Fork boots -- which ones?

[mneblett]

I'm currently planning the next task in my on-going 1988 R100RT re-do.

I managed to get 165 miles in on the newly dual-plugged, 9.5:1 piston motor before the white stuff buried the roads around here, and all seems to be well with all the work done to date.

The only remaining significant tasks are to:

(i) completely go through the front brakes, including replacing the 22 year old OE hoses and the pulsing EBC rotors (they developed the pulsing in <4k miles, so I suspect the OE hoses are acting like check valves, not releasing residual pressure and thus leaving the pads lightly engaged and heating the disks);

(ii) redo the front forks to address the substantial stiction in the lower 2-3 inches of motion, and to install accordian fork boots (to protect the fork tubes and fork seals, and eliminate the high-stiction fork dust boots); and

(iii) address the constant seepage of gasoline occuring at the lower front face of the left Bing (appears to be seeping from one of the brass passage plugs; I'm currently waiting to see whether a bit of JB Weld over each plug takes care of the issue.


While I'm sure I'll have several more Qs on the above, the current Q is:

Which set of accordian fork boots should I buy to fit the Type V fork legs and fork tubes? late GS boots? early /5 boots? something in between? I have no idea what fits, so all suggestions are welcome!

Thanks,
Mark

 

[jhnmso]

79 r100rt

I'm doing the same thing to a 79 and went to www.realoem.com and looked at a R100T and got:
(2) 31421234908 Boots
(2) 07119941470 Anti-Rattle pins
(4) 07129952121 Clamps
Haven't installed them yet. Will probably trim the top rubber Fairing gaiters so they fit clean. What's your thoughts on doing the XYZ plane setup on the fork tubes? Seems high tech but it seems to me I wouldn't be able to keep them in tolerance (like .001) when I cinch everything down. Still mulling it over.

 

[mneblett]

I'm doing the same thing to a 79 and went to www.realoem.com and looked at a R100T and got:
(2) 31421234908 Boots
(2) 07119941470 Anti-Rattle pins
(4) 07129952121 Clamps
Haven't installed them yet. Will probably trim the top rubber Fairing gaiters so they fit clean. What's your thoughts on doing the XYZ plane setup on the fork tubes? Seems high tech but it seems to me I wouldn't be able to keep them in tolerance (like .001) when I cinch everything down. Still mulling it over.

Thanks for the thought -- the big Q, of course, is whether the R100T boots will fit the '88 Type V forks (anyone know for sure?).

On the careful alignment of the forks, I followed the glass-plate/parallelism procedure on my wife's /5 and it made a *significant* improvement -- much smoother action. Definitely worth the time to do to me, as I didn't mind the time it took to methodically go through the steps; YMMV. An important step once the tubes are properly aligned is to not just bolt on the fender holder/fork brace, but to carefully bend it until it *just* slides into place, with no pressure to push the fork legs apart or pull them together. If properly fitted, you don't loose the precise alignment you just obtained.

 

[ccolwell]

EBC rotors can go bad in 4k. If you have a sympathetic parts or service guy, you may be able to get a set on warranty or at least a reduced price. My local shop got me a replacement for a disc I didn't even buy from that shop. (I will admit that the service manager and the parts manager are riding buddies)

 

[mneblett]

EBC rotors can go bad in 4k. If you have a sympathetic parts or service guy, you may be able to get a set on warranty or at least a reduced price. My local shop got me a replacement for a disc I didn't even buy from that shop. (I will admit that the service manager and the parts manager are riding buddies)

Good to know. The prior owner purchased the rotors from Ted Porter's Beemer Shop a couple years ago (he gave me the receipt in a *very* complete package of documentation on the bike, which goes back all the way to the bill of sale from the original dealer). I think that's long enough ago, and the condition of the OE hoses too suspect, for me to go knocking on Ted's door at this point.

 

[RonKMiller]

Good Morning Mark: (yawn)

I picked up some fork boots at my local 4X4 Store for a grand total of $7.00 last week. Black in color.

They have 13 ribs (I think OEM have 11) and fit perfectly with no trimming needed. I used some thick black wire ties that you can really crank on to get them tight. Snipped off the tails flush with my dykes, and singed the ends with a lighter.

I tossed the packaging, but I'm pretty sure they are available just about anywhere.

I'll call the place I got them from later this morning and see if I can get the brand name. Failing that I'll stop by and pick some up for you this weekend.

I have no idea if they will fit your forks, but they fit like a glove on mine. My tubes are 36mm and the top rim of the slider is 52mm.

I've used them before on the LT and my 79 XS650 and they have worked out just great.

When I see OEM individual boots selling for up to $28.00...

Here's what they look like on the LT - I'll take a picture of them on the R80 in a few minutes - AFTER I've have my second cup of java!

 

[RonKMiller]

boots mounted on the R80

They are "hyperextended" a bit, awaiting new parts before final reassembly:

 

[RonKMiller]

...and a thought on those pulsing rotors

I would suspect you have invisible (literally) deposits on the rotor surface from the original pads which create high spots.

EVERYONE will say that your rotors are "warped" - but warping a rotor is of course impossible.

