Topic: My other last question about twindiscs

[robvangulik]

I tried it for a while, long time ago, and didn't notice any real advantages. I went back to the normal spot in front of the forklegs because of the easier accessability, easier to work on...

[timtune]

The reason for flipping them is to lower the weight - that and it looks way cooler.
No doubt the effect is most minimal that it's hardly worth the effort but I'm retired with time to fritter.

[timtune]

Won't the speedometer turn backwards? Will it cause you to time travel? Will the bike be new after it zeroes out again?

Yes! It's much easier than rebuilding everything.

A comment about the brake: the dual-disc mod fits well except on the K0 bikes made before 4/69 (and a few later than that). Those don't have the right-side of the hub machined off to accept a disc.

My other comment about flipping the calipers to the rear: I discovered, during a [quite rapid] descent from Mt. Evans, 14,259 feet high, that if it sleets and rains together while you're doing this, the pucks don't grab well until for 3 times longer than when the pucks are up over the top of the discs, in the rain. The following weekend found me in the garage, flipping them back to the top.

...just thought I'd mention it, just in case...

HM : Why do you think the rear position would be worse at shedding water? I find that surprising.

[bryanj]

So when i did an early 500 with one in front and one behind what did that do

[Tracksnblades1]

So when i did an early 500 with one in front and one behind what did that do

Twice the braking power on a single disc. ??

[bryanj]

Nope twin disc but had to use 2 lh sliders as the rh one had no mountings

[HondaMan]

Won't the speedometer turn backwards? Will it cause you to time travel? Will the bike be new after it zeroes out again?

Yes! It's much easier than rebuilding everything.

A comment about the brake: the dual-disc mod fits well except on the K0 bikes made before 4/69 (and a few later than that). Those don't have the right-side of the hub machined off to accept a disc.

My other comment about flipping the calipers to the rear: I discovered, during a [quite rapid] descent from Mt. Evans, 14,259 feet high, that if it sleets and rains together while you're doing this, the pucks don't grab well until for 3 times longer than when the pucks are up over the top of the discs, in the rain. The following weekend found me in the garage, flipping them back to the top.

...just thought I'd mention it, just in case...

HM : Why do you think the rear position would be worse at shedding water? I find that surprising.

When riding in heavy rain, the water flings off the disc straight at the oil filer's finned housing (I've watched in on many a friend's bike during tours in the wet). This meant that the water was about 1/4 of the way up into the brake pucks: when I went to flip mine back over to the top I found lots of sand and grit already packed in around the (then front) of the pucks. I had flipped them on a weekend and rode it 2 days before rain (commuting to work, about 24 freeway miles/day then) and then 2 days in the rain, followed by 1 day with no rain. In just that much time it had collected quite a bit of debris in the front side of the pucks. That made me pretty wary of it, so I flipped them back the next weekend.

Something to notice: whenever bikes have the calipers behind the fork legs, the calipers are way up on the back of the leg. The calipers on these bikes are on a longish arm, so it puts the pucks quite a bit further back and down by comparison. Honda was concerned enough about wet-riding that they put it on the top, and in the K3 and later 750 they added a little water umbrella to keep the water from flinging off the disc and up in the ignition coils: I can attest that is EXACTLY where the water goes when it is deep on the pavement and you are running 70+ MPH. That's a longish story, but it ended up causing me to be frequently shocked in the left leg when riding in very heavy rain (which the Vetter lets you do, probably not that wise, really) with over-aged sparkplug cap rubber booties!   

[newday777]

Won't the speedometer turn backwards? Will it cause you to time travel? Will the bike be new after it zeroes out again?

Yes! It's much easier than rebuilding everything.

A comment about the brake: the dual-disc mod fits well except on the K0 bikes made before 4/69 (and a few later than that). Those don't have the right-side of the hub machined off to accept a disc.

My other comment about flipping the calipers to the rear: I discovered, during a [quite rapid] descent from Mt. Evans, 14,259 feet high, that if it sleets and rains together while you're doing this, the pucks don't grab well until for 3 times longer than when the pucks are up over the top of the discs, in the rain. The following weekend found me in the garage, flipping them back to the top.

...just thought I'd mention it, just in case...

HM : Why do you think the rear position would be worse at shedding water? I find that surprising.

When riding in heavy rain, the water flings off the disc straight at the oil filer's finned housing (I've watched in on many a friend's bike during tours in the wet). This meant that the water was about 1/4 of the way up into the brake pucks: when I went to flip mine back over to the top I found lots of sand and grit already packed in around the (then front) of the pucks. I had flipped them on a weekend and rode it 2 days before rain (commuting to work, about 24 freeway miles/day then) and then 2 days in the rain, followed by 1 day with no rain. In just that much time it had collected quite a bit of debris in the front side of the pucks. That made me pretty wary of it, so I flipped them back the next weekend.

