Older DR 600/650 thread (Pre mid 90's)

[DeepBass9]

Agreed, gooi 10w like the manual says, you in for a 200k test ride Volroom? 31st of March

I'll likely come a join you on that Breedt's nek ride.

[Wildcoast]

Marvelous DB9 now we need Volrooms boney for a full pre-96 turnout, ooooops Superdave you in?

[DeepBass9]

Cool, I'm keen to see that pimped DR of yours in the flesh!

[Wildcoast]

  as am I to see your original legend

[SuperDavexlv750r]

I wish I could join. Really. Really.

But I can't. I am waiting for a gasket set already forever, and my ...

Pro-Cycle parts are also finding their way to me. Decided against going for 100mm bore as having looked closely at the head there is simply not enough meat to go up 5mm in dia.

So I ordered some nice goodies including the Wiseco 97mm piston.

When parts arrive will have them Power Koted i.e. barrel, piston top, combustion chamber including valves and springs, exhaust, and tappet covers. The exhaust system 3mm larger if possible and balanced crank.Possibly a larger oil cooler will also do service.

The head will be modded to big valve head i.e. 32mm and 36mm valves with reprofiled cam. Some flowing of the head as well.

Dynotuned BST40 carb with slide mod and we will have a very nice spread of torque for the bike and  that can run at high revs without any risk of overheating.

So I hope by end of April we will be up and running.

Now - to say a prayer and ask for some help here is probably the right thing to do at this point. LOL

 

[Veemax]

I will know tomorrow morning , if I am coming to Vaalie Land. I am in the procurement process again ... pretty unexciting V twin to kick back on to ride with the Missus ...  ( who is now on this Forum as Goshawk.....when in DualSport mode on her XLX350R....)

Anyway , some of the best rides I have done in life, have been with mates on similar hardware, so if I have to suck it up on an 805cc Cruiser to ride tar with the wife, so be it.

If this Benoni Bike comes together , it would be great to meet you guys for a beer, and make larger, more elaborate plans for later this year, for an Ole DR gathering ?!

If any of you volunteer to ride an 800cc Marauder down to CT , let me know : ) : ) ..... I might be an ou ballie turning 50, but I can suck up kilometers as good as any of yer !

[volroom]

Yeah, I'm in but can only pitch at 12pm..buisy in morning, sunday can also work?
10W..what about mixing it with gear oil? Got some 80w90. What would the ratio be? I'm thinking take fork legs out, pour out as much oil as will come out and measure quantity. Then, put same volume back but mixed

Good idea?bad idea?

Superdave, that boney you are buisy with sounds awesome..strongs for the process

[Wildcoast]

Put the exact amount as the manual tells you in your forks Volroom.
Go and buy some 10W, suspension is prob the most important thing on a bike so don't skimp on it 

Superdave, what gaskets are you waiting for? You can prob make up all gaskets besides the head and base gaskets.
I wanna see how your DR runs after those mods, she should be a flyer 
What valves will you be using? Sounds interesting 

Veemax, are you spending a few days up here?

[Veemax]

SuperDave ! Your SuperDR camshaft reprofile ... will of course change the nature of the beast in it's entirety. Do tell us more ... what profile will you choose ? Benchmark from another enjin ? Concoct by rule-of-Dave your own open/close/lift/duration curve ? This is fascinating ... have you an engineering firm in mind already able to anneal, regrind, reharden etc ?

Bigger everything with better heat conduction and more compression is going to do great things , but the cam will dictate the persona won't it ?

Years ago I soooooped up an XT500 with Wiseco pooftin , hot cam et al , I went with a bigger header .... was a disaster.....I recall someone giving me a fat lecture on Exhaust Velocity ..... have you seen the skinny headers on superbikes these days ? I'm just sayin' .... beware this variable does not work backwards on yer ... exhaust design is a tricky thing, maybe a stepped header or a careful logical approach with a Before and After factored in, might serve you well. Just sharing and caring here : )

[SuperDavexlv750r]

@veemax - cam shaft profile is Pro Cycle 190. I have all the specs and durations and overlaps and , and, ...
Been proven by Procycle so if the cam engineer knows what he is doing we have a winner.

