“Light” trail bikes

I think I need to borrow some scales from other forum users, some of these bikes are remarkably light 🤔

Measuring 15kg with a decent degree of accuracy isn’t very difficult.

I think I need to borrow some scales from other forum users, some of these bikes are remarkably light 🤔

Measuring 15kg with a decent degree of accuracy isn’t very difficult

Agreed, but measuring 12kg does seem to be 😁🤣🤩

Interesting feedback, appreciated. I don’t need to lose any weight thanks, I’m 81kgs and 6:2ft. The issue it not really getting airborne, more that the bike just feels heavy and cumbersome when flicking the rear whilst in the air and not a very lively bike sometimes, this is definitely due to weight, dropping to a 12-13kgs bike would be very noticeable. I rode a Giant Anthem 27.5 recently and whilst a million miles away from being a trail bike it felt really lively and playful, this reminded me of how much more fun light and nimble bikes are. I can’t see much that can easily/cheaply be upgraded to save much weight. I have raised the “flip chip” and played around a bit with the dampening (increasing the rebound), will report back. TBF the bike is only 6 rides in from new and may not be set up correctly. It’d this Giant Trance:

https://www.giant-bicycles.com/gb/trance-x-29-2-2021

I’m thinking something along the lines of:

– Carbon fibre frame

-Fox 34 (130-140mm)

– Light wheel set around 1,600-1,700gms

-11speed

when flicking the rear whilst in the air

Are you trying to do big whips on your 29er trail bike?

The smaller wheels will make the Anthem more flickable, but then it won’t be as rollable over lumps.

I want a Specialized Epic Evo 8…. looks an awesome light trail bike, it’s only 130mm up front (Fox 34) so may be a bit limited on bigger stuff. I do think some of the modern “down country”/”trail light” look really fun bikes. May be my next bike in a year or two.

My Spur with Fox 34 Factory SC, XX1 cranks, Roval Control wheels comes in at about 11.5kg. Its probably no good for a heavy rider doing jumps but I’m only 58kg so don’t often brake parts but do notice a light bike.

It’s an interesting conundrum. Maybe it’s as much size as much as weight. As a tall chap you must be on a large I’m assuming. Bike have got longer for their size too. And 29er wheels are 29ers no matter how light you build them.

TBH a ‘downcountry’ bike built to fit you….beyond being a bit lighter are they actually any more lively – I don’t know. Are they just not an XC bike built to get from A to B quickly but built a bit burlier, slightly longer and slacker than an XC to cope with rolling over/through rougher stuff……but still built to get from A to B fast rather than with more smiles. And at 6’2″ it’s going to be a physically big bike.

Could this not be an n+1 moment. Keep the current bike with the few tweaks already made and build up a jump bike with a different set of compromises – maybe a bit shorter, maybe smaller wheels purely for dicking about (well, it’s all dicking about really).

Hi Convert –  I’m on a XL @ 6:2ft. I just weighted my Giant Trance at 15.2kgs, so a bit lighter than I thought and certainly towards the lighter end of current trail bikes (150mm+ front suspension). I’m hoping some of the tweeking with rebound settings and shock pressure should liven the bike up some. I also raised the bike using the “flip chip”, so will be interested to see the effect. I do think there is may be a good middle ground and that’s the new down country bikes in the 130-140mm range. I don’t do Alpine riding, my riding is UK mixed woodland trails, Bike Park Wales, 417 Flyup, Sustrans routes, Glentress & Innerleithen type riding. I may be better suited to a shorter travel/lighter down country bike.

Ok. If nothing else certainly a reason to test ride a few if you can.

On the link you put up further up for your current bike I looked on the size guide for what they are worth and 6’2″ is firmly in size large territory. Back in the day (so maybe an outdated philosophy) when buying a bike you sized up for charge through everything ability and sized down for playfulness. Maybe it’s worth making sure the next bike is on the smaller side of the Goldilocks compromise if flickability/playfulness is your priority over ploughing through everything and anything. Save a smidge if weight too. And maybe go for something with short chainstays…..not that yours currently are long.

You are correct about the Giant size chart putting me on a “large”. However, their size charts are way off. I fond Giant Trance frames run on the small size and the bike feels perfect size wise (6:2ft – XL). They have the XL starting at 6:4ft, which is way off IMO. I tried a few smaller “large” size bikes but they were all too small, in particular the Nukeproof Reactor which I was keen on. I don’t think this is a size issue, more I may be slightly over biked.

My large Spur on 2.4inch winter tyres with X0 AXS and Tech 4 E4s  is 11.1kg (without pedals).  Pedals are 250g.  Calibrated digital scales, bike held by the saddle nose.

On summer tyres it saves around 250g and with a lighter dropper, brakes, groupset, etc, you’d be able to get another 500g off it fairly easily.  So, low 10s for a 120mm trail bike is easily possible.  I’m also using King hubs, standard spokes etc, so not the lightest.

The current carbon Stumpjumper meets your requirements perfectly. It often gets overlooked as it’s not as fancy/cool as the Evo version, but it’s fair bit more capable than the Epic platform. It’s a proper ordinary trail bike with 130mm rear, and although they ship with a 140mm fork they can take a 150mm. The weights are good – the cheapest comp model (which I have) starts at around 30ib for a size s4. Sub 13kg easily achievable for a more blingy build. Good trail geometry – 65 HA and 77HA, decent reach etc.

