Posted this in C&V because it's an older bike but it's a general question so maybe it goes better here. (admins, feel free to delete either of these if they're in the wrong place)
Browsing Marketplace I see this old Bridgestone BB-1for a decent price. Says it's 17" frame. Seems they use inches for MTB sizing and it always confuses me. This bike looks fairly small right? Looking to build out something new for the wife who's about 5'3" with shorter legs. It has 26" wheels. Getting confusing info on 17" sized bikes. Any thoughts?

Not quite sure what you wish to be discussed. However the frame does look quite small. Maybe even smaller than described, though the downward angle and distance of the camera certainly doesn't help the perspective. The main clue visually when other info is lacking that most bikes are small is the very short headtube.

If you are buying it just for the frame and fork at a very low price, then your spouse might have a nice bike to ride when you get it built out with newer components and a proper saddle and bars.

yeah, just looking to get some opinions on the size. Someone mentioned in the other thread that Bridgestone uses CM not inches for their sizing so not sure where this person is getting the size. According to charts 17" should be a medium to large bike, this clearly is not. Looking at the frame compared to the 26" wheels. According to Bridgestone catalog I think it's either a 42, 46 or at most a 50.

And yeah, would definitely change out the saddle and bars.

A 17" 90s MTB will be pretty big for someone 5'3. Not for sure insurmountable, but 50/50 as to making it fit well.
The camera angle makes that bike look small. Who knows if it was measured correctly.

looks like it would be fine for a 5'3" rider. a 17" would be around a 43cm bike.

fYeah, just did the conversion actually. Here's another pic just in case. Not much better but it really looks like a small frame.

You can always ask the seller to verify how they measured it. Nor do I know how Bridgestone might have measured it. Sometimes mfrs. did it differently than the expected BB center to top of seat tube. If Bridgestone measured to center line of the top tube where it intersects the seat tube then maybe it's a 42 cm.

Looking as a 1992 catalog, that seems like a pretty heavy frame. Though it say Frame Weight, I think they meant bike weight, 29.8 lbs.

It'll be okay for riding on flats or for other short leisurely rides. But if you two are wanting to ride for serious fitness type riding and will be in rolling or hilly terrain, then you'll need to also get a heavy bike to handicap yourself so y'all can still be together at the end of the ride.

Old School MTB bikes are way different from the current MTB offerings and the sizing is quite different. A Modern 17" would be quite a bit larger than old school 17".
Visually, aside from headtube, the other thing which can be used for approximation is comparing the crank length to the seat tube. This seat tube appears to be approx 2x+ the length of the crank Length - cranks are generally a bit over 7" long ...
This looks almost identical to my wife's bike/mtb. She's 5'3 and has short legs - fits her nice. Also same era mtb and 26" and same color red. LOL!
She uses to cruise around the neighborhood... same gearing.
- "Looking to build out something new for the wife who's about 5'3" with shorter legs."
It's not a bike I would 'build out' . It's 'make it all work well' and then ride as is. WOrks well for someone who is not put off by the toptube and is not a step-thru frame.
A rear rack fits nicely.
Seeing in person is knowing.
Ride On
Yuri

Thanks all, for "build out" I'd probably just change the seat and bars. The rest of the bike looks decently solid. And she's not going to be doing a any long touring with me, just some short day rides on rail trails and maybe locally around town the the restaurants/breweries. Thanks for the input! Definitely going to reach out to the seller. I biked to work today so sadly can't take off to go check it out or pick it up.

looking at the catalog that looks like a 1992 catalog for the bb1 and 42 and 43L were the small sizes.

A 43cm road bike would be fine for a small rider. A 17” mountain bike isn’t the same as a 43cm road bike. It’s actually designed for someone who rides a 52cm road bike which is way to big for someone 5’3” tall. The bottom bracket is taller than a road bike which makes the standover a bit taller and the top tube length is way too long. A 15” mountain bike is probably too tall for someone that small. A far better choice would be a 13” mountain bike but those are very rare.

Don’t. Just don’t. As the husband of a petite woman who has fought the size wars for 40 years, I can tell you that your wife would suffer if you stuck her on that frame. It is built for someone who is 5’8” to around 5’10” tall. In other words the frame is at least one size too big and more likely 2 sizes. Ask yourself if you are willing to ride a bike that is 2 sizes too large?