As for the slightly larger header pipe - Iam not sur eyet of the effect of the gas velocity and will be doing some calculations with a fundi on this. We will still decide on this.

As for the bigger valves - its no bigger than the Honda XR650, KLR650. In fact it is a little small for the bike and this should relase some volume of gasandhence the possible size increase on header. More volume in thin pipe will speed up velocity but it may also restrict it. The fundi's will know better.

Now the ride to Breds Nek 3121 March 2012 - I was contemplating the Honda XRV750R but it has no protection bars and if I should drop it(it weighs like 220kg), gonna damage this collectors item and there are precious little if any parts around.

Maybe take it vewry slowly - but still no guarantees of not slipping or falling.

So then perhaps the wife's Aprillia Pegaso - but the tires are Kenda on rear and if there is any hint of water it will be like riding on an ice rink.

Dunno- decisions decisions

[volroom]

Now you are playing to my core competence as a retired inkmaker : ) , I used to ( sadly past tense ) have access to very advanced viscometry equipment ...

ATF is very thin , little wonder your bike feels bouncy .... spec is for SAE10W.....

Try straight 10W pukka fork oil before doing anything else ?

You can blend 10 W with 15 W , even use gear + fork oil blends if you need to get really serious !

There are oils and oils, without advanced equipment to test them , you can be all over the place within the SAME so-called rating.

I found one manufactures 5 is thicker than another 10 !

But foam and temperature in the real world changes everything in the dynamic environment of a motorcycle.

One crude way to measure viscosity is via efflux time through a flow cup, such as a Zahn or Shell cup, but that is special lab equipment, so alternatively you can make a crude flow cup from an upside down bottle with a hole in the lid and a stopwatch.  At least in a crude way you can quantify with some degree of science whether an oil is thicker or thinner than another.

ATF makes good fork oil , but it's not the best solution in the modern world of specialised designed oils , nor is it likely going to behave like a purpose formulated 10W .... especially in an offroad application!

I was on my way to buy proper fork oil when I heard from another dog to simply use ATF. I have used ATF before on my HONDA XL500R. So, I did and now I wish I did different since the ATF cost me about the same as Motul fork oil. Thing is that the motul is R110 per litre, I need 1.1L. Buying two bottles because you need an extra 100ml...

Veemax, you say mixing gear oil with Fork oil is an option. Well then, if I mix some gear oil with the ATF won't it help?

[Veemax]

By some miracle I have a printout of a R0.5 million Haake viscometer under linear shear mode,  in my hand of some value to this fork oil discussion, I just happened to be tidying out my study !!! Sjoe, I retired > 2 years ago, and have this right here ...weird !

Here is some hard data:

Gabriel Red oil                20 cP
Castrol AWS 10              22 cP
KTM OEM WP                   39cP
IGT Shocks 25% Gearbox Oil / 75% Garbriel Red   43 cP
Putoline HPX5                  44cP   
Castol SAE 10 W Fork Oil  67 cP
IGT Shocks 50% Gearbox Oil    85 cP

I dunno what to advise you VR , because I have no datum for ATF ... but it looks like as a starting point you could blend about 33% Gearbox Oil with 67 % ATF and come within 44 to 67 cP ?

If it's overdamped just let it down with more ATF until you hit FRTM * point , or vice versa.

Gearbox oil is designed not to foam , and handle high shear , same condition as inside suspension, so it makes sense.

Hope this helps.

I am flying to Jhb arriving 12pm Thursday , paying a guy for a bike, and heading out on it towards Potch right away , no chance to see you ... unless you can provide dancing girls , infinite booze, and a four poster feather bed for the night.

I have to outrun the holiday crown headed for CT , who will be doing their best to overtake me on Friday.

* Feels Right To Me





       

[Wildcoast]

Stefan Hessler racing, the DR guru from Germany advertises headers that are 3mm bigger than stock if I remember correctly

[DeepBass9]

@veemax - cam shaft profile is Pro Cycle 190. I have all the specs and durations and overlaps and , and, ...
Been proven by Procycle so if the cam engineer knows what he is doing we have a winner.

