Korina

Cross-posting from the Women's Cycling forum:

I had an idle thought, that 29" wheels on a size small frame isn't the smartest idea. I'm 5'4", about average length legs, and I'm wondering if 27 1/2" wheels might make more sense, seeing as even with the sloped top tube my lady bits are touching the top tube. Here's River (aka Baby); we've known each other for two years. She's my everything bike; I commute on her, take her on fun rides (only in the 20+ miles range so far) and last night we took our first real trail ride (it was a blast!). Thoughts? Opinions?

fietsbob

In the past Woman bike company founder-designer Georgina Terry mixed wheel sizes to get the top tube length shorter without excessive toe-wheel overlap..




a set of 650B wheels* with disc brakes is certainly possible given your bike has disc brakes..

Sutherlands ; '40-584 will have a radius of 335mm with that 40mm wide tire, to compare with your wheel radius.. [D 622] r=(311 + tire width/height).
say a 40 tire thats a r=351 minus 335, that's just 16mm smaller (pedal wrenches are 15mm, so that's not much)..
the BB will be lower, and the steering trail a little bit less..



* Aka 27.5"

....

Tim_Iowa

Yes, geometry for shorter riders is one of the reasons that bikes with 27.5" wheels are gaining in popularity.

26" wheel MTBs worked great for shorter riders. 29" wheel MTBs work great for many riders, but those tall wheels can make for weird geometry on small frames.

However, although you could swap your 29" wheels for 27.5" ones, that would drop your whole frame 19 mm (assuming same tire width). Lowering your frame would improve the clearance at the top tube, but it would decrease the clearance at the crank arms and it would affect handling.

Looks like you have about 1.5" tires on your 29" wheels currently. If you went with slightly wider tires on 27.5" rims, that would lower the frame a bit -- hopefully the "just right" amount.
WTB Horizon tires are a good choice in 27.5 x 47 mm; they also offer a Byway model with a little more tread. And there are lots of choices in 2" (~50-55 mm) width for 27.5".

Next time you go to your Local Bike Shop, maybe ask if they have any MTBs with 27.5 wheels on them, and then ask nicely to see if you can swap wheels and try it out. An offering of beer to the shop may help with this request.


However, if you can't comfortably straddle the top tube on your bike as it came from the shop, then you bought a frame that is too large. And I agree that the 29" wheel size may have contributed to that size problem.

Korina

Thanks. I've seen Georgena's videos about bike design on YouTube several times; I would love to just have a smaller front wheel, but the husbeast thinks it would throw the bike's geometry off. Personally, I still think I'd just need to level the saddle and adjust the handlebars (I'm thinking I need some Jones bars), but I'm fairly ignorant of these things.

Korina

Wow, I'll have to read that a couple of times, thanks.

I REALLY need a newer pic; that was taken right after I bought it, before the rear tire self-destructed on the highway. I'm now running a pair of 38mm Specialized Hemisphere Armadillos. Two years and zero flats. I also have a different saddle, and I've tweaked the fit. Still tweaking.

Tim_Iowa

I'm a big fan of Jones bars; I have Jones Loops on two of my bikes.

There are lots of "alt" bars now, here's an article: https://www.oldglorymtb.com/round-up...ke-handlebars/

Any bar that sweeps back will affect the reach, and may require a longer stem. Your local shop should have stems to try out for size.

SkyDog75

I promise it's not just a matter of guys sticking together, but I'm with him.

If you take a look at Georgena's designs with small front wheels, you'll notice her frames have a long head tube to accommodate that small front wheel without altering rider position. (Her web site talks about rider position a little bit HERE.) Just as importantly, if you were to put a small front wheel on a bike that wasn't designed for it, you'll be altering the bike's head tube angle and trail, both of which are critical to handling.

fietsbob

both wheels down sized, your gearing becomes a little lower too.. as I said trail is shorter because the wheel is smaller, but not much.
some people go to great lengths to reduce the trail, on Francophile 650B randonneur bikes,,




Im getting a lot of pootling on my Bike Friday .... 20" wheels solve the TCO. and there is nothing cheap about them , want a high end group? just ask..

they are using a JIT build... much like ordering food at a cafe, you pick from the menu, and your order goes into the build queue.





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Kapusta

I agree with the husbeast on this one. That will definitely effect the handeling.

Regarding 29ers and smaller riders: yes there can be some geometry challenges and compromises designing a 29er for small riders, but standover hieght should not be one of them. You should be able to get a 29er with enough standover.

fietsbob

Trade it in and get a better fitting bike? Now georgina has a symmetry line of bikes, a same sized pair of wheels that are smaller.

Korina

::drools:: Sadly I have champagne tastes and a Kool-ade budget.

Korina

Thanks everyone for pointing out what I was missing about a smaller front wheel. Duh.

Retro Grouch 

I think that when you evaluate a bike you have to assess it as a whole.

I think that the most important thing is fit. Smaller bikes are smaller all over. If you start with the premise that you have to have 29" wheels, you are going to have to make some comprises in top tube length, head tube angle or toe clip overlap for the larger wheels to fit.

