[TrialsRider]

... polypropylene and delrin....

money.


btw: for drilling holes in the plastics you will get far better results using Forstner drills instead of twist drills.

 

[deaconblues]

any sharp tools that work on wood will generally work on the plastics.
Is best to make your bore holes undersized and then ream or machine them to an accurate size rather then turning a bushing and compressing it into a tight sleeve fit where the material will compress and distort from the desired bore size.

Used in swingarm bushings the plastic will have some advantages but a needle roller bearing is still the best performing swingarm pivot bearing available, rollers have the advantage of negligible friction and free-play clearance approaches zero. You don't want any free-play or bushing flex in your swingarm pivot or your bikes handling goes for a shit.

Honda engineered some type of comfort clutch into the driveshaft of this bike so any free anything in the swingarm is now exacerbated with the increased torque. I have had a few shafties and none ever had this clutch in them. My Virago makes almost twice the power it did stock and there was no change in the elevator effect or shaft jack or whatever they call it these days.
This system is not ideal right between unloading and loading. It is numb and wallowing and designed for throttle hands that can't decide what they are doing. So a workaround to that is now on the to do list if I truly want to be able to squeeze any performance out of this relic.

Edit; I have a set of Forstner bits in the wood shop. Same ones won't get all gummed up in the plastics?

 

[TrialsRider]

I have a shaft drive bike too 1986 K100RS
Jack shafting is only a problem on that bike if I am doing some fairly extreme engine braking on rough road surfaces, the entire rear swing assembly is cast and runs on roller bearings. Bike has a dry clutch so the clutch itself has springs to take up some of the axial load shock that your bikes clutch thingy is probably attempting to eliminate. BMW created the far more complex and heavier para-lever design to address the concerns over jack shafting.

Shaft drive works way better on a bike like my BMW K bike where the motor is mounted longitudinally, instead of traverse which requires an additional 90 degree crank in your drive train.
BMW also designed the transmission to rotate in the opposite direction of the crank which reduces the tendency for the bike to lean under hard acceleration. Next time you want to make a shaft drive bike that goes fast, recommend you start with one that has a longitudinal engine layout, it will ultimately outperform the others.

 

[deaconblues]

Next time you want to make a shaft drive bike that goes fast, recommend you start with one that has a longitudinal engine layout, it will ultimately outperform the others.

There are probably a metric craptonne of abandoned cx500 "cafe projects" around....

Ugh, I hear that. Since I started this thing, a salvage operation with parts on hand, I now have so much time and favors into it that it will be finished. I knew I would be pushing a bunch of rocks uphill. All because I fell in love with engine and it's lineage. Next time will be a more prudent choice.
Did I forget to mention this has a hydraulic clutch? Yup. This bike literally feels like an electric vehicle sometimes. There is zero engine vibration and with that clutch plus the stock power curve where it has no torque until 7000 rpm make for quite a detached ride. It feels worlds better with stiffer everything and quicker steering. Power is still on/off but it's closer to 6100 rpm now. There is no adjusting the clutch but has anyone played around with master cylinder bore sizes? Go from 12mm to say 14? Probably just start blowing seals.... Oh well, I had already told myself I could live with the clutch. But the driveshaft issue. Thing wants to try some snap oversteer in the esses if your not gentle with the gas. I bet some flatslides would reaalllly liven up the action.

 

[XB33BSA]

any sharp tools that work on wood will generally work on the plastics.
Is best to make your bore holes undersized and then ream or machine them to an accurate size rather then turning a bushing and compressing it into a tight sleeve fit where the material will compress and distort from the desired bore size.

Used in swingarm bushings the plastic will have some advantages but a needle roller bearing is still the best performing swingarm pivot bearing available, rollers have the advantage of negligible friction and free-play clearance approaches zero. You don't want any free-play or bushing flex in your swingarm pivot or your bikes handling goes for a shit.

the iglide bushings set at zero clearance are better than needle bearings mainly because they wont corrode but also because of zero clearance which is impossible with rolling elements
no you do not ream iglide bushings they are precision and the best practise is to design the housing fit to size rhje bearing in this way they are same as a needle bearing which is sized by the housing
i fab my own shock spring dual rate sliders using a hard material like delrin and i cut 2'' to 2-1/2 discs out of 1/2'' sheet
holesaws suck in plastic
i drill a 1/2' hole at each disc center layout on the sheat then use a flycutter with a good anount of clearance on the sides
thev ketyy is not go all the way thru
i set the quill stop leaving a 1/16 or so the flip sheet ovetr and finish with the fly

plasics in the lathe can be very tricky delrin is hard but also self feeding like brass but worse
too much hook in tool and its trouble
the trickiest shit is the polyurethane shock eye bushings that i fabricate
it would be ideal if the tool for turning that shit was surgically sharp that is what they have when machining the hydraulic seals and wipers
the key being the hooked top surface where the continous chip flows needs a fine polish
i kinda knew it had to be like this to succeed but had never needed to machine the shit for my own product and i needed badly to be able to set up and get repeatable results and not fight as the loser everytime
after being frustrated i finally hit google and there it was free POLYURETHANE MACHINING INFORMATION

 

[XB33BSA]

igus also has plastic rod ends for like shifter linkage
they have a plastic bushing that i want to try as a cam bushing heat ?it does 500f continouos no problemo that's more than double the temps in the head at cam journals
also plastic cam follower pads for rocker arms on vintage shit would be useful aaannnd the shit in my opinion could be used to fabricate no wear cam lobes

 

[Andyshep]

money.


btw: for drilling holes in the plastics you will get far better results using Forstner drills instead of twist drills.

