RD350 front and rear disc hubs

[kar1zma]

i had 400 mags on there prior with a rear disc actually. the wire wheels with the larger tires made it a wash. On the lightweight RD, i would have never run a stock rd rear disc anyways.

for the lc, I have a small caliper and i can make the bracket and rotor hat (already have a small 220 rotor from an aftermarket grom disc  , just haven't gotten around to it yet.

Looks like rear drum it is then .
Much simpler and enough stopping power

Now for the front what would be better the stock RD hub+disc or
As others mentioned a TX500 or XS650 hub + discs

Final recommendations for master cylinder as well please

[m in sc]

me? id run a stock 350 front hub, single disc off an fzr or ducati, you need a spacer, blue or gold dot caliper. KTM390 or grom or cbr 250 master gives perfect feel.

[EE]

Aaron Barry and i built this RD400 to race at Willow Springs and break the RD track record there  http://erlenbachracing.co/roadracing.htm  like everybody else we were hot to put a twin disc front end on the bike but found: A it was too much brake and B: it slowed steering due to the added front wheel weight so we took off one disc, saved it as a spare and never looked back. If that bike only needed a single disc i can't think of another RD Roadracer that would. And Soooo many really fast spoke wheel RD roadracers ran RD350 drum rear and single disc fronts with fantastic results. Rear disc is nice just be ready for the work or $ or both to do it and you could be spending that time and $ better going faster and riding harder..  Ed

[teazer]

We ran a TZ350 years ago and the rider/owner wanted twin disks.  They did exactly what Ed E said.  Front end didn't steer as well, worse over bumps and the brakes were awful for the weight of the bike.  I tried racing it at a couple of circuits and it pattered almost off the track at Grattan and had me stop at the side of the track at Mid Ohio wondering if something had come loose or fallen off.

That bike had lightened TZ750 disks not stock RD disks but still not a happy a bike. Next one we built, was fitted with a single disk and the right master cylinder and went way better.

On a street RD a single disk should be more than enough with the right pads and M/C.

[Jspooner]

On my TZ replica street bike I run a single disc in front. The disc is a replica of a TZ750 disc made out of an XS650 disc mounted on a magnesium TZ 750 hub. I'm using a grimeca caliper and a 13mm master from a ninja 250. It has plenty of stopping power. I also run a disc in the rear but it is not needed, way overkill. It is a modified RD disc, on a euro RD hub, diameter cut down to 220mm (IIRC) and thickness cut down to 4.5mm. Caliper is a brembo off of a Duc monster.

[oxford]

I did dual disc in mine using the tx500 setup but honestly did it for looks more than anything else.

I did thin the discs down to just under 5mm, 100 3/8" holes drilled per rotor, lighten the carriers,  aluminum calipers with Eric's aluminum pistons, speedo drive deleted, aluminum wheel spacers, and aluminum rims.  I didn't weigh anything but I figure I am at a wash to where it was stock. 

[m in sc]

it def affects the handling in a negative way, i also felt a more sluggish front end result after going to dual discs vs single.

[quocle603]

Drum rear and disc brake from 350.

[85RZwade]

Perfect example of the value this site offers; I would have over-braked my RD project had I not read this topic. Thanks for starting it and to those who chimed in with the wisdom of experience!
Wade

[pdxjim]

Perfect example of the value this site offers; I would have over-braked my RD project had I not read this topic. Thanks for starting it and to those who chimed in with the wisdom of experience!
Wade

This setup worked very well for us on the kart track bike last year, Wade.  The track in McMinnville is very tight, so constantly going from full throttle to hard on the brakes.  This was an endurance race, so even after 6hrs at hot race pace there was little fade and plenty of power.  Ducati/FZR 290mm disc, Brembo caliper and 12mm master cylinder.  Stock drum in the rear with basic shoes.

[Organicjedi]

Perfect example of the value this site offers; I would have over-braked my RD project had I not read this topic. Thanks for starting it and to those who chimed in with the wisdom of experience!
Wade

Agreed! I think the big thing is the amount of money you save with a rear drum. I sold a rear spoked disc hub with a front 400 spoked hub included for $550 last year... That's just the hub. Now add up the cost of building the wheel.

[rodneya]

Perfect example of the value this site offers; I would have over-braked my RD project had I not read this topic. Thanks for starting it and to those who chimed in with the wisdom of experience!
Wade

This setup worked very well for us on the kart track bike last year, Wade.  The track in McMinnville is very tight, so constantly going from full throttle to hard on the brakes.  This was an endurance race, so even after 6hrs at hot race pace there was little fade and plenty of power.  Ducati 290mm disc, Brembo caliper and 12mm master cylinder.  Stock drum in the rear with basic shoes.

Are those 350 forks swapped sides so that the caliper is on the left and behind the fork?

[pdxjim]

Are those 350 forks swapped sides so that the caliper is on the left and behind the fork?

Yes.  Standard RD350B forks.  Swapped sides like you describe.

Sorry the pic is so big!  Will try to fix it.

[85RZwade]

Now that's a sharp eye! That setup looks the business, Jim.
Wade

[rodneya]

Are those 350 forks swapped sides so that the caliper is on the left and behind the fork?

Yes.  Standard RD350B forks.  Swapped sides like you describe.

Sorry the pic is so big!  Will try to fix it.

I hate the way my caliper looks in front of the fork
Think I will have to try this