Free-Floating Rear Brake Disc Conversion

[The Mighty Volt]

Hi all.

I was just looking to get some more information and opinions on these devices.

I am planning to lace my 5304 into a 24" rim and use it on my 21" IBOC bike frame, for reasons that included lowering the ride height, getting more torque out of my 24s setup and to allow me fit fatter tyres to aid suspension.

Unfortunately, and typically, this means that the existing brake arrangement would not work anymore.

So I came across this arrangement:

Now, this sort of thing might work fine on a regular bike with regular issues pertaining to stopping power, etc, but how would it work with a heavier-than-average bike, which, albeit that it has a disc brake up front also, is trying to stop a heavy spinning motor?

Is such an arrangement safe, practical, worthwhile, etc.

Does anyone have any more general information, background etc?

Many thanks indeed.

 

[Thud]

Hey volt,
The only reason to float the brakes is to keep the suspension as free as posible. lets the wheel follow the ground in braking bumps, There is argument as to reducing wheel hop & all sorts of things that are on the extream edge of performance. I seriously doubt you will find a boost to performance at bicycleing speeds (unless you are charging into your drive way & panic bracking into every turn )

More to be said for a favorite pad compound for stopping performance.
Then there is the "everyone else has them " peer pressure thing.
Hope that helps.

(edit..looking twice, are these just floating brake mounts? If these let you get disks back on the wheel then I say they are +1)

 

[Drunkskunk]

Looks like something I've been trying to design. Infact, got a link? I might order one.

The design is shifting the force latterly against the old rim brake boss. its not exactly the way that boss was intended to take the load, but it was built to handle it. unless the bike is a light weight race bike, I imagine it should hold up to more than the the disk rotor can.

 

[Hillhater]

Why is it described a a "floating" brake disc conversion ? ... is the disc actually free to float ?
That set up looks like it was designed as a conversion to adapt a disc & caliper onto a "V" brake frame.
It uses the "V" brake mounting post.
I dont think slowing a hub motor requires any thing like a much braking force as slowing a 200lb rider from 30mph down a steep hill !

 

[The Mighty Volt]

Why is it described a a "floating" brake disc conversion ? ... is the disc actually free to float ?
That set up looks like it was designed as a conversion to adapt a disc & caliper onto a "V" brake frame.
It uses the "V" brake mounting post.
I dont think slowing a hub motor requires any thing like a much braking force as slowing a 200lb rider from 30mph down a steep hill !

Thats precisely what it is.

As soon as I switch over to 24's, my wheel becomes too small to work with the existing V brake mount post.

They are referred to as "floating" as the caliper is not dependent on a pre-existing and immovable mount.

 

[The Mighty Volt]

here is a variation on the them, from Merida.

 

[Hillhater]

.... its not exactly the way that boss was intended to take the load, but it was built to handle it. .

Agree... that rod mount should have been designed to transferr the braking force low down near to the point the post joins the stay. :wink:

 

[Thud]

Why is it described a a "floating" brake disc conversion ? ... is the disc actually free to float ?

The caliper actualy "floats" to the degree of suspension geometry. a floating disc is a diferent option.

Every motocross bike in the early 80's touted their "floating" rear brakes as a suspension nesecity for performance....wich some how disapeard on the 1st generation of rear disk brakes in 87'. I don't think they have ever returned to the motocross scene. Suddenly having the brake mounting plate float was no longer nessi'sary?
I have both versions in the garage now & I can tell if a bikes full floating brake has a bushing stuck.(its the most neglected wear point on a bike) that said, rear wheels still hop under hard braking...floating or not.

I don't ride that way on the street & doubt you would notice it unless hard braking into some severe rip/rap braking kickers.

