Boardman 8.9 adv gravel -size up or down?

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Rock bus
Posts: 20
Joined: 22 Mar 2016, 10:46pm

Boardman 8.9 adv gravel -size up or down?

Post by Rock bus »

I’m looking at getting a boardman 8.9 adr gravel bike.
At 5ft 10 I shoukd be looking at medium size But bit confused as frame is only c54 and my road bike is a 56.

I’ve tried a large and it does feel a stretch but “doable’ but this just might because thar one is for sale at decent price?

Anyone have this bike and can advise or any general advice on whether should size up or down for a gravel bike?
Jdsk
Posts: 24478
Joined: 5 Mar 2019, 5:42pm

Re: Boardman 8.9 adv gravel -size up or down?

Post by Jdsk »

General advice seems to be to choose the smaller frame and then adjust the fit or replace components to bring it up to perfection.

Jonathan
Nearholmer
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Joined: 26 Mar 2022, 7:13am

Re: Boardman 8.9 adv gravel -size up or down?

Post by Nearholmer »

I had a Boardman CX bike, nominally 55.5cm frame, and with me at 5ft 10.5in it fitted perfectly, so well in fact that I neither changed the stem length or seat setback from factory settings. That bike was almost exactly the same geometry as the ADV series.

How you transfer that to your case, I know not, because torso to leg-length ratio is different between individuals.
Stevek76
Posts: 2084
Joined: 28 Jul 2015, 11:23am

Re: Boardman 8.9 adv gravel -size up or down?

Post by Stevek76 »

nominal top tube lengths like 56 etc are fairly useless for bike sizing.

Suggest you compare the bike geometry with your old bike (sites such as 99spokes can assist with this by overlaying two bike frames for comparison and have a database of old model geometries) specifically looking at effective top tube, stack and reach and seeing how that compares.

Do factor in any differences in stem length and so on though as frame measurements are of the frame.

For 'rougher' off road use the more recent trend has been for longer reach and shorter stem, this puts the front wheel further out which helps stability and confidence when dealing with bumpy and downhill things so factor in your intended use.
The contents of this post, unless otherwise stated, are opinions of the author and may actually be complete codswallop
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531colin
Posts: 16034
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Boardman 8.9 adv gravel -size up or down?

Post by 531colin »

Rock bus wrote: 9 Aug 2022, 9:23pm I’m looking at getting a boardman 8.9 adr gravel bike.
At 5ft 10 I shoukd be looking at medium size But bit confused as frame is only c54 and my road bike is a 56.

I’ve tried a large and it does feel a stretch but “doable’ but this just might because thar one is for sale at decent price?

Anyone have this bike and can advise or any general advice on whether should size up or down for a gravel bike?
Probably depends whats important to you.....height of bars, reach to bars, standover.
Is the seat tube angle the same between the 2 sizes? Whats the difference in head tube length between the 2 sizes?
Is the difference in reach mainly due to a longer stem on the bigger bike or a longer frame?
If you post a link to the geometry table you might get a considered answer.
Is the boardman frame "sized" the same as your road bike?
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