New rider on a great bike

[Thievel]

Hello!

I'm a beginner rider that has been lucky enough to receive a very nice 1980 XS1100 GS (I think), that is in very good condition. Unfortunately I know very little about bikes and less about maintaining them, but I listen well and learn quickly. I also have a good friend that is an experienced mechanic that will be helping me get this gem roadworthy. If anything I say below does not make sense, it is most likely because I don't know what I'm talking about

I've had the bike checked out by a venerable mechanic that specializes in old Yamahas. For the good news, the engine is in great condition (with the exception of some rubber gaskets that are starting to crack).

The most pressing issue with the bike is the brakes (both front and rear) and the front fork. The tubes are pitted in the travel area and are leaking some oil/fluid into the front brakes pads, which are also worn down. The pads in the rear need changing as well as the rear tire.

I was able to ride for the first time on Saturday, and I couldn't wipe the stupid grin off my face all weekend. The bike holds some sentimental value and I've already fallen in love.

Now to get my hands dirty. I need to replace the front brakes (pad and probably the cylinder) as well as the front fork. I've been able to find the brake pieces online (and will likely order soon), but the front fork assembly has been a little harder to find, and I'm not entirely sure what I'm looking for.

I would like to get this bike up and running as quickly as possible, and the ineffective front brakes are most pressing issue...

Are there any nuggets of wisdom for a beginner? Any direct way to get a new front fork? I've checked out the forums quite a bit (awesome stuff in here) but haven't quite found the answer.

Looking forward to spending some quality time on this bike and this forum!

[crazy steve]

Nice looking SG (not GS..), also known as a 'Special'. Good looking original exhaust, most of the other bits are present, a much better start than many have had... Looks like a set of Progressive rear shocks too.

The brake parts are all readily available, do yourself a favor and tear down the complete brake system and clean everything.

The front forks are a bit harder; there's only one supplier of new tubes anymore, these guys: http://www.frankmain.qpg.com/ I don't know what their current costs are, you'll have to call. Otherwise you're looking for used units; again, your model is a special, any '79-81 Special forks will fit. The 'standard' forks won't work unless you change the whole front end.

Welcome!

[Shockman54]

forks

i have some forks off of a 79 special. they look pretty good at a glance, but i can check em out closer if you are interested. PM me

[mack]

Forks

Hi and welcome, good looking bike. Not to hijack this thread but are the fork lowers and calipers the same for SF and SG's. Anyone?

[bikerphil]

Hi and welcome, good looking bike. Not to hijack this thread but are the fork lowers and calipers the same for SF and SG's. Anyone?

Yes they are. All 79-81 Specials are the same except the 81 MNS.

[Thievel]

Thanks for the welcome and the info!

I'll order the brakes today. Taking apart the brake system and cleaning it sounds like a great first step. I'll assume that I should use a degreaser on the parts once it's been taken down. Correct me if I'm wrong

Thanks Shockman - PM sent

[DGXSER]

The forks and calipers are the same for all the Special models (excpet the LH or 81 Midnight Special, linked brakes). Even the rotors are more or less the same, the 80-81 Specials got slotted rotors, but they will work and interchange with the non slotted rotors.

You may not need new parts for the brakes, tear both calipers down, and the front Master Cylinder, pretty simple really. Clean them up really good, especially the groove in the calipers where the O-ring seal sits.

Why do you feel you need new forks? Depending on the cause, the solution may be simpler or not so simple.

[jetmechmarty]

You can use JB Weld to fill the pits in the fork tubes. It's not pretty, but the most economical option.

[Thievel]

Mostly I'm just going on the advice of my friendly mechanic. Apparently just replacing the seals will still leave me with leaks from the pitted travel area, and I imagine that the JB Weld would have to be very well done to have a perfectly smooth travel area. Is it simpler than I expect?

You guys are awesome.

[jetmechmarty]

Fill the pits and sand it smooth with fine Scothbrite. Steve's option is by far the best. It is also the most expensive.

[CaptonZap]

Thanks for the welcome and the info!

I'll order the brakes today. Taking apart the brake system and cleaning it sounds like a great first step. I'll assume that I should use a degreaser on the parts once it's been taken down. Correct me if I'm wrong

Thanks Shockman - PM sent

Glad to see you are willing to get your hands dirty. So, for the rest of your life, remember, NO grease or oil or petroleum solvents around the brake systems. Use alcohol, and let it evaporate before reassembly. Lubricate all rubber parts with fresh brake fluid before reassembly. And remember, water is the enemy of brake fluid, so keep them seperated. CZ

[Thievel]

Well, I'm glad I asked! Just goes to prove there's no such thing as a stupid question. I have some industrial 99% ethanol I'll use to clean the pieces.

No water, no solvents. Got it.

[DGXSER]

The advice ont he water goes for the internal components of the brake system. you can feel free to use soap and water and a brush to scrub the crud and crap off the caliper housing and such.

Even inside the caliper can be cleaned with water, bu tyou want to make certain it is very dry before you assemble the components. Brake fluid wil absorb moisture (which is why it has a sealed cap on the master cylinder reservior) and then the water int he fluid will rust the components and create alot of mess and corrosion in the system. They sell brake cleaner, I use that to spray out everythign before I reassemble as it does remove moisture. Definitely lube it all up with fresh brake fluid for assembly.

As for the pitting, it all depends where the pitting is on the brakes. If it is on the piston but in the "exposed" area above the seal interface, then no big deal, clean it best you can and go on. If it is in the area where it rides on the seal, you want to get that cleaned and smooth. Depending on the severity of the pitting you may need a new piston.

[tom clisham]

Get a couple spray cans of brake cleaner from Wallyworld.
Get a pair of 79-81 forks from ebay. Just look out. for bent ones or pitted ones like yours.
When you clean your brakes you must clean the groove in the calipers where the rubber seal resides. Thats the most common cause of binding brakes. Also the infamous spooge hole in the master cylinder.

[Thievel]

The forks and calipers are the same for all the Special models (excpet the LH or 81 Midnight Special, linked brakes).

I may have found a parts bike, but it's a 1980 LG Midnight Special.

Would I be able to replace the front fork? Or better yet the entire front end if it's in good shape?