the DR650 thread

[nat_han]

Double Posting.
Sorry...

[Snowy]

The UK DR forums had something on fitting the freewind head to a DR.

There were some issues if I remember correctly. I looked at getting a head, but the UK guy selling it dicked around.

I can't for the life of me remember if they were single inlet dual outlet, or dual inlet dual outlet. I think single inlet dual outlet.

Did the freewind frame have a single front down tube or a double?

There was an issue, not insurmountable, but something.

[Snowy]

Originally Posted by nat_han

questions...

Try checking your front preload. Remember the basic formula is with the bike fuelled and loaded with you on it you should be using about 1/3 of the available front and rear travel. Check both, the rear being too soft will add rake to the front and make the wobbles potentially worse. If you have PVC spacers you change the preload by changing the length of the spacers.

Try swapping the wide flat front mudguard for something smaller along the lines of the motard Acerbis guards every one seems to use.

At 57kg, without being nasty, I'd say you're on the light side of what the spring rates are best for. Your front end is probably just not reacting to bumps and irregularities on the road surface. Stiction in the fork seals, and the heavy springs, combined with the wrong pre-load will make the front end feel rigid.

I'm guessing you may not be super tall either, forgive me if that's too direct. So perhaps the lowering option will help when getting the pre-loads and set up correct.

[Speirsy]

Can someone tell me the measurement of the stock front springs?
Bought some springs off fleabay claiming they are ohlins? i thinks me might have been shafted?

The one's I have here are 550cm long.

[Rusty Rocket]

Originally Posted by Speirsy

Can someone tell me the measurement of the stock front springs?
Bought some springs off fleabay claiming they are ohlins? i thinks me might have been shafted?

The one's I have here are 550cm long.

Many of the aftermarket springs are quite a bit shorter and require a longer preload spacer.

The Suzuki service manual says the service limit is 548mm

[nat_han]

Originally Posted by Snowy

Try checking your front preload. Remember the basic formula is with the bike fuelled and loaded with you on it you should be using about 1/3 of the available front and rear travel. Check both, the rear being too soft will add rake to the front and make the wobbles potentially worse. If you have PVC spacers you change the preload by changing the length of the spacers.

Try swapping the wide flat front mudguard for something smaller along the lines of the motard Acerbis guards every one seems to use.

At 57kg, without being nasty, I'd say you're on the light side of what the spring rates are best for. Your front end is probably just not reacting to bumps and irregularities on the road surface. Stiction in the fork seals, and the heavy springs, combined with the wrong pre-load will make the front end feel rigid.

I'm guessing you may not be super tall either, forgive me if that's too direct. So perhaps the lowering option will help when getting the pre-loads and set up correct.

Thanks for the reply.

Yes, I'm only 167cm tall.

I've installed the lowering links from Procycle, and have lowered the rear suspension(using the upper hole attachment at the bottom of the shock).

How do i go about checking for the usage of the 1/3 travel length of my front forks? When I'm on the bike(fully fuelled), only the rear suspension sags. The front never moves unless I apply front brakes or go over humps..

[ChromeSux]

[QUOTE nat_han My Dr650 with loads of add ons and farkled for my liking.

Just 1 question to ask regarding the front suspension 'problem' i might be facing...
History: Installed Ricor Intiminators, Progressive Springs, 5wt Maxima Fork Oil, Original Suzuki Spacers.
I'm 57kilos/ 130lbs, always ride with those 3 alu boxes.
Changed tires to the Tourance at 4000kms. Did not do Balancing after that.

Perceived Problem: At slower speed of between 30-50 km/h, on road/tarmac conditions, the handlebar jerks up and down over every single unevenness I ride across. There's no smoothness. I want to feel less of such vibs on the handlebar- the throbbing feeling..

2nd Problem- At speed of 120km/h(74.5 mph) and above, on open highway, the front catches wind easily causing the front tire/rim to wobble left and right. If I do not slow down, a 'tankslap' would likely happen. I would like to ride constanlyt at 130 to 135km/h without feeling that instability at the front.

Would reducing the original spacers' thickness help in solving the first problem I have? I got a feeling that there's too much "preload"...
Should I try Balancing of both front and rear rims? I did not do that after I changed tires couple months back.

For the 2nd problem, I've a safari tank on the bike and the RalleMoto Damper wouldn't fit without some major shifting and such... So, I'm thinking that maybe a Fork Brace together with lowering the triple clamps on the fork tubes will settle it for me...

Comments and advice?

Thank you![/QUOTE]

I just went thru this same thing yesterday, i know someone is going to say what i tell you is WRONG but it worked for me, take the forks off and look at your fork fluid level, the one i did yesterday was not full enough and did exactly like your bike.

