Mojo’s groundbreaking Geometron 29er won’t cramp your style, no matter how tall you are

Product Overview

Overall rating:

Score 8

Mojo Nicolai Geometron G13 29er (2016)


  • Laughing when I thought a car was following me up a road climb, then I turn around to realise it was actually just my own rear wheel.
  • Feeling like I was having a crash at the back of the bike, but had enough room to move my weight forwards onto the front wheel which wasn't crashing, and ride out of it.
  • Riding Snowdon and feeling like there couldn't possibly be a better bike for it!


  • The first ride can be a little interesting, ride like you would on a more conventional bike and you'll make mistakes until you've adapted.
  • Going to put the G13 in my van and realising it's the only bike I've ever put in which doesn't fit without removing a wheel.
  • The endless abuse from friends the first time they saw the size of the bike. We'll gloss over the fast that their own choice of bikes have been getting longer year on year...


Mojo Nicolai Geometron G13 29er longtermer final verdict


Mojo’s groundbreaking Geometron G13 29er won’t cramp your style, no matter how tall you are. Here’s Roo’s final verdict on his longtermer.

After eleven months the lease is finally up on the limo…

Mojo Nicolai Geometron G13 need to know

  • One of the largest trail bikes on the market.
  • Custom set up by Mojo for each customer.
  • Handmade in Germany.
  • Progressive geometry with a super slack head angle and steep seat angle.

Geometron G13

What attracted you to the Mojo Geometron G13?

Size is the big one here, it’s only recently that bikes have been growing in size, and anyone over 6ft has had to put up with something smaller than is ideal. Mojo have been brave and have increased the length of their bikes, not by a little, but by a lot!

>>> Size matters: why we’re all riding bikes that are too small

Did you change anything straight away?

At this price level, you’d hope that there is very little that needs changing, and you’d be right, with a Fox/Shimano/Hope setup, everything worked spot on out of the box. A few months down the line, I swapped out the 50mm stem for a 35mm one, to be fair that was my own mistake putting a 50mm on, it’s the first time I’ve ever been able to choose the stem length I’ve wanted without ending up mashing knees and bars together!

Was the bike easy to set up?

The Geometron uses unconventional geometry and unconventional sizing, so setting up the suspension is a little different. I found that the longer length of the bike meant I wasn’t weighting the front so much and I added some volume spacers to the fork to allow more sag without bottoming out when using the travel. What helps, is that if you pay for a demo day riding a Geometron, you’ll get to experiment and perfect your setup prior to actually taking delivery of the bike. Also, the guys at Mojo who have experience setting these up, will happily point you in the right direction.

How did it ride?

Quite simply, it really doesn’t ride like any other bike I’ve ridden before. The first ride out can be a little bit overwhelming, it takes a good few runs, if not days to get fully adapted to the way the bike rides. The feeling of stability is the biggest shock, where you once might have struggled in a section, you can now blast through full of confidence, but equally, just try and flick it into a turn, and you might miss your line, this just takes a little time to adapt to.

Did anything break or wear out?

I had one minor problem with a knock in the Fox Float X shock, this was an easily identifiable warranty problem that Mojo sorted out straight away, otherwise the bike has been spot on.

If you could change one thing about your longtermer what would it be?

I’d seriously consider trying a smaller size, this is absolutely the first time I’ve ever thought about running a smaller bike than the largest available.

Previous longtermer updates

  • £2,350 frame-only with Fox Float X2
  • 29er version of the groundbreaking Mojo/Nicolai Geometron
  • 150mm rear travel married to a 160mm fork
  • Fully customisable geometry and sizing
  • Flip chip in the suspension linkage offers two geometry settings

Big bikes are all the rage — longer, lower and slacker replacing lighter and stiffer as the latest marketing buzzwords. But what happens when you’re 6ft 4in and you’re all of the way over on the right-hand side of the sizing chart? When I look back at all the bikes I’ve ever ridden over the years, I can honestly say none have ever felt too big. Then I rode the Mojo Nicolai Geometron 29er.

>>> Size matters: why we’re all riding bikes that are too small


Pipe dreams: finally a bike built for riding giants

With a name like Geometron, it’s clear from the off that this collaboration between Mojo and Nicolai is aiming to offer something very different.

