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
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....
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.
Single disc with a modern clamper is more than plenty of braking power for a little RD.
Quote from: oxford on December 31, 2019, 04:15:41 PM
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
Quote from: pdxjim on December 31, 2019, 05:09:15 PM
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
keep the stock drum on the rear.
Quote from: m in sc on January 01, 2020, 08:37:25 AM
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 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.
Quote from: kar1zma on January 01, 2020, 08:48:49 AM
Quote from: m in sc on January 01, 2020, 08:37:25 AM
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)
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
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.
(http://www.2strokeworld.net/wp-content/uploads/LC-HYBRID/spoked-wheels/RDWHEELS_FINAL_5_zpsw5frdyku.jpg)
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.
(http://www.2strokeworld.net/wp-content/uploads/LC-HYBRID/2018-updates/forks-cleanup/IMG-20160713-00249_zpstb9rjfby.jpg)
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
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 :whistle:, just haven't gotten around to it yet.
Quote from: Dvsrd on January 01, 2020, 12:25:26 PM
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
Quote from: m in sc on January 01, 2020, 09:13:02 PM
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 :whistle:, 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
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.
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
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.
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.
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. :busey:
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.
Drum rear and disc brake from 350.
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
Quote from: 85RZwade on January 04, 2020, 09:58:17 AM
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.
(https://i.ibb.co/MZS01NT/Travis-Bol.jpg) (https://ibb.co/gm9KWg1)
Quote from: 85RZwade on January 04, 2020, 09:58:17 AM
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.
Quote from: pdxjim on January 04, 2020, 12:10:48 PM
Quote from: 85RZwade on January 04, 2020, 09:58:17 AM
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.
(https://i.ibb.co/n6mJ1k2/Travis-Bol.jpg)
Are those 350 forks swapped sides so that the caliper is on the left and behind the fork?
Quote from: rodneya on January 04, 2020, 05:16:35 PM
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.
Now that's a sharp eye! That setup looks the business, Jim.
Wade
Quote from: pdxjim on January 04, 2020, 05:50:45 PM
Quote from: rodneya on January 04, 2020, 05:16:35 PM
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
Quote from: rodneya on January 04, 2020, 06:08:17 PM
Quote from: pdxjim on January 04, 2020, 05:50:45 PM
Quote from: rodneya on January 04, 2020, 05:16:35 PM
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
Yeah, caliper went behind the fork leg on the rd400 and pretty much every modern bike after that
downside is you should flip the wheel, and the speedo drive, which then wont work. But, if you are running a digital speedometer good to go. (im pretty sure you cant use the wheel right way around on flippd forks but i could be wrong)
Yes, right fork leg goes to the left, moving the disc to the left side, meaning the wheel must be flipped.
You can keep the speedo drive as a spacer and either take the guts out or remove the tab washer thingy from the wheel hub. It'll be spinning the wrong way to properly drive the speedometer.
I specifically bought a speedo drive adapter for my Acewell gauge that goes into the factory speedo drive at the wheel because I did not want to use a magnet. So much for that plan
Quote from: rodneya on January 04, 2020, 08:44:27 PM
I specifically bought a speedo drive adapter for my Acewell gauge that goes into the factory speedo drive at the wheel because I did not want to use a magnet. So much for that plan
What does that look like? You may be ok with the wheel flip and that setup. The acewell should be looking for a pulse, I don't think it cares which way it is rotating to get it.
the acewell should work as direction of rotation wont matter on an electric pickip
This is what the acewell speedo adapter looks like.
Hope you guys are correct about the direction
My garage is a bit too cold to hang out in at the moment to check
i know, it shouldn't matter its just looking for rotation, not direction specific. try it in your drill. spin the cable one way, then the other with the gauge wired up on a test bench. should work both ways. :science:
If I was fitting an electronic speedo to a non-stock RD, I would have skipped that adapter, and used a normal pickup +magnets, or an inductive pickup that senses normal steel bolts, like the 6 pcs M8 holding the brake disc. The stock speedo drive is pretty heavy, requires a bit of oil or grease from time to time, and can be replaced with an aluminum spacer with a thin aluminum washer pressed on. That is what I did on my XS650, when mounting Daytona Velona electronic speedo and tach.
Quote from: Dvsrd on January 05, 2020, 06:37:33 PM
If I was fitting an electronic speedo to a non-stock RD, I would have skipped that adapter, and used a normal pickup +magnets, or an inductive pickup that senses normal steel bolts, like the 6 pcs M8 holding the brake disc. The stock speedo drive is pretty heavy, requires a bit of oil or grease from time to time, and can be replaced with an aluminum spacer with a thin aluminum washer pressed on. That is what I did on my XS650, when mounting Daytona Velona electronic speedo and tach.
I bit the bullet and just went with a gps speedo. I didn't even want to deal with the pickup and wires running up.
I have been running a Sigma bicycle speedo on my TDR for 10+ years since i swapped to supermoto wheels.
It cost like $20 and has been faultless.
Quote from: Jspooner on January 03, 2020, 12:26:02 AM
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.
Finally found some pics of my brakes.