Question and update...1985 700es (Tires - Brakes)

[makarov]

Had to replace tires on my 700es this season. Went with Bridgestone BT-45 110/16 on the front 120/17 on the rear. Much better handling than the ME-33 that was a 120 on the front and a Marathon in 130 on the rear.

Replaced the brake pads on the front, glad I mounted the tires myself and took the time to inspect things. It really isn't that hard to mount them yourself. Invested in a nice tire spoon to go along with the two short levers I already had. Bought the NAPA tire goop just to be official and some stick on wheel weights from a car tire store. With the money I saved doing it myself I put towards a small compressor from Costco....

Now for my question.... The 700es has an air valve on it - the front fork states 36psi max. What pressure do people run in these forks? Any? I know some people run progressive springs and ditch the anti-dive etc.. But this bike is all stock. Any helpful suggestions for setting up the forks or rear shock would be great. I weigh 170 BTW.

Thanks

[makarov]

Another picture. This one is with the old tires. Also installed a headlight modulator - will see how that works. They seem to really make bikes stand out, I notice them all the time, but I watch for bikes anyway.....

Took some time when I first got it and polished the sidecovers and repainted the exhaust and windshield (the previous owner had painted them, so I had no choice really, but I sanded them down and did a better job....) I kind of like the black exhaust and windshield - it is low enough I don't miss not being able to see through it....

[Macmatic]

Hi Makarov, welcome to the forums...nice bike!

Mine is pretty much the same beast, for simplicity I'll say its an '84 GS750EF.

I run 10psi in the forks with progressive spings and 2in spacers for preload. This gives me 1.25in of sag on the front which seems to be near the magic number. I know it made a big difference in feel, not really any one thing I could put my finger on but the bike just felt more solid and planted with the preload adjusted.

You might want less pressure, a lot of people run 8psi, a lot run no extra air in the forks... I'd take the time to set the sag on the front forks. Simple to do really:

Put the bike on the center stand, make sure the front wheel is fully extended (step on the rear foot peg to drop the rear tire) and slide the tye-wrap you already put around one fork leg down to the top of the dust cover.

Sit on the bike and rock it off the centerstand. I try to stand over it and then sit once its down. Don't bounce. Get off and put it back on the stand.

Now measure the space between the tye-wrap and the dust boot at the top of te fork leg. Do it a couple of times to make sure you're getting a good reading.

Bleed the air out of the forks.

Bleed the air out of the forks.

Again...

Remove the fork caps and measure the inside of the fork tube.

Go to the hardware store and buy the smallest section of PVC pipe you can in something a little under that size.

Now just cut equal lengths of the PVC, put a section on top of one spring, cap it with the fork tube cap and push it all down.... very simple.

Now track down the parts that flew all over the garage and try it again.... On my bike its some half a$$ed disc and spring clip thing holding down the sping, one some its a threaded cap. Hope for the cap!

The hardest part (for me) is getting the whole spring/pvc/cap/clip assemply back in place and being able to get the clip in. Its a fight all the way.... I found the best way was with a ratchet and socket I could use for a handle which I'd push down and then pin with my shoulder while I used a pick to push the clip in place with my other hand.... (hope for the screw caps!)

It might sound complicated but it really isn't. You're just using the PVC to add preload to the spings which helps reduce the initial sag of the front end. I lucked out and found two $.69 PVC pipe couplers that where just the right length for me. I also used a fairly thin stainless steel washer between the spring and spacer....just because it seemed right.

With the spacer and no air I had about 2in of sag. With 10psi its 1-1/8 to 1/1-4in of sag.

I weigh in around 250lbs...so you might need less air.

/\/\ac

[kalessin]

I strongly suggest using a small bicycle pump (the kind that rides in the frame) and a gauge that is calibrated for low pressures (many car air gauges aren't).

I just changed my fork seals and fluid, and the forks felt wrong with no air in them, and felt much better when I put in 7 psi per side. I'll try a few more psi if i get around to it, but with the one-air-inlet-per-fork style, it's a pain to get them balanced. I wouldn't put in much more than 15 for my bike, i tend to go through fork seals quickly.

[makarov]

The fork says 36 psi max. There appears to be only one fill location on the left (clutch handle side) of the bike. It had zero psi, but I put in about 10 lbs. I didn't use a bicycle pump, but maybe should have. I figured if it could handle 36 psi, I was alright with the compressor.

[kalessin]

Does the front suspension feel any better when riding now?

The reason for the hand pump is that with metal walls and only a small air volume, it's very easy to put in too much pressure... and if you do, your fork seals are where the fork oil will start exiting..

I suppose using the little tiny compressor i have (made by Coleman, 12v cig-lighter plug, lives in my car) might also do the job, it's slowwwwwww, but with a hand pump, it's possible to "feel" the air getting compressed in the fork tube.

[kf4vtt]

Tires

Thanks for the information regarding the tires you put on your 700. I have no problem with the 130/90-V17 on the rear, but are you having any rubbing problems with the 110/90-V16 for the front? I hope it works fine so I can do the same thing.

It seems really tight when I feel between the tire and the fender support bracket. If it works, great.

Tire choices are getting pretty slim for this model. I am running a Avon Super Venom AM-18 120/90-V17 on the rear and a AM-20 100/90-V16. The only problem is the AM-18 is no longer available in that size. Also it only lasts about 3-4K miles.

I heard good things about the BT-45 Battle Axes and saw them recently installed as OEM's on a brandnew Triumph.

BTW, here is my bike http://www.unc.edu/~gfleming/cycles/gs700e.jpg


Thanks.

[graymulligan]

OMG...an actual 700 thread? I'm interested in whether there's any rubbing on that front tire size as well, as I'm going to be tire shopping for mine by mid summer.

(and I really should check my fork PSI while I'm thinking about it)

[kf4vtt]

Air Pressure

Oh, also the manual suggests a pressure of 2.8psi. 35psi is the max and will probably blow out the fork seals.