OK, here it goes... Call me crazy, but:
I'm going for a disc brake in the front next year. Plan is it's gonna be almost
invisible. Original lever on handlebar, wire in under dash/btween tanks
where cylinder is placed. Brake line out same way and into stock tube
alongside fork. And - here's the thing - caliper and disc fitted INSIDE
drum. Looks stock but will stop is the idea.
I shamelessly stole the idea with the hidden brake cylinder from a friend, but
I haven't seen tha hidden disc trick yet... for a reason, maybe?...
Ouestion:
Will the stopping power of this small disc be no better than a proper adjusted
stock drum brake? If so, it seems like a lot of work wasted for nothing.
IF possibly increasing the stopping power, and therefore worth hassling with,
do you think one should ventilate the drum in some way? Drill a cpl of holes
isn't too hard, and should make it cooler inside (YES - of course we're talking
a repop drum! I'm not THAT silly...)
Any other thoughts, suggestions or warnings highly appreciated!
Post by DuoDave on Oct 30, 2003, 12:32am
It would certainly make for a neat setup and sounds like the sort of project
you should do just for the heck of it. BMW did the hidden master cylinder trick
back in the seventies and Honda soon followed with a fully enclosed disc brake
on the front of their CB 550. The enclosed brake never caught on because it was
a real pain to work on. It will have to be a real small disc and caliper to fit
in the drum. Try the rear brake on modern Jap sport bikes. Your main problem,
though will be heat build up. The drum will have to be very well ventilated or,
under heavy use, your brake will fade like crazy, the brake fluid will boil and
you will end up with no front brake at all.
Post by DuoDave on Oct 30, 2003, 10:44am
Oops, just noticed I missed the X out of Honda CBX 550. The CB 550 was an earlier
Honda with a conventional front disc. Anyway, I've been out in the garage, and
looking at the front brake on the Harley, normal size motorcycle disc brake components
just aren't going to fit in there. Maybe you could find smaller parts from another
application, but I seriously doubt that anything that small will give you effective
stopping power. I've never understood why H-D went to so much trouble to fit
a hydraulic brake to the back of the Duo-Glide, but left the feeble cable operated
drum brake up front. Now you've got me wondering how hard it would be to convert
the front drum to hydraulic operation.
Post by Dereborn on Oct 30, 2003, 12:58pm
Now, that's another angle... Maybe one should look into the hydraulic drum idea!
I was thinking of using a disc brake from a scooter o r something. Seen it used
on choppers as rear brake. Also, one could let the top of the caliper pop up
an inch or so through the drum, and that way get a little more disc diameter
space. I think the ventilation issue is not that big a problem, i'm thinking
10mm (7/16?) holes all around the drum should keep it ok. and fading isn't really
a new experience... the ol' drum fades pretty quick when you start using it!
Let me know if you come up with anything more on the hudraulic drum!
Post by DuoDave on Oct 30, 2003, 8:20pm
I think you will be struggling to fit even a scooter brake in there. You will
certainly stop effectively, though, if you have the caliper poking through the
brake drum, as the drum revolves with the wheel. Maybe I,ve misundertood you
on that?
Post by Dereborn on Oct 30, 2003, 8:31pm
;D
The shield...
I mean the shield of course!
Sorry.
Post by haggis on Nov 3, 2003, 5:50am
Hey Dereborn,
I was thinking about your idea go check this out, forget the disc and go with
a double cam shoe up front, Panhead tuned me into these guys a while back...it's
a great idea! WWW.45partsdepot.com.
Haggis
Post by Dereborn on Nov 3, 2003, 11:19pm
Yeah, haggis, I've seen that one, but it's only for springers
I suppose? Ive got the ol' hydra you know...
Post by suicideshovel65 on Nov 4, 2003, 4:58am
Hi Dereborn,
I've seen some interesting parts on ebay that might work with
what you are trying to do - it was a mini disk set up by Airheart
(spelling?) I believe. Closed some time ago and I deleted the
link so I can't send you a lot number I'm afraid.
Let me know if I can help you with scooter parts if that's the
route you decide to take - I do live in Japan afterall!
Also, have you thought about using an early shovel wideglide?
looks very similar to the pan front, but with a bracket for the
old banana caliper. I know it isn't as tricky as what you're
proposing, but it will get you a disk pretty easily. It's what
I'm currently running on mine.
BTW what about running a disk and caliper behind the fixed shield
only, and covering the other side with a hubcap? ie don't use
the drum hub at all. That way you wouldn' t have the problem
of heating, yet the parts would be mostly hidden from the sides.
Not looking at the bike as I say this, so don't know if it would
work.
cheers,
S.
Post by Dereborn on Nov 4, 2003, 10:12am
Yeah, I was thinking about the shield only and hub cap setup
if I decide to go for double discs. But then I decided that if
not hiding the disc totally, I don't have to hassle with hiding
at all, and so I'm back to the drum path again!
I will try to find the airheart (airhurt?) things, and if you
have info on scooter parts, pls let me know!
Thanx
/J
Post by Panhead on Nov 4, 2003, 11:06am
This link? http://www.prodorutti-supply.com/index.html
Post by Dereborn on Nov 4, 2003, 1:00pm
5,5' discs seem 'bout the right size i think! Thanx panhead!
I found this site http://www.sscycle.de/Main_e.htm
the mini setup looks real nice! I think a brembo caliper is the
smallest I've seen so far, and these are not unusual in Sweden!
Might be possible to make a reasonable deal on one.
Thanx for all your input so far! Please keep it up!
Post by relic on Nov 6, 2003, 11:59am
Hello. Your idea did ring bell in my head, there is or was somekinda
kit with brake disc and caliber integrated inside almost stock
look shield.If you got Finish Kopteri-magazine 6/97-1/98,theres
a pic of it,in for sale adds.
It is not mentioned who is the manufacturer,but in a foto it
does not look bad at all,allthough I ain't never seen or noticed
it alive....
Post by Dereborn on Nov 8, 2003, 12:17pm
No, Relic, that magazine is not very common in sweden... Have
you got a copy of it? Maybe you could scan it and mail it to
me? Or xerox it and snail-mail it? Would appreciate that!
