Archive for the ‘SR500’ Category

XS650: Viton® Valve Seals   Leave a comment

Had in mind to tart up one of the XS1 heads I have lying around. Picked up a set of Viton® valve seals for it. Reputed to outperform the originals. Got sidetracked and they sat on the shelf a while.

Viton® valve seal … metal jacketed

 

These are available with or without a metal jacket.

unjacketed valve seal

 

I am now sorting out a head for an extra SR500 motor. To go in the sidecar. Emphasis torque. Early 78/79 crankshaft and cases (larger crankshaft counter-weights), specially ground cam, larger valves, lighter valve springs, thinner spring plates, modified ports, carillo rod, O/S piston, modified/heavier flywheel etc. The XS650 and the SR500 use the same valve seals. No point leaving these sitting. Collecting dust.

Wonder how they will work.

Viton®. Flouroelastomer (FKM/FPM). A fluorocarbon based synthetic rubber. These contain 5% Teflon for reduced friction and wear.

Advantages:

  • have a wide and stable Temperature Range -30°C to 225°C (-10°F to 400°F)
  • resist hydrocarbons (fuel/oil)
  • excellent oxygen, ozone and weather resistance
  • incombustible
  • have excellent dynamic properties (coeff. of friction, tensile strength, range of hardness and resistance to compression set etc) – good abrasion resistance
  • have low permeation rates (esp. relevant to alcohols, hydrocarbons and biofuels (biodiesel, ethanol)
  • be solvent, mineral acid resistant (don’t really like ketones, amines or low mw esters,)
  • show low compression set

Disadvantages:

  • low alkali resistance
  • relatively poor mechanical properties
  • limited elasticity at low temperatures
  • the tensile strength decreases substantially at elevated temperatures
  • high price

The fluorocarbon rubbers are used for special applications that require good heat, oxygen or corrosion resistance and hot solvent and oil resistance.

Applications:

  • car and airplane seals and hoses
  • fire-resistant coverings
  • heat-resistant insulators
  • o-rings, shaft seals
  • gaskets, fuel hoses, valve-stem seals

Note: Viton® is a registered trademark of DuPont. It is often misleadingly used as a generic term for FKM/FPM flouroelastomers.

For the chemically-minded FKM’s thermal and fluid resistance are a function of 3 main features

  • Extremely strong bonding between the polymer backbone carbon atoms and the pendant (attached) fluorine atoms
  • High ratio of fluorine to hydrogen atoms bonding to the carbons (high fluorination levels tend to create stable compounds)
  • Full saturation of the carbon backbone .. no covalent double bonds between carbons minimizes attackable sites

Structures of fluorocarbon rubbers

Monomers Structural unit Type designation Commercial types
VF 2 + HFP

FKM

Viton A, AHV, A-35, E-60,
Fluorel 2140, 2141, 2143, 2146
SFF-26
VF 2 + HPFP

FKM

Tecnoflon SL, SH
VF 2 + HFP + TFE

FKM

Viton B, B-50
VF 2 + HPFP + TFE

FKM

Tecnoflon T
VF 2 + TFCIE

CFM

KEL-F 3700, 5500, SKF-32
PFMVE + TFE + X

FKM

ECD 006

 

Typical FKM structure … flourocarbon rubber

 

An example of a structure of the fluorocarbon rubbers, VF2 / HPTFP / TFE -copolymer.

 

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Posted March 23, 2014 by xscafe in Motor - Head, SR500

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XS650: SR500, Velorex Sidecar   1 comment

Once upon a time I had this nice little SR500.

my 48T SR500

 

I got it into my head to build a sidecar – to take my son to school. Started collecting bits. And ideas. (I did consider using the XS650. Decided against it as the SR and the Velorex match pretty well. Both light and manouverable.)

 

making a start … leading link forks, box section swingarm and front disc brake … ended up reworking the forks – added an extra 1cm castor (nachlauf)

 

Got hold of a Velorex 562 sidecar. How to connect? Collected a lot of ideas.

