The Alta Factory LHRB

[Philip]

He tells me prior to 2001 CRs had dual pistons in the rear.

Those CR calipers won't create an increase in the braking force that we are looking for. You need a bigger total piston area. Two (small) pistons does not always mean the total piston area is larger. What you simply need is a caliper from a heavier bike.

Perhaps even a single piston KTM Adventure or Super Duke rear caliper would be good enough. If you find a supply of any kind of large and cheap calipers, that would be the way to do it.

 

[snydes]

What is it exactly you guys don’t like about the factory rear brake? I haven’t had as many bikes as most of you guys but this thing has the best brakes out of anything I’ve ridden.

 

[Philip]

It would be perfect if it was possible to fully modulate the rear brake with one finger. It should be as powerful as the front brake, and should be easier to lock up than the front brake.

 

[snydes]

Honestly I feel it fits that exact description now. Not to be contrary or anything.

 

[WoodsWeapon]

Honestly I feel it fits that exact description now. Not to be contrary or anything.

It does, but Im after doing being able to do it from a hand operated lever.

 

[snydes]

It does, but Im after doing being able to do it from a hand operated lever.

That’s what I have.

 

[Philip]

We will see. If I have time, them perhaps today I will install my own Alta LHRB knockoff kit with dual actuation. I will then test it tomorrow and will be able to tell if I still want a bigger rear caliper.

 

[WoodsWeapon]

That’s what I have.

Sorry I didnt realise you have the LHRB. I also dont onow if my dual activation setup is going to be powerful enough, maybe getting a bit ahead of myself.

 

[snydes]

Sorry I didnt realise you have the LHRB. I also dont onow if my dual activation setup is going to be powerful enough, maybe getting a bit ahead of myself.

No problem. Like I said, I wasn’t trying to be contrary just wanted to understand what everyone was after.

 

[Philip]

I might have found an off-the-shelf hose, but I am waiting for a new 9mm master cylinder to arrive first to tell for sure.

The off-the-shelf hose is KTM P/N 60032063100. It is from the 2014+ KTM Adventure. The length is perfect, it matches the Brembo clutch master cylinder at the top and the Clake rear master cylinder insert at the bottom.

There is just one caveat... it has a 90deg bend near the banjo fitting. Ideally there should be no bend, although a small bend is okay. I put it in a vice and straightened it to only about 45 degree bend. That worked, until I installed it already and then out of curiosity decided to straighten it a bit more. Well, it broke. Cannot straighten it more than 45 degrees.

Other than that the hose is perfect. It even comes with the rubber stress relief piece near the hand cylinder. Costs $65-70 from most KTM parts stores.

 

[OneLapper]

The off-the-shelf hose is KTM P/N 60032063100. It is from the 2014+ KTM Adventure. The length is perfect, it matches the Brembo clutch master cylinder at the top and the Clake rear master cylinder insert at the bottom.

There is just one caveat... it has a 90deg bend near the banjo fitting. Ideally there should be no bend, although a small bend is okay. I put it in a vice and straightened it to only about 45 degree bend. That worked, until I installed it already and then out of curiosity decided to straighten it a bit more. Well, it broke. Cannot straighten it more than 45 degrees.

Other than that the hose is perfect. It even comes with the rubber stress relief piece near the hand cylinder. Costs $65-70 from most KTM parts stores.

The local KTM dealer is going to let me go through their stock of hoses to find a match. Havent gotten there yet tho

 

[snydes]

I’ve had a few rides now with my LHRB. Initially I wasn’t sure I liked it, wasn’t use to not having the foot brake and it was unnerving going for it and it not being there. I must say though now I am really liking the configuration, total control in your hands and I’m using the rear brake more than I ever did. I don’t find myself going for the pedal anymore either. Two thumbs up

 

[Mark911]

If there's enough interest I can create a CAD drawing/IGES file for the dual piston rear brake caliper mount. I can design it to be as basic as possible to make machining as cheap as possible. Most machine shops will take an IGES file and use it to generate machine code for their CNC equipment. I can even supply the machine code but most shops typically want to write their own as they know their equipment and operators better. I suspect the CAM work and machine time would be around 5-8 hours for the first part and about 1 hour for each additional part. You'd need about 4 or 5 parts to make it reasonable cost wise.

 

[Philip]

If there's enough interest I can create a CAD drawing/IGES file for the dual piston rear brake caliper mount. I can design it to be as basic as possible to make machining as cheap as possible. Most machine shops will take an IGES file and use it to generate machine code for their CNC equipment. I can even supply the machine code but most shops typically want to write their own as they know their equipment and operators better. I suspect the CAM work and machine time would be around 5-8 hours for the first part and about 1 hour for each additional part. You'd need about 4 or 5 parts to make it reasonable cost wise.

I source CNC machined parts from China all the time. I can get them machined there dirt cheap. Even after the shipping is paid the US machine shops still cannot compete on price. And the quality has been very good too, if the parts are not overly complex.

The key is to pick the correct caliper, Mark. Can you find 10-20 more calipers like yours at a below $200/each price?

 

[Mark911]

According to my notes the caliper is KTM PN 6001308000130. It's under $200 new without pads (assuming it's still being stocked). There are several other PNs, like 6001308000101 and 6001308000103, the difference is the color I think.

 

[Philip]

2010 KTM 990 Supermoto SMT
CALIPER REAR WITHOUT PADS $209.55

2007 KTM 950 Supermoto
CALIPER REAR WITHOUT PADS $191.52

6001308000103 is not coming up anywhere.

The pads should be $20-30.

Depending on the quantity and complexity, I figure the bracket cost will be $50-100 each.

 

[Mark911]

Question is, is it available? I think I got a bunch of "on backorder" results when I was looking. That's why I went to E-bay.

 

[Philip]

I just got one on eBay too, with a bracket. But it looks like new calipers were available. I saw them listed as available on more than one site.

 

[Mark911]

Ok, I'll start the measurement process.

 

[Mark911]

Got the initial model done. Need to make a rapid prototype and validate it before spending money on an actual part. Since my mod bracket was fabbed using an oversized rotor this engineering model will be the same. I'll scale another for the stock rotor.