Sizing for mountain bikes is 3” to 4” smaller than a road bike. The use of inches for the frame size is a hold over from the 80s when most bikes in the US (road and mountain) were sized in inches. Road converted to centimeters but mountain bikes didn’t follow. You have to do the conversion but we all carry phones that are fully capable of doing that.

For your wife’s size, a 43cm road bike (17”) would probably be the best fit. She might be able to ride a 49cm (19”) but I would suspect that is too large. Thus you should look for a 13” mountain bike if you want to convert mountain to road use. A 15” might work but I doubt it.

in the Bridgestone catalog they say the BuB the 43Lcm fits most riders 5'2 it is marketed as a city bike.

Looks like a 17 inch to me, from that period. Unless your 5'3" wife has arms like a spider monkey, it'll be too big for her as the top tube will be too long.

You need to be looking for a 15 inch frame in a MTB. Unless you find something at the high(est) end of any bike manufacturer's lineup, it'll be a very heavy bike, for its size.

If you want something vintage and a bit more nimble..then a 15" Trek 750 Multitrack might work well. With components updated (nothing crazy..just mid-level+ good components) you'll net out with a very nice handling bike at sub-25 lbs. (Someone here posted an updated Trek 750 a while back on a scale at something like 24.3 lbs...never thought a 750 could end up there..no exotic weight-weenie components on it).

For something definitely less vintage, lighter in weight, more nimble(?) and faster..look for a Trek 7.5FX 15 inch, WSD model. May or may not cost more as updating and older bike (to a level of a 7.5FX or more) can cost more than one expects..speaking from experience..

edit..regarding the 7.5FX route..you definitely need to toss the stock Hardcase tires..they ride like they are made out of beef jerky..replace them with Gravelking slicks(38mm) or Schwalbe Marathon Supremes(622 x 35 or 622 x 40)..same tires for the 750..

I'd agree with cycco's comments..a 15 inch may be a stretch for her..possible good fit with some back-swung bars, but a 13 inch is a more sure choice. They are tough to find though.

I'm re-building a Trek 7.5fx into a drop bar bike for my girlfriend right now. 17" WSD frame(2007). It has a 53cm eff-top tube and fits her well..she's 5'6".

Thanks all, glad I asked as I proved I am indeed not great with MTB sizing. She already has one bike, so nothing urgent. Just saw it listed and got the wheel turning for a new project. I'll most likely skip.

I would question that assessment. It’s hard to compare directly because Bridgestone didn’t make a 17” road bike but from the 1992 catalog the 50 cm BB-1, the standover height is 763mm while the standover for the 50 cm RB-1 road bike is 743mm. The BB-1 is 20mm taller than the corresponding road bike. The 42cm BB-1 has a standover of 694mm and a corresponding road bike would likely be 2 cm smaller than that.

The “L” model is a “ladies model” and has a diagonal top tube which makes the standover smaller. The bike partyanimal is looking at isn’t an L model.

My wife is around 5'3" and her mtn bike is a '98 Kona Lava Dome--16". The top tube of the Kona has a good amount of slope, looks much more sloped than the pic. Looks like the Bridgestone might be too large for someone 5"3".

Hybrids aren’t a bad place to look. This bike is a XS Specialized Vita. It’s a nice little bike and, with judicious used of carbon, I’ve got the weight down to around 20 lb.

DSCN1059 by Stuart Black, on Flickr

This one is a 13” Schwinn Homegrown that I recently found. I had the fork reworked to reduce the travel (and height) to 60mm from 100mm to bring the headset down.


You might also look at Specialized Myka 26. They came in a 13” size but they are a little taller in the front end to accommodate a 100mm fork.

A friend of mine (woman, 5'3") bought a 13 inch Marin Muirwoods and is (last I heard) converting it to touring use. It requires a taller seat post than stock, but the top tube is the right length for her. She did a short tour on it last weekend..haven't heard a review yet.

IMO, You are right it looks small, there is ZERO chance that bike is too big. She has short legs, so therefore a long torso. Anyway, slimmer seat and a comfort swept bar would fix that.
She's NOT that small. RUN over there and try it.
I'm 5'8" and ride 23" bikes with level toptube.