 

[The Mighty Volt]

I'm to worried about wheel-hop, more the stress along a brake mount and an 18cm length of aluminum alloy as a 5304 tries to climb down from 40Mph

Anyways folks here is the online Ebay linky: http://cgi.ebay.com/New-MTB-Rear-Disc-Brake-Convert-Kit-170mm-Black-/370450243641?pt=Cycling_Parts_Accessories&hash=item56408e2039

 

[Thud]

LOL, & OOps.
After carefule study, the bracket in the OP is not a floating unit at all. Its just a disc brake bracket & a cantilever to anchore it. (unless you count some bicycle designs where the dropout rotates with the suspension action)
I wouln't worry about the strength of the unit. More of fitting over the hub motors axel.
I'll shut up now

 

[The Mighty Volt]

LOL, & OOps.
After carefule study, the bracket in the OP is not a floating unit at all. Its just a disc brake bracket & a cantilever to anchore it. (unless you count some bicycle designs where the dropout rotates with the suspension action)
I wouln't worry about the strength of the unit. More of fitting over the hub motors axel.
I'll shut up now

No need to stay quiet, we like detail and clarification around here. I have PM'd the guy selling them on Ebay should have more detail later.

I had worried about the axel but now I think that I could get the bracket to double as a torque arm on that side.

Cheers!

 

[teklektik]

Any updates on this v-brake to disc brake adapter (realizing that it has nothing to do with floating brakes at all )?
Did you give it a try or move on to another plan?

 

[MadRhino]

I just took off the floating caliper mount from my V10, integrating an IS mount to my custom dropout to make room on the other side for a 5 speed freewheel on my 5404. I couldn't notice much difference riding it with a fixed caliper, needless to say that regen is doing most of the rear braking anyway. I've been riding hard yesterday, about 60 miles DH and urban with some jumping. The bike does better every day, the suspension tuning is almost completed and surprisingly, this heavy motor might end up being a good mountain ride.

 

[teklektik]

I just took off the floating caliper mount from my V10, integrating an IS mount to my custom dropout to make room on the other side for a 5 speed freewheel on my 5404.

MR-
Apologies - I didn't quite understand the response. I'm trying to find out if anyone (e.g. The Mighty Volt) has used this adapter successfully. This unit is not a floating caliper so I'm thinking you are talking about something else entirey, yes?

 

[MadRhino]

I just took off the floating caliper mount from my V10, integrating an IS mount to my custom dropout to make room on the other side for a 5 speed freewheel on my 5404.

MR-
Apologies - I didn't quite understand the response. I'm trying to find out if anyone (e.g. The Mighty Volt) has used this adapter successfully. This unit is not a floating caliper so I'm thinking you are talking about something else entirey, yes?

Sorry for the confusion. i was mislead by the title. Yep, I took off a real floating brake.

This adapter is nothing interesting, you'd better do a custom dropout plate with IS mounts like I did to replace my floating brake that was using too much space on the axle.

 

[teklektik]

This adapter is nothing interesting, you'd better do a custom dropout plate with IS mounts like I did to replace my floating brake that was using too much space on the axle.

It's for a low speed GF bike with aluminum frame. For $50 this looks quick and simple. No point in fabbing parts if bolt-on is adequate at a fair price (too many projects... ).

 

[aroundqube]

That looks familiar. I think that this design was created by a company called 2btherapy. I decided not to go with it because I did not have the u-brake boss on my frame. Try 2btherapy.com and look under "bikes"

 

[hydro-one]

Sorry to Jack the thread,

Mr Rhino, : I am very interested to see what u did with your V10. Im doing a rear hub to 2009 stinky. has the floating rear brake (looks like it). I am thinking of using a 1/2 steel plate to replace the whole thing, incorporate some mounts on the tourque plate itself, do i even need to connect the floating arm back near the top of the brake mount? I guess i could i would help stiffin things up?? or does it need to pivot at the axle to avoid binding...... Do you have a pic of what you did?

KILLER DH

ps the stinky is white with monster t.s 2002 mint condition!!!!!!!!!!! my buddy got lucky

 

[MadRhino]

I just included the IS mount in the bolt-on custom dropout plate that I made, then fitted an IS 203mm Magura Gustav M adapter. Should be very similar with the bolt-on dropout of the Stinky.