DRZ Forks and HPN Tank on a R100 GS PD

[Dmaster]

Originally Posted by Phreaky Phil

Been thinking about this, i'm sure the BMW triple clamps are closer together than the DRZ ones, therefore with the axle point raised, you could slide the forks down in the clamps and maybe run a flat bottom clamp, not needing a gull wing type ? These are more redily available. I'm thinking about this for a long travel rear end.
I will have to wait until I get our DR home so I can measure. ( picking it up tomorrow )

This mod brought it to this:

Fully compressed the tire (90/90-21) hits the fender and there is just enough space for the dust seal.
Running a "flat" bottom triple tree is still not a option unless you want much clearance between tire and fender fully compressed. If you want to use full stroke (285mm i guess i measured) your front will be high (something i do not want) I shortened it anyway I'm using my stock swing arm at the back and i still use my stock center stand .

[Phreaky Phil]

Originally Posted by Dmaster

This mod brought it to this:

Fully compressed the tire (90/90-21) hits the fender and there is just enough space for the dust seal.
Running a "flat" bottom triple tree is still not a option unless you want much clearance between tire and fender fully compressed. If you want to use full stroke (285mm i guess i measured) your front will be high (something i do not want) I shortened it anyway I'm using my stock swing arm at the back and i still use my stock center stand .

I was thinking of this setup with a long travel rear and sliding the forks down in the clamps by approx 20mm to use a flat bottom clamp. On page 1 a pic shows a spacer under the top clamp to pack it up as the BMW steering tube is shorter than the DRZ one. Without this spacer, the forks tubes could be slid down. I hope that makes sense !

[Prutser]

Originally Posted by Phreaky Phil

I was thinking of this setup with a long travel rear and sliding the forks down in the clamps by approx 20mm to use a flat bottom clamp. On page 1 a pic shows a spacer under the top clamp to pack it up as the BMW steering tube is shorter than the DRZ one. Without this spacer, the forks tubes could be slid down. I hope that makes sense !

Using the flat tripple would make the bike higher.
Dmaster made a new stem. And isn't using a spacer under the top triple.(correct me if i'm wrong mate)
If you would use a flat bottom triple clamp and would fully compress the fork untill the sliders touch the clamp.
Than there is about 1" of space between the tire and the clamp. This 1" is extra height at the front that can not be used for wheel travel. For the handling of the bike you need to lift the rear end. You could give the rear less sag but that way you will loose traction and comfort.
Keeping the bike high for ground clearance is nice but the lower bikes handle much better than the high ones with technical riding. ( not talking about fast or straight tracks)

With this mod the bike can still be low at the front with a lot more travel than original. And some real damping !!!!!
The damping of the drz fork can be tuned to the needs of the airheads and still use soft springs without the bike bottoming out all the time or dive to the max with hard braking.

The long travel rear does cost a lot for a few cm's extra wheel travel.
With the drz fork mod u can gain a lot of travel and controle but still use the stock swing arm.

[Phreaky Phil]

Originally Posted by Prutser

Using the flat tripple would make the bike higher.
Dmaster made a new stem. And isn't using a spacer under the top triple.(correct me if i'm wrong mate)
If you would use a flat bottom triple clamp and would fully compress the fork untill the sliders touch the clamp.
Than there is about 1" of space between the tire and the clamp. This 1" is extra height at the front that can not be used for wheel travel. For the handling of the bike you need to lift the rear end. You could give the rear less sag but that way you will loose traction and comfort.
Keeping the bike high for ground clearance is nice but the lower bikes handle much better than the high ones with technical riding. ( not talking about fast or straight tracks)

With this mod the bike can still be low at the front with a lot more travel than original. And some real damping !!!!!
The damping of the drz fork can be tuned to the needs of the airheads and still use soft springs without the bike bottoming out all the time or dive to the max with hard braking.

The long travel rear does cost a lot for a few cm's extra wheel travel.
With the drz fork mod u can gain a lot of travel and controle but still use the stock swing arm.

