheels for like $30. So everything you want to do can be done, but it's just a bit complicated unless you scrap everything and buy new.

Now, for .833 stems- you can find them on ebay occasionally. I have a few myself, I've been hoarding. If what you want is something lower and longer than what you have, I probably have a stem for you. If what you want is something higher and/or shorter, good luck. BMX stems will work but who wants a clunky bmx stem with no reach on their road bike? Wald makes some really craptacular stems that will work, they're rolled chrome steel, real heavy, don't look good, and only come in a couple configurations. Other than that it's ebay hunting.

I myself have two .833 nishikis. My wife's bike has been rebuilt and is here: https://www.flickr.com/photos/timrose...7594546525758/

Nice little bike. Luckily the stem was long enough. That's a new bar, made by dimension, they sell bars that are 25.4 clamp diameter. That's another thing- your stem is probably 25.4 clamp diameter which is the mtb standard. Only a few options for drops in that dimension. The other one I have is just a frame right now, but same deal- .833.

It's a pain in the butt.

well biked

Yes, I've done that, it works fine. I've also gone the other way, using a dremel to sand out the inside diameter of a locknut meant for a .833" stem, and then used the whole headset on a bike with a 22.2mm stem/steerer-

well biked

Well, there's the question of whether it's an ISO or JIS headset. With an older Nishiki, I'd guess it might be either. But even then, the crown race size will need to be determined, it's not uncommon to have a headset that's ISO everywhere but the crown race-

well biked

The BMX stems will have a 21.15mm (.833") quill, but they'll have a 22.2mm clamp diameter, which is the size for BMX handlebars I believe. If the OP wants to use aluminum drop bars, he'll need one of the older stems with a 25.4mm clamp diameter-

gooseodyssey

I just got an old Schwinn Le Tour III and planning to convert it to single speed. Just pulled the stem out, believe it's an .833. I have another stem from an old bike that's a bit longer, but I guess it's like 1mm wider? Is that the more common size (if so what is that called)?

Going to examine the headset and clean the bearings, etc. If I decide I need to replace the headset, can I NOT buy headsets for .833 stems? If so, would I have to buy a more common headset and also replace the front forks? Just getting my head around what I might be up against during this conversion! Cheers

Schweinhund

There's old American .833, aka 21.1 (Schwinn Murray, Huffy, BMX) and the European standard. 22,2
Legacy BMX is going to be your best bet.

mpetry912 

0.833 X 25.4 = 21.58 mm

I would certainly try and see if a French sized stem (22.0 mm) would fit.

at least as a 1st step - rather than "upgrade your fork"

/markp

kommisar

I have a bike with a .833 stem. I eventually got a .833 threaded to threadless adapter and now use what ever 1 1/8 threadless stem that I want. Now I have a lot of angle and length options.

Breadfan

I have an early Nishiki and I just upgraded the stem/quill and used 21.1mm. Now I can just put whatever stem on I want to.
https://www.ebay.com/itm/204207934062

kommisar

Here is an alloy .833 adapter:

https://www.ebay.com/itm/321296124414

dedhed

13 year old thread I'm pretty sure it got figured out

kommisar

Another user piggybacked a couple of days ago on the old thread with essentially the same question as the OP, so new answers are timely.

bikemig 

This is a neat solution.

gooseodyssey

Thanks guys. I got some calipers The old stem on the Schwin is 21.1mm (is this the outdated american and bmx standard?) and the other stem I have lying around is 22.2 (is this the euro standard?).

That threadless stem adapter looks cool. Maybe I'll get one.

The other question I have is: THe Schwinn handlebars are about 24.7mm. I have some newer bars that measure 25.3mm. I can juuust about get them to fit in the Schwinn stem, with a bit of playing and force. Is that okay or am I doing something dangerous? Am I trying to match two differing standards/eras there too? Cheers

SkinGriz

I think the 24.7mm bars used to be 25.4mm and were crushed. I also think whoever crushed the 25.4 bars made the stem shrink below the 25.4 it’s supposed to be.

Here is an opinion that is of the minority on this site. I don’t like aluminum stems with one pinch bolt to hold the bars. If something is going to open and close a few times in its life, I want it to be steel. If it’s aluminum, I want a removable faceplate.

I think the usual (handlebar mount diameter) options are 22.2 (7/8”), 25.4 (1”), 26.something (spandex hamsters), and 31.something (fancy newer bikes).

gooseodyssey

Okay, so the original Schwinn stem is probably 25.4mm and it's just shrunk a bit over time? And shoving my new 25.4mm bars in there is fine?

SkinGriz

If the stem is steel I think you’re OK to just put a big flat tip in the slot and turn to open it up a bit.
If it’s aluminum I don’t know.