  • Original Velorex frame clamps. Too much point load on the frame. And they work loose.
  • Mount points welded directly to frame. Weakens frame. Point loading.
  • Subframe. Bolts directly to frame. Sidecar mounted to subframe. Load distributed. Solid.

Sounded good to me. What about TÜV (MOT) certification? Could make my own subframe but I’m not a ticketed welder. Visited my local friendly greycoat (TÜVler). Fixed his brown-eye on me and shat on my ideas. Some people simply have no imagination. No sense of adventure.

Found a list of Gespannbauers (sidecar builders). Rang around. Karl Schmid from Mickhausen near Augsburg was the most approachable, and fitted into my time frame. So, off I went. Beginning of September. Said he would try to have it ready by the end of the month. OK by me. Spent the next week constructing at Automechanika – Automobile industry Trade Fair. Stand handover Monday. Home late. Phone rings 08.00 Tuesday morning “TÜV is on Friday. You can pick it up then.” Hang-on? It’s not even midmonth! I’m not ready! Cant believe it’s early. Kool!!

Commitments, illness, work, rugby meant I wasn’t able to get down there for a week. Got a train ticket, €39 to Schwabmünchen. Left Frankfurt at 05.30. 20 minutes late. By Stuttgart the train was getting pretty full. Ah, yes, 1st day of Oktoberfest. God I love girls in Dirndls. Nothing quite like it. Eye candy.

Was picked-up at the station. Sweet.

 

finally there

 

half workshop half house … nice

 

Smells just like a metal workshop should.

Karl Schmid: Gespannbauer

 

there she is … waiting

 

Took my time getting home. 650km. The first 3 hours in driving rain. Forgot to switch back from reserve and ran out of gas in the middle of nowhere. Great way to meet friendly strangers. Took the sideroads. No map. Using the sun position – when I could see it. And geography. Had a great day. Perfect way to meet my new toy. Glad I took 3 pairs of riding gloves. Meant dry warm hands. Mostly. Uses more gas, be careful cornering, no need to put your foot down when stopped.

 

front on

 

rhs … the boat is sitting on the original frame podests … it is possible to rework these and lower the body 30-40 mm … lower centre of gravity … adding an MZ torsion bar (bike swingarm to sidecar swingarm) helps handling too

 

you can see the body mount podests on this frame

 

as a reference: this velorex frame has been heavily modified – cross bracing, lowered body mounts, bolt on lower frame mount points, extended rear, self-made shock tower, self-made extended swingarm

 

lhs … have some longer konis I may swap into the forks – lift the front a little

 

324mm konis up front, from my guzzi … replace the series SR shock 316mm … feels better

 

connected – front view … exhaust pipe is very close to the lower car mount – i have now ground the mount to give more free space for the pipe

 

connected – rear view … the lower rear sidecar mount, seen here has been shifted to the rear of the sidecar to leave space to kickstart … the upper rear mount is just on the limit of being restrictive, my boot heel hits the bar if Im not careful

 

front – upper … boxed over the frame

 

front – lower … bolted to the front engine mount

 

rear upper, subframe fixed to the shock mount, sidecar mounted off the subframe … you can see the lower sidecar mount point going off to the left … rear lower subframe mount uses the footpeg mounting points (will take photos of these and post as well)

 

right hand rider footpeg now welded directly to the subframe … subframe mount uses the frame points previously used by the footpeg

 

sidecar brake cable … attached to footbrake rod – pulls against the alu block

 

brake cable mounted to the swingarm shock mount

 

nice bonus – the front lower sidecar mount serves as a perfect footrest – very comfortable riding – need to practice braking with my heel

 

Fully certified (TÜV)!!

Now I’m ready to take my 6yo son to school.

off to school

 

I’ve now ridden this a couple of thousand km. Not bad for a month.