I have thoughts of building up an Expedition bike using my paralever GS and converting it into a longer travel monolever.For 2up riding long travel is needed as you cant stand in the rough stuff so the suspension must soak up everything. Another reason for a long swingarm is with 2uo it moves the weight behind the rear wheel forward. ( I would like to try a longer swingarm in my DR to see if would help stability and steep climbs) The Paralever is maxed out at 190mm of travel. The 1100/1150 Paralevers can be grafted in but the monolever i think is simpler and tougher, and probably lighter ? I think 250mm of Travel would be good. More may be better but the seat height may become a problem. I'm only 5'10" My DR650 with DRZ front and rear running minimal sag before luggage has me on tip toes. You mentioned wanting a clamp with more offset for the DRZ front. I have not ridden an Airhead with small offset clamps and am interested in your thoughts on the handling between the two ?
Cheers Phil

[Dmaster]

Originally Posted by Prutser

Using the flat tripple would make the bike higher.
Dmaster made a new stem. And isn't using a spacer under the top triple.(correct me if i'm wrong mate)

I do use a spacer but it's thin only 10mm i guess (can't remember the exact size)
I made the new stem as long as the stock DRZ stem but with the bearing sizes and spacing of the BMW bearings.

what triple tree are you planning to use?

Suspension wise this is the best i've had.
Handling wise it's not.
If i'm riding it with my "super motard" setup (110/70-17 and 130/80-17) at the time it steers well (lowering the front) it will get unstable. I've had a Showa UDS fork with KTM triple tree, this setup was way better (at handeling, but the fork was .)
With my offroad setup (90/90-21 and 110/100-18) its steers ok, but is unstable. I've compared it with a stock R65GS and its way better, but the suspension sucks

Much ground clearance isn't a holy grail IMO.
At times i got stuck i saw lightweight enduro's all around me get stuck......
Using your brains before riding into a puddle of mud will help more
And if I topple over because I can't get my feet to the ground what did I actually win?

And i always wondered, why a huge HPN tank? The stock PD is big enough right?
Where are you going if you really need all that gas?

[Ras Thurlo]

Originally Posted by Dmaster

And i always wondered, why a huge HPN tank? The stock PD is big enough right?
Where are you going if you really need all that gas?

The HPN tank allows you to have petrol far lower down and further forward than the stock tanks - which IMHO really helps handling off road, the key is to be disciplined in limiting the amount of fuel you fill it with.

I would rather have 19l in the HPN than the stock G/S for the above reason.

I really feel this benefit when going very slowly over technical ground, as you can almost balance it like a bicycle courier at traffic lights.

[Prutser]

Originally Posted by Phreaky Phil

I have thoughts of building up an Expedition bike using my paralever GS and converting it into a longer travel monolever.For 2up riding long travel is needed as you cant stand in the rough stuff so the suspension must soak up everything. Another reason for a long swingarm is with 2uo it moves the weight behind the rear wheel forward. ( I would like to try a longer swingarm in my DR to see if would help stability and steep climbs) The Paralever is maxed out at 190mm of travel. The 1100/1150 Paralevers can be grafted in but the monolever i think is simpler and tougher, and probably lighter ? I think 250mm of Travel would be good. More may be better but the seat height may become a problem. I'm only 5'10" My DR650 with DRZ front and rear running minimal sag before luggage has me on tip toes. You mentioned wanting a clamp with more offset for the DRZ front. I have not ridden an Airhead with small offset clamps and am interested in your thoughts on the handling between the two ?
Cheers Phil

Phil,

Keeping a low seat height and gaining more travel is tricky.
If you would like to do so you might end up with travel that can not be used, because the sump and center stand will be touching the ground.
I totally see that creating the longer wheel base would give more room to keep the weight off the luggage between the wheels and not behind the rear axle.(specially with 2 up)

On the Sibirsky trip I started with the luggage right above the rear axle. At the end of the trip it was all moved forwards.
Until it was almost touching my heels. With every cm I moved it forward (and down) the handling improved A LOT !!!!

