Rear Suspension

[ProXimaCore]

Can anyone tell me how a rear suspension affects how the bike handles? I'm not entirely convinced my replacement (2nd hand) shock I got is much better than the old one that started leaking. It doesn't leak at least and isn't all springy. But it just feels a bit dead. The adjuster is set to maximum but it still feels quite soft.

Not that I'm planning on splashing out on a race shock or anything. I'm just curious as to what sort of difference you'd notice.
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Honda NSR125R -> Suzuki GSXR400R GK76a -> Kawasaki ZX636 B1H -> Honda CBR400RR NC29 -> Nothing

[stryker]

A soggy shock can affect your ability to corner. Not experienced it myself.

Also while coming to a halt on bumpy surface like where those stupid lines are across the road at an island, your braking distance can be increased as your wheel is not held to the road so well.

[ProXimaCore]

[MarJay]

I would say that if the shock is genuinely soggy on maximum preload then you are in trouble really.

Personally I would say that adding preload to the spring is just masking the problem of lack of damping.

Believe it or not, I reckon that you might actually be faster with less preload. Loads and loads of people that I talk to about suspension seem to think that maxing out on preload helps cornering. Well nine times out of ten I think it doesn't.

If you set the preload on the rear shock of your bike so that the static sag is correct for your weight, then the bike should handle better. If the rear shock still does feel soggy, then I would reccomend either getting that one rebuilt by a professional ( I used www.race-components.co.uk The guy there told me that the chap who runs Maxton suspension was once his apprentice!)Or a new shock. For a new shock I reccomend www.hagon-shocks.co.uk .

You could go for Ohlins or Maxton or Penske or whoever, but Hagon are half the price and just as good on the road IMO.

In the mean time, have a gander at this
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Rory]

Give me a go on your bike and I'll tell if you the rear's soggy or not

(I'm about twice his weight and about the same height - not huge, just dense )
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My Old CBR400RR | Bike Oil FAQ | Petrol FAQ

[Kickstart]

Hi

In very simple terms.

Set the rear shock too hard and the back end will not grip as well, but set it too soft and the bike will bounce around so that it is not in contact with the road (and so won't grip as well).

If you turn the preload up then you need to turn the damping adjuster up as well.

If you have insufficient damping then the bike will oscillate, too much damping and the rear suspension will not have a chance to react to bumps.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Rory]

Have you only got preload adjustment on the shock, Prox?
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My Old CBR400RR | Bike Oil FAQ | Petrol FAQ

[Andy99]

Have you measured the static sag of the back end? If you try measuring it with the preload wound full on then fully off does it give different measurements? If not the shock is no good,most people reckon to allow about 10-15mm static sag at the back end.

If the preload is wound on too much(ie fully loaded) the steering should feel faster as the back is higher,but may skip about and give a very bumpy ride as the back end is not be compressing enough over bumps.if the preload is set too loose then the bike will feel lower at the back with slower steering,it may feel 'bouncy' at the back as the spring keeps moving after hitting bumps.Both of these examples are extremes,you will need to find out what amount of preload suits your weight,bike and riding style.
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Nothing gets the point across quite like a raised middle digit.

Just call me General Crazypaws.

[ProXimaCore]

Thanks for the help so far guys. Quite good information there!

Right, a quick query. See the attached picture. I've marked the two adjustable areas with red arrows. The one on the actual shock itself, is that what you call the preload adjuster? That one is currently sitting half way up the thread, so there's plenty more room for it to adjust. I just don't have any tools I can use to shift it. Any suggestions?

The 2nd arrow (top arrow) pointing to the little canister type thingy (technical term ) That's on maximum setting. I really don't think it actually works. My old shock never actually had this part. But on the manual for my bike I have. It shows two seperate diagrams for the shock. One like the pic attached, and the other one like my old one.

I think this is actually turning into a workshop item. Maybe it should be moved.
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Honda NSR125R -> Suzuki GSXR400R GK76a -> Kawasaki ZX636 B1H -> Honda CBR400RR NC29 -> Nothing

[dainesefreak]

Something else to consider is the rear tyre. Tyre wear, inflation and rear wheel adjustment can also affect the way the bike handles, ranging from a vague, to a loose feeling at the back end.

[ProXimaCore]

[m i k e]

Why not try www.patternparts.net That'll get you a cheaper rear shock!

Just a thought

HTH

Mike
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Bom Chicka WAHHH WAHHHHHHH!

[ProXimaCore]

[m i k e]

They are brand new, i've ordered a fair few parts from them, they're not original manufacturers parts though. But for certain parts like bars, levers, etc they've been great! If you can't find any parts on there for your bike, have you tried ebay? or have you tried one of those breakers lists? Where you'd list the items you need and and it sends a list to breakers all over the country? I used one of these for a few parts the other week for a second time, found them very useful! Although the first time I tried them for my last bike they never even responded!

Hope you find your parts!

Mike
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Bom Chicka WAHHH WAHHHHHHH!

[ProXimaCore]

[m i k e]

Is that because it's christmas in twelve weeks?

" Muuuuum, you know it's christmas soon...? Well my bikes needs a few simple parts and I can't afford them all what with buying christmas presents and all........" {flutter eyelashes}



Mike
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Bom Chicka WAHHH WAHHHHHHH!

[ProXimaCore]

[MarJay]

[ProXimaCore]

[MarJay]

The same is true for the forks. The article covers the suspension as a whole.
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Kickstart]

Hi

You say the shock is not springy but just feels a bit dead. Not sure from that description but it does sound as though maybe the preload is too low and the damping adjuster too high.

Have a fiddle before splashing out £250 on a new rear shock.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[ProXimaCore]

[Kickstart]

Hi

Yes the big threaded adjuster is the preload, and you should use a C spanner to adjust it (or 2 C spanners if there are 2 nuts, one as a lock nut). You can also bodge it and use a hammer and a small punch to tap the adjuster nuts round (just to give a few professional mechanics nightmares).

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[MarJay]

[Rory]

If you want a second opinion, I'll pop round and have a look for you, Prox. Not that I know very much about shocks, but...
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My Old CBR400RR | Bike Oil FAQ | Petrol FAQ