  • Have added a longer set of shocks to the forks-a bit more height (not too much)-needed to alter the sidecar settings slightly.
  • The rear shocks are far too weak. Tried a set of SR500 konis – still too weak. Looking for a better solution.
  • In retrospect I might design the subframe somewhat differently. As a 1 piece there is structural integrity and load-spread across the whole frame but the thing will need to be removed to repair things like clutch, kickstart, oil pump. A 2 piece subframe, although loading the front and rear of the frame separately allows access to the right hand case. Just how strong is the original frame?
  • I will add a rollbar and 4 point seatbelt.
  • Am glad I didn’t use the XS650. The Velorex is light and flies easily. Great for freaking out cagers that follow too close.
  • Had forgotten just how physical sidecar riding is. Body position is critical when racing through corners. My 6 yo son is becoming a good monkey.

Couple of updates …

 

VM32SS carb from an early XT500, rejetted … large increase in torque for minor loss of top speed (-10kmh max.) … purrfect fit … have ordered a new boot

 

Have exchanged the carb. Taken the BST34 flat slide out. Put a VM32SS round slide from an early XT500 in. Direct fit. Mates to both the carb boot and air filter

no problem.

Starting point : 41mm single wall head pipe … K & N filter insert, open carb boot.

  • Pilot Jet 25
  • Main Jet 260
  • Needle Clip position #4
  • Float at 21mm (float was twisted-one side sat higher than the other)
  • Cables are different, (both 2 cable system) … shortened the BST push cable outer and used it as a VM pull cable, added a second nut to give myself adjustment at both the carb and handlebar.

I love the difference. Not quite as much top speed (I rarely travel more than 100-105kmh anyway) BUT there is a noticeable increase in torque from idle. Pulls great through the complete rev range. Fuel consumption is better too.

Exchanged the std Velorex lights for LEDs. Figured it would be easier on the batteryless electrics I run. Had halogen blinkers on the left hand side. Load-independant blinker relay. Seems to work with halogen front and LED rear but not halogen left and LED right. Appears to require the same combined load on both sides. Swapped the halogens for LEDs and all was well. Except for the headlight the bike now has LEDs all round.

 

LED rear

 

and LED front

 

Have booked the bike in to have the subframe modified. Never liked the front top mount – headstock. Transfers the stress directly to a known weak point. The square section tube under the oil tank. Cracks along the weld – both sides.

 

subframe top monut, front … at headstock … clamped to known weak point – leads to cracking along the welds

 

Had a front brace made up. Clamps to the frame. Bolted up through the steering head – 2 bearings keep the steering operating. Brace back to the subframe.

 

brace from the rhs … can see the frame clamp, the bearing housing under the steering head – there is a bolt through this from below attaching it to a block inserted into the lower yoke (this is held in place with the bolt coming down through the top – could also have been cemented in place)

 

brace

 

front brace – rhs – showing link to subframe – note, this is all easily removeable, clamp releases, link unbolts from brace, brace separates from bearing house

 

my other three-wheeler … shop hack … sharing space with the XS

A common SR500 rear wheel problem is the wearing out of the rear sprocket carrier. If this isnt regularly greased via the provided grease nipple the wear accelerates. Result? Sloppy rear wheel. The added stresses imparted by running a sidecar exacerbates this problem.

This can be rectified by machining the carrier  ID to fit 1 or 2 bearings and reducing the existing stem in the hub. I tried contacting an SR500 forum member here in Germany but he never replied. A pity as he provided a nice 2 bearing modification. While looking for a solution I found complete a rear wheel, already modified, on fleabay. New bearings, brake shoes, carrier dampening rubbers. For cheaper than used wheels usually go for. Score!

complete rear wheel – already modified – single carrier bearing and reducing spacer

 

rear sprocket carrier – machined to fit a bearing – reducing spacer fitted – i have covered this with the plastic cover found on XT500s – lube as normal using the grease nipple provided

 

rear view of sprocket carrier – can see both the bearing and reducing spacer … fits as normal to the hub

 

XS650: K&J Swingarm   Leave a comment

Been busy lately. Summer (well not really much of one) riding. Work. And, best of all, play.

