The frame is the most important part of any mountain bike, but unfortunately there’s no blueprint on which all trail frames are based. Travel can range from 110mm through to 140mm with wildly different schools on what the best geometry or material is – and that’s before we even touch on wheel sizes.

Unfortunately it may be a case of buying the bike that best suits the conditions you ride most often and then compromising on the rest. So, if you ride a lot of trail centres then a short travel whippet would be your first port of call, alternatively a 140mm cruiser might suit someone who rides a lot of natural stuff. It’s horses for courses though and buying one certainly won’t exclude you from any form of riding.

Geometry and sizing are incredibly important and this is where some bikes shine and others are a let down. Get this right, and choose the right size frame and you’re onto a great start. This is one area where buying from a bike shop has an advantage – you should be able to sit on (and possibly test ride) the bike of your choice, although some of the direct-sales brands do have demo days where you can try before you buy.

There are no hard and fast rules for geometry but expect a head angle of 66-68°, a wheelbase a touch shorter than an enduro bike and bottom bracket a shade higher. Modern trail bikes will be built around a short stem and wide bars so will compensate with a long reach. The latest fad is for short chainstays, especially on 29ers, that will increase maneuverability.

Thankfully, if you can’t quite pick a bike with perfect geometry, then a lot of trail bikes now have adjustable geometry with high and low settings to give you one version for climbing and then a totally different one for descending. Some systems, such as Canyon’s Shapeshifter, even allow you to change geometry on the fly.

Check the warranty on the frame – it’s an expensive part of the bike and it is reassuring to have it covered for more than a year or two. Some brands will offer a crash replacement scheme too.

Trail bikes have the biggest variety of wheels on offer for any bike category. A few years ago it seemed like 650b had the market sewn up but the introduction of Boost (and now Super Boost Plus) hub spacing has made 29ers viable again. 29ers offer superior ground covering abilities and float over small holes while 27.5 wheels offer better maneuverability, but don’t be fooled into thinking 29ers are the ‘wagon wheels’ they’re often derided as, you can still get a flickable bike with big wheels

There’s also the emerging Plus bike market that fits large volume tyres up to three inches wide on wheels with 27.5 inch diameter. At the moment Plus bikes are being pushed towards the beginner and intermediate market for their superior grip and cushioning, but when the tyre tech starts to become more refined we could see them become more ubiquitous.

Tyres

Tyres will be a bit lighter than on an enduro bike but still durable enough to handle the rigours of all day riding. They will probably also be a bit narrower (maxing out at about 2.3 inches) so that they aren’t too draggy. An aggressive tread pattern up front with a faster rolling lower profile tread at the rear is a good set up once conditions dry up and speeds increase. The Maxxis High Roller 2, Schwalbe Magic Mary and Rock Razor are all recommendations from us here at Dirt.

Brakes 

Lightweight two or four piston hydraulic disc brakes are standard kit on a modern trail bike – reliable, powerful and with good controllable modulation. Rotors sizes will be 180mm with maybe a larger size up front. Shimano, Hope and SRAM are favourites but we’ve just found favour with the new MT5 from Magura.

Gears

It’s still a toss up between 1x and 2x drivetrains for trail bikes. Top end bikes are starting to move away from 2x but a lot of consumers still like having the security of the extra low gears for getting up climbs easier.

You will likely have a ten or 11 speed cassette at the back, however the recently released SRAM Eagle has introduced 12 speed for the first time.

Controls

The bike industry is finally catching on the idea that the short stem/wide bar combo works as well for trail bike as it does for enduro and downhill bikes. No longer are trail bikes equipped with shoulder with bars but confidence inspiring ones between 720-780mm wide.

Modern trail bikes are made with long reaches so should be fitted with a short stem to compensate – think 35-50mm. The Dirt 100 has our pick for equipping your bike’s cockpit.

Dropper Post

This won’t be a universally popular statement but if you’re riding a trail bike you really should fit a dropper post. Yes, people used to cope just fine without them, but when you’ve ridden one you won’t ever be tempted to go back. They don’t have to break the bank, with the Orba Digit starting at £60, but if you really want to push the boat out the RockShox Reverb Stealth takes some beating. 

Pedals

Pedals are very much a personal choice here. Objectively being clipped in will give you a mechanical advantage if you’re on a long ride, simply because you’ll have better pedalling efficiency. But if you don’t get on with them then there’s no point in forcing yourself to ride them.

All pedals need well sealed reliable bearings and a good build quality to put up with plenty of knocks and abuse and will need to work well with your footwear choice. Budget for £60 upwards for a pair of pedals – check out the Dirt 100 for our choices.

Where to buy a trail bike

You have two main choices when buying a trail bike. Do you go to a local bike shop or buy online?

The biggest advantage of buying from a shop is the ability to demo a bike before you buy it. For a small fee (compared to the price of the bike) you can take the bike out to your local trails and really get a sense of how it feels. This experience is priceless because you can never truly understand a bike from spec sheets and geometry charts alone.

A shop will also be the first port of call for any warranty issues you might have with it. Check what the shop offers in the way of after care servicing that goes with a bike sale. Make the most of what is available to you and build up a relationship with them.

If you go online you’ll probably save yourself a packet but remember you won’t be able to size up the bike or resolve any issues easily. Take a look at the YT Jeffsy and Canyon Spectral for capable and great value direct sales trail bikes.

Not enough travel or ability? Then check out our buyer’s guide to ENDURO bikes HERE.