Hear me out, dirt-jumper-slash-commuter?

I just discovered that our work cycle scheme has been reinstated. I’ve been thinking about a dirt jumper for a while but expect that like many people I’d buy one, use it three times and then put it in the shed. I have a 2014 vintage hardtail that gets used for occasional gentle family rides and as a base for the kids ride shotgun seat.

I’m thinking, could a bike like a Transition PBJ serve as a dirt jumper and also commuter / family bike? I think single speed would be fine (my kid’s bikes are single speed so I’d better be able to keep up with them without gears myself), when I compare the geometry between a long Transition PBJ and my hardtail they’re remarkably similar.

I think it would even work better as a city bike for occasional commuting (I usually wfh) since it’s simpler and will be rolling on dirt jump tyres rather than knobby MTB tyres.

What am I missing? This might work, right?

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Here’s the geo comparison along with a few other contenders.

do you intend to stand to ride, or planning to get a long seatpost

Ah yeah, I should’ve mentioned. The idea would be to have a second long post & seat combo ready to go out of the parts box and swap between them.

I guess a followup question is does anyone know somewhere with a size long previous model PBJ in stock? I like the old colours much better than what’s available now.

So, I am currently buggering about with a similar idea.

I already have a DMR Rhythm that I built up as a pump track bike. I kept looking at it wondering how it would ride in general… mainly because I want to ride it to the pump track a few miles away. But also because I’m doing a bit of a train journey in a month or so where a small bike to get from car park to station then station to hotel (and visit Skelf pump track when I get there…) would be handy.

So far my main finding is once the seat is high enough to pedal, it is getting a fair distance from the bars. Not sure how the seat tube angle sessions are calculated but it seems like some report effective vs actual. It felt generally OK, front was a bit low too, thinking a higher bar may be on the cards.

I’ve not worked up the resolve to ride it to the pump track yet… maybe one day this week…

Personally I think one of the late 26″ steel hardtails would be the ticket for my use case if I can track one down.

I bought a jump bike in the CRC sale earlier in the year. I’ve used it way more than I thought, particularly because I now have a good pump track 5 mins away. Great for a quick 45min morning work out and my jumping and berm technique has definitely progressed.

Not sure I would fancy commuting on it more than a few km, but for short distances not in a rush it’s fine.

Also consider whether you should really have a front brake on when out in public places and on roads. (I do, because I’m a bit scared not to have one!)

I do not have a pump track unfortunately but I do have a set of dirt jumps about a 2 mile pedal from my house – that’s another reason to see if I can make it nicer to pedal.

Yea it works fine to an extent, there even seems to be a bit of a fashion for ‘upcycling’ unloved DJ bikes into bling commuters. I saw a DS-1 the other day complete with mudguards and front pizza rack, it looked fantastic.

Depending on the geometry though you might want some seriously high rise bars (like BMX cruiser bars) as the slacker seat angles and shorter reach mean you sit way more upright (which is what you want on a commuter) so you also maybe don’t want a “long” version with low bars.

Yea it works fine to an extent, there even seems to be a bit of a fashion for ‘upcycling’ unloved DJ bikes into bling commuters. I saw a DS-1 the other day complete with mudguards and front pizza rack, it looked fantastic.

Funny you say that, my other plan is rebuilding my old DS-1 but the frame it is just so tiny that I don’t know if it’s going to work out. It’s currently at the welders having tyre rub holes in both chain stays and both seat stays repaired because 16 year old me “needed” to run a 2.3″ Tioga Factory DH.

Can you fit a massive dropper post on it?

Can you fit a massive dropper post on it?

Not a bad idea, especially as I have a 240mm oneup in the shed that was a warranty replacement but the PBJ at least (and my DS-1 also) has a 27.2mm seat tube which I think is prohibitive.

Comparing the stack between my Sentinel and a PBJ, the dirt jumper is about 60mm shorter so that could theoretically be mostly made up for with something like an 80mm riser bar.

Can you fit a massive dropper post on it?

Main problem is no internal routing, not sure there are any external ones that work. I’ve not found any.

Funny you say that, my other plan is rebuilding my old DS-1 but the frame it is just so tiny that I don’t know if it’s going to work out. It’s currently at the welders having tyre rub holes in both chain stays and both seat stays repaired because 16 year old me “needed” to run a 2.3″ Tioga Factory DH.

Maybe it was a DS2, the steel version anyway. But no reason other than steel frames look better that it wouldn’t work on an alu frame.

Forget MTB/Roadie geometry and sizing based on reach and top tubes, for commuting the important thing is maximizing the measurement from the BB to the bars. With a long set back seatpost you’re rotating your whole body back compared to a long/low MTB. Think of it as halfway between an MTB and a recumbent (0deg seat angle and the steering is pretty much in your lap). With high enough bars and a slack enough seat angle you can make one frame fit just about evryone.

Here’s my effort – https://www.icloud.com/photos/#029lUrlM8uRjO7qWwSCV4YjVw

While it looks somewhat odd, and the pedalling position puts weight very far back, I found it fairly OK to pedal with the saddle slammed forward. Few tweaks and it works.

Super harsh ride mind, but that’s an AL frame with a fairly chunky 31.6 seatpost. Reckon a steel one would be a nice place to be.

Do it.

This is what I bought with the cyclescheme

This is me fulfilling Dad duties by playing out with the family

My commute takes 9 minutes stood up all the way. I used to ride BMX so it feels fine.

It rolls so fast compared to the other 2 MTB’s. Plus they’re just fun as hell to ride so why not. If you have local pumptracks, jumps and skateparks and stuff you might as well scratch the itch.