Korina

True. Oh, the joys of not being a man. :-\

1500SLR

I know you want to hear good news by the tone of your post. But there is a whole lot of challenges. You could put 650b wheels on and wider tyres might drop your bike down a little bit. The problem is you then have to worry about the top tube length. Can you still reach the handlebars easily? I don't know its your body. Reading thing like this when you're not in the bet of moods yourself makes it really difficult to say, but its a bag full of compromises. If you wanted to you could make the person suit the frame but its better off to start with a frame that suits the person.

On the plus side, so long as you can physically stand over the frame where a flat top tube would be you can still ride the bike without any problems.

fietsbob

A bit More .02p, sorter stem & figure 8 bend trekking bars are an easy swap... such bars have a near side, a far side and side-sides..


putting near side closer to you, far side helps you bend lower , into a headwind..

a 16mm radius, 32 diameter, difference may not be worth the bother going to 650b.






..

BlazingPedals

It is??? I thought the main reason for 650B was in converting a 700C road bike to fat tires while still being able to fiddle brakes to work. Otherwise, 559 (regular 26") wheels will be shorter still, and have many times more tire choices. The bike pictured has discs, so she's not limited to any particular size. 650B are just the fad-of-the-year because they're halfway between 559 and 622.

I'd just get a whole new bike, but that's just me.

Reynolds 

I've always thought that 29ers are better for taller people, but one of my friends just got a new Cannondale that fits her perfectly, and she's about 5' 2".

Korina

And I thought 26" wheels were out of fashion and therefore hard to get.

Ignorant question; how does wheel size affect the top tube and reach?

Tim_Iowa

Adult humans come in more than two sizes.

Although the 559/26" and 622/700c/29" wheel sizes seem eternal, there have always been alternative diameters, both smaller and in-between.
For example, Schwinn made millions of bikes with the S-7/571 and S-6/597 wheel diameters.

Most of the contributors to the recent resurrection of the old French 584/650b/27.5 rim diameter were searching for a Goldilocks "just right" wheel size, in-between 559 and 622, especially with wider tires.

There was a core group of retro-randonneur enthusiasts, trying to keep tires on their specific old rides. So, when folks like Pacenti and Petersen went looking for an in-between size (early 2000s), the Japanese companies (Mitsuboshi, Panaracer) were already producing a few 584 tires.
Pacenti keep advocating for 584 as a MTB size, since 29er wheels (with 2" tires) are too tall for extra-small frames. It grew from there, and now tons of folks are realizing that they have a use for an in-between diameter. 700-to-650-converters (like me), 27+ fat MTBs, hybrids and town bikes, e-bikes, and just mainstream bikes in smaller sizes.

I can't swear that the 584 diameter will last forever, but I believe there will always be a similar "in-between" size.


As for 584/27.5 being a "fad-of-the year" and the "many times more tire choices", that may have seemed true 5 years ago. But 27.5 is elbowing the 559/26" size out of the lineup for many bike and tire makers. For example, Schwalbe is reducing the 559 production of most of its premium tire lines. Some 559/26 tires will be in production for a long time (like Marathons, cruisers, and for cheapo and juvenile MTBs) but the quality choices in 26" are already getting thin.
Perhaps 559 will eventually die, and 571/S-7 will come back as the new hot wheel trend for 2030?


Back to the bike of the OP (@Karina), I believe 26" wheels on her frame would lower it too much.
I agree that she should consider a different bike that fits her better, and bikes designed with 26" wheels would be good candidates.

Tim_Iowa

It doesn't, directly.

But it's tough to design a bike with a short enough top tube for a small woman if the bike is designed around 29er (622 with 2" tires) wheels. By no means impossible, but the geometry gets wacky. So, a bike designed around smaller wheels can have more ideal geometry AND a shorter top tube.

Is your bike the smallest size in that model? Sometimes a smaller size is available but not in stock at the shop. Not that it would help you, but just saying that "29er wheels" and "fitting you" may not be exclusive, with the correct frame size.

For your bike, see if you can borrow some 27.5 wheels to swap in for a test ride?

Aubergine 

I would try to find a set of 650b wheels and test them out. That is the best way to see if they work for you.

Korina

My baby is this, a 2016 Liv Rove Disc Lite, in size small. It does come in XS, but I thought that would be too small. I wanted a rugged, do-everything bike and I didn't have a ton of money. The Giant won out over the Specialized Vita by a nose. I've learned a lot in the last two years, and I still think I'd go with the Giant. Probably.

Tim_Iowa

Unfortunately, I think that's the crux of the problem. You say to yourself "At 5'4", I don't consider myself "extra-small"."
But bike sizes are designed around dudes, even though women are shorter on average. Even Liv, Giant's women-centric subdivision, uses the same notional sizes as their men's bikes.
I wish they would just use an actual measurement, like inches or cm.

Otherwise, I like that bike. Specifically, I like that you chose the rigid fork instead of suspension. The suspension forks on budget bikes are really heavy and poor-performing. You saved a couple pounds with the rigid fork.

Korina

Even then I knew better than to get shocks. Annoyingly, after 2016 Giant started putting shocks on all their Roves. WTH?

And yes, I've noticed that "unisex" = "men's". By the Great Bird of the Galaxy, I need a Georgena Terry bike. Someday, when I win the lottery.