Seem to have mislaid a disc

[northwind]

My front wheel is Fireblade-fitment, which with Honda's standardisation means I've got a choice of a few different discs. Usually I use SP2 320mm discs but they're a wee bit overkill frankly, very very strong. So, I was thinking off going down to CBR600RR 310s when I found out that the 954 Blade had a 330mm disc- found one cheap on Ebay and decided to see what happens if I on;y use one...

http://i74.photobucket.com/albums/i264/Northwindlowlander/dymag/Front%20end/singlediscfromfront.jpg

http://i74.photobucket.com/albums/i264/Northwindlowlander/dymag/Front%20end/singlediscfromside.jpg

Obviously the caliper and mounts are all still there for the RHS disc, just with nothing to bite on. So it does look a bit silly. So first question folks, does it just look daft? Try and imagine it with no caliper etc.

The weight saving is quite solid- discs and caliper together is nearly 2 kilos, even with just the disc removed it's noticable on steering. The weight's moved out a little on the one larger disc though, and it's around 100 grams heavier.

Performance... Meh. It's very damp here so I can't exactly test it properly, but it has next to no initial bite. I quite like that, but there's a big loss of power. I actually expected a loss of feel, with the 18mm master cylinder now pushing half as much fluid, but it's not worked out like that. What remains to be seen is how much real power it loses- I've tried some hard stops on shellgrip, and it takes a lot more effort but it does stop pretty sharpish. If I could combine this gradual initial bite with more power as I brake harder it'd be lovely...

Anyway, just thought I would post this up as a work in progress, the weight reduction is pretty nice but I'm not sure it's worth it, I need to decide if I'm going to work with it- maybe with a different caliper or stronger pads- or if the looks are just too offputting :scratch:

[Stig]

Nah put the other disk back on. It looks like you have a 400. Also why the weight saving :?: You going racing :?: Get the other disk back on and have nice light braking.

[fizzwheel]

I dont know if that looks right, but I think its because you have an S.

I reckon that'd look better on a Naked.

Oh and nice touch with the shelby stripes up the top box :cool:

[northwind]

Nah put the other disk back on. It looks like you have a 400. Also why the weight saving :?: You going racing :?: Get the other disk back on and have nice light braking.

Bingo... does look like a 400, that's exactly my first thought. I don't actually like the look, I was avoiding mentioning that though in case I steered anyone's thoughts that way! Usually I work on my mods til I'm happy with them before I do pics etc, but this one I'm really not sure about by which is why I'm doing that now.

You don't need to be racing to notice the weight difference though, just like with the wheel it makes steering and changes of direction easier- not so much faster, just less effort, sort of like longer bars do but without the drawbacks. Very nice for those "oh s**t moments".

I'm quite liking the reduced power in some ways, it's making me think that the setup I have normally isn't just powerful, it's too powerful... I need to be a wee bit careful with it, and it's not always much fun in the wet. Maybe I'm a wee bit too cautious of the power, not sure. This might be too far in the other direction. Or possibly, I just need to get used to it.

Fizzwheel, the box stripes are electric tape, just to give it a quality look to go with the mud and massive scratches in each side of the box :wink:

[hovis]

all i can see is your headlights?

[Keith1983]

Hmmmmmmm, really not a big fan of the look. Why not go for a couple of nice wavy jobs?

[Stu]

I like it, like a single sided swing arm.
Get the caliper off & get the rear to match :)

[northwind]

Hmmmmmmm, really not a big fan of the look. Why not go for a couple of nice wavy jobs?

Tried that, I prefer boring round ones that look like brake discs ;) Actually, what I really like cosmetically is totally plain, undrilled discs, or slotted discs. But mostly they're ductile iron, which isn't very practical for a bike that sees winter.

Right, wee follow on performance wise, I had a play in a nice dry multistorey car park. It's not lacking in stop at all really, it'll still stoppy frinstance, but I needed an extra finger on the lever. So, I've shifted the entire master cylinder along the bar, which moves my hand position further away from the pivot and increases the leverage, and now it's back to 2 fingers. Still a lot less strong than the dual discs, but I need to ride about a bit more and decide if that's an issue.

I'm also managing to convince myself it doesn't look rubbish. Slowly. But I think it probably does :smt045

[northwind]

Oh yeah, there's no reason at all the disc couldn't go on the other side, other than that it's easier to access the left hand side in my garage as it's a bit pokey. That'd be a bit less obvious, but then if I'm looking for less obvious I suppose I'm admitting I don't like how it looks :scratch:

You know, for a £25 experiment this is using up an awful lot of brain.

[mister c]

I was expecting a thread about the government here with names & addresses...........................







I'll get my coat.

Seriously, I think on the looks front, it doesn't look right, but for weight saving & if there is no real drop in brake performance, then, why not?

[pmapp]

Mmmmm, 2 discs for me, 1 just looks odd - but it's not my bike :-D

[DarrenSV650S]

:smt115I've got the perfect solution! Stick on a false disc and caliper on one side made of light weight material. You have now saved weight, without loosing the looks


I'm a genius :smt045

[Stu]

:smt115I've got the perfect solution! Stick on a false disc and caliper on one side made of light weight material. You have now saved weight, without loosing the looks


I'm a genius :smt045
No, get another 330 mm disc and furrow tarmac when you stop!