If you only have HSS twist drills you can use a bench grinder to put a flat, like the Forstner bit onto the cutting edge and it will drill plastic a lot cleaner.

 

[TrialsRider]

...
Did I forget to mention this has a hydraulic clutch? Yup. This bike literally feels like an electric vehicle sometimes. There is zero engine vibration and with that clutch plus the stock power curve where it has no torque until 7000 rpm make for quite a detached ride. It feels worlds better with stiffer everything and quicker steering. Power is still on/off but it's closer to 6100 rpm now. There is no adjusting the clutch but has anyone played around with master cylinder bore sizes? Go from 12mm to say 14? Probably just start blowing seals.... Oh well, I had already told myself I could live with the clutch. But the driveshaft issue. Thing wants to try some snap oversteer in the esses if your not gentle with the gas. I bet some flatslides would reaalllly liven up the action.

I'd really like to understand what you are talking about the hydraulic clutch :| a hydraulic clutch actuator is awesome compared to a cable actuated one, but I don't think that's what you mean.

 

[deaconblues]

I'd really like to understand what you are talking about the hydraulic clutch :| a hydraulic clutch actuator is awesome compared to a cable actuated one, but I don't think that's what you mean.

Compared to a cable clutch I sometimes have trouble finding the bite point with the hydraulic clutch. It really only effects take off/ reaction time. I can get a bit OCD about data logging and especially before and after timed runs.

 

[hillsy]

Compared to a cable clutch I sometimes have trouble finding the bite point with the hydraulic clutch. It really only effects take off/ reaction time. I can get a bit OCD about data logging and especially before and after timed runs.

You get used to the "throw" of the lever after a while and it's hard to adjust to a different set-up. That's where span adjustable levers are a great thing. You adjust the engagement point to where you want it

 

[deaconblues]

You get used to the "throw" of the lever after a while and it's hard to adjust to a different set-up. That's where span adjustable levers are a great thing. You adjust the engagement point to where you want it

That is one piece of this bike that the P/O really baffled me by messing with. It had a nice Nissin M/C with both throw and leverage adjustments and he tried to cut it down to a two finger jobby and filled it with moose piss...

That's a bigger sin than the Spongebob duct tape he put the turn signals on with.

 

[hillsy]

He's just bodged up a broken lever.

 

[TrialsRider]

That shit is half the length my shorty levers.

Hydraulic clutch if it doesn't have air in the system should provide you with the smoothest most predictable and reliable clutch engagement/disengagement there is, lever pressure is much lower and linear, the fluid reservoir and hydraulics makes it self adjusting.

The only force that the actuator should ever be subjected to is the force of the clutch pressure springs, so no; altering the dimension of the pistons in that simple system will not cause anything to burst, all it would affect is the amount of lever action required relative to the pistons travel and the pressure that you need to apply at the lever. Let's refer to this as the clutch release and engagement 'sensitivity'

... the range of motion required to disengage your clutch is fixed by the design of the clutch plates and the nature of the lubricant they run in (unless it's a dry clutch, then it is running in air)

 

[deaconblues]

That shit is half the length my shorty levers.

Hydraulic clutch if it doesn't have air in the system should provide you with the smoothest most predictable and reliable clutch engagement/disengagement there is, lever pressure is much lower and linear, the fluid reservoir and hydraulics makes it self adjusting.

The only force that the actuator should ever be subjected to is the force of the clutch pressure springs, so no; altering the dimension of the pistons in that simple system will not cause anything to burst, all it would affect is the amount of lever action required relative to the pistons travel and the pressure that you need to apply at the lever. Let's refer to this as the clutch release and engagement 'sensitivity'

... the range of motion required to disengage your clutch is fixed by the design of the clutch plates and the nature of the lubricant they run in (unless it's a dry clutch, then it is running in air)

Once I got all the sludge out of the slave cylinder and bled the new M/C it felt a bit mushy, I guess is what I'd describe it as. So I put a stainless line in place of the old rubber one and it felt a lot better but it still disengages real close to the grip even with the lever adjusted all the way out. I like to have it bite about 15mm in (I run about 5mm free play in a cable).
If I can run a larger piston to shorten the throw without damaging anything it would definitely be worth it to put in a new one.

 

[deaconblues]

I was talking to a old head racer this week and we were discussing frame gussets and their placements. While it was awesome to pick the brain of someone like that some things are hard to translate into a physicality. I replaced and added bracing (neck/down tube area) to my frame and while I'm fairly confident of the placement he got me questioning the welds. I welded around the entire outside of the two in front of the rear upper shock mount. The original gussets had a relief or just a hole? Question is, did I create a situation where all the stress is now exactly where I don't want it? If so, can I drill or should I cut them out and redo?

