My First Bike... Sizing Confusion!

RobynMcMillan
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Joined: Thu Jul 12, 2018 6:15 pm

My First Bike... Sizing Confusion!

Postby RobynMcMillan » Thu Jul 12, 2018 6:27 pm

Hello there, I am wanting to purchase a bike online. This will be my first bike since childhood. I am after a vintage style with a basket. I am 151cm tall and I measured my inseam to be 68cm. I am seeing conflicting things about the correct size. I have seen on the Reid site that I need the Small frame which is 46cm frame (18 inch) but on the Progear site I was recommended the 13-15 inch frames for the vintage line and 20inch for the tricycle style which I was also looking at. I'm thoroughly confused but would really like to make a purchase during these sales. Please, any advice for me would be greatly appreciated. Thank you!

Link to the Reid site: https://www.reidcycles.com.au/bicycle-size-guide

uart
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Location: Newcastle

Re: My First Bike... Sizing Confusion!

Postby uart » Thu Jul 12, 2018 10:56 pm

Hi Robyn. If (as I think it is) the "size" is just the length of the seat tube then it really doesn't tell you very much about the fit. Not unless you have the full geometry specifications as well.

Look at the pictures of the Reid vintage ladies bikes here : https://www.reidcycles.com.au/bikes/lad ... bikes.html
and compare with the Progear ones here: https://www.progearbikes.com.au/collections/vintage

Notice that the seat tube geometry is quite different. The seat tube on the Reid extends all the way to the height of the wheel (or even a bit higher), whereas the Progear seat tube length is much shorter. In other words, the 15" Progear frame with a longer seat post may be the same fit as the 18" Reid with a shorter seat post.

The best bet would be to try them out. Sit on them in the shop and see how they feel.

As a rough guide though, with 68cm inseam your ideal length from crank spindle to saddle top is about 60cm. Take off about 5 to 6 cm for the saddle (rail to saddle top height for ladies saddle) and a 46cm frame should leave you with about 8 to 9 cm of seat post exposed.

The Progear bikes are just designed so the the seat tube stops sooner, and you just need a longer seat post to achieve the same fit.

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MattyK
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Re: My First Bike... Sizing Confusion!

Postby MattyK » Fri Jul 13, 2018 8:54 am

At 151 cm you might be better on a 24" (wheel size) bike
e.g.: https://www.reidcycles.com.au/ladies-pe ... ge-24.html

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Thoglette
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Re: My First Bike... Sizing Confusion!

Postby Thoglette » Fri Jul 13, 2018 11:47 am

MattyK wrote:At 151 cm you might be better on a 24" (wheel size) bike
e.g.: https://www.reidcycles.com.au/ladies-pe ... ge-24.html

+1

Particularly with a 68cm inseam.

E.g. Rivendell would recommend only one of their 26" bikes (the Clem-L) and again only because of the length of seat post. (Rivendell sensibly change wheel sizes as the frames get bigger/smaller but currently don't do a 24" bike)
Stop handing them the stick! - Dave Moulton
"People are worthy of respect, ideas are not." Peter Ellerton, UQ

RobynMcMillan
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Joined: Thu Jul 12, 2018 6:15 pm

Re: My First Bike... Sizing Confusion!

Postby RobynMcMillan » Fri Jul 13, 2018 6:49 pm

Thank you so much for your responses, it is muchly appreciated!

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