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Suspension upgrades 83 R100RS

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Brian Swanick
(@thundermotive)
Posts: 76
Estimable Member
Topic starter
 

New tires and some time off work to explore the twisties has proven that this is a 35 year old motorcycle. That being said, I'm hoping it can be improved a bit at a reasonable price.
I've been reading about fork braces, both the Telefix and the San Jose. Lots to read and it's a bit contradictory. Does anyone have experience with either or both these pieces?
I posted earlier about the Works Performance shocks which apparently are no longer in production. PO installed them on the bike. Any idea where I should start with air pressure. I can't find any service information on them.
Thanks in advance.

 
Posted : 05/28/2018 20:36
Richard W
(@wobbly)
Posts: 2590
Member
 

I own 2 RS's and can tell you what I did. I ride fairly aggressively in the Blue Ridge mountains and have gotten fairly happy with the results.

• Tires. Obviously you need modern profile tires. If you are still running a Metzler front rib, then ditch that immediately. Bridgestone S11 Spitfire are the bare minimum. 100/90-19 Front, 120/90-18 Rear works good. It's really hard to fully seat a modern tubeless tire on a snowflake, but without it the tire will not run "true". Not sure who mounts your tires, but it's going to take a little more than the pimple-faced summer help at the local discount cycle shop to do it correctly. If you take the wheel into a shop, then BE SURE to mark the rotation on the brake rotor with a marking pen. Don't forget balancing.... which CANNOT be done with the wheel's own bearings.

• Air Pressure. Modern tires need 10-15% more air than what your owner's manual is telling you. Experiment in the 33 to 36 psi range for F and R. Check the pressure every day before riding. If you are using your snowflakes as tubeless rims, then air is going to leak faster than using a tube.

• Fork Oil. Change your fork oil to BelRay 7W or 10W depending on road surface quality. 250cc in each leg.

• Fork Springs. Early BMWs went in for long travel front forks, for comfort while touring. By 1983 things were much stiffer, but you still may have too much sag. You can adjust the spring weight inexpensively by adding flat washers and/or plumbing couplings to the top of the stock 1983 springs until your measurements check out.

• Fork Brace. Yes, you need one. I use the San Jose brace and found it to be very, very high quality product. Just be sure to place rubber shims between metal bits and the fiber glass front fender. I use plumbing faucet repair washers.

• Rear Shocks. You need good, name brand rear shocks which are sprung correctly for your riding weight. Again, you need measurements with your normal loaded weights.

• Bearings. Head post bearings will typically need to be removed, washed out, re-packed with new water-proof grease, and re-installed. Sing arm bearings will need to be adjusted, torqued, and lubed.

► There's lots on the internet about setting up shocks and forks. The percentage of settling and sag. Read up and measure what your bike is doing under your weight.

Hope this helps.

Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.

 
Posted : 05/30/2018 10:57
Brian Swanick
(@thundermotive)
Posts: 76
Estimable Member
Topic starter
 

Thanks Wobbly,
I've already upgraded the tires to the Pilot Activs. I had to unload the compressor into them to get them to bead up properly. Glad to know that's not just me.
So Nobody anywhere appears to have any info on the Works Performance mystery shocks. They currently have 100psi in them and I'd like to firm things up a bit more. Any idea how high is safe to go?

 
Posted : 05/30/2018 21:19
Brian Swanick
(@thundermotive)
Posts: 76
Estimable Member
Topic starter
 

I guess I can answer my own question on the shocks. If anyone is interested, they are WP Steeltracker shocks, more popular with the Harley boys. The pre-charge is 250psi and they must be sent to the factory for service. Fortunately I work in a factory and have a nitrogen bottle.

 
Posted : 05/30/2018 21:54
Richard W
(@wobbly)
Posts: 2590
Member
 

I've already upgraded the tires to the Pilot Activs. I had to unload the compressor into them to get them to bead up properly. Glad to know that's not just me.

That would be the Michelin Activs. Did you fit the "vintage sizing" 4.00-18 or their metric sizing 120/90-18 tires ? I fitted the vintage sizing. Great handling tires, but they were gone in 3500 miles.

So Nobody anywhere appears to have any info on the Works Performance mystery shocks. They currently have 100psi in them and I'd like to firm things up a bit more. Any idea how high is safe to go?

That pressure.... is that the "air spring" pressure, or is that the internal "anti-frothing" pressure. Because if it's the internal pressure, I don't think you're going to see much change in the ride quality. In my limited understanding, the shock is still filled with shock oil which does all the dampening. The nitrogen simply keeps the oil from becoming aerated and filled with bubbles during the ride session. No bubbles being equal to more consistent ride quality.

So if your shocks don't dampen properly, it may simply be time for new shocks.

Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.

 
Posted : 05/31/2018 11:03
Brian Swanick
(@thundermotive)
Posts: 76
Estimable Member
Topic starter
 

I went with the 3.25 and 4.00 tires with tubes. There is definitely room for wider tires. They feel nice and grippy so I'm not expecting a lot of miles.
I'm thinking the PO may have removed his really good shocks before he sold it to me. I see the Ikon shocks are popular and moderately priced. I ride solo and two up with and without bags so I need flexibility. Have you used Ikons?

 
Posted : 05/31/2018 20:23
Richard W
(@wobbly)
Posts: 2590
Member
 

I went with the 3.25 and 4.00 tires with tubes. There is definitely room for wider tires. They feel nice and grippy so I'm not expecting a lot of miles.

I also went with those vintage sizes. I loved the handling, but all the reviews said "high mileage" and I didn't get that. I was just wondering if the 120/90-18 wears any better than the 4.00-18 ? The fender will accept wider tires, it's the swing arm that's the limitation.

I'm thinking the PO may have removed his really good shocks before he sold it to me. I see the Ikon shocks are popular and moderately priced. I ride solo and two up with and without bags so I need flexibility. Have you used Ikons?

Old Koni is the new Ikon. Bought a single-sided Airhead that came with a new Ikon, and had questions about setup. My 7 reply email even got passed to the CS dept head and still, all they would say is "buy another spring". But knowing my weight, they could not recommend one of their 16 springs. So in their eyes I was simply supposed to buy $70 springs until I tripped over one.

I've really enjoyed the Hagons I got from Hagon USA, but they have recently closed shop in the colonies. All orders are now done direct from England, making any returns unaffordable. I would buy Hagons again, but then I know the spring that works for me ! http://www.hagonshocksusa.com/

So I'm not sure what to tell you. 😳

Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.

 
Posted : 06/01/2018 16:01
Brian Swanick
(@thundermotive)
Posts: 76
Estimable Member
Topic starter
 

Well this has certainly turned into a learning experience. I found the biggest problem was the polyurethane snubbers in the shock eyes had begun to disintegrate and one was only half there. I used 5/8x7/8 rubber hose. Recharged them to 250psi. I can put it up on the drive-off stand now with two fingers and a foot. I'll probably keep them for a while and research my next set.

 
Posted : 06/01/2018 20:42

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