(Please pay no mind to the ridiculous brake line, it's just to make it easier to move on the lift and ramp)

 

[TrialsRider]

Is a lot easier to route a cable to the rear drum then to work with a solid rod, but you do need to come up with a way to hold the cable ends in the correct place.

One problem with adding gussets to your existing steering head is; welding creates tremendous pressure on areas that expand due to the heat of the weld and then contract as that weld cools, cracks can be created right along side the welds as a result. Your frames rigidity is tremendously limited by the single backbone design ... at least I think it's a single backbone but for some reason you have the fuel tank installed :/ fuel tank installation is the last thing to install.

... your steering head isn't necessarily weak only because of poor materials, it simply lacks geometry.

I think you have something similar to this:

you are going to wish you had something like this:

 

[TrialsRider]

on the subject of rear shock gussets :/
your rear axle is a half inch diameter steel bolt with 2 of the cheapest magneto roller bearings known to man running on it,

your swingarm was built for low cost and it rides on plastic or at best brass bushings, this area is subjected to several times the stress that the shock absorber top mount will ever see, the loads on the top shock mount are only in one plane, stress at the swingarm pivot point are extreme in all directions and need to allow Only movement in the direction of your shock absorber travel.

here is something similar to the axle you bodged onto the front of your motorcycle:

If you are going to ride this bike spirited like and on modern rubber, it's going to feel like a wallow wagon with a big rubber hinge in the middle,
and then the frame cracks will begin to appear.

This is why it is a really dumb idea to attach a cheaply built old bone motorcycle frame to a modern performance sportbike front end

 

[deaconblues]

If you are going to ride this bike spirited like and on modern rubber, it's going to feel like a wallow wagon with a big rubber hinge in the middle,
and then the frame cracks will begin to appear.
This is why it is a really dumb idea to attach a cheaply built old bone motorcycle frame to a modern performance sportbike front end

I'm glad you are concerned for the rideability of my bike and if I hadn't already built this thing I might even reconsider or at least talk to even more people that have already done fork swaps like this, but the reality is that the bike rides incredibly well and would have probably been fine with just the stock frame bracing and swingarm bushes. It's not like this bike originally came with bendy straws holding the front wheel. I haven't bolted two steel girders onto it. It handles better. It turns better, it stops faster. Jesus, you all are going to make me go buy one of them go pro's. It easily handles my mediocre riding ability. I'm nothing special on a bike. Never be more than a midfield rider. Hell sometimes I'm just another chicane. I've been hunting for just that little bit more. I'm chasing tenths of seconds at this point.
I was asking about the specific area in the upper rear "triangle"
As to the rear brake actuation, that will be all tossed in the bin once the US customs clears the new 17" rear wheel and brake disc.

You are more than welcome to say my ideas are dumb, it's the internet! Troll on! I think it's a stupid waste to stand up on a motorcycle and try to ride over rocks

 

[jcw]

I agree with Trials, when you talk about frame bracing you are looking to stiffen the connection between the steering head to the swingarm. The gussets to the rear shock mount area will not likely contribute much to the stiffness of the chassis. Not completely useless but there are much more important areas to reinforce. Think about grabbing the rear wheel and twisting it. Visualize where the frame bends and twists.

Of course, if the bike handles fine as it sits for you, i doubt the extra frame bracing is needed. In which case any additional gussets will be just for bragging rights.

As far as whether a relief is made in the gusset, i doubt it matters much.

 

[deaconblues]

I agree with Trails, when you talk about frame bracing you are looking to stiffen the connection between the steering head to the swingarm. The gussets to the rear shock mount area will not likely contribute much to the stiffness of the chassis. Not completely useless but there are much more important areas to reinforce. Think about grabbing the rear wheel and twisting it. Visualize where the frame bends and twists.

Of course, if the bike handles fine as it sits for you, i doubt the extra frame bracing is needed. In which case any additional gussets will be just for bragging rights.

As far as whether a relief is made in the gusset, i doubt it matters much.

I already don't relish the thought of stripping the bike down again to put it back in the jig and there's no guarantee that if I cut those gussets out nothing is going to move and that's the wrong direction.
The problem arises from the fact that the rest of the frame was done by someone with considerable expertise and the two in question were put on by a shmuck.
I'm satisfied that the frame is stiff enough for how it will be used.
My initial complaints about the wallowing rear end were due to my improvised urethane bushings and a acid washed swingarm.
It now has bushings made out of some weird space plastic that really pissed off my boss when he machined them and the swingarm was swapped for a 2013 Honda Shadow aero.
I really expected it to feel more nervous with it's 55" wheelbase but it still has 5.1" of trail that keeps it kind of manageable.
Where the hell was I? Oh yeah, I should
A: leave em?
B: cut em out and replace?
C: ??? Drill a relief?
D: part it out on ebay?