My '85 has non stock bars and controls on it including the Master Cylinder.

I have a pretty good grip and when working the brake lever I get very little movement before it can't move any more - thend of the lever may move ~1/2".

On stock bikes with brakes in good nick, how much does the end of the brake lever move until 'locked'?

I'm asking because the MC I have may be perfect for a swap to the later 4 piston calipers...

Thanks for the info.

Brad

The 2V bikes have a 13mm master cylinder and the 4V bikes have a 20mm master cylinder.

Usually the brakes on 2V bikes are somewhat anemic since the old brake lines are mush.

You can't just swap 4V calipers onto a 2V bike as they don't "bolt right up."

The 20mm master cylinder from a 16V gives the best 'feel' when using later, BMW-Brembo four-piston calipers, but as Duck says, they don't just bolt up (well, they do, but won't align with your standard 285mm discs). The 13mm M/C doesn't do well with the four-piston calipers; the feel goes away. The four-piston calipers do bolt onto the fork leg but at a quite disagreeable spacing over the discs. See the front of my bike for one 'solution': aluminium spacers 8mm thick which rest on the wheel hub and place the discs in the centre of the caliper. But then you don't have enough disc up inside the four-piston caliper clamping on the discs to make it worth it, hence, my answer: larger diametre, modified Suzuki 292mm discs.

Mate, unless you have the entire front end off a 16V model it ain't hardly worth the trouble. Even that can give you a headache, offset-wise.

A 13mm master cylinder, well-bled and with good hoses (I'm using HEL brand stainless steel) does a fine job with the two-piston Brembos which came with the bike.

+1 on what Duck said . there is a way to get the 4 piston calipers onto a K100 front end. You need to also fit the 285mm discs from the BMW R100 mystik which is the very last of the airheads. you would be better off buying an after market set new as I have only ever seen one set of used discs for sale.
If you want to get good brakes just get a complete front from a K1100 RS or LT and put it on ,it is the easy way to do it and the brakes are a heap better than the smaller K100 discs.

You also get better forks if you swap in a whole front end.

You can't tell by looking at it (except for the OEM K75 exhaust) but this is my K75 with a K1100 front end.

+1 on the braided lines making the pull up  really good....verry little moovement required after the upgrade from old rubber lines to braided ones

This works pretty well.  

Braided stainless line direct from master to right caliper.



You can't see it in the picture but then there's a "solid" metal line from the right caliper to the left caliper. BMW part 34322312691.



And you can take some play out of the brake lever if you get the one that has the little set screw in it.



Top it all off using sintered brake pads.

Thanks for all the info, and Duck - glad to see you back!

I'm sure I speak for everyone when I say that you have been missed.

I guess I should have stated that I have a 4v front end to put on, as well as everything but a rear shock for a 4v/K1100 Paralever rear, having just purchased 3 spoke wheels.

I DO have an aftermarket shock of unknown manufacture that if good may convice me to lower the mounting of the triples on the front forks...

I have SS brake lines.

The brake lever moves less than even my RD350's w/SS lines, and they have a 16mm MC for a single disk - 13mm is the perfect size for the  RD's w/stock brakes....

I'm thinking I have a MC that will work w/the 4 piston calipers because of the lack of lever travel, but was trying to gauge it by how much the stock setup w/SS lines travels....

Anyone care to provide a measurement?

Thanks,

Brad

RicK G wrote:If you want to get good brakes just get a complete front from a K1100 RS or LT and put it on ,it is the easy way to do it and the brakes are a heap better than the smaller K100 discs.

Ya, I've been wondering bout that too since I plan to go to 3-spoke rims in near future. Seems everyone must be doing it given the dearth of front rims for sale these days.

Along the same lines, mine isn't a sport bike. So, what would be your opinion of a milder upgrade to a 3-spoke rim from a K75s and reuse the old brakes, only with braided lines? (Is my current plan)

AJ.Valente wrote:
Along the same lines, mine isn't a sport bike. So, what would be your opinion of a milder upgrade to a 3-spoke rim from a K75s and reuse the old brakes, only with braided lines? (Is my current plan)

I'd go for it - same size rims as you already have, as long as the rotors bolt on w/proper clearances....

I'd use the tires from your bike tho' - V rated for heat from heavier/faster vehicle.

If you're switching to 3-spoke wheels then you can run radials. I run these and they are awesome.

BT-023 110/80ZR-18 front

Avon AV46 140/80ZR-17 rear

I put the 3 spoke wheels from a K1100RS on my K1100LT and the difference from being able to get a good choice of radials is terrific, you wouldn't believe it's the same bike. I am currently using Michelin PR2s and so far 21,000kms with at least 4000 to go on the rear and probably only half gone on the front.
Buy why do just that go buy a K1100RS and have the lot in one go and still the nice K100 in stock trim.

So I guess no one out there has stock 2V brakes w/SS lines that can measure how far the end of their brake lever moves....

I fitted stainless lines to a K75S a while ago ans it did make a big improvement but as to how much less the lever moves I cant say because the lines were cactus when I started. But thinking back and comparing it to my wifes K75RT there was a small difference as to how much movement there was but it was much firmer.