Mojo currently offers three standard sizes (Long, Longer and Longest) for the Geometron 27.5in, however this particular bike is a custom 29er version of the Longest frame size.

The result? It’s massive. In fact, this is a bike that pushes the boundaries well beyond where they’ve ever been pushed before, and for riders over 6ft tall, that’s a huge step in the right direction.


Stealth bomber: understated looks for this outlandish design

The sheer length of the bike is evident from the moment you first sit in the saddle and place your hands on the grips. For the first time it felt like I could breathe openly and deeply while seated — something I’d not thought much about before with regards to sizing.

With such long, low and slack numbers, it’s easy to think this bike is aimed squarely at descending, but that’s not true. With the extra traction of the 29in wheels, long 445mm chainstays and steep seat-tube angle, it proved surprisingly capable uphill, not least because the large sizing is just plain comfortable for taller riders.


Flip chip gives you two bikes in one


With a reach measurement of 520mm and a wheelbase of 1,307mm, there aren’t many bikes that come close to the size of this particular Geometron — downhill bikes included!

At 6ft 4in I feel no need for anything longer, but if you do have your own ideas on sizing or geometry, then you can customise the geometry at no extra cost. Alternatively, the standard 27.5in Geometron frame is available in three sizes and costs £500 less. You also have the benefit of actually being able to try the 27.5in bikes before you commit, something that simply isn’t possible with the custom sizing/geometry option.


Hope calipers offer assured braking with bags of feel

On the descents, it’s a bike that rides like nothing else I’ve tried. Grip is every bit as ample as the sizing, but it’s also the way you can use the grip that makes this bike feel so different; basically you can control what each wheel is doing individually more so than on a shorter bike.

On anything steep, technical or fast, the Geometron really comes alive. Once I got it on slower, tighter trails however, it started to feel like too much bike.

Thankfully, the geometry and attitude can be adjusted quickly and easily via a ‘chip’ in the linkage, and after switching to the higher, steeper setting, the bike felt much more dynamic, with no drastic loss in stability, a change that seemed to better suit the trails around mbr’s favourite test ground, the Surrey Hills.

And judging by the reaction of just about every tall rider I’ve bumped into when out riding the Geometron, the guys at Mojo and Nicolai are really onto something. The big question is, how long will it take for the rest of the bike industry to catch up?


Month 4: A shock fix and some tweaking from the guys at Mojo

After four solid months of hammering I’ve hit my first issue with the Geometron, or to be more specific, the Fox Float X shock. It works just fine in the open and lock-out modes, but in the mid-compression setting it’s developed and audible knock that can be felt through the pedals in the initial part of travel. It wasn’t like this from new so it was obvious something wasn’t quite right.

A quick visit to Mojo in South Wales, and the guys identified the problem before even opening the shock up. It turns out that the piston bolt had loosened in the Rezi cartridge allowing some free play in the shims, hence the knocking.

It was a quick fix under warranty, and while I was there Chris Porter provided some additional feedback on how best to set up the G13. In short, the main changes to the suspension were to add a volume spacer the fork while reducing the pressure, so I could weight the front end more easily without the fork bottoming. We also removed a volume spacer from the rear shock and swapped out the 780mm handlebar and 50mm stem for and 800mm bar and a 35mm stem. Taken together it’s made quite a difference in the car park, now it’s time to see how Mr Porter’s tweaks translate on the trail…

geometron g13

Month 5: Not much riding but a lot of head scratching

I’ve got to be honest, I’ve not had too much time to get out and ride the G13 since my last update. Just one ride in fact, so I’ll save my thoughts on the modifications Chris Porter made to the set-up when I went to Mojo HQ to get the shock fixed for another time.

Even on that single outing I had lots of people asking about the G13 and what I really thought about it? More specifically, that wanted to know if I would choose it over a more “conventional” bike? It’s a hard question to answer, and still one I’m getting to grips with as my position seem to ebb and flow on this one depending on the trail.

There’s no doubt that the for taller riders, the G13 makes more sense just because it fits better than a conventional bike, but what about the super slack headangle, the extreme wheelbase, the long chain stays etc…?