Edit to add as it sounds like I’m being too much of a fanboy. It is flex stay single pivot which some people won’t like – it’s not as supple as an fsr model. I’m not very rich so mine has to be a ‘one bike rules all’ build – I’m considering adding a burlier 150mm fork to mine and adding slightly burlier tyres to increase its remit a bit further. But if I had more spare money I’d go the other way with it – lighten the wheels and tyres, keep it at 140mm and then have a bigger 160-170mm bike alongside it.

That transition…I do love a ‘seat stay’ that aligns perfectly with a top tube. And the tope tube/fork angle of near 90 degrees also pleases me! It looks lovely standing still.

On summer tyres it saves around 250g and with a lighter dropper, brakes, groupset, etc, you’d be able to get another 500g off it fairly easily.  So, low 10s for a 120mm trail bike is easily possible.

Yep, which is fine if you are riding blues & reds at trail centres, but from experience, the SID’s on other half’s Spur lasted a matter of weeks before they got bushing play, the damping cartridge was consistently leaking & the shock went back repeatedly for leaking & knocking. As many a suspension service centre has said, they just don’t belong on a bike like that.

I appreciate my idea of ‘trail riding’ might be different to others, but experience has taught me to accept a weight penalty for reliability & it seems to be around 13kg with suitable parts is that point.

If I want to go & ride my (very) local trail centre, I have a lovely set of very light wheels with Fast Tracks on & the bike is nearly 12kg, but it its not going anywhere near the off piste, as I don’t want to be walking home with a hole the size of my hand in a tyre 😆

What is this 120mm trail bike of which you speak?

This thread is making me feel really bad about my latest build! I managed to get my Genesis Tarn under 12kg (just) by chucking a rigid carbon fork on it – granted I haven’t spent a lot of money getting the weight down, and really other than wheels and cassette I don’t know what else I could lose any serious weight off.

What I will say, is that doing weighlifting will massively help with this issue you’re having with the bike feeling heavy. My ebike is 26kg and I used to hate it, but after going to the gym properly for a year it’s way more manageable and feels a lot more playful even at that scale-smashing weight! (Added bonus that I’m in much better shape)

Yep, which is fine if you are riding blues & reds at trail centres, but from experience, the SID’s on other half’s Spur lasted a matter of weeks before they got bushing play, the damping cartridge was consistently leaking & the shock went back repeatedly for leaking & knocking. As many a suspension service centre has said, they just don’t belong on a bike like that.

I appreciate my idea of ‘trail riding’ might be different to others, but experience has taught me to accept a weight penalty for reliability & it seems to be around 13kg with suitable parts is that point.

If I want to go & ride my (very) local trail centre, I have a lovely set of very light wheels with Fast Tracks on & the bike is nearly 12kg, but it its not going anywhere near the off piste, as I don’t want to be walking home with a hole the size of my hand in a tyre 😆

Fine, but a 34 Stepcast is almost the same weight and perhaps more reliable and for summer tyres, I always run higher pressures anyway.  I’ve only damaged one tyre in 3-4 years of riding and that was on the Quantocks going waay faster than I should’ve been as I could’t really slow down.

thegeneralistFree Member
What is this 120mm trail bike of which you speak?

What would you define as a trail bike?  I’ve had 150mm Ibis and Yeti Bikes before this and whilst there is less travel, the Transition seems to make batter use of less travel.

My large Spur on 2.4inch winter tyres with X0 AXS and Tech 4 E4s  is 11.1kg (without pedals).

Do you choose the components based on weight or on the performance you desire?

I’m not judging, but I think this weight weenie approach is fading out and most riders are choosing the parts they need (or can afford) and the overall bike weight just “is what it is”.

And XR4s would be a summer tyre for me, not a winter option. So perhaps we’re using our short-travel bikes for different riding anyway.

Fine, but a 34 Stepcast is almost the same weight and perhaps more reliable and for summer tyres, I always run higher pressures anyway.  I’ve only damaged one tyre in 3-4 years of riding and that was on the Quantocks going waay faster than I should’ve been as I could’t really slow down.

I wouldn’t run one of those either to be fair, but as I said we all have a different view of what trail riding is, which is why bikes like these & various specs exist – to suit what you do.

As to what a trail bike is these days, given quite a lot of XC bikes are up to 120mm travel now, I think it’s generally more than that, with geometry thats designed not to have you sat there in Lycra, chewing the stem off for hours at a time.

There are bikes like the Epic Evo, which is right at the XC end of the spectrum, with the Spur & Element not far behind, then I think something like the current Top Fuel & then the shorter travel stuff thats more capable and can take the abuse, like the Tallboy & Spectral.

They all have their place & they are all great bikes, just a case of picking the one that suits what you do best.

Interesting thread. It’s served to remind me why I don’t own and must never own bike scales!

I’ve got an idea… ride my Raaw Madonna with coil front & rear then get back on your bike. It’ll feel like yours has instantly lost 10kg.

I don’t own bike scales, but I’m guessing it weighs marginally less than my car. I don’t have any issues with jumping or popping off trail features. Now hills… that’s another story 😂