[northwind]

:smt115I've got the perfect solution! Stick on a false disc and caliper on one side made of light weight material. You have now saved weight, without loosing the looks


Or... I could attach an old record to the other side, and replace the caliper with a stylus... And fit goldwing speakers in the cockpit! Nailing that retro look.

[DarrenSV650S]

Perfect!

[petevtwin650]

So I read the experiment is still continuing:o

Can't say I like the look but it's function over form.

Is your radial brake a four pad or two pad item? Cos I was reading in Bike mag that a four pad caliper gives better bite.

Article added as it might be of some interest.

http://i72.photobucket.com/albums/i184/petevtwin650/Brakearticle.jpg

[jambo]

I tell you what, I quite like it. I always think it's a shame to have a nice front wheel that no-one can see for the discs, but then I had the loan of a Bros 400 for a bit and that had lovely interesting wheels:cool:

It's going to be a judgement call on stopping power but I really wouldn't want to be giving up a lot of initial bite or power, but then, I'm pretty heavy on the brakes and quite happy with the power I've got.

It's different, and kinda cool I think. It's probably worth putting my boring hat on for a sec to say if you do get in an accident, most police know enough to realise you should have a 2nd disc. It'd be a shame to give people an excuse to claim you could have stopped to avoid the car pulling out if you hadn't removed half the front braking system. The argument doesn't quite hold water because the one disc and caliper you've got is better than a single SV disc and caliper but you see where I'm going with this....

Jambo

[charlie13]

It looks like you've got a Dymag wheel in the front, so the steering already feels light and flickable. Do you really need to lose any more mass on the front end, even if you think if feels OK on one disc, and wouldn't you rather have all the braking power there if you ever need it?

[Berlin]

If you remove the second caliper and just run one on a single disk the way it feels now and the way it will after the change will be significantly different.

At the moment, the movement at the lever produces movement in both calipers. If you take away one caliper you will get twice the movement in the other for the same lever movement.

Carl

[northwind]

It'd be a shame to give people an excuse to claim you could have stopped to avoid the car pulling out if you hadn't removed half the front braking system. The argument doesn't quite hold water because the one disc and caliper you've got is better than a single SV disc and caliper but you see where I'm going with this....

Yep, it's a consideration. I'd be quite happy to defend that legally if need be though, it's not quite like a chopper with no front discs at all and if need be it could be replicated for testing easily enough. It's got potential to be a hassle, though. If I was to make it permanent, it wouldn't be obvious that there was a bit missing, I'd modift the fork leg etc and blank the wheel. But I'm still not 100% sure I will.


Is your radial brake a four pad or two pad item? Cos I was reading in Bike mag that a four pad caliper gives better bite.


Aye, I'd heard that (and from RobW#70 who told me that the 4-pads can have a ramping-up effect, which I noticed slightly on Scooby Drew's ninja but put down to general setup). These are the 2-pads off a GSXR thou.

If you remove the second caliper and just run one on a single disk the way it feels now and the way it will after the change will be significantly different.


Yep, I've removed the other caliper already, it wasn't making a big difference but it was there to feel. The movement in the other caliper was pretty minimal as it naturally had less "bounce"- without the disc in the equation the pads didn't back off much, they never released their grip on the ally blank I'd fitted in place of the disc (for easier refitting of the disc, y'see) But there was definately a difference. TBH I preferred it with both calipers! The master cylinder i have fitted is too much for one disc, for my tastes, and the wasted movement from the other caliper helped offset that.

It looks like you've got a Dymag wheel in the front, so the steering already feels light and flickable. Do you really need to lose any more mass on the front end, even if you think if feels OK on one disc, and wouldn't you rather have all the braking power there if you ever need it?

No particular reason not to, the braking power is still more than good enough for road use- my big concern is that it might fade quickly in more constant use, the weather at the moment has meant I can't do a proper continuous test.

There's still very little initial bite, but for me that's not a big concern, I prefer a very linear braking action without that initial step. Riding home in the snow last week I reckon the first touch was actually better than with the dual 320mm discs. But then, I was already of the opinion that the dual 320mms were overkill, and lacked subtlety- too much bite.

One thing which I'm putting down to the lower gyroscopic force is that it tracks road defects more than normal... Quite offputting that, it's the single worst thing I've come across so far. t's not unsafe, but it's taking some getting used to- sort of like having a skinny tyre on the front.

I've picked up a pair of CBR600RR 310mm discs to try out too, as well as a cheap R6 15mm (or possibly 16mm) Brembo-badged Yamaha part which should work better with the single disc. All cheap bits so I can always sell 'em on.

Glad my silly project is still getting interest :) I shifted the disc and caliper to the other side, which reduces the visual impact a bit. It currently has no mudguard, as it's off the bike for a little repair, and I have to say the front end looks ridiculous :smt090 But the single disc is growing on me, it's more an impact thing. You don't look at a Buell or the KTM concept and think "Not enough discs" after all.

[northwind]

Ridiculous front end sighting:

http://i74.photobucket.com/albums/i264/Northwindlowlander/other/wideloadfront-1.jpg