Torn over bike sizes - please help!?

Jimbles666

Member
Hey folks

I'm doing my research on current year models, with the intention of grabbing an end of season bargain in a few months. I've not got my heart set on a specific brand. I've made a list of those I fancy and it'll be just a case of which looks the best deal. I'm not a great climber and slightly nervy descender but very quick on the flats and rolling hills and ride a sub 5 hour century if there's not too much steep stuff. So looking at more aero bikes to capitalize on my strengths.

Currently ride a 56cm 2014 Cube Agree GTC. Fits good. Thing is, although I'm average height at 5'10'' I'm not averagely proportioned, which makes sizing a bloody nightmare. I have a short 29" inseam and long torso/ arms. Ive been very close to pulling the trigger on a 2017 Ridley Noah with £800 off RRP. Their size chart suggests I would fit either a small or medium based on my height but I'd be right at the top end of small. I feel with short legs this would be the best option but don't want the reach to be too short.

When I did a sizing check for an Oreba Orca I had to increase my inseam by a cm to even get a result and then it said I should get a 49 which is just ridiculous. It just confuses the hell out of me. Any generally advice from more experienced folks would be fully appreciated.
 

vickster

Legendary Member
You should really go try the bike you're looking to bike. Presumably the Ridley still isn't inexpensive if there's £800 off

@bpsmith and @Elybazza61 are Ridley owners and might have some advice (although it still shouldn't supersede you actually test riding!)

Generally it's better to get the smaller frame if on the cusp and fettle the sizing with longer stem, layback post etc which is easier than making a too big bike smaller.

If the cube is to right size, get a piece of paper and compare the two geometries side by side
 

Spiderweb

Not So Special One
Location
North Yorkshire
Always best to sit on a bike and give it a try for correct fit. If I were you I would look at the measurements on the geometry chart for your current cube agree, you said it's a good fit so you need to make comparisons with the geometry charts of the bikes you are interested in. Top tube length in my opinion is the most important measurement.
Cube sizing was always a little on the small side, at 5' 10" with a 29" inseam I would be looking at a 54cm frame in most other brands.
 

vickster

Legendary Member
You could also phone the seller of the Ridley. If they are an established Ridley dealer, they should be able to advise. Years ago when I was buying my first roadbike, a Ridley was on the list and I seem to think they come up big comparably (as Cube come up small). I have a feeling that at 5'10 but with an inside leg of 33" or thereabouts, I was looking at a small (all my current bikes have a ~54cm TT)
 

smutchin

Cat 6 Racer
Location
The Red Enclave
I would agree with @vickster - it's easier to make a small bike fit you than one that's too big.

A good approach would be to measure the stack and reach of your existing bike (assuming your existing bike is a good fit) and check the new bike to see if it's possible to replicate those figures - the new bike won't have exactly the same frame dimensions, but you can make adjustments to stack and reach, eg by raising the bars and fitting a longer stem.

How to measure stack and reach:
https://rideonmagazine.com.au/how-to-measure-stack-and-reach/
https://www.bikeradar.com/gear/article/your-top-tube-length-is-irrelevant-50174/
 
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bpsmith

Veteran
As above, definitely need to try the bike where possible. In saying that, I was fitted for my Noah SL but ordered my Helium SL online, based on the fit of the Noah.

This chart is very useful for sizing comparison:

https://ridleybikes-ridley2.netdna-ssl.com/wp-content/uploads/2017/08/sizing-chart_280x200.pdf

As per the chart, the Noah and the Noah SL is the same frame but with different carbon layup and weight. Helium is also the same fit incidentally.

The chart shows that for your height @Jimbles666, you could ride a Small or a Medium, or squeeze onto an X-Small even. Now this may sound confusing, until you delve into the bike geometry charts as linked to already above. I don’t recommend an XS frame for you btw, but putting that out there.

For starters, the Ridley sizing is known to be 1 size lower than what you may be used to. So a Small equates to what others may call a M or a 54.

