Custom Fighters - Custom Streetfighter Motorcycle Forum banner

Is Smoking Permitted?

832K views 3K replies 254 participants last post by  Smoker 
#1 ·
Just found this website and love the bikes and custom mods!

I'm working on a custom streetfighter, but not sure if you guys are into smokers around here.

I would appreciate any advice or tips on modding you guys can provide. I've made a lot of progress, but still have a long way to go.

The bike is a 1985 Yamaha RZ350, but there won't be much left of the original bike left when I'm done.

I'll post some pics of my build to get you guys caught up to where I am now.





 
See less See more
3
#1,616 ·
Picked up some parts today from the anodizing shop - and there were a few casualties.

The plan was to mask the brass overflow tubes and anodize the float bowls gold. The bowls and drain plugs were polished to the max before anodizing. The drain plugs were supposed to be anodized red.

Here's the result:



You can see the brass tubes were melted by the anodizing process. The shop said the masking must have leaked. No shit.



The drain plugs came out even worse. They went through the (red) anodizing process and this is all that's left. The plug is supposed to scrrew into the float bowl, but it dissolved so much, it just drops through the threaded hole:



Will call tomorrow to find out if I can order (just) new float bowls. I did get a part number.
 
#1,620 ·
The anodizing shop (Stephan) said he felt bad about the float bowls.

So, he said- "Take all the anodized parts, and don't pay me any cash until you find out about the float bowls."

No complaints about that. They also haven't charged me for the stripping and polishing.

So, I'm still okay with this shop.

Still have a lot of parts to unpack.
 
#1,627 ·
Aren't the brass parts like the fuel line barb and such just press fit into the aluminum? I was under the impression that you could remove most (maybe not all of them) like that...

Sad to hear that you didn't have much luck, but I guess it's live and learn, good thing they weren't important or NOS parts that couldn't be replaced.
 
#1,628 ·
Been talking to Ohlins and found out there's an aluminum shock body replacement for the steel shock body on the Ohlins RZ rear shock.

Almost went for it, but realized that a steel tube coated with DLC will retain it's coating WAY better than anodized aluminum.


Brycoat said they shipped out the titanium nitride coated shock shaft on Monday. Should arrive next week.
 
#1,632 ·
Almost went for it, but realized that a steel tube coated with DLC will retain it's coating WAY better than anodized aluminum.
Is there really any reason why the DLC would be longer lasting than anodized aluminum? AFAIK there's no physical wear on the shock body. Do you mean that the anodizing will fade after time?
 
#1,631 ·
Lol so I'm jumping the gun a bit to think we will see a bike any time soon lol. Well there's always your motard for me to drool over lol. What did you end up doing with the frame you built?
 
#1,641 ·
I want to get a titanium spring for the rear shock, but not sure what rate to choose.

The bike should be around 300lbs, I'm 156lbs, and the fork springs are .700.

The Ohlins racing spring is way too stiff (600lbs/10.7kg).

Any help is appreciated. :smt006
 
#1,642 ·
Pete, I can help you with this, however it isn't straight forward.

The first step is to determine what "axle rate" is desired. This is the stiffness that you feel when you push down on the bike. Knowing what the correct number should be is the key. It is based on bike weight, rider weight, and riding style... however very little has has ever been published on target numbers for axle rate. You won't find good numbers in magazines as you will for rake and trail and those such numbers. So, this can be a bit tricky to determine and optimize.

The second step is to back calculate from the theoretical desired axle rate to the actual rate of the suspension spring. This calculation takes into account the geometry (linkage, etc) of the suspension system, and thus can vary greatly from bike to bike. Luckily there is good suspension software available to do these complex calcs for most of the common suspension types.

The only alternative is experimentation. If your RZs suspension is relatively stock in terms of the linkage geometry and how the shock is actuated, then I would start with the stock RZ spring and experiment from there getting stiffer or softer, depending on how the bike handles.

600lb/in spring is about right for an RZ350. Is the pre-load jacked up, or has the suspension geometry been changed? ...otherwise it should be okay.

Just an FYI - Back when I was doing the original suspension design for my forkless RZ I did a lot research into this and ended up developing my own software to plot the rate curves (the stock RZ350 has a very rapid rising rate by the way). One thing I noticed was that very slight changes to the linkage in terms of length of dog bones and linkage joint, or the mounting locations on the frame or swingarm could have very significant changes to the (axle) rate curve and thus greatly effect the ride characteristics of the bike.

Julian
 
#1,643 ·
Thanks for that, forkless!

Unfortunately, my rear suspension link and dogbones aren't stock, and they aren't identical to the OEM pieces.

Maybe a good place to start is to compare the measurements on my suspension pieces to the OEM ones. This may give an idea of whether to go heavier or lighter on the spring (compared to OEM).

The 600 lb Ohlins racing spring is too heavy for my use.

I wish I could experiment with a few different springs, but I don't want to keep changing the spring out and scratch up all the newly finished parts. Was thinking about getting some used steel springs to test before buying titanium - but what a big job.

Might just have to make my best guess and go with it.

Seems VERY difficult to get the right spring. I think the titanium springs are available in differences of .2kg (7.2 - 7.4 - 7.6 - etc). They also cost A LOT!!! So, getting the right one is pretty important.
 
#1,645 ·
Unfortunately, my rear suspension link and dogbones aren't stock, and they aren't identical to the OEM pieces.

Maybe a good place to start is to compare the measurements on my suspension pieces to the OEM ones. This may give an idea of whether to go heavier or lighter on the spring (compared to OEM).
If the 600lb/in spring is too stiff and you know that the dog bones and link aren't stock length anymore, then it is likely that the dog bones and/or the link are shorter than stock. This geometry would yeild a great mechanical advanatge to the shock/spring and this would feel stiffer. Can you confirm the length of these parts (compared to stock)?

If they are in fact of different length (shorter or longer) then the rate curve is sure to be different than stock. To know what the new rate curve is, we would need to (CAD) model the suspension in a simulation. From there we could also model the stock geometry, compare curves and extrapolate from there to find the correct spring rate. The unfortunate part is most likely the slope and progression of the curve is also likely to change, so the axle rate is not going to match the stock RZ over the full range of the curve even if we get a corrected spring.

Anyway, try to determine if the individual dog bones and linkage got shorter or longer than stock and we'll go from there. Also need to consider where the dogbones attach to your new swingarm... is it in the same location as on the stock swingarm? Keep in mind that a few milimeters difference in any one piece of the puzzle can make a big difference in what you feel on the bike.

J.
 
#1,650 ·
Anyway, try to determine if the individual dog bones and linkage got shorter or longer than stock and we'll go from there.
I'm going to get good measurements on the new pieces and the OEM pieces to get an idea of how things should have changed.

Also going to put the shock back together with the 10.7kg spring - or maybe get one used 8.0kg - 9.0kg spring so I can get some initial sag settings with the new suspension parts. Then I can make a better guess on the Ti spring.

So, I'll have to swap out the spring at least once.
 
Top