G/S dedicated thread for various upgrades

[AKjeff]

Anymore word on these peg lowering brackets? I need to do something about the peg location if I'm going attempt to ride this bike as it was intended.

Originally Posted by Dustdevill

This is what the PSP bracket looks like...



I will post another image with the bracket fitted to a bike in due time.

[cenji]

Have a 1981 G/S:

Like to add a wider rear-tire - 2mm to 4mm- BMW dealers only have four lugs and wrong diameters in stock. Does anybody know where to purchase spacer?

Did anybody add the oilpan extension and compared drop in temp before and after.Keep seeing the extensions popping up on ebay.de. Thinking about it, since I converted to 1000cc and don't run an oil cooler.

Your input is appreciated.

[zenben]

Originally Posted by cenji

Have a 1981 G/S:

Like to add a wider rear-tire - 2mm to 4mm- BMW dealers only have four lugs and wrong diameters in stock. Does anybody know where to purchase spacer?

Did anybody add the oilpan extension and compared drop in temp before and after.Keep seeing the extensions popping up on ebay.de. Thinking about it, since I converted to 1000cc and don't run an oil cooler.

Your input is appreciated.

The bike actually handles much better on original spec tires.
4.10 is as wide as I'd go. A 120/80 is usually too wide for the stock rim.
OTOH; You seem to realize that increasing rim size is required fror the wider tire.
So: You can substitute a monoshock rear drive with four lug configuration, and spacers can be sourced from an early K100.
The gearing may be taller, but this is probably a benefit for road duty.

Sump extenders are a mixed bag. Reduced ground clearance is undesirable off road, and ISDT bikes had no pan at all; Simply an aluminum plate bolted directly to the block.
Again, OTOH; I've added a GS pan and guard to an earlier model BMW, then added a spacer to retain approximately the original oil capacity.
This netted a stronger pan with nearly same capacity as the RS deep sump.

[Mendodave]

Hello all..

I had a chance recently to put a real load on the Enduralast alternator install.

Old Saingear electric vest, approx 40w
new Aerostich electric jacket (I think 70w)
Lights approx 70w
BMW heated grips on full power ?w
iphone charging
ipod playing
Garmin 276c
engine (duh)

12.2v at idle
13.4 at 4500 rpm

normally runs about 14.1v with just the lights and engine

these are all measured using the built in volt meter on the Garmin.

Happy Campers!

With the stock alternator I could run the grips OR the Saingear electric vest, not both.

Mendo

[Dustdevill]

Originally Posted by Mendodave

Hello all..

I had a chance recently to put a real load on the Enduralast alternator install.

Old Saingear electric vest, