R90S ATE caliper rebuild - Page 7

craydds · 01-25-2012, 06:41 PM

Quote:

Originally Posted by _cy_

hasn't leaked a drop since new seals installed between brake fluid reservoir and cylinder. brakes work great!

cy, all sounds well. Good luck with your bike!

Xcuvator · 01-25-2012, 09:54 PM

Quote:

Originally Posted by _cy_

nope... checked out both calipers, clamping properly with normal travel/release and no leaks. so left them alone. brake master cylinder was done immediately. I came up with correct seals that are not included in brake master cylinder kits. really wanted to stay with stock BMC to keep R90S original. hasn't leaked a drop since new seals installed between brake fluid reservoir and cylinder. brakes work great!

I remember you talking about the kits not coming with all the orings because that was a little disappointing. Anyway I hadn't put a kit in for about 6 months until this week and the kit came with everything I needed. So maybe the kit you looked at had been robbed? I mention this so someone doesn't think they will need to search around to get what they need.

surtees · 01-25-2012, 10:20 PM

Quote:

Originally Posted by craydds

How does one calculate the leverage? Seems like it is a simple ratio of (area of caliper piston)(2*) / (area of MC piston). I don't know how to type out arithmetic formulas on my keyboard --- pi x r-squared = A.
*for two calipers

Yes that it as far as I understand. Here is a table as well.
http://roadstarclinic.com/content/view/89/95/

supershaft · 01-25-2012, 11:04 PM

Quote:

Originally Posted by craydds

supershaft, I think these YSS shocks are height adjustable. I'll check into that. Back now. Yes, the shaft length is adjustable. Of course, I can also adjust the spring preload for the proper sag.

They look to me like they are. That's way the flats are there on the lower shock body? Awesome if it does have adjustable ride height. I wish my Fox did!

craydds · 01-26-2012, 03:43 AM

Quote:

Originally Posted by surtees

Yes that it as far as I understand. Here is a table as well.
http://roadstarclinic.com/content/view/89/95/

Thanks for the link. Good info. With my 14 mm MC and two 38 mm calipers the leverage is 14.7. According to this article I may have a very stiff feel at the brake lever, should have used a 12 mm MC to get a 20.0 ratio. We shall see. How does yours feel?

craydds · 01-26-2012, 03:57 AM

Quote:

Originally Posted by supershaft

That's way the flats are there on the lower shock body?

Yes, flat and lock nut.

_cy_ · 01-26-2012, 03:58 AM

Quote:

Originally Posted by craydds

cy, all sounds well. Good luck with your bike!

thanks my R90S has really come together. starting to feel road worthy.
looks like yours is on the way...

Quote:

Originally Posted by Xcuvator

I remember you talking about the kits not coming with all the orings because that was a little disappointing. Anyway I hadn't put a kit in for about 6 months until this week and the kit came with everything I needed. So maybe the kit you looked at had been robbed? I mention this so someone doesn't think they will need to search around to get what they need.

got my kit from Bobs BMW, which was suppose to be as supplied from BMW. NO seal under reservoir provided. not available (except with new BMC $375) according to feedback from several folks way more experienced than me. ended matching seal up with brake fluid resistant rubber at a local industrial seal company.

where did you order your BMC kit from that included the reservoir seal?

Quote:

Originally Posted by supershaft

They look to me like they are. That's way the flats are there on the lower shock body? Awesome if it does have adjustable ride height. I wish my Fox did!

I've got the Fox too... sure make things easier if mine was adjustable

craydds · 01-26-2012, 04:02 AM

Trying to keep myself entertained. Disassembled, cleaned, and repacked the wheel bearings.

My ol' Lesters.

surtees · 01-26-2012, 07:47 AM

Quote:

Originally Posted by craydds

Thanks for the link. Good info. With my 14 mm MC and two 38 mm calipers the leverage is 14.7. According to this article I may have a very stiff feel at the brake lever, should have used a 12 mm MC to get a 20.0 ratio. We shall see. How does yours feel?

Yes, yours should be 14.7 (sorry I reversed the numbers in my post) and mine with the 13 mm and 40mm calipers is 18.9. But at least according to that link "Single piston calipers are much happier in the 14:1 to 12:1 range" So you should be just about right. Mine so far feels nice - very easy to pull and control but the travel is quite long and the max is pretty close to putting the handle all the way to the grip (it may firm up a bit more with use). I think you will love the difference when it is together.

craydds · 02-19-2012, 05:33 AM

Getting things reassembled. Got a new upper triple clamp from Toaster.Tan.

