Hey all; Im in the process off bringing back my Daytona. I know they all came with a single front disk; but I was wondering if anyone out there has been able to convert it to a dual front disk? Im trying to keep the 35mm forks and have been all over the net. Mikes xs other cross referencing applicability. Has anyone done this and have the recipe for success? And if so... Pics? Thanks in advance.
Hi I certainly don't have a recipe for these but the brakes on a Daytona are more than capable on a bike of this weight. I did have mine drilled mainly for the bling and they look nice but the added weight of the disc and caliper etc.. in my opinion is not worth it. Just my opinion.
Upgrading the caliper and rotor are a much better idea.
Quote from: pdxjim on November 12, 2019, 12:04:23 AM
Upgrading the caliper and rotor are a much better idea.
That's what I've always been told. Another caliper, rotor and mount will add a lot of extra weight.
Quote from: The Red Scourge on November 12, 2019, 10:52:22 AM
Quote from: pdxjim on November 12, 2019, 12:04:23 AM
Upgrading the caliper and rotor are a much better idea.
That's what I've always been told. Another caliper, rotor and mount will add a lot of extra weight.
Dual discs look cool, but weigh a ton. A modern rotor and caliper combo weigh much less and stop way better than the OG setup.
I realize theres are those that will say the stock single is capable. Im aware of that since it stopped before I tore it apart. I do have an upgraded drilled rotor. Weight is not an issue. But I am trying to get that dual disk for for my personal wants. Anyone out there?
The SR500 had a disc on the other side...but I don"t remember what size the tubes were though.
XS750 front...?
(https://uploads.tapatalk-cdn.com/20191113/f87c6b7cdcda4a47013727d227ba9b57.jpg)
Dual disc. 35mm forks. You'd need a lower triple and stem but that's easy to locate. DM me if you're interested.
Quote from: Daytona Z on November 12, 2019, 07:18:22 PM
I realize theres are those that will say the stock single is capable. Im aware of that since it stopped before I tore it apart. I do have an upgraded drilled rotor. Weight is not an issue. But I am trying to get that dual disk for for my personal wants. Anyone out there?
Are you trying to keep the cast wheels? There is a spoked front hub with dual discs and a 14mm axle. I have to look around a bit, I forgot what bike it was used on. There are some xs400 cast wheels that have dual discs but I think they are 17mm axles.
Early RD's up to the Daytona's used 17mm axles. The '79 Daytona Special front dropped to a 15mm axle.
Chuck
Thanks for the input fellas! I was trying to keep the stock cast wheel but I'm open to options. Thanks Chuck!
Any one have a master cylinder recommendation for dual disc with stock RD calipers?
Have you read this?
https://www.vintagebrake.com/mastercylinder.htm (https://www.vintagebrake.com/mastercylinder.htm)
(https://www.vintagebrake.com/images/mastercylinder.gif)
I personally like my ratio #'s to be 23:1
Not wooden like a stock RD400 at 18:1 (48mm x 2 pistons using a 5/8 or 16mm) Excluding the Daytona Special model
On stock RD's mostly I drop the stock master cylinder from a 5/8 or 16mm to a 14mm master for a 23:1
if you like a more powerful 2 finger lever a 13mm is better at 27:1
Micheal likes close to 27:1 and I don't like it that powerful and soft.
Stock RD caliper are 48mm X 2 pistons
If you follow that, at using 48mm x 4 pistons with a 19mm master you'll be in the right area at 25:1
This is the reason most modern calipers have to use much smaller caliper pistons as I don't think there are huge car like master cylinders available for motorcycles and smaller is lighter.
Thanks Chuck! Thats all good info I hadn't considered to that degree!
I have seen the chart but thanks for the additional info. 19mm seems to be a popular size in radial master cylinders but not so much in a conventional axial master.
I have a simple adaptor plate and FZR600 4-piston calipers with the stock master cylinder on my Daytona. The ratio works out to about the same as stock as I recall, and I'm happy with the way it feels. Huge improvement in braking. You could try that and upgrade the M/C later if you don't like the feel.
