RD350 front and rear disc hubs

[kar1zma]

I would like to add front and rear disc hubs to my RD350 build
I prefer to go stock or slightly restomod on those but nothing too mordern

I was told that for the front TX500 hubs would be perfect . I can't seem to find any on eBay
Finding the rear euro hub is near impossible

What options do I have

[bitzz]

XS650 for the front.
Should be easy to find. Mike's XS sells a new knock off.

The rear is a bit of a unicorn....

[oxford]

Are you looking for dual disc on the front?  TX is bolt on for the rd350 if you are.  XS650 front hub doesn't work on Rd350 triple tree spacing for dual disc.  If going for single disc why not just use a rd350 front hub?

You could use the dual disc xs front hub on the rear but you will need adapters and spacers made and also lose the cush.

[pdxjim]

Single disc with a modern clamper is more than plenty of braking power for a little RD.

[kar1zma]

Are you looking for dual disc on the front?  TX is bolt on for the rd350 if you are.  XS650 front hub doesn't work on Rd350 triple tree spacing for dual disc.  If going for single disc why not just use a rd350 front hub?

You could use the dual disc xs front hub on the rear but you will need adapters and spacers made and also lose the cush.

My RD is in India and we have drum hubs and spoked wheels
so i prefer to keep it as close to stock as possible by avoiding any heavy modifications
I will stick to the RD350 or RD400 forks at most

what about the standard front USA RD350 disc hub. I think that could be sourced
is it good enough for a 55-60 HP long rod motor

[kar1zma]

Single disc with a modern clamper is more than plenty of braking power for a little RD.

o yes single should be plenty enough

any suggestions on the rear . keeping it clean and simple

[m in sc]

keep the stock drum on the rear.

[kar1zma]

keep the stock drum on the rear.

any particular reason to go with the rear drum?
chuck is building me a stage2 long rod 350 motor
is the front disc enough for stopping

plus I think a rear disc would have a "wow" affect

[m in sc]

I have a rear disc and a rear drum bike. rear drum is plenty with an upgraded front. bike weighs same at 30 or 50 hp.

[Dvsrd]

keep the stock drum on the rear.

any particular reason to go with the rear drum?
chuck is building me a stage2 long rod 350 motor
is the front disc enough for stopping

plus I think a rear disc would have a "wow" affect

I guess the main reason for sticking to the rear drum is simplicity/ no hassle, and that it is more than sufficient for an RD. When braking hard, the rear wheel is hardly touching the ground anyway. But a rear disc conversion, if done right, should help save some weight, both from the wheel (unsprung) and the brake arm/shaft/linkage. An Aprilia 125 brake pedal (super light alloy) and a Brembo master is a good start.  Another drum brake option would be to use a cable actuated drum brake hub from an older dirt bike. This should still be sufficient for any RD ridden solo, and should also save a few pounds.

For the front, good pads, a single (one piece) brake line, and a 12-14 mm bore master cylinder should be good enough. Some master cylinders have a brake light switch, if not use a banjo bolt with a switch. The stock disc is pretty heavy for its size (267 mm) and can be replaced with something lighter, or skimmed 1-2 mm, and drilled as well. Or have a disc custom made by ISR of Sweden, to fit the OEM RD350 disc hub. ISR make really good discs. I had a 298 mm OD/ 5 mm thick disc made for a TX650 disc hub. This looks just like the RD350 disc hub, just larger. The plan is to use TX650 fork sliders as well, to avoid a caliper adapter plate. I just need to turn down the TX sliders to RD thickness first. Should look 99% stock when finished, just with a larger, thinner disc.
I already use the alloy reproduction caliper from EC, it is a lot lighter than the OEM cast iron caliper, and works just as good for street riding (I do not race my RD)

[85RZwade]

I get the appeal of the rear disc, planning one of my own. At the same time, I think the drum on Mark's lightweight is pretty damn wow!
Wade

[m in sc]

i didnt want the complexity, or weight of a rear disc setup. i could have gone with a dirt bike hub (actually have a few i sourced for that , so i did consider it), small motocross rear disc, but for what? the weight savings total was negligible at the end of the day for the aggravation and no benefit on the rear braking, the drum IMHO has more pedal feedback, especially on a light bike.

I have gone the other way with twin discs up fropnt and a disc on the rear, i swapped the front back to a single. did the dual discs up front look good? oh hell yes. but, way too sensitive even on the lc which is not really super light.





fwiw, down the road, i DO plan on getting a smaller disc and different caliper for the rear to lighten up the unsprung weight on the back
But right now its pretty easy to lock up the rear tire. the rear wheel being large has helped (think i have a 130? on the back).

The front, now with a single disc, is way more braking than it needs

as it currently sits. yes thats a euro RD rear disc hub and an xs650 front hub.

[Dvsrd]

Mark,
No wonder you saved no unsprung weight! ;)  That OEM rear disc is a right boat anchor. And the OEM caliper is not much better. Surely, with a smaller, thinner disc (220 mm OD, 4 mm thick) and a lightweight caliper, you should save 2-4 lbs right away. And a 220 mm rear disc is more than enough brake for any RD anyway. This ISR caliper has an integrated bracket, saving a couple of bolts and some material as well, made for a 210 mm or 250 mm disc. 210 should be fine for an RD.
http://isrbrakes.se/products/calipers/22-029.html

[m in sc]

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.

[kar1zma]

Mark,
No wonder you saved no unsprung weight! ;)  That OEM rear disc is a right boat anchor. And the OEM caliper is not much better. Surely, with a smaller, thinner disc (220 mm OD, 4 mm thick) and a lightweight caliper, you should save 2-4 lbs right away. And a 220 mm rear disc is more than enough brake for any RD anyway. This ISR caliper has an integrated bracket, saving a couple of bolts and some material as well, made for a 210 mm or 250 mm disc. 210 should be fine for an RD.
http://isrbrakes.se/products/calipers/22-029.html

Those ISR products are pretty cool but I bet they cost a whole lot as well