A few days ago we did the install, and never could get the front forks to ride smooth, it was just as you described, we checked the fluid level again and it was low, we added fluid, set to the correct level for the second time, its real smooth now.

Edit. you may try to Ricor and ask their opinion, its damn near impossible to get them on the phone though.

[Snowy]

The front is your problem then. The easiest way is to have a stand, or centre stand that can take the full weight of the bike.

With the weight on the stand and the front tyre only just touching the ground, measure from axle centre to the bottom of the lower triple clamp.

Then, sit on the bike and have someone repeat this measurement for you.

You should get a measurement approx 85mm shorter than the first.

If not, you'll need to remove the spacers from the forks and try again. I can't remember if the springs are actually long enough to run without spacers completely. I got rid of the DR forks before I'd played with them much.

I would try it without spacers, then add only enough to get pre-load right. Which you can calculate based on the difference in measurements and the length of the spacer. I suspect you will need some spacer, and that the spring rate will still be too high to give you the right "rider sag".

From the sound of it, the original standard spring rate would be stiff for you. How high did you go with the front spring rate when you fitted the new springs?

I'm about 90kg without riding gear and I have 0.55kg/mm springs, and they are stiff on road with light load. I think standard the DR was around 0.44kg/mm from memory. Which I read somewhere is for a rider of about 60kg.

Feel free to correct me you other guys...oh wait..DR forum...someone will be along any second...

[KaaJa]

Originally Posted by Snowy

The UK DR forums had something on fitting the freewind head to a DR.

There were some issues if I remember correctly. I looked at getting a head, but the UK guy selling it dicked around.

I can't for the life of me remember if they were single inlet dual outlet, or dual inlet dual outlet. I think single inlet dual outlet.

Did the freewind frame have a single front down tube or a double?

There was an issue, not insurmountable, but something.

Freewind head is dual inlet and single outlet. It has 33mm mikunis.

[ram1000]

Originally Posted by MeterPig

Why do you say you would do the DRZ conversion over your USD forks now? I am actually curious since contemplating the change over. DRZ forks can be had for fairly cheap as can RMZ forks.

The DRZ forks have 11" travel which is plenty to work with, and the internals are such that they can be brought up to competition specs. The DRZ forks also have cartridge dampening which allows total adjust ability. The DR 650 is maybe 400 lbs wet and although I gained a lot of speed over whoops I don't often ride that fast and if I did I would go back to an mx bike. The RMZ forks required the RMZ front wheel assembly and I found the front brake for the RMZ to be too small- since then I bought an EBC over sized brake for the RMZ wheel which puts things back into perspective, but the DRZ brake assembly and wheel would have been satisfactory especially off road where the change over does any good. The RMZ forks have more than 12" travel and even with the forks slid into the triple clamps 1 1/8" the natural ride height between the front and rear is still too low in the back. I had Cogent rebuild my rear shock and he added some internal travel to the shock giving somewhere around another inch in the back- that would put the rear at 11" or so. This is still not enough to raise the back to the point the front is steep enough for tight turning so I also had him increase the assembly length of the rear shock. This raised the back another half inch or so and I now have a decent turning bike although I would prefer even more difference between the front and back to play with for different tire sizes. When I had stock forks on it I used Eibach springs and slid the stock forks up about 3/4" and set my sag according to mx specifications. This gave me much quicker steering on the trail, and I wanted to match that effect with the new forks. As it sits with no rider the seat height is now 36 1/2". This is not excessive for me but I like to keep my trail bikes as low as possible for easier hill climbing and single tracking, although I am 6' 1". As the forks are set now there is 11 5/8" between the top of the front tire and the bottom of the plastic fender with the forks topped out. With 12+ inches of travel I bottom out rarely but some times into the fender. There is not enough traction between the fender and the tire to create an unexpected stop. In spite of this steep steering angle the bike slams whoops at much greater speed with no hint of tail swapping. I figure I can crash at 20+ mph more than before!

One advantage of the RMZ forks is they come stock (2007) with .47 springs. This is the exact rate I had for my aftermarket springs in the stock forks so I didn't have to change the spring rates for my ideal rate.

If I had used the DRZ forks I would not have had to extend the rear and would have kept the seat height lower. This bike is set up for me to ride and not to race but past racing experience has given me an understanding of whats needs to be done.

[nat_han]

ChromeSux & Snowy,

Thanks for your replies.

I'll get the forks off to check out the fork fluid again.

