Topic: UK 500 four cafe racer build

[Ewan 500K1]

That mudguard bracket looks way off, doubt if you can get wheel and tyre in place set up like that
 
Also, you do have the axle installed correctly?

cheers for the bracing tip crazy , good idea and simple to execute. I'll have  a think about doing that before it goes off to the powder coaters.                                                                                                                              On the front mudguard stay issue, the tyre and wheel sit in fine and mudguard is sitting nicely in line with the tyre when the mudguard is sitting on its bracket. I think the left hand side of the bracket if offset as standard to allow the fixed brakeline section to pass through. The only  issue is the fact that I had to shim out the left side caliper arm to get the caliper to line up with the disc and the fact that I didnt need to shim the right hand side at all to get the additional caliper to line up, which as mentioned above seems well odd
.... now you have me worried about the axle though.. I've had the front axle in and out tons of times ... are you seeing something in the photos ?  When I was lining up the caliper the dust seal retainer on the front wheel was a bit messed up and would only screw in halfway when I was lining up the calipers and discs ... but that wouldnt affect fork spacing, caliper alignment  etc I dont think. Got a new retainer now but havnt tried seeing if it has an affect on caliper / disc alignment. (later on ...see my seperate thread at http://forums.sohc4.net/index.php?topic=125869.0 for the agonies I'm going through with setting up my Dual Discs)

[Ewan 500K1]

Forks all done and dusted: new oil seals, new oil seal retaining clips, new dust covers , 165cc of 15w fork oil in each, repolished. That'll be me for a while till I can get hold of a steering lock key so that I can get the steering lock out ready for frame, swing arm, stand and lower triple T powder coated. Many many thanks to all who have provided advice and comment so far

[crazypj]

Had to open pictures in different program so I could enlarge them
 Looks like the left side bearing isn't fully seated which is pushing wheel to right.
You shouldn't need any spacing on the left side, if you have to use it, something is assembled wrong
Axle looks like it's installed from correct side

[crazypj]

Pretty sure it was posted recently, the later wheels have a slightly wider hub.
You'll need a shorter spacer on the 'nut' side of wheel (left) I forget if it's 4 or 6mm difference (measure the 'spacers' you fitted behind brake arm and shorten spacer by same amount)

[Ewan 500K1]

After much gnashing of teeth my Dual Disc calipers all set up now , 0.06 inch clearance between both fixed pads and their discs and a freely rotating wheel. This was the most trying part of the build I have done so far .. as I didn't originally realise that the caliper arms I have were not identical, that the mudguard bracket is non standard and that I have a narrow 500 hub on 550 forks.

The right hand side needed no modifications sch as shims or filing ... just the simple addition of a caliper arm, a caliper pin, a caliper pin bracket and a caliper. On this side the mudguard bracket is sandwiched between the caliper pivot pin bracket and the fork. All that was need was a few washers on the spring adjuster screw to give the spring some compression (see photo)

On the left hand side all that was needed was to file down the leading edge of the pivot pin bracket.

 ... not that this reflects the fact that it took me all day trying different combinations of pivot arms, pivot pin brackets and mudguard bracket placement. Full agony is exposed in my other thread for the agonies I had setting up the dual discs : http://forums.sohc4.net/index.php?topic=125869.0.

Thanks go to BryanJ, Oddjob and Crazy P for sharing the pain

[Ewan 500K1]

.. and just as I finished getting my dual discs set up right a man in a van arrived with my new Hagon rear shocks. These are a special build at 361mm between centres (standard are 315mm) , needed longer ones as clearnace at the back wheel has reduced due to insertion of the plate in the rear hoop to hold the battery and electrics

later edit : Taking the longer rear shocks and the issue with their effect on geometry , rake and trail off to a bespoke thread at
http://forums.sohc4.net/index.php?topic=126131.msg1434603#msg1434603

[crazypj]

You probably should have modified the frame, fitting shocks that long is going to make it very twitchy unless you raise the front end as well

[Ewan 500K1]