I am 175cm tall with an inseam of 82cm and so I had the choice of S or XS. I chose to go with the XS for my Noah SL. The only change being that I fitted a longer 120mm stem. I wanted the shorter head tube as I am pretty flexible and wanted to get down very low for the aero gains. Bike fits me lovely in fairness and I’ve used it for all types of riding from flat short blasts to hilly longer rides, including the Velothon twice.

When fancying the Helium SL, I looked at the charts again and decided to get a Small. The reason being that I didn’t want to get down quite so low and allow myself some breathing space on the climbs. I have a 110mm stem on the Helium SL and a 10mm spacer underneath, whereas the Noah is slammed. This bike feels really nice too, albeit different.

I have loads of seatpost showing on both models.

My opinion, based on your height and inseam, would be for you to aim for the Small. It will allow you to get the saddle in the right place with respect to the bottom bracket and you can factor in a longer stem or adjusting spacers to get the reach right. If you go with the Medium, you would also need to consider how far the seatpost can go down, as it’s an aero post and there is a cut out in the seat tube where the wheel ticks up closely. Therefore, you won’t be able to drop the seatpost extremely low in the larger frame without considering cut it perhaps.

Definitely compare the stack and reach figures as they don’t always scale evenly. Need the exact model and year of your Cube in order to help out with comparisons. Post this up and I will be happy to take a look, as will others on here.

It’s all opinion though, so try in the shop where possible.

In work now, but happy to answer any other questions later.
 
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Different manufacturers have different interpretations of a (seemingly) similar size. There are a lot of different components the size of which, relative to the other bits, can be critical. The frame size is just one component.
 

Cycleops

Legendary Member
Location
Accra, Ghana
You've had good replies on the sizing but if I could make a recommendation always buy product rather than discount. In other words buy what fits you and fits your needs rather than price.
 

bpsmith

Veteran
You've had good replies on the sizing but if I could make a recommendation always buy product rather than discount. In other words buy what fits you and fits your needs rather than price.
I would have to agree with this without question. Of course, combining the two is the real challenge. :smile:
 

bpsmith

Veteran
Just noticed the model and frame size in your first post @Jimbles666. Can’t brlueve I missed that.

Assuming that the geometry of the 2013 model matches that of the 2014 one that you have, I found the Stack to be 541mm and Reach to be 385mm on your current bike.

The Stack of the Small Noah is 542mm and Reach is 384mm.

Effective Top Tube, Head Tube and Seat Tube Angle are exactly the same. Overall wheelbase is 10mm shorter so handling should be more nimble.

Small appears pretty darn perfect, if your current bike fits correctly.

I am not affiliated in any way to Ridley or any bike shop, but I got my Helium SL from De Ver Cycles. They were great to deal with on the phone and in shipping the bike to me. They have a deal on a Noah 60 2916 model which is an Ultegra bike with 40% off at £1,749. Last one is a Small. :smile:

Not sure what your budget is, so apologies if higher than you planned.
 
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OP
Jimbles666

Jimbles666

Member
Some extremely helpful replies here people, thank you

Absolutely a good plan to compare the geometry charts, although @bpsmith has essentially done that for me it would appear! Definitely looks like the small would be about bang on based on those numbers! Cheers

Its not inexpensive, no. Still £1750. I unfortunately cannot sit on one as nowhere in Leeds sells them as far as I am aware. I'm still thinking that waiting a bit and getting a deal on a 2018 model is my best bet. If my current bike snapped on my next ride I'd order the Ridley without question but I reckon there will be a lot more choice in 3 or 4 months when the 2019 bikes are released.

Totally agree with the point of not buying based on discount alone. That's why I've done my research and have a list of about 10 different bikes that all fit my needs and get great reviews. But of course, wouldn't buy one that didn't fit just to get a bargain. The challenge is to get all the peices to fit!
 
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