As for the slightly larger header pipe - Iam not sur eyet of the effect of the gas velocity and will be doing some calculations with a fundi on this. We will still decide on this.

As for the bigger valves - its no bigger than the Honda XR650, KLR650. In fact it is a little small for the bike and this should relase some volume of gasandhence the possible size increase on header. More volume in thin pipe will speed up velocity but it may also restrict it. The fundi's will know better.

Now the ride to Breds Nek 3121 March 2012 - I was contemplating the Honda XRV750R but it has no protection bars and if I should drop it(it weighs like 220kg), gonna damage this collectors item and there are precious little if any parts around.

Maybe take it vewry slowly - but still no guarantees of not slipping or falling.

So then perhaps the wife's Aprillia Pegaso - but the tires are Kenda on rear and if there is any hint of water it will be like riding on an ice rink.

Dunno- decisions decisions

Its easy enough to get up breedt's nek. Its just a bit tricky to go down the north side in a car, bike is a piece of piss.

[volroom]

By some miracle I have a printout of a R0.5 million Haake viscometer under linear shear mode,  in my hand of some value to this fork oil discussion, I just happened to be tidying out my study !!! Sjoe, I retired > 2 years ago, and have this right here ...weird !

Here is some hard data:

Gabriel Red oil                20 cP
Castrol AWS 10              22 cP
KTM OEM WP                   39cP
IGT Shocks 25% Gearbox Oil / 75% Garbriel Red   43 cP
Putoline HPX5                  44cP   
Castol SAE 10 W Fork Oil  67 cP
IGT Shocks 50% Gearbox Oil    85 cP

I dunno what to advise you VR , because I have no datum for ATF ... but it looks like as a starting point you could blend about 33% Gearbox Oil with 67 % ATF and come within 44 to 67 cP ?

If it's overdamped just let it down with more ATF until you hit FRTM * point , or vice versa.

Gearbox oil is designed not to foam , and handle high shear , same condition as inside suspension, so it makes sense.

Hope this helps.

I am flying to Jhb arriving 12pm Thursday , paying a guy for a bike, and heading out on it towards Potch right away , no chance to see you ... unless you can provide dancing girls , infinite booze, and a four poster feather bed for the night.

I have to outrun the holiday crown headed for CT , who will be doing their best to overtake me on Friday.

* Feels Right To Me
     

Thx VM. Had a look at the oils out there. Guy at bikeshop in Edenvale says that changing the preload can help. Even though the spring fee length is still good, when I push the front down..it goes way down almost bottoming out. Not supposed to happen. So...changing the oil to a heavier weight would make the forks compress SLOWER, but the sag when loaded with full tank would be exactly the same. Changing the preload would change that. And when the springs do eventually die..I'll get new ones.

I'll use Motul 10W oil with the preload adjusted  - will get the right diameter PVC pipe. 

[volroom]

BTW, the 1 tooth less front sprocket is working great for the jerkiness at slow speed. 5000rpm at 100km/h. On gravel that seems right doesn't it? Engine provide max torque at cruising speed. Really does feel better. will update about fuel economy

[DeepBass9]

BTW, the 1 tooth less front sprocket is working great for the jerkiness at slow speed. 5000rpm at 100km/h. On gravel that seems right doesn't it? Engine provide max torque at cruising speed. Really does feel better. will update about fuel economy

I have a 47 rear and it give me slightly longer legs than that, 5000rpm is about 107kph. What rear tyre are you using? The D606 I have is slightly larger diameter than a 50/50 type tyre.

[volroom]

DB9, I used gear gearingcommander to check things out beforehand. Rear tyre Mitas E09 130/70/17. Put in specs of your rear tyre, sprocket sizes and it will tell you exactly what speeds you can do at whichever revs. Changing the front sprocket did bring down max speeds some 10km/h which I don't mind.

Now, when I'm cruising and I open throttle it picks up nicely and when at slow speed it's more smooth - technical riding might benefit

http://www.gearingcommander.com/

[DeepBass9]

Something wrong with gearing commander's calcs it seems. Stock is stock, Current is my setup, Custom is your setup. RPM at 120kph

[Wildcoast]

Think I should go count the teeth on my sprockets 
Bike has no legs over 120