Ok, decided to have a go at this dirt jumping malarky, and have sourced a frame, forks and wheels at a very reasonable price and am just trying to get a finishing kit sorted. I have a thomson elite x4 50mm stem and a pair of ea70 bars from anothr bike. Would these stand up to that level of abuse?
Also which tyres are people running?

that’s a sh1t load to spend for “deciding to have a go”.

😯

Well i suppose, got rid of one frame that was a little excess to requirements, and fancied a change, and got all that for about the same money, so cant complain. Been toying with the idea for a year or so, as all my mates do it, whereas im strictly wheels on the ground, but now i get sickpay, and am still young enough to heal, so took the plunge.

Would it not make more sense to ask your mates?
afterall they know the trails/you

Well yes, but isnt that the point of a forum??? Im stuck offshore on a computer, and STW is here.

In terms of jumps – Start small and build up to it… heard some horror stories of people going big first off!

Stem should be fine, but not sure about the bars!

Try them and see – just keep an eye on them for any “changes” or get a cheap set of ruffty tuffty bars in the sale until you get into it and reward yourself with some new bars when you achieve a certain goal – like doing your first double.

EA70 bars and thomson stems are pretty tough, you’ll be sweet.

Fairy muff!!

What I’m getting at is more.. er.. what sort of level of dirtjumping are you talking about, your riding style/traits and what you weigh would be helpful too (even your height for that matter).
you’re a beginner so I’m guessing small stuff to start with but being a beginner you may be pretty harsh on kit until you become smooth and even once you do get to a decent standard if you are riding decent sized trails you may need something that’s gonna be able to survive multiple bails.
for instance a lot of DJ riders perfer steel bars to Alloy.
tyres depend on the trail surface but generally something with a smoothish tread for proper ‘dirt’
I’d get a strong seat and a post with a reliable clamp (actual post strength is not majorly important as it’ll be slammed into the frame)
strong cranks (especially if you are harsh/heavy)
single speed is a good idea if you ride the same spots a lot and will cost you a lot less in repair bills in the long run.
What frame, fork and wheels have you gone for?

The Thompson should be fine (I hope it will be I have one on my jump bike) For starters the ea70 should be strong enough you wont be going that big when you start off. Try get your hands on some saint cranks from ebay nice and strong and lighter than 3 piece cromo. Have a look at DMR kit for saddle tyres and other bits and bobs. Some of the kids these days are running singlespeed for less weight and less brake downs. They run rear discs only too one on the front would compress the suspension too much under breaking.
This is all for dedicated jump bikes. I run a double and bash with 9 at the back 24″ wheels and both discs, U-Turn forks and high rise bars on a tiny frame.
Have a look. Its not finished in this pic.

Im an experienced rider, but no jumps approaching the size of a proper double. And most of my jumpy friends ride bmx’s, which i just cant get on with.

That was very helpful thanks I_Ache.

When you say the kids are only running one brake, is this an endorsement of this? As a traditional mountain biker, i like the idea of front AND rear brakes. I think singlespeed probably, but i do have a choice of rear wheels (hope single specific on leaf or xt on 321s) What kind of ratio should i go for for a good balance?

I’d definitely go for a Single speed design, much easier. The bike will be abused, well mine did, and having gears although nice going to the trails, you just don’t need them for jumping.

In terms of ratio i used a 32 up front with a 16 at back, worked fine for me. I always had two brakes, but that was only because i did some street to, and wanted two brakes, if your just doing DJ, then one rear brake would be fine.

When i was doing it, i understood that less is better, basically less to brake. DJ bikes are meant to be cheap and cheerful fun bikes.

Unfortunately i wont be Dirt jumping and more, and nasty crash scared the life out of me, and sent me over to A&E lol

You can dirt jump on ANYTHING as long as the stem is short and the frame small. Those bar/stem will be fine. Any xc tyres will be fine. I’m no dj guru but I’ve ridden everything from a large rigid xc bike to dh bikes through modest sized sets fine.

I prefer to have a front brake as it’s what I’m used to.

I know which bike you’ve bought and it will be perfect for the job.

Tips I can give you (after years of jumping mtb and bmx)

Run your forks hard
Run a little more rebound than usual (personal pref on this one though)
Run your tires hard (40 psi min)
Any tires will do, but the lighter the better
Run ss
Run only a rear brake (front is not necessary and adds weight and gets in the way)
The bars and stem you’ve got will be ok, but the ones coming with the bike will be a bit more rugged, and plus there higher rise bars which I think is more preferable for dirt jumping.

Thats it

Thanks david, have a pair of conti racekings, in 2.3 i think, these seem to be an ideal tread for dirt, think theyre worth using? Im sure ive seen them on another dirt bike somewhere. Think i may run front brake for a bit of street action tho.

I used to use moto’s whihc were pretty good at our trails but also used high rollers too depending whihc bike I used. Wish I could build a bike to that spec to ‘have a go’!!

I put gears and two discs on mine because I wanted to use the bike for short blasts in the woods too.

davidt when you say more rebound you mean more damping to make the forks slower so they dont throw you off the back dont you?

With regards to tyres I shouldn’t think you would want a really knobbly one as this will slow you down because of the extra drag and will mean you will have to pedal more in betwen jumps and this will upset your balance. You only really need enough grip to stop you. An old tyre that has worn down in the middle should be pretty good as you wont be riding through deep mud or needing loads of grip on roots ect.

I’d not bother with a front brake – too much temptation to pull it and throw yourself over the bars!!!

Defo Single speed!

I’d echo Solamandas comments. Anything will work for starters that isn’t a pure XC race machine. I don’t do a lot of DJ stuff (dabble at Chicksands), but my 36lb 6&6″ Turner can hack it, as can my 24lb Soda if I’m smooth. Both have a trail riding build on, and I run normal tyres, although I accept that balder ones at higher pressure would make life easier.

Usual suspension set up, so I don’t get surprised by what the bike does. 2 brakes, because I won’t be doing bar spins for a while, and why would you grab a handful of front brake anyway?