Cheers

[buls4evr]

I see a thread like this and always wonder why someone who would go to all the effort to change their forks would pick a 20 yr. old design for a replacement. May I suggest to anyone else doing this that USD MX forks are plentiful on the used market and already come with very stiff springs for MX jumps. They can be altered internally for length or travel ala flattrackers. Why not use those? DRZ forks are notorious for their many "needs".

[Stagehand]

USD's are not without their troubles. Stiction, and lack of steering radius. WP 4860's are already 15 years old technology. There are lots of good forks out there. DRZ's are Cheap and very decent. And an easy swap, compared to some, so you calculatethe plusses and minuses.

[Prutser]

Originally Posted by buls4evr

I see a thread like this and always wonder why someone who would go to all the effort to change their forks would pick a 20 yr. old design for a replacement. May I suggest to anyone else doing this that USD MX forks are plentiful on the used market and already come with very stiff springs for MX jumps. They can be altered internally for length or travel ala flattrackers. Why not use those? DRZ forks are notorious for their many "needs".

Because the 20 year old design still works fine and has less friction than most modern USD forks.
The top of the fork is thinner than an usd so you could keep more steering angle before you hit the fuel tank.
They can be altered internally for length or travel too, just like the MX USD forks.
BECAUSE A LOT OF PEOPLE THINK THEY ARE WORSE THAN THE USD THEY ARE CHEAP

[Ras Thurlo]

Originally Posted by Prutser

Because the 20 year old design still works fine and has less friction than most modern USD forks.
The top of the fork is thinner than an usd so you could keep more steering angle before you hit the fuel tank.
They can be altered internally for length or travel too, just like the MX USD forks.
BECAUSE A LOT OF PEOPLE THINK THEY ARE WORSE THAN THE USD THEY ARE CHEAP

....and maintain the traditional look that some of us love

[hardwaregrrl]

Originally Posted by buls4evr

I see a thread like this and always wonder why someone who would go to all the effort to change their forks would pick a 20 yr. old design for a replacement. May I suggest to anyone else doing this that USD MX forks are plentiful on the used market and already come with very stiff springs for MX jumps. They can be altered internally for length or travel ala flattrackers. Why not use those? DRZ forks are notorious for their many "needs".

USD's are also notorious for blowing forks seals way more often than conventionals. If you really look around at people using their DS bike for true off road traveling, the forks are the first to go. Either they go after market, or backwards. Manufactures are noticing the starbucks adventure bike trend and cutting corners in the suspension department, so the 20 year old design is actually better than some of the forks on modern DS bikes.

[Daithi]

Originally Posted by buls4evr

I see a thread like this and always wonder why someone who would go to all the effort to change their forks would pick a 20 yr. old design for a replacement.

For all the reasons above and because all the parts I needed were available and very cheap/free.


After going to the trouble of offsetting the 18" rim 25mm it looks like I'll need a spacer to keep the disk away from the boot. I have a choice of three disks, 1100GS, K100 or 1100R......

[Rucksta]

Originally Posted by buls4evr

I see a thread like this and always wonder why someone who would go to all the effort to change their forks would pick a 20 yr. old design for a replacement. May I suggest to anyone else doing this that USD MX forks are plentiful on the used market and already come with very stiff springs for MX jumps. They can be altered internally for length or travel ala flattrackers. Why not use those? DRZ forks are notorious for their many "needs".

Plus the rear end is still the weak spot with suspension performance (para or mono) and there is only so much to be gained upgrading the front end until the rear is addressed - even then there is only so much you can do with the rear.

[buls4evr]

Originally Posted by Rucksta

Plus the rear end is still the weak spot with suspension performance (para or mono) and there is only so much to be gained upgrading the front end until the rear is addressed - even then there is only so much you can do with the rear.

OK if you just want a "look" I can see it..... but no way is that DRZ fork as good as a nitrided USD fork in any way... strength, stiction, triple clamp rigidity are all way better on the USD. The DRZ forks are just CHEAP and are a really old design. As far as the rear shock goes, you get what you pay for . An Ohlins would be a drastic improvement.