You probably should have modified the frame, fitting shocks that long is going to make it very twitchy unless you raise the front end as well

Have you experince of this Crazypj .. what mod would you suggest ?, been keen to know. Issue is that with the plate welded into the rear hoop, there's  only an inch and a half of clearance at the back end. I'll let you know how it goes.... but there will be near on 17 stone on it ... with the arse over the shocker mounts.

later edit : Taking the longer rear shocks and the issue with their effect on geometry , rake and trail off to a bespoke thread at
http://forums.sohc4.net/index.php?topic=126131.msg1434603#msg1434603

[SOHC4 Cafe Racer Fan]

Raising the rear will quicken stearing, but could make the bike prone to tankslappers at higher speeds.  You can fit a steering damper, and that should resolve the stability issue.

[Ewan 500K1]

Raising the rear will quicken stearing, but could make the bike prone to tankslappers at higher speeds.  You can fit a steering damper, and that should resolve the stability issue.

thanks CB750 CFR, I'll have a look into that

later edit : Taking the longer rear shocks and the issue with their effect on geometry , rake and trail off to a bespoke thread at
http://forums.sohc4.net/index.php?topic=126131.msg1434603#msg1434603

[Ewan 500K1]

having cleaned the frame ready for powder coating I found some cracks and corrosion under one of the rear footrest mounts. Also the cafe bars hit the tank on full lock, so thinking that the steering stop on the lower head stock need to be a bit wider

[crazypj]

A steering damper is no substitute for bad design. Get rid of the plate you welded in and re-think your 'styling'
I used CB750 fork tubes as they are longer than 500/550 ones
Depending on exact fork, you may need 550 lowers

[SF]

just read the thread nice job

[Ewan 500K1]

A steering damper is no substitute for bad design. Get rid of the plate you welded in and re-think your 'styling'

not an option at this stage Crazy ... forks are 550K3s.....  have you put longer rear shocks on ?have you had a rear end twitching or tank slapping as a result of longer rear shocks ?.. or you just playing safe with longer front forks ?. Really keen to find someone who has got longer shocks without doing frame or front end mods. Just because I baled out my mech engineering degree in year one doesnt mean I have any idea at all what I'm doing

later edit : Taking the longer rear shocks and the issue with their effect on geometry , rake and trail off to a bespoke thread at
http://forums.sohc4.net/index.php?topic=126131.msg1434603#msg1434603

[Ewan 500K1]

just read the thread nice job

thanks SF ... gimme strength

[Ewan 500K1]

crazypj, CB750CRF .. okay I get it now  .... spent all night reading about geometery, rake and trail .... well you learn somethin new every day on the fourm  . Thanks both for pointing me in the right direction. I now know that what I need to do when the bike is built back up is to calculate  the trail and make sure that its within reasonable bounds ( > 3.5 inch ??) ... and if not to raise the front forks (longer stanchions ?)  or get a new top yolk and triple T with smaller offset. One thing in my favour is that in stripping the bike I found that the triple T was pretty badly bent ... this would have reduced rake and trail in the old set up ... so with a new stright triple T and longer rear shocks maybe I'll end up where I was in the first place . We'll see ....   ... and having read of the horrors of tank slappers I think I'll go for an insurance damper in any case. I also see that the racing boys generally raise the back end and run with an 18 inch front wheel .. wonder what kind of trail that results in ?

later edit : Taking the longer rear shocks and the issue with their effect on geometry , rake and trail off to a bespoke thread at
http://forums.sohc4.net/index.php?topic=126131.msg1434603#msg1434603

[crazypj]

Racing is a different ball game, you may want it to steer real quick
On the street it isn't generally a good idea

[Ewan 500K1]

Racing is a different ball game, you may want it to steer real quick
On the street it isn't generally a good idea

still be interesting to know though ?

later edit : Taking the longer rear shocks and the issue with their effect on geometry , rake and trail off to a bespoke thread at
http://forums.sohc4.net/index.php?topic=126131.msg1434603#msg1434603