Aligned and bolted together.

Removed sliders as a rigid unit.

Then back together one more time with gaiters.

Going with Hyper Pro fork springs from Tom Cutter, http://rubberchickenracinggarage.com/ .

5 wt. fork oil.

Preload spacer used. Attemping to achieve sag of 45 to 65 mm.

Springs, spacers in place.

Picture.

Front wheel and rebuilt calipers. New EBC brake pads from Ted Porter, http://www.beemershop.com .

New master cylinder from Max BMW.

Next up, new brake lines. Stay tuned.

surtees · 02-20-2012, 09:31 AM

Looks great Ray, coming along - I like the looks of that triple clamp. Did you do the replacement for strength or ride or cosmetics?

supershaft · 02-20-2012, 09:45 AM

I run my headlight like that and have for 25 years now on different bikes. I run a /6 style ignition switch. I made my own mounting system that mounts a National Cycle normally handlebar mounted windshield on to the head light mount. It works perfect and comes off and on minutes. It makes working on the forks so much easier. Especially setting them up!! I think the bikes handle better for it too!

craydds · 02-20-2012, 10:12 AM

Quote:

Originally Posted by surtees

Did you do the replacement for strength or ride or cosmetics?

I had serious "stiction" problems; the forks were terribly out of alignment. Got everything into correct alignment now with the new upper clamp; it was not possible with my old clamp. The main reason is to get the best RIDE possible out of these old damper rod forks.

craydds · 02-20-2012, 10:14 AM

Quote:

Originally Posted by supershaft

I run my headlight like that and have for 25 years now on different bikes

I'm working on the bracket and instrument mount today. Any tips are appreciated.

supershaft · 02-20-2012, 10:27 AM

Without the R65 style wiring harness i think it is too much trouble to frame mount the instruments. I run a short stock instrument mount. I double rap the harness coming up through the middle of the headlight mount and grind the inside of the headlight mount to minimize rubbing. Sorry no pics. I have regular pics but no scanner. Right now I have to make a new setup since I smashed it all off a while back.

01-26-2012, 04:02 AM	#98
craydds ^OP Studly Adventurer Joined: Aug 2010 Location: Las Cruces, NM Oddometer: 999	Trying to keep myself entertained. Disassembled, cleaned, and repacked the wheel bearings. My ol' Lesters. __________________ Ray ABC #12947 '75 R90S

02-19-2012, 05:33 AM	#100
craydds ^OP Studly Adventurer Joined: Aug 2010 Location: Las Cruces, NM Oddometer: 999	some progress Getting things reassembled. Got a new upper triple clamp from Toaster.Tan. Aligned and bolted together. Removed sliders as a rigid unit. Then back together one more time with gaiters. Going with Hyper Pro fork springs from Tom Cutter, http://rubberchickenracinggarage.com/ . 5 wt. fork oil. Preload spacer used. Attemping to achieve sag of 45 to 65 mm. Springs, spacers in place. Picture. Front wheel and rebuilt calipers. New EBC brake pads from Ted Porter, http://www.beemershop.com . New master cylinder from Max BMW. Next up, new brake lines. Stay tuned. __________________ Ray ABC #12947 '75 R90S craydds screwed with this post 02-19-2012 at 05:45 AM

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02-20-2012, 09:31 AM	#101
surtees Adventurer Joined: Oct 2011 Location: la la land Oddometer: 27	Looks great Ray, coming along - I like the looks of that triple clamp. Did you do the replacement for strength or ride or cosmetics?

02-20-2012, 09:45 AM	#102
supershaft because I can Joined: Sep 2010 Location: San Francisco Bay area Oddometer: 6,088	I run my headlight like that and have for 25 years now on different bikes. I run a /6 style ignition switch. I made my own mounting system that mounts a National Cycle normally handlebar mounted windshield on to the head light mount. It works perfect and comes off and on minutes. It makes working on the forks so much easier. Especially setting them up!! I think the bikes handle better for it too!

02-20-2012, 10:27 AM	#105
supershaft because I can Joined: Sep 2010 Location: San Francisco Bay area Oddometer: 6,088	Without the R65 style wiring harness i think it is too much trouble to frame mount the instruments. I run a short stock instrument mount. I double rap the harness coming up through the middle of the headlight mount and grind the inside of the headlight mount to minimize rubbing. Sorry no pics. I have regular pics but no scanner. Right now I have to make a new setup since I smashed it all off a while back.