I got my k100 as a running road bike.
Its now a café racer and going again.
The issue is it had 4 pot brembos on it but still the 13mm master.
I can get a 15mm r100r master unit new. Do you think the brakes will be firmer? They work well now but don't have the great bite that they should. Kind of soft and can be pulled all the way in. Pulled all the way in they stop well but maybe not emergency braking well.

I have read about a k1100 master conversion but I would like keep the original look of the k100 style.

Opinions please.

In spite of the smaller master cylinder bore used on Airheads with four piston Brembos as compared to the K, I was never able to make anything work and have good feel unless it was a 20mm master cylinder from a K11. Even on my '91 R100 I used a 20mm master cylinder with R1100GS callipers as the mm bore choices didn't provide decent braking. It looks close to stock, though not a white reservoir, you change the twisty bit too, but you get excellent feel as a reward. It's worth the mod. All model Oilheads (1100/1150) and 16V Ks use the 20mm M/C.

Bonus: the brake lever is adjustable and your switch gear screws right on.

Two Wheels Better wrote:In spite of the smaller master cylinder bore used on Airheads with four piston Brembos as compared to the K, I was never able to make anything work and have good feel unless it was a 20mm master cylinder from a K11. Even on my '91 R100 I used a 20mm master cylinder with R1100GS callipers as the mm bore choices didn't provide decent braking. It looks close to stock, though not a white reservoir, you change the twisty bit too, but you get excellent feel as a reward. It's worth the mod. All model Oilheads (1100/1150) and 16V Ks use the 20mm M/C.

Bonus: the brake lever is adjustable and your switch gear screws right on.

So will I need a 1100 throttle cable etc and mod the injector end?
Would need a complete unit including slide etc less the switch block and assume the brake switch also.

Quick question. I have braided all the way even the top hose. Assume your 15mm trial was braided also or if stock hoses how much pressure difference would there be.

The guy before me must have been running the 13mm and still getting warrant of fitness on the bike but idd say idd like to see the ability to lift the rear off the ground under extreme braking but idd say its only 80% there at the moment.

http://www.ebay.com/itm/Bremspumpe-vorne-brake-master-cylinder-front-BMW-K-1100-LT-/361138003185?pt=DE_Motorradteile&hash=item5415809cf1&vxp=mtr
That's the only one I can find and idd need buy a throttle cable also.
I am picking the fact the banjo is at the bottom means my top brake hose(new) will be to short.

EDIT; Its broken on the bottom on that one.
Does anyone have one for sale incase I go that direction.
Or a 15mm r100r master that they don't want.

I spotted a 20mm M/C with lever and brake switch, from an R1100RT (same as 16V K) with 25,092 miles, in our Seattle dealership's parts and accessories swap meet for this Saturday. Unfortunately I won't have access to it until the swap's end, which means it might have a chance to sell. I cannot grab an item before customers have a squiz at it. My hunch is it won't, and if it doesn't I'll let you know. I cannot grab an item for myself.

Two Wheels Better wrote:I spotted a 20mm M/C with lever and brake switch, from an R1100RT (same as 16V K) with 25,092 miles, in our Seattle dealership's parts and accessories swap meet for this Saturday. Unfortunately I won't have access to it until the swap's end, which means it might have a chance to sell. I cannot grab an item before customers have a squiz at it. My hunch is it won't, and if it doesn't I'll let you know. I cannot grab an item for myself.

Nice let me know. Thanks.

I was thinking the 15mm new item r100r verses 1100 20mm.
Does anyone have the volume of fluid moved figures?
If the 20mm moves a shorter distance than the 15mm they may move the same amount.

I was trying to work out the area in the 13mm diameter and 15mm and came up with 132mm and 176mm squared. Even though the 15 is only 2mm bigger the percentage increase is 1/3 and assuming stroke is same which it should be it would make a large difference.

Does anyone have the fluid volume shifted stats on the 15mm and 20mm.

I got the boss to grab it out of the pile for you. It's back at the workshop, clean and has been in indoor storage for two years. PM if you're interested further.