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Old 11-11-2012, 11:34 AM   #46
Beastly Adventurer
Prutser's Avatar
Joined: Aug 2012
Location: The Dutch swamp
Oddometer: 1,030
Thanks Rucksta. That a great report !!

All the things you mention are the same as I notice on my bike(s).
Using the bikes for the same sort of riding.

I do have a long fork in my bike now.WP48mm with 300mm travel.
The long straight center stand is changed for one with an angle in the middle. To be able to use some wheel travel before the thing is dragging through the sand.

Next to my R80ST I do have a R65GS thats still original. The low center of gravity is the best for the handling IMO.
But the wheel travel and ground clearance from the ST is great too.

If I would have to choose between the 2 options it would be a real difficult choice.

After riding Dmaster's bike a few times I think thats the way to go. (R65GS with original swing arm length using max travel with custom shock and a shortened DRZ fork.) (Now only some wing shaped custom triples with the proper off set)

Originally Posted by Rucksta View Post
Can't look at either end in isolation, one affects the other so thanks for this.
I notice you have a long centre stand.
Do you have a long front end already?

Best all round geometry I've had is stock.
Next best was 1" rise in the front and 1.5" rise rear.
Bike became a slider with seamless transitions in and out of a slide.
It used more gas as it sat higher on the road and created more drag.
Top speed was down.
Bike became a bit harder to flick through esses on road and became more lively pushing it down into a turn on dirt while maintaining an upright body position.

Tyre selection is becoming more agressive as the thing becomes a dirt bike.

Changes to swing arm
- shorter better turning. twitchy under power. great wheels stands. reduced travel. didn't like it.
- longer more progressive transition into slide and able to feed heaps more power through the slide to maintain it
without the back wheel chasing the front. Less so returning to staight tracking about the same as stock.
- Longer tavel.

Longer also meant it was harder to break into a slide and the forward weight bias made the front stick better which was OK for 'wheel in line' dirt riding but made it a leap of faith to break the bike into a two wheel slide.

On road behaviour is starting to fall off now as the lean angles required to turn the bike are becoming more than the knobby tyres are prepared to give.
The bike is now a dirt road screamer with OK road manners and the potential to be an off road bike except for the front end It has to go.

With a front end replacent and a long swing arm I have a great off road touring bike with heaps of clearance good travel great weight distribution when carring a load, stable in a straight line and hard to get a leg over worse with luggage on the rack.

Fork offest is 20mm with Axle lead at 30mm travel is 270/240 and 'Im using 260/235.
Bike is stable especially in a straight line even in sand but it is hard to dig the front end out of a rut using throttle.
Weight transfer on the suspension needs to be controlled and some planning is required to throw the bike around.
Dive under brakes is controlled by lever modulation.

I want most of that but long distance offroad touring is not the the bikes primary or only use.
I want to ride dirt roads, fire trails, farm tracks, and enough single track to join them together.
I want to keep pace with the traffic on the motorway and have effective passing performance from legal speeds on two lane and single lane back roads.

Changes were required.

I now have a bike that sits on the standard centre stand with both wheels on the ground under compression (stable on the forecourt of a gas station but only just)
Ride attitude is level as stock with about a 2" rise front & rear.
Swingarm is std length with mods described elsewhere
Wheelbase is near standard (shorter on suspension extension longer on compression)
Travel used is 220/210
Triple clamp offset is 25mm
Axle lead is 30mm.
Weight bias is towards the rear over the stock bike.

I'd like some more axel lead.
I think it will get me closer to the sweet characterisitcs of the original bike.
I'd also like a little more rear wheel travel and / or a lot less unsprung weight in the rear.

For me any comparison of the pros & cons has to be filtered by the bikes intended use and what compromises the owner is prepared to make to achieve what he preceives as a pro.
BMW R100'91/R80'93/R75/6 R80ST'83/R65GS'87/GasGasTXT300/DouglasW20-1920

Ride Report 2012
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