Comparing different brand bikes 29 vs 27.5 weights, seems the 29 ers are around 1KG heavier for similar spec. I thought 29 wheels/tyres wouyld be heavier but not by that much!

It’s not only the wheels / tyres. It’ll be frame & fork too.

And cables.

And chain.

And brake hoses…

Have you looked at 26ers? Bit lighter, niche product…

29er tyres are 10% heavier, maybe a bit less. Rims about 5% heavier. Longer spokes add a bit too. Longer fork lowers, longer chainstays/seatstays, and both of those needing slightly different butting/reinforcement as a result. And slightly longer sundry bits like cables, chainstay protectors, chains etc

But yea, 1KG extra still seems a lot, even considering that.

About right IME.

Extra weight gives more momentum for crushing rivals

Like for like, 29er wheels and tyres are around 10-12% heavier, this is the bulk of the difference.

Difference in frame weights will be almost negligible since geometry seems to be less influenced by wheel size than it does intended use (as it should be) these days.

Forks are a little heavier like for like because they need that bit extra length like for like, typically around 5% in my experience.

Nothing else on a bike is “29er specific” (unless you believe the marketing bullshit!) so on a typical bike I’d say you’re looking at an extra 200-250g in the wheels, same again for a pair of tyres, approx 100g for the fork. So “like for like” a 29er should only weigh roughly half a kilo or so more than its 27.5 equivalent…

200-250 for wheels seems a lot. Hope quote this for their Fortus 35: 27.5”- 2100g/29” – 2200g – so only 100g there. 1055g for a 2.5 Minion DHF WT in 29, 980 for 27.5.

Both of the above are at the heavier end, and front and rear is still only 250g total difference (wheelset and 2x the tyres)

Fox quote 1956g for a 27.5 36, and 2006g for a 29, so again only 50g. That’s 300g total.

Forks are a little heavier like for like because they need that bit extra length like for like, typically around 5% in my experience.

Nothing else on a bike is “29er specific” (unless you believe the marketing bullshit!)

Well the wheels are kind of “Specific” too, as is the frame…

Everything is just scaled up a wee bit more.

38mm more wheel diameter means ~19mm more fork is needed, and about the same for chain/seatstays, and each spoke…
theres almost 120mm additional circumference per wheel/tyre which is about 6.5% (x2)…

Lot’s of little incremental additions will all add up to bump a bikes weight ,and given the construction and materials don’t really differ then yeah… a 29er will work out a bit heavier…

I’ve had this argument with my friends. I’ve got an xl 29er and they always say it’s really heavy especially compared to their small 650b.

It is what it is

Not much difference between frame sizes on road bikes.

Comparing identical models with identical spec, YT give 12.9kg for the 29er Jeffsy CF Pro race, and 12.7kg for the 27.5 version.

13.0kg for the CF pro, and 12.9 for the 27.5 version.

13.4kg for the 29er CF Comp, 13.3 for the 27.5 version.

2-300g in it, that’s all. There’ll be that much different between sizes in the same bike.

I would say you should stop worrying about weight and just enjoy riding the bike that fits you. If you’re tall that will be a Mojo Geometron (27.5 rear 29 front).
I used to obsess with weight charts but now its performance that interests me.
My sturdy 29 front Hope/Spank wheel with 2.5 Bontrager G5 tyre weighs a lot In the hand, but the way it rides is to die for. Grip and damping are fantastic.
I used to ride a fairly spindly XC/ trail 29er with light wheels and it was just scary on off camber roots or rocks. It just wasn’t worth the weight saving as it spoiled the fun bit.
My mate has cushcore in the same front tyre (that’s a 1.3kg wire bead tyre) and it’s even better. Rolls better too (even though his is 27.5). Go figure.
Yeah cushcore upfront increases grip and improves rolling resistance. I’ve yet to manage to fit one!
Neil

So “like for like” a 29er should only weigh roughly half a kilo or so more than its 27.5 equivalent…

My thoughts exactly. Bit less of a difference on the more XC end of the spectrum, maybe slightly more if you’re running a 29er specific saddle 😉

Forks are a little heavier like for like because they need that bit extra length like for like, typically around 5% in my experience.

Nothing else on a bike is “29er specific” (unless you believe the marketing bullshit!)

Well the wheels are kind of “Specific” too, as is the frame…

Holy selective quoting, Batman!

Theres a but of creative specification too from some manufacturers.

E.g. going ‘up’ a rim profile to maintain stiffness adds more weight than just the additional circumference. Other bikes go the other way and spec a lighter rim to keep the weight more constant.

Not worth worrying about though, the benefits of big wheels massively outweigh the 300g of difference. It’s like wondering if 100mm more reach is worth the weight penalty vs trying to take a cx bike down a downhill track.

For me the benefits of 27.5 would outweigh a 300g difference if that meant a heavier bike.
Although I am probably an hypocrite as my front wheel with a 2.8 is very close to a typical 29 front wheel size. But the added air is a benefit in itself…