Our son turned 6. School. Need to get him there and pick him up. Started a while ago collecting bits to turn my SR500 into a sidecar. Velorex 562. Leading link forks. Box section swingarm. Steering damper. Better shocks. May yet even add a battery. Had a subframe made up – bolts directly to the frame. 4 point sidecar connection bolts to this – no welding to the frame – better load distribution. Easier to get certified.

Got a K&J box-section swingarm for a price I couldn’t refuse. Included all the bolts, bearings, axles … ca 5.7kg.

 

k&j box-section swingarm … shock mount bolts, axles and chain tensioners  not shown

 

Checked the existing bearings – OK. But the bearing races showed definite wear marks where the rollers have contacted. No internal spacer!! Checked their website. This is standard-no spacer. Means the bearings take all axial load. Anyone who has left the internal spacer out of their wheel when replacing bearings soon learns not to do this. Their instructions say to tighten the swingarm pivot to the point that the swingarm slowly lowers itself from a raised position. Fully loaded bearings – no wonder the races are marked. New bearings.

Measured it up. Figured there was 164.5mm space between the bearing centres. 16mm internal diameter. 22mm OD would fit inside the bearing cages. Cut myself a bit of pipe. Fitted it – too long – too much play. Remove. File. Refit. Did this 3 times before I got the fit I wanted. Now, there is no sideplay and the swingarm can move freely.

 

spacer … 164.5mm long …. 16mm ID … to the left is one of the bearing carriers, greased, ready for installation

 

Next problem. No chain-rub protector and the pivot tube has a larger OD than the original. Had a polyeurethane bread board the wife wont miss. Grabbed my holesaws and cut myself a new rub protector.

Mounted the chain guard. Shock mount bolt is in the way.

 

shock mount bolt blocking the chainguard

 

A bit of violent grinding soon fixed that.

For some reason K&J decided to reinvent the wheel. Put the brake plate anchor topside. Original is underneath. Must rotate the plate. The brake actuation geometry is now all fucked up. Bright. On researching they fixed this later – gave the choice of over or under. Later models are fitted for the original anchor. This didnt help me. Made myself a new anchor. A comprimise, but helps.

External dimensions of this swingarm are slightly larger than original – means the brake rod runs real close. A little judicious bending solved this. Also took the time to remove the brakearm pivot. Like the XS650, the SR500 has no grease nipple here and people forget to regularly repack it. Tends to seize when least desired. Fucking Murphy!!

 

brake arm pivot – getting a bit dry … caught just in time

 

Things to do:

  • Dechrome the swingarm – i hate chrome just as much as i do policemen
  • reposition the brake plate anchor
  • powdercoat it black
  • replace the missing grease nipple – swingarm pivot shaft
  • keep riding

If you’re wondering why I’m writing this, you may not have figured out that the SR500 and XS650 swingarms have the same pivot dimensions.

Posted August 31, 2012 by xscafe in Frame - Handling, SR500

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XS650: SR500 Rear Wheel Bearing Spacer   Leave a comment

I need one. A bearing spacer. Rear wheel. SR500. Drum brake.

Goes inside the hub. Between the bearings.

If anyone has a spare one handy please drop me a line – reply below.

Seems the drum and disc brake versions are different:

SR500

XS650

Drum Brake (spoke/mag)

275-25317-00

90560-20135

Disc Brake    (mag)

 90560-17311-00

2M0-25317-00

drum brake rear wheel bearing spacer (XS650)

 

This is from an XS650, but you get the idea.

Thanxs …

Rear Wheel Bearing Spacer

SR500 

mag/spoke: drum  #275-25317-00

XS650

mag/spoke: drum #90560-20135

Length:

100mm

84mm

OD:

24mm

27mm

ID:

17.2mm

20.2mm

Ring OD:

29mm

43mm

Posted December 7, 2011 by xscafe in Frame - Wheels, SR500

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