Dave
The 1978-79 XS400 front wheel is the same as the Daytona wheel but drilled for dual disc. Both are 15mm axle
http://www.2strokeworld.net/forum/index.php?topic=65.msg11799#msg11799
FWIW, I went from the stock dual front discs to a single 320 mm ISR disc, 13 mm Brembo master, and a 4 piston Brembo caliper on my 77 XS650. MUCH better brakes, and 4 kg / 9 lbs less unsprung weight. Replacing the steel front fender with an alloy one saved another 1 kg/ 2 lbs. This really did wonders for the front suspension and handling.
IF going to dual discs, I would recommend looking for the lightest possible discs and calipers. That would NOT be 70s or 80s OEM Yamaha parts. Jim Lomas has some nice Brembo replica discs, 260 mm diameter. Those may be suitable for a dual disc setup.
If you want to go dual disc and stay with stock looking parts you can get the weight down quite a bit.
Here's what I did,
Stock RD 350 rotors thinned down to 5mm thick
Rotors drilled. 3/8" diameter holes, 100 holes per rotor
The disc carriers were lightened up some
TX500 front hub, pockets milled out between the rotor mounting holes
Aftermarket(stock replacement) aluminum calipers with Eric's aluminum pistons
I also deleted the speedo drive and made aluminum wheel spacers
This is still no where near as efficient for weight as a single disc setup but not as bad as just slapping a second stock rd caliper and rotor on.
Thanks for all the input gentlemen. Not sure what im going to do yet.
So how about going spokes and a dual setup? It seems easier than an 18" Mag. That doesn't seem doable. Its not just for a dual disk. I always wanted spoked rims to begin with; but thought I might be able to convert the mag. I know guys have done this. Any pics and details of year hubs and forks......?????? Thanks in advance.
(https://live.staticflickr.com/65535/49412456136_fe77b321e3.jpg)
Thanks! I did get some lower legs and some other parts to try it.The problem is the Daytona has an 18" mag. Getting one in a dual setup. The 650 and 550's are 19". If I go spokes I can get an 18" as wide as I need. I just would like to see some examples of what some members have done. Any pics are appreciated.
Quote from: Daytona Z on January 20, 2020, 09:32:55 PM
Thanks! I did get some lower legs and some other parts to try it.The problem is the Daytona has an 18" mag. Getting one in a dual setup. The 650 and 550's are 19". If I go spokes I can get an 18" as wide as I need. I just would like to see some examples of what some members have done. Any pics are appreciated.
The XS400 wheel I posted above is identical to the Daytona except it is provisioned for dual rotors. 18x1.85". Direct bolt on.
yup.
xs400 wheel, 18".
(http://www.2strokeworld.net/wp-content/uploads/LC-HYBRID/GENERAL-PICS/lcpreblowup-12-2011-1.jpg)
fz600.
maybe fzr 600. anyways, i eventually moved to radian stanchions because the fzr ones were too long. and yes, 15mm axle, there was a fair amount of machining to get it right (spacers, etc). Regardless, it was still way too much braking and the front end felt heavy with the twin discs. to the point, when i rebuilt the forks last year i cut the lugs off the RH fork because its totally unnecessary. don't do it, its def not worth it. (the dual discs)
Thats what I'm talkin bout! freakin sweat! In my looking around I never found the xs400 to have a dual disk? Guess I didn't look hard enough. Thanks for posting fellas!!!
Quote from: m in sc on January 21, 2020, 10:29:21 AM
maybe fzr 600. anyways, i eventually moved to radian stanchions because the fzr ones were too long. and yes, 15mm axle, there was a fair amount of machining to get it right (spacers, etc). Regardless, it was still way too much braking and the front end felt heavy with the twin discs. to the point, when i rebuilt the forks last year i cut the lugs off the RH fork because its totally unnecessary. don't do it, its def not worth it. (the dual discs)
M in SC ,Understood and appreciated.
its only like 1 or 2 years that were 18" mags like that.