I used to commute a few miles on a bmx, and occasionally do the same on my current dj bike. Never put the saddle up on either, the low gearing means that you can just cruise sitting down or stand up and sprint, pedalling efficiency was never a big deal for me.

50psi and dth tyres make for a quick ride

Yeah it’s effortless on tarmac, you barely have to pedal. I can get all the way home from my nearest pump track almost without turning a crank and I can hit 40mph on the way!

someone in our bike shed uses an airdrop dirtjumper, think he parks his van just outside town then I assume manuals in doing bar spins off the kerbs.

That transition does look lovely – how twitchy is it at 30+ mph?!

Just enough to keep your attention! There’s some big hills in Sheffield you get used to bombing them.

This is exactly what I did with one of those Planet X jack flash frames and a 450mm seatpost.

Gets used quite a lot by both me and my OH because it’s so small and light. Easy to chuck in the roofrack or in the boot.

NS Clash also seemed similar

That raw finish on the transition is looovely. I wish they still sold that colour.

That transition does look lovely – how twitchy is it at 30+ mph?!

I’ve never considered a DJ bike to be “twitchy”. they don’t spend much time at speed, but it just isn’t an issue. Not sure why it would be?

When I lived 6 mins ride from work with a bmx track on the way, a 24” dj bike was awesome.

any further, no chance.

Gusset do a lofty post that’s 550mm if you want fixed.

Mine is sort of similiar-but-different, I took a mk1 1 Cotic Soul and stuck a set of wheelie bike slicks on it (GT Smoothies). Not as fast as my proper hybrid but way more fun to just cut about on, and for the tarmac pumptrack and the local jumps (as long as they’re dry) it works well too. If I was doing more dirt I’d have to swap the tyres from the slicks though, luckily I can’t jump for shit so it doesn’t really matter.

Gusset do a lofty post that’s 550mm if you want fixed.

That’ll help for sure, I could stick the little DJ seat in a backpack and swap them when I get there. I wonder if I could also / instead use a layback style post flipped around to bring the seat back towards the bars if it feels too spread out.

Go to a BMX track or skatepark and see what the kids are riding. They’re all riding crappy BMX’s or mutant mtb’s and they ride for miles all day long and most of them will be better at shredding and jumping than most of the people on here. They don’t worry about tyre pressure or spare seatposts.

Just get the bike and have fun. I mean this in a friendly way- don’t be such an adult about it!

Hah! You’re totally right, 16 year old me with my tyres rubbing a hole straight through the chainstay definitely didn’t give a shit.

(Having said that, have you ever put a shotgun seat on your pbj? Does it fit?)

Main problem is no internal routing,

easily fixed

fwiw i have a kona dew as a commuter which is fast and very nice to ride

i also have a kona unit which isnt as fast as a commuter, but an absolute laugh when i do take it, lots of fun on steps and the local skatepark, way more capable on a bmx track than a 29er should be (sliding dropouts means I keep the back end short)

Couldn’t find the 550mm gusset lofty – anyone got a link?

This looks interesting extender

Having said that, have you ever put a shotgun seat on your pbj? Does it fit?)

I do have a shotgun but I’ve never tried it. I don’t think it would work. I can imagine just kneeing the little fella in the back constantly.

It works perfectly on this though…

@sharkattack that PBJ looks lovely! Always had a thing for raw frames and tanwalls.

If you want something that can do it all I’d maybe look for a used Charge Blender frame. Really fun bike, to me it felt like a successor to the DMR Trailstar (which I’ve also owned and loved) – used mine for everything from commuting/pub rides, DJ, skatepark, DH and even took it XC round the Long Mynd once. I’d love a modern take on this type of bike – 120/130mm ish fork, just fun for ragging about everywhere without being too worried about being the long/slack/lowest.

Just avoid the tips in the commuter tips thread to put rack + pannniers + full mudguards on it 🙂

This is my dadcountry, jump, short commuter bike (complete with Jnr mechanic)

I ride it on forest loops with the kids, to the pumptrack half a mile up the road and to and from the train station (2 miles). 65psi in the tyres helps it roll well (it’s now got a 50mm stem, 2 brakes and 700mm bars). It’s got a rather long seat post in it but unfortunately Blenders we’re infamous for super slack seat angles so I tend to just ride standing most of the time.

Great fun though and manualling down the street is still as much fun now as 15 years ago.

A longer reach and steeper Seat angle would be nice though. Oh and taller bars as well.

You’re right about the slack seat angle on the Blender, forgot about that. It can work though. Here’s my old one at Cannock with a comically long seatpost! Think I had to get a Thomson as everything else I tried bent after a while from all that leverage. I did have a shorter pivotal type seat for DH/DJ days. Very fun bikes.

The newer Saracen Amplitude looks really cool too but would def be too small for sit down riding.

Amplitude AL Team

Couldn’t find the 550mm gusset lofty – anyone got a link?

I think they only come in 450mm, I had one on my Swobo.

I got mine from Slam69, maybe get in touch with them to see what is available

Gusset Lofty XXL Super Long Seat Post – 27.2, 30.9, 31.6mm

Worth looking out for a Dialled Prince Albert or Love/Hate.

Dialled PA did well for me for everything for 8 years, got shifted to jump/pump/pub duties, until one mate wanted to shift his DMR Sect and another wanted an xc/do everything bike. One in, one out, nil cost.

If anyone’s interested I have a P7 for sale, more all round than DJ but it’s got to go.