I do not quite get what you mean and all those intricate steps of measuring the front fork travel length with my weight and bike being fuelled. Thinking of bringing the bike to a local suspension guru to ask for his opinion.
But I'd changed out the stock springs due to the 40kilo weight of the Safari Tank(with the fuel within) at the front.

I'd thought a thicker rate spring would help in this aspect. I might switch back the springs to stock just to try out the difference...

Thanks again guys!

[TinkerinWstuff]

Originally Posted by nat_han

..... Thinking of bringing the bike to a local suspension guru to ask for his opinion. .....

Would be money well spent. I have never regretted a moment or a nickle I've spent learning from my local suspension guru.

[Snowy]

Originally Posted by KaaJa

Freewind head is dual inlet and single outlet. It has 33mm mikunis.

That's it. I knew it was dual something single something. That was the pain in the ass part I think, trying to figure out how to get the carbs and filters to fit into the frame.

Anyway, the guy selling it wanted what amounts these days to "big valve head" money almost. I figured if I wanted extra go there were better ways to get it.

and to be honest, in off road terms, I could do with actually being able to ride better before I made it any faster.

[NordieBoy]

Originally Posted by nat_han

ChromeSux & Snowy,

Thanks for your replies.

I'll get the forks off to check out the fork fluid again.

I do not quite get what you mean and all those intricate steps of measuring the front fork travel length with my weight and bike being fuelled. Thinking of bringing the bike to a local suspension guru to ask for his opinion.
But I'd changed out the stock springs due to the 40kilo weight of the Safari Tank(with the fuel within) at the front.

I'd thought a thicker rate spring would help in this aspect. I might switch back the springs to stock just to try out the difference...

Thanks again guys!

I'd be looking at about 5mm of preload.
The stock springs may be better in your situation too.

Try the stock springs and spacers and see how it goes.

[Snowy]

Originally Posted by nat_han

ChromeSux & Snowy,

Thanks for your replies.

I'll get the forks off to check out the fork fluid again.

I do not quite get what you mean and all those intricate steps of measuring the front fork travel length with my weight and bike being fuelled. Thinking of bringing the bike to a local suspension guru to ask for his opinion.
But I'd changed out the stock springs due to the 40kilo weight of the Safari Tank(with the fuel within) at the front.

I'd thought a thicker rate spring would help in this aspect. I might switch back the springs to stock just to try out the difference...

Thanks again guys!

For the suspension to work properly it needs to sit at a certain point in it's travel.

If the springs are too hard the fork will be "topped out" in that it is fully extended. This, in handling terms, means that for every small bump you hit the wheel will "hop"off the ground after it passes the top of the bump, because there is no further extension of the fork available and because it's too firm to compress the fork as it hit's the bump.

Which is the thumping you are feeling.

Worst case, when cornering on fast choppy tar the front will just chatter across the surface and low side you.

By having some sag, ideally about 1/3 of the travel, and having the correct spring rate, the wheel rises far enough to absorb the bump, and can travel downward far enough to keep the tyre on the ground even if there is a small hole on the other side of the bump.

This means you have traction at all times, because the tyre has pressure maintained between it and the ground under a wider variety of surfaces.

Controlling the acceleration and deceleration in either direction is what you installed the Intiminators for. This helps to keep the pressure of the tyre on the ground more consistent and arrest the tendency of the spring to over react and oscillate.

You'll see this in cars with worn out shocks where the wheel is hopping up and down like mad while moving over what seems like a smooth surface. It reduces traction.

Creating traction over a wider variety of surfaces is what suspension is all about. Having a comfortable ride is nice, which is why it's a bit of a compromise. For a track bike or race bike you generally have a stiff ride to get better traction at the expense of comfort, for a cruiser you have softer more luxurious ride for comfort at the expense of traction.

For a touring DR you have relatively long travel, that needs to carry varying loads over the widest variety of surfaces. Which is about the hardest set-up to really get right. Hence the really wide variety of solutions that DR owners claim to be "it".

You are aiming to measure the suspension with no load at all, and then with the "normal" riding load. The difference between the 2 measurements, done front and rear, should equal approx 1/3 of your available suspension travel. You can measure between a point on the bike and the ground, or between a point on the bike and the axle, as long as the measurement reflects directly the difference in axle travel in linear terms. So I measure from the axle in the direction the axle is travelling to get an accurate representation of the difference.

Getting the rear right makes a big difference to the front because it changes everything about the geometry of the front. Rake and trail, the turning rate and self centring abilities, are altered by the height of the rear relative to the height of the front. This is possibly where your high speed "wobble" is originating. The more rake you have the more open the big mudguard is to catching wind. So it may be a factor as well. But fix one you fix the other.