[Ewan 500K1]

Taking the longer rear shocks and the issue with their effect on geometry , rake and trail off to a bespoke thread at
http://forums.sohc4.net/index.php?topic=126131.msg1434603#msg1434603

[Ewan 500K1]

some random photos including longer rear shocks

[Ewan 500K1]

so .. the speedo cable rubs against the new disc. High tech fencing wire speedo wire restraint fabiricated and installed

[Ewan 500K1]

so after trying all sorts of ways of assesing the effect of the longer rear shocks on rake and trail I finally found a method that I'm happy is giving consistent results. I used a digitial protractor (or inclinometer), see first picture below.... it was absolutely consistent in the change effects that both the new shocks and changing the Triple T had on rake and trail and this gives me loads of confidence in the figures, see third picture below. So thats me done and dusted with rake and trail measuring. Its been an education for me at least  .

So, I now reckon (with confidence) that..

1. A one degree change in rake = a reduction in trail of more or less 6.5mm (quarter of an inch)

2. For every 10mm increase in rear shock length there is a 0.48 degree reduction in rake and a 3mm recuction in trail.

and with a bit of acceptable tolerance that..

3. With the new longer shocks I've got a rake of 23.5 degrees giving a calculated trail of 91mm (3.64 inches). Stock figures are 26 degrees rake and 102.5mm (4.1 inches trail)

So, I'm happy to stick with damper to minimise any tank slapping tendencies induced by the new longer shocks, rather than messing about with the Triple T to compensate. I got hold of a bargain basement GSXR steering damper today... might be a wee bit on the short side for a stock 500, but as I'm putting 10mm extra on the steering stop so that the ace handlebars dont bang off the tank I reckon it should do the job.

Next up then ...
•Stripping back to bare frame again and getting a wee bit of welding done to one of the passenger footpeg mounts and the steering stop
•Make up my mind whether I want the frame silver or gloss black, then getting it powder coated
•Ordering my rear sets now that the Italians are back at work
•Make up my mind if I want to drill some holes in the front sprocket engine casing
•Bit of alloy polishing refresh
•Stick it all back togeather
•Bit of a tune up service
•Refine the rear light set up

And then we're ready to roll I hope.

[Ewan 500K1]

Sorted on the steering damper clamp front , got a 30mm one from Dennis Trollope Racing at http://stores.ebay.co.uk/Dennis-Trollope-Racing . He's quite a bit cheaper than others for the same clamp. Although the 500 frame measures 29mm in diameter, the 30mm clamp tightens on fine. Not too happy now with the GXSR damper though. On the good side it bolts straight into the hole on the bottom of the 500 lower yoke. On the down side it does not allow the steering to go full lock to lock, this isnt really a problem for me as I intend reducing the lock to lock distance to stop the ace handlebars hitting the tank anyway. What I'm less happy about is the height the GSXR damper needs to sit at ... it sits too high and spoils the lines of the tank (see photos) Going to order an NHK ODM 500 damper from Dennis Trollpe instead now which should sit better.

GSXR Dimensions
Mid point to eye (extended)  150mm
Mid point to eye (closed) 85mm
Travel 70mm
Body Length 128mm

NHK ODM 500 Dimensions
Mid point to eye (extended)  227mm
Mid point to eye (closed) 141mm
Travel 85mm
Body Length 154mm

[Ewan 500K1]

NHK ODM500 steering damper (as originally fitted to the Kawa Z1) in place. Much more pleased with this one, it sits much better than the GSXR one. At full right hand lock it just misses hitting the engine. Next up, a wee bit of welding on the frame and then off to the powder coater.

[Ewan 500K1]

Had to extend the steering stop by 10mm either side to stop the clubman bars banging off the tank.

Also, one of the rear peg mounts was corroded through and needed welding .

Finally .... tarozzi rear sets have arrived These will be mounted on the rear passenger footpegs instead of using the tarozzi mounting bracket

...... so nearly there as ever. Just need to get powder coated and the front muguard rechromed.  Bring it on Santa