Replace cheap coil spring rear shock. Advice?

cosrush

I have a Floating Drivetrain full Suspension frame which has a standard and cheap coil spring rear shock. It does not have any damping at all, just a spring. Its great when landing big jumps but also 'bobs' a lot when pedalling.

I have been considering replacing the shock and I keep finding words like 'ProPedal and 'platform' and these appear to be something to do with lessening or preventing the bobbing effect when pedalling. I have seen lock out shocks and these seem to be good too.

Can any body please give me any advice about a good rear shock in the range of £100 to £200.

The current shock is 165mm x 38mm.

I am only a recreational rider i.e. just for a bit of fun and exercise occasionally, but when I ride is often very sandy and the bobbing effect just makes it hard work.

Thanks in advance.

nicklouse

What is the frame?

cosrush

Its a DDG Hitman

Like this one
http://www.google.co.uk/imgres?q=ddg+hi ... UDg&zoom=1

cooldad

Fox make a Float in that size.

nicklouse

just becareful id you can get a spring rate that you need.

But as it is a URT design there is not much you can do to change the feel of the ride. Want less bob then sit down.

cosrush

Thanks for the replies. So I guess I could try a stiffer rated spring? I do not know the rating on the spring fitted.

Would you not suggest a change of shock to one with damping then?

nicklouse

Call MOJO or TFtuned and talk to them about what may work.

Spring rate is given by a ratio of travel to shock stroke and rider weight. Again spring calls can be found on their websites.

No point in buying a shock that will not work or you can not get a Spring for.

cosrush

Just some more info to add:

I've just had a look at the fitted spring on my bike. It says 1100 on the spring itself. And in order to give the amount of sag whilst riding (for my weight) it is compressed just over 1 inch before I even sit on the bike.

The spring appears to be approx. 1 3/4" in width and 3" in length.

I do not know whether that spring rate is average low or high. But I guess that I should at the very least be using a higher rated spring such that I could achieve the same amount of sag without having to compress the spring so much in the first place.

The Rookie

HIGH, typical rear spring rates are in the 500-650lbin category, try to work out the leverage ratio (how much the spring compresses per how much the rear wheel moves up, easy to do if you take the shock out, start at normal sag position and then move the wheel up and inch and measure shorteneing of shock gap.

Simon

nicklouse

cosrush wrote:

Just some more info to add:

I've just had a look at the fitted spring on my bike. It says 1100 on the spring itself. And in order to give the amount of sag whilst riding (for my weight) it is compressed just over 1 inch before I even sit on the bike.

The spring appears to be approx. 1 3/4" in width and 3" in length.

I do not know whether that spring rate is average low or high. But I guess that I should at the very least be using a higher rated spring such that I could achieve the same amount of sag without having to compress the spring so much in the first place.

as i feared you are going to strugle. You will not find a suitable air shock.
as for a coil shock as mentioned above talk to Mojo and TF and see what thay can do.

cosrush

Thanks for the reply.

I just gave TFtuned a call and basically they advised against changing the shock as it would not only be costly but would never eliminate the flaws in the design of the frame, in other words it'll always bob.

This then leaves me with the following options:

1, Keep what I have - No additional cost

2, Try a different shock. Perhaps one with a lockout. This might give me the best of both worlds combining the ockout making the frame feel more like a hardtail and then normal shock operation to absorb the heavy landings

3, Ditch the frame and buy a Hard tail instead

4, Ditch the whole Full Sus frame and shock and replace with a newer Full Sus and shock - very expensive and not likely to happen!

:-|

nicklouse

1 works.
2 you will not find one. or it will only be as "good" as the one you have.
3 ....
4 fun.

but as it is a URT you can not change the bobbing.

cosrush

Any comments on this particular frame? I could stretch to one of these and it comes with a shock. I liked my DDG and it has stood me well for 15 years or so i've owned it. The cost of the this frame is the same as I had budgeted for a new shock.
http://www.rocknrollbikes.com/downhill/ ... shock.html

:?

386ka

I would go for option 3. It will be lighter bob-free.

cosrush

I took my shock off today to have a good look at it.

Details as follows:

DNM DN88
Shock length eye to eye = 152mm
Max length between spring platforms face = 77mm
1100 spring uncompressed = 62mm
Spring ID = 45mm
Spring OD = 30mm
Shock body max diameter = 48mm

It says on it 'warning: contains pressurised gas' but being able to close the shock easily by hand tells me the gas has long since left the shock!
So the shock is even smaller than I first thought.

My only concern with buying a new hard tail frame is that its been over 20 years since I've ridden one, and my only memory of it was that it was hard going in the wrists especially. This was before I ever bought any front sus forks though.

The Rookie

Hardtails hurt your butt, rigids hurt your wrists....I have wrist problems and don't suffer any wrist pain on my HT.

Simon

cosrush

Oh I should have mentioned in case it changed peoples opinions, most of the components on my current Hitman frame are XT or XTR, plus custom Mavic freeride wheels. The reason I mention this is that I wouldn't expect to change any other components except for either a replacement shock for my current frame or get a new (if cheap) frame instead and change all the components over.

I have been looking at some second hand frames, hardtails being obviously considerably cheaper. I have seen a 2007 Specialized Hardrock which seems ok, but im also still considering the Full Sus. DDG Mutha.

mrmonkfinger

cosrush wrote:

The reason I mention this is that I wouldn't expect to change any other components except for either a replacement shock for my current frame or get a new (if cheap) frame instead and change all the components over.

Expect to change some or all of: headset, fork if old frame is 1" steerer and new isn't (it won't be), seatpost & clamp, brakes if old are V and new isn't, wheels if going v -> disc

cosrush

mrmonkfinger wrote:

Expect to change some or all of: headset, fork if old frame is 1" steerer and new isn't (it won't be), seatpost & clamp, brakes if old are V and new isn't, wheels if going v -> disc

That's a very good point. A new seat post wouldn't break the bank, but new forks would!

I don't plan to switch to disc brakes just yet as my wheels are on non disc hubs, and i'll have to rebuild them on new hubs but the statement about the steerer is valid and one i'll have to look into. If I cant swap my forks over then i'll definitely just settle for a replacement shock as anything else will prove far to costly at this time.

cosrush

I've just checked the steerer tubes/headsets on my current frame and the Spec HR sport and they are both the same (1 1/8") so that's a plus, but it doesn't have rear V Brake mounts so a disc conversion would be needed.