2002 Rocky Mountain RM 9 came with a 24" rear wheel?

machinebike

I bought a used rocky mountain RM 9 , I'm trying to make it original... can anyone confirm this is the rear wheel size it came stock with?

Where could I buy this size rim and will the hub that is now on a 26" rim fit on the 24 inch rim or do I need to buy a new hub and spokes as well :roll: ?

cooldad

Good luck with finding a rim or wheel though - it was a stupid idea then (basically trying to use a small wheel for strength, and cram more travel in) and hasn't improved.

You can use the hub if the rim you find has the same number of holes, but you will need the correct size spokes.

People did use 26 inch wheels in them, makes for crazy BB height and probably hit the frame at full compression.

There are probably better bikes to waste money on, IMHO.

machinebike

cooldad wrote:

Good luck with finding a rim or wheel though - it was a stupid idea then (basically trying to use a small wheel for strength, and cram more travel in) and hasn't improved.

You can use the hub if the rim you find has the same number of holes, but you will need the correct size spokes.

People did use 26 inch wheels in them, makes for crazy BB height and probably hit the frame at full compression.

There are probably better bikes to waste money on, IMHO.

The MTX 33 Double wall has a 24 inch rim. I was wondering about buying the rim and the right spokes but use the hub that is mounted now. The hub is a Movaic DEE TRAKS 26 inch.

My guess is they modeled it after a dirtbike since all dirtbikes have a larger front wheel.

The Rookie

As CD has said, you can use the hub as long as it has the same number of spoke holes.

It's a daft idea as the smaller wheel needs more travel to match the feel of a bigger wheel, so the right travel with a 26" wheel make a better bike, but it's your bike to play with!

machinebike

The Rookie wrote:

As CD has said, you can use the hub as long as it has the same number of spoke holes.

It's a daft idea as the smaller wheel needs more travel to match the feel of a bigger wheel, so the right travel with a 26" wheel make a better bike, but it's your bike to play with!

Thanks for confirming what CD said

Ill be using it mostly for trails and I like the dirt bike look.

Heck, dirt bikes have the front wheel bigger set up for quite some time.... still not sure why its not as useful on a Mountain bike, but who knows, maybe Ill be learning the hard way

machinebike

Im a little confused on how the rim sizes measure...
so If I bought a 24 inch mtx 33 rim, the rim itself only measures about 22 inches :?: :?:

24 inches with the tire mounted :?:

Will a 2.75 wide tire fit on an mtx 33 rim :?:

What are some cool looking tires wth nice knobbies and white lettering?

ohh..what is a good spoke set to buy for the mtx rim?

Sorry for all the questions, Im just starting out with a downhill bike...a whole new world has opened up

The Rookie

MTB sizing convention is the outer diameter of the tyre with a nominal 2" tyre fitted, so a 24" will be about 20" at the bead seating point (bigger at the rim extremity). Confused slightly as a 29er is actually a 28.5" rounded up while a 27.5" is actually 27" but called 27.5 to put it halfway between a 26 and a 29 (which of course is actually 28.5".....).

Good quality butted 2.0-1.8-2.0 spokes, DT Swiss or Sapim would be my choice, little to choose between the two. Rim has next to no effect on spoke choice.

Internal width of the MTX33 is 26mm, it will take a 2.75" tyre but will be a bit rolly poly, I'd stick to 2.5" max to be honest, check your frame and see what will fit as well. Most decent brands have white lettering on the side. You won't have much choice in 24" these days anyway!

machinebike

The Rookie wrote:

MTB sizing convention is the outer diameter of the tyre with a nominal 2" tyre fitted, so a 24" will be about 20" at the bead seating point (bigger at the rim extremity). Confused slightly as a 29er is actually a 28.5" rounded up while a 27.5" is actually 27" but called 27.5 to put it halfway between a 26 and a 29 (which of course is actually 28.5".....).

Good quality butted 2.0-1.8-2.0 spokes, DT Swiss or Sapim would be my choice, little to choose between the two. Rim has next to no effect on spoke choice.

Internal width of the MTX33 is 26mm, it will take a 2.75" tyre but will be a bit rolly poly, I'd stick to 2.5" max to be honest, check your frame and see what will fit as well. Most decent brands have white lettering on the side. You won't have much choice in 24" these days anyway!

Thanks, Im downloading the info into my brain...

Is that spoke size 2.0-1.8-2.0 the size needed when ordering the length for a 24 inch rim?

rockmonkeysc

An RM9 will make a terrible trail bike, they weigh a ton and steer like an oil tanker.
Good luck getting it up any hills! It's a downhill bike so has zero climbing ability.
They do ride better on 24" wheels but only because a 26" will hit the seat tube on full compression.

machinebike

RockmonkeySC wrote:

An RM9 will make a terrible trail bike, they weigh a ton and steer like an oil tanker.
Good luck getting it up any hills! It's a downhill bike so has zero climbing ability.
They do ride better on 24" wheels but only because a 26" will hit the seat tube on full compression.

I may change the front sprocket to a 32 tooth from 36...I think that will make it peddle a little easier, if not, ill put a 3 chain ring set up up front.

rockmonkeysc

You won't be able to fit a triple chainset.
It's not the gearing that's the biggest problem, it's the suspension and geometry. It's designed to go down hills as fast as possible, which means it has very active suspension which is awful for climbing and the geometry is all wrong for it.
You'll never turn a downhill bike in to a trail bike, it'd be like turning a car ferry in to a supercar. They're too different.

machinebike

RockmonkeySC wrote:

You won't be able to fit a triple chainset.
It's not the gearing that's the biggest problem, it's the suspension and geometry. It's designed to go down hills as fast as possible, which means it has very active suspension which is awful for climbing and the geometry is all wrong for it.
You'll never turn a downhill bike in to a trail bike, it'd be like turning a car ferry in to a supercar. They're too different.

Bike store recommended a 32 tooth sprocket for the front, whats your opinion?

Im going with a 24 inch back rim with a 2.75 tire and a 2.35 tire in the front.

I figured the wider smaller tire in the back will get more bite when peddling (pushing) and with a narrower front tire, may be less fricition when "pushing" the front wheel.

The shocks I dont think are original, they are the avalanche and the front is boxer.

The front can stiffen and the rear shock has a little turn knob on it...not sure if I can make the shock less bouncy when peddling.

Im hoping to get a work out while riding this bike.

As far as weight, I lifted it up and it didnt feel much different then lets say an MTB Mongoose from walmart.

As far as geometry, not sure what you mean because when i sit on it, it feels oh so right

I was reading various opinions about this bike, some say makes a great free ride/play bike.

rockmonkeysc

Freeride/play bike means it's good for messing about on huge jumps and hucking off cliffs.
Cheap Mongoose bikes are extremely heavy compared to even a low end proper mountain bike, roughly 50% - 70% heavier!
The forks are at a very shallow angle, so is the seat tube. The back end is very long and the cranks are very high. All that is bad for pedalling effectively. The suspension needs different dampers to stop it bobbing as you pedal, stiffening it won't do anything.

The Rookie

machinebike wrote:

Is that spoke size 2.0-1.8-2.0 the size needed when ordering the length for a 24 inch rim?

That's the diameter (butting is the narrowing in the centre lower stressed part of the spoke), lengths you get from a spoke length calculated based on detailed measurements of the rim and hub, if you have to ask, probably best you get someone experienced to do it. Spoke length has to be accurate to within 2mm.