Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: captaindonutbikes on March 15, 2010, 03:01:09 PM
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I have the auto cad file for a 750 disk rotor and wanted it machining out.
firstly they are the same as the 550 ? and
any one know of a good place to try in the London area ?
cheers
;)
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750 bigger than 500
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Would it be possible to scale the drawing down to the correct size?
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Are you talking about your brake disk and having it drilled?
Does it make much difference? I have a drilled one under my workbench but have never bothered to fit it.
Would you be able to take a pattern from it?
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Looking at mine very carefully I would say that it has been drilled by hand because one of the holes is v.slightly off centre. I would imagine that with careful use of a professional bench drill it should be possible to do it oneself. What do people think?
Also has anyone used a drilled disk and are they worth the trouble?
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There's a guy on another forum (Scimitar owners club) that's bought a milling machine and is offering to do cheap 1 off work to recoup the cost. If the consensus is that it's a worthwhile mod and greater than manual accuracy is required then I can ask him for a price. I think new disks were on offer at cmsnl as well.
He's done a very tidy job of fitting a 3L 24v Omega engine to his Scimitar.
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Making a template for disc drilling isn't rocket science. I made my own template & drilled my own discs.
http://www.sohc.co.uk/index.php?topic=2451.0
I'm not sure what the differance in weight is, but reading the scientific reason that John Robinson from Motorcycle Mechanics came up with as justification for doing the job made it all worthwhile.
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Reason given when i was in the trade in the 70's was it was somewhere for the rainwater to go
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quality answer Brian.
so everyone seems split on the disk drilling. my brother in law maybe able to help out but i would interested in hearing the price of schmitar owners club guy ?
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John Robinson said that the holes had something more to do with the barrier gases given off by the friction of the pads...
The book by John is in a box somewhere up in the loft (the missus had a tidy up) so i'll find it & post up a few quotes.
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Well my front brakes are dragging (blasted winter salt has made the aluminiun go furry) so it's time to take the caliper off and strip it so while I'm there I might try putting on the drilled disk and see if it's better.
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quality answer Brian.
so everyone seems split on the disk drilling. my brother in law maybe able to help out but i would interested in hearing the price of schmitar owners club guy ?
I've just sent him an pm through the club forum.
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cheers totty ;)
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One word of warning
Do you really want brakes that work so well they lock up in the wet?
I decided from experience and hole in wallet it wasnt that good an idea!!
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http://www.sohc.co.uk/index.php?topic=2451.0
Which is why I had Vesrah rubbish pads on one disc & decent Ferodo pads on the other....
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Well my front brakes are dragging (blasted winter salt has made the aluminiun go furry) so it's time to take the caliper off and strip it so while I'm there I might try putting on the drilled disk and see if it's better.
A friend of mine turned up at my place one day many moons ago & I noticed that his front disc of his CB750F1 was sizzling in the rain. I asked him about the brake & he said that the pads were only lasting about 1000 miles & that his top speed was down to about 80mph. As he wasn't mechanically minded I asked him to go & make the tea & by the time he returned with the refreshments the piston had been removed, the seal cleaned, the seal ring land cleaned, seal lubed with seal grease, newish pads installed, disc deglazed & I was busy bleeding the brake.
His complaint was that the local bike shop had quoted him over
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Good heavens you work fast, whenever I try to take my bike apart there is always some corroded bolt that refuses to come undone and turns a ten minute job into half a day spent cursing. Having said that, all the bolts were greased when I put the bike together but then some of them haven't been touched for fifteen years.
I don't think the brakes have been dragging for long, I just noticed it when I wheeled the bike back to get on the other day. Looking at the caliper it has oxidised quite a bit more than usual this winter and I suspect the pivot at the top is not moving as it should. One day I will learn and will clean my bike occasionally and perhaps even put it under cover. Then again it's probably wishful thinking.
What you have said is very useful because it has reminded me that I will need to buy a new piston seal before I take it apart as well as some new brake fluid.
Someone mentioned brakes locking up in the wet. Can others please confirm this. The brakes on mine have so far been pretty rubbish so I find this revelation rather surprising. Does this mean that the only advantage of drilled disks is in wet weather?