Well, there are inevitably some drawbacks and the most evident to me is how the bike rides in tight corners. Sure you can nail them just as fast as on a shorter bike, but I do find myself questioning if some of the fun has been lost. Actually, lost probably isn’t the right word; it’s more like the fun has shifted away from tight corners towards fast and/or steep riding where this bike is unparalleled.

That’s my current thinking anyway, but as I said, my opinion seems ever changing. Maybe this new set up will shift my focus once again as I recently rode a track with some tight turns and messed up on two of the runs, then on the third attempt I felt like a total hero! Hopefully a little more saddle time will help to clear things up and not muddy the waters further.

geometron g13

Month 6: Back out on the bike, and better than ever

It was interesting to read aletter in last month’s mbr, as it’s something I’ve thought a lot about since getting the G13 longtermer… Why don’t we see more long bikes on the trail and why aren’t longer bikes winning DH races? I’m not sure there’s a simple answer, though. A lot will be down to personal preference, rider height and not wanting to break with convention.

The letter also raises a very good point about stability; it is great in some areas but the flip side is that it can be a hindrance in others. For straight-line speed and cornering stability, I genuinely believe the Geometron is in a class of its own.

What happens when things get tight and twisty though? It’s hard to tell without a stopwatch, but it still feels fast at least, and I believe I am quicker on the G13 than I have been on any bike previously. But that’s just me on my local trails.

I’ve not always felt like this on the G13 though. It was only after the guys at Mojo added a volume spacer to the fork, reduced the pressure, and removed the volume spacer from the rear shock that the bike really stated to sing. The G13 now feels spot on, the front and rear in perfect harmony, despite the front having more travel.

It also feels more active, and I realise that I was guilty of running too much pressure in the fork as a default, thinking I needed the extra support. I now realise that the Fox 36 suspension fork has plenty of support from the damping and doesn’t need extra air pressure to prop it up.

I recently got asked how the G13 feels on longer rides, so with the longer days it now seems like the perfect time to put some faster tyres on and head out on an all-day epic to find out. I’ll keep you posted.

Month 7: Not quite so long, or so low, but faster?

Not wanting to gloat, but we’ve been having some great weather in the South of England lately and it’s proved the perfect opportunity to see how the Geometron copes on longer rides.

To put it to the test, I fitted some lighter tyres and headed out on a 90km all-day epic taking in a mix of prime singletrack linked together with quite a bit mile munching. The result is that the G13 felt great and passed with flying colours.

At first this might not seem like much of a surprise, as it is a 130mm travel 29er, but when you take into account how capable it is at descending, I did wonder if it might feel a little sluggish by the end of the day; something I experienced when riding the longer travel G16 last year. Thankfully it didn’t.

In last months report I also raised the question about the G13 possibly being too stable. So this month I’ve raised the BB height to see if that make the bike feel more dynamic. This is super easy to so thanks to the geometry adjust “chip” in the linkage, which shifts between a low/slack setting to a higher/steeper setting, with nothing more than a 4mm Allen key.

To date, I’ve been running the G13 in the low setting, so it’s been a well overdue a swap… To keep things simple and consistent, I performed multiple runs on the same section of track with the chip in both positions. The most telling result was that I missed one tight little line twice in the low setting, but managed to get it each time in the high setting.

It’s hard to identify exactly why this was, but it felt like a combination of two things. First, the long wheelbase and slack head angle feels like the front and rear wheels take noticeably separate lines when turning onto this tight turn, effectively making it feel even harder to achieve. Second, it is that stability thing; the long, low and slack poison feels amazing when carving around turns, but when it comes to a tighter twitch of the bar to get onto an alternative line, I just felt like I had no time; I almost had to pre-plan the move much further ahead on the trail to stand any chance of getting it right.

So the combination of the higher BB and steeper head angle seemed to allow that quicker turn in. No doubt this change is at the expense of other aspects, but on this particular track, the higher and steeper setting seemed to be the one to go for, and one which in general suits the tighter, twistier riding of the Surrey Hills. Oh, and the bike seemed to climb better too, probably due to the steeper seat angle; another bonus on the short steep punches on my local trails. At the end of the day, which is better simply comes down to what trails you’re riding, and with such a simple swap, it’s a great feature to have.

Month 8: The ultimate jack of all trades?

Following on from last month’s update where I played around with the geometry adjust chip on the G13 frame, I thought it worth expanding on why I feel like this bike is so adaptable.