That reminds me of my ride back from Daytona 1980 to Goldhill CO on my K6 with rear side calipers. It had rained all day coming north through the Mtns of New Mexico  and turnd to freezing rain, lots of rain and puddles going up the dirt roads from Boulder. I got up to Goldhill in the dark, parked it on the hill side drive of where my friend lived so grabbed a handful of front brake to hold it while I got the kickstand down, in the cold freezing rain, soaked to the gills and shivering. Knocked on the door no one home,  so I walked over to the town watering hole to find my friends and found out they moved up the street to another house. So I walked up to their new place and got warmed by the fire with a hot drink with a kick. We went to collect the bike and found the brakes were locked solid so I unloaded it and hauled the gear in my friend's truck, covered the bike until the next day, it snowed 6 " that night. Anyhow, I  freed up the caliper with a screwdriver and then I had to rebuild the calipers. Lots of mud in them. I left them on the rear without problems and sold the bike 3 years later. I thought I had much better braking performance on the rear side of the forks.

[HondaMan]

Won't the speedometer turn backwards? Will it cause you to time travel? Will the bike be new after it zeroes out again?

Yes! It's much easier than rebuilding everything.

A comment about the brake: the dual-disc mod fits well except on the K0 bikes made before 4/69 (and a few later than that). Those don't have the right-side of the hub machined off to accept a disc.

My other comment about flipping the calipers to the rear: I discovered, during a [quite rapid] descent from Mt. Evans, 14,259 feet high, that if it sleets and rains together while you're doing this, the pucks don't grab well until for 3 times longer than when the pucks are up over the top of the discs, in the rain. The following weekend found me in the garage, flipping them back to the top.

...just thought I'd mention it, just in case...

HM : Why do you think the rear position would be worse at shedding water? I find that surprising.

When riding in heavy rain, the water flings off the disc straight at the oil filer's finned housing (I've watched in on many a friend's bike during tours in the wet). This meant that the water was about 1/4 of the way up into the brake pucks: when I went to flip mine back over to the top I found lots of sand and grit already packed in around the (then front) of the pucks. I had flipped them on a weekend and rode it 2 days before rain (commuting to work, about 24 freeway miles/day then) and then 2 days in the rain, followed by 1 day with no rain. In just that much time it had collected quite a bit of debris in the front side of the pucks. That made me pretty wary of it, so I flipped them back the next weekend.

That reminds me of my ride back from Daytona 1980 to Goldhill CO on my K6 with rear side calipers. It had rained all day coming north through the Mtns of New Mexico  and turnd to freezing rain, lots of rain and puddles going up the dirt roads from Boulder. I got up to Goldhill in the dark, parked it on the hill side drive of where my friend lived so grabbed a handful of front brake to hold it while I got the kickstand down, in the cold freezing rain, soaked to the gills and shivering. Knocked on the door no one home,  so I walked over to the town watering hole to find my friends and found out they moved up the street to another house. So I walked up to their new place and got warmed by the fire with a hot drink with a kick. We went to collect the bike and found the brakes were locked solid so I unloaded it and hauled the gear in my friend's truck, covered the bike until the next day, it snowed 6 " that night. Anyhow, I  freed up the caliper with a screwdriver and then I had to rebuild the calipers. Lots of mud in them. I left them on the rear without problems and sold the bike 3 years later. I thought I had much better braking performance on the rear side of the forks.

The one performance improvement I noticed when I had them on the backside was: less nosedive  in hard stops. Essentially it jams the fork lowers into the tubes with increased side-loading. In roadrace conditions I could absolutely agree this was the superior method, but in the 1970s rules we had it wasn't allowed.

[newday777]

"The one performance improvement I noticed when I had them on the backside was: less nosedive  in hard stops. Essentially it jams the fork lowers into the tubes with increased side-loading. In roadrace conditions I could absolutely agree this was the superior method, but in the 1970s rules we had it wasn't allowed."

I usually rode it hard into the corners.
They were acquired from a race bike, possibly were taken off because of the rules(1977 when I got them), I don't remember the details as one of the guys in the shop knew of their availability and set them up on my bike with the motor work he did to it, gonna go faster, gotta be able to stop too.

[MauiK3]

I don't ride much in the rain, many years ago I did and I didn't seem to have braking issues but I was always extra conservative when it was raining.

[Don R]

 When I did the double discs on my 76F I scalloped the front tire practicing emergency stops. When I pushed it out of the shop, I could hear the tread squishing on the floor.

[scottly]

I thought this would be mostly a bolt on affair.......

It would be if you didn't try to flip the calipers to the rear. The off-set in the forks matches the off-set in the hub. It's like Honda planned a second disc from the start!!?? 

Tim, make the right side caliper mount on the fork leg match the left side, so the caliper spacing stays the same as before. With the left side fork now on the right, you will need a spacer equal to the amount removed from the right leg, as well as the previously mentioned fender brace/spacer at the top.

[Don R]

 When you move the calipers to the back and reverse the forks, you also have to flip the fender around on the bracket right?  For anyone reading along that is gathering info. I think in this case he is removing the fender.