Looking for Brake Disc Dimensions T3/SP LM spoke

[OldJock]

So I'm trying to determine the dimensions of the discs as installed to LMs and T3

This is to replace a set of Magni rotors on a Sfida 1000 which have warped but I can get no definitive info and wondered if anybody could assist.

From what I understand already I believe the discs have are 300mm diameter, 26.5mm offset (including the disc thickness) 5mm thick, hub diameter (to fit over the bearings on the wheel) 80mm and a bolt pitch circle of 101mm. That's what I measure off the existing Magni discs on the EPM wheels

I've been told these are identical to the discs fitted to the T3 and early LMs, hence the question.

The reason for this is to get a set of full floaters made by ISR but I need to be sure I have my dimensions correct, so if anybody can help I'd be very grateful.


John

 

[guzzigray]

So I'm trying to determine the dimensions of the discs as installed to LMs and T3

This is to replace a set of Magni rotors on a Sfida 1000 which have warped but I can get no definitive info and wondered if anybody could assist.

From what I understand already I believe the discs have are 300mm diameter, 26.5mm offset (including the disc thickness) 5mm thick, hub diameter (to fit over the bearings on the wheel) 80mm and a bolt pitch circle of 101mm. That's what I measure off the existing Magni discs on the EPM wheels

I've been told these are identical to the discs fitted to the T3 and early LMs, hence the question.

The reason for this is to get a set of full floaters made by ISR but I need to be sure I have my dimensions correct, so if anybody can help I'd be very grateful.

In true scatter gun fashion I'm going to ask the same question on Wild Goose so apologies to those who frequent both forums

John

Hi these dimensions are the same as one piece Convert/G5/T3 and 2 piece Convert (the two piece Convert has a shallow disc carrier). Lemans (two piece) have a deeper carrier and are not compatible.

EBC in the UK makes compatible full floaters : http://www.mgcycle.com/index.php?main_page=product_info&products_id=2652

If you go with ISR, I would love to get your thoughts on them. I've been considering them for my racer.

 

[OldJock]

Guzzigray of course you will get feedback if I go that route

Thanks for the reply appreciated, however due to time constraints I did not fully explain the motivation.

The bike already has a set of ISR 32 series 6 pots installed, these are optimized for 320s but do fit 300s. They are actuated by an ISR radial master

Next the difference in cost between going to 320s vs 300s is minimal compared with the initial outlay for either

A 320 gives a nearly 15 increase in area, so that's got to help heat dissipation

As I replied to this and the Wild Goose post, I have got my answer via Stein Dinse, who also sell a 320mm as well as a 300 and give me the dimensions.

http://www.stein-dinse.biz/Brembo/B...Brake-disc-320mm-Guzzi-Bimota-INOX::9314.html

The ISR 32's are awesome and I just love dealing with Acke of ISR although he is quite pricey.

The Magni although not looking heavy is a lot more weighty than it looks. When I had to loose a lot of speed recently (on warped rotors) the 2, 32 series pots had the bike doing a stoppie, I could feel the back end skipping screeching and weaving around through lack of grip and I could have pressed harder

A photo of the ISRs when trial installing

 

[OldJock]

Just one more

After looking around in Stein Dinse's site I also stumbled across this and thought it would be useful for others

2 drawings with dimensions, but no tolerances unfortunately, for brake discs. The one I was looking for is there so RESULT!!!

 

[OldJock]

So the ISR 320 rotors arrived a few days back, now I've got the aggro of trying to get new caliper carriers/brackets made

I'll post up again once they have been made

John

 

[guzzigray]

Very nice

 

[OldJock]

So its done when the bike is out the shed I'll take some pictures and post up the drawing of the caliper carrier.

That should at least serve as a starter for anybody going from 300 to 320 rotors. Although these are ISR calipers the centers are Brembo 40mm so the drawing should also be good for Brembo calipers (BUT CHECK IT I CANNOT GUARANTEE IT)

It was a real PIA the first set of carriers ended up scrap so I got them slotted. This enabled me to get a good accurate position of caliper to disc, by moving the caliper in the slot.

I then bolted it all up and took the calipers and carriers to the machine shop. From the slotted carriers he got the centers required and made me a new set with the correct dimensions and marked the changes onto my drawing

John

 

[OldJock]

Photo of the finished item.

The cap heads are going when the hex head Ti bolts I have on order arrive

 

[john zibell]

That is some serious braking capability. Is the tire sufficient to handle all that? Looks like it would be easy to lock things up.

 

[OldJock]

Plenty feel John

But yes at the MOT test they check braking capability and it will lock up the front. That said the rear can also lock when pushed hard.

I normally brake with 2 fingers on the lever and this makes it real easy, however I hear ya, with the 300s I could get the front tyre howling and lift the rear.

John

 

[john zibell]

A brake should be able to lock a wheel, you just don't want it to be too easy to do so. It will probably take some practice to get the feel of those brakes. Front wheel locks at speed are an immediate disaster, rear wheel, not so much.