It’s fair to say that you can make a huge difference to the way any bike rides by simple playing with the set up or swapping components, but I do wonder if any other frame can take those changes and amplify them as well as the Geometron.

Being a 130mm travel 29er, you could opt for a Fox 34 fork at 140mm travel, choose some light rims with fast rolling tyres and in the high setting, it would be a relatively light and extremely capable all day trail bike. The open cockpit feels like a comfortable place to be for extended rides, and with only 130mm of rear travel, long chainstays and steep seat tube angle, climbing performance is unrivalled.

At the other end of the spectrum, with a 150mm travel Fox 36 or similar, wider rims, higher volume tyres and the flip chip in the long/low setting, the G13 feels like a bike that could embarrass a full-on downhill rig.

The point I’m trying to make is that the G13 has such a broad range of applications. Better still, you can get it built up to suit your particular choice of trails and style of riding – something that just not an option when you buy an off the shelf bike that’s been built to hit a specific price point. Sure the G13 is never going to compete on price, but if you want a bike that’s tailored specifically to your needs the G13 is hard to beat.

Month 9: Shorter, Higher, Steeper

For the past few months I’m mostly been onboard the Geometron, so I feel I’m well in tune with the way it rides. I was interested to then get back on a more conventionally sized bike, in this case an XL Orange Five, and see how that felt.

Yes it felt small, almost comically small at first, but it wasn’t long at all before it became “normal” again, and it then proceeded to zip and bounce down the local trails like some overexcited puppy. I was surprised at quite how different it felt!

But was it better? That’s no simple question, I’ll delve into the complexities of that in next month’s conclusion.

Once the ride took in steeper tails, I felt like I was missing out on the Five, and I could’ve got that line better on the Geometron but I feel I’m splitting hairs; both are fantastic bikes, and from trail to trail, one would feel the more appropriate bike than the other.

If there was one major difference, it was how the bikes seem to respond to your efforts. Pedal into a trail half heatedly on the G13 and not much goes on, you just cruise down the trail, but go full tilt, and the bike comes alive, you are rewarded for your efforts.

On the Orange, it’s quite happy to plod down half speed and it still seems like something is going on, flat out though and it’s not long before mistakes seem to happen.

It’s a hard one to explain, but it does seem to be the case that the more effort you put into riding the Geometron, the more you get out of it – you just have to be prepared to put that effort in!


Would I buy this bike? This is as above really, this bike yes, but maybe in a smaller size. I think the G13 is a fantastic bike, I love the way the geometry seems to be so uncompromising for downhill, and yet it's great for climbing as well... The suspension feels way more capable than the 130mm suggests, and in general, the bike feels hugely capable. The one issue that I have is my local trails aren't fast, steep or rough, so the three main areas where the Geometron feels at it's best, aren't a huge factor in my local riding. This is why I talk about the idea of running a Longest instead of the extra longest. With a bit more time I'd have loved to try a smaller size. Even the Longest boasts a reach around 35mm longer than the XL Orange 5 that I spend a lot of time on. If however, fast, steep and rough is what your local riding is all about, then you'll be laughing, the G13 will be an absolute blast, and I seriously doubt there is a bike more capable out there at a similar travel and weight! I think it's brilliant that the size and geometry thing has been giving a bit of shake up, mostly down to Mojo's Chris Porter, and just about anyone over 6ft now has an increasing choice of bikes to choose from.


Frame:Mojo/Nicolai custom Geometron, aluminium, 150mm travel
Shock:Fox Float Factory X2
Fork:Float 36 RC2, 160mm
Wheels:Mavic Crossmax XL 29in, Schwalbe Magic Mary front/Rock Razor rear, 29x2.35in
Drivetrain:Hope cranks, Shimano XTR shifter and r-mech
Brakes:Hope Tech 3 levers, V4 calipers, 180mm
Components:Hope AM 35mm stem, Kore OCD 20 800mm handlebar, Fox D.O.S.S 125mm seatpost
Weight:14.3kg (31.5lb)
Size ridden:Longer
Rider height:6ft 4in
Head angle:63.6°
Seat angle:74°
BB height:343mm
Front centre:862mm
Down tube:770mm
Top tube:660mm