The cure is to vigorously scrub them with a block of wood wrapped in garnet paper to remove all traces of old material, and to give the new pads a clean surface to bed in. Garnet is the only thing hard enough to cut the old stuff along with the stainless, and it does not leave any residual grit embedded in the metal. I used 120 grit for a final finish, but attacked it first with the next larger grit to speed up the job.

Make sure to completely clean all the holes as well. I snipped off the handle from a wire tube cleaning brush (available in different sizes and commonly used for cleaning copper pipe joints before soldering) and chucked it in my cordless drill. Approached the holes from both sides, then followed up with Q tips soaked in Acetone.

I cleaned the rotors multiple times until I could wipe it all down with Acetone and have a completely CLEAN rag after finishing.

I sure do like the idea of new brake hoses - but I suspect the above is your culprit.

A lot of elbow grease for sure, but time well spent. BTW, you are going to need new pads, again. The ones you have on there are contaminated, sorry.

 

[mneblett]

They are "hyperextended" a bit, awaiting new parts before final reassembly:

Ron -- thanks very much -- those would do the trick. When I get home this evening, I'll measure the forks to verify the sizing. I appreciate the offer to pick a pair up, but I don't want to put you to the trouble. If you do find the brand name, that bit would be helpful.

Best,
Mark

 

[mymindsok]

On a different tack....

I recently changed out the old fairing boots on my RS and don't want to screw em up by installing BMW OEM fork boots, even though I have several pair on the shelf.

LAst week I saw a note on advrider.com talking about some of the new aftermarket wrap arounf fork boots that are less than $20 per pair. I'd defonately going to try a pair and you might want to check out your local DS shop for some ideas.

ALso... Last year I went to SS lines on my bikes and experienced a real improvment in braling feel and power. There are several good reasone to change brake lines on an Airhead!

 

[mneblett]

EVERYONE will say that your rotors are "warped" - but warping a rotor is of course impossible.

Agreed -- that's why I always refer to "pulsing" now.

The cure is to vigorously scrub them with a block of wood wrapped in garnet paper to remove all traces of old material, and to give the new pads a clean surface to bed in. Garnet is the only thing hard enough to cut the old stuff along with the stainless, and it does not leave any residual grit embedded in the metal. I used 120 grit for a final finish, but attacked it first with the next larger grit to speed up the job.

That's probably the key -- I had pretty aggressively scrubbed them, but with a less aggressive material. I'll give the garnet a try -- if it works, it beats paying the $$$ for new rotors.

Make sure to completely clean all the holes as well.

Will do.

BTW, you are going to need new pads, again. The ones you have on there are contaminated, sorry.

Ouch -- so they're dead after only 165 miles -- but still, better than a set of rotors. BTW, are you talking about contamination from the previous pad material? What if the previous pads were the same material as the new pads?

Thanks again,
Mark

 

[AnnapolisAirhead]

On a different tack....

I recently changed out the old fairing boots on my RS and don't want to screw em up by installing BMW OEM fork boots, even though I have several pair on the shelf.

For what its worth Mark, I installed gators on my R100-to-R100RT conversion and omitted the fairing boots. A lot of folks say you'll get soaked in the rain, bits of road debris will fly though, etc. Mostly I heard this from folks who had no experience without the fairing boots. A good Airhead friend who does a serious amount of riding dry, wet, short, long, etc. recommended leaving them out too. Since he's done the Alaska trip a couple time, DC to Florida in the pouring rain many o'times, I took his advice.

I know you are considering an alternative fork boot. If you went with the stock ones, they will squeak and squeal rubbing against the fairing boots.

My $0.02. Glad you got a few miles on the ole gal. Now you have me thinking about the 9.5:1 pistons...

 

[Anyname]

My 86 R80 was originally an RT. When I went to measure the brake hose there was a good 40 inches of nice squishy old hose. It went from the master cylinder, to a junction under the tank and then forward to the left caliper. I replaced it all with a nice short stainless Spiegler hose that took the short route to the left caliper. The improvement was most gratifying.

 

[RonKMiller]

Agreed -- that's why I always refer to "pulsing" now.


That's probably the key -- I had pretty aggressively scrubbed them, but with a less aggressive material. I'll give the garnet a try -- if it works, it beats paying the $$$ for new rotors.


Will do.


Ouch -- so they're dead after only 165 miles -- but still, better than a set of rotors. BTW, are you talking about contamination from the previous pad material? What if the previous pads were the same material as the new pads?

Thanks again,
Mark

For some reason I thought you had 4K on them... just scrub 'em with the large grit garnet and you should be good to go...

The boots are Daystar brand.

Contamination from old fork fluid, brake fluid, latex from the road, etc. - all more or less ground into the surface.

 

[brownie]

Fairing boots

Concur with NO boots......had 'em on "Igor" for a while, but there was always resistance.......have since removed everything around the holes......very smooth action with regard to top of gaiters......

 

[rpeckham136133]

Especially when dealing with a fairing, it is much easier to remove/install the SealSavers kind of "boot".... they have a velcro opening and can be wrapped around the shaft at any time.... they are used alot for dirtbikes, do a google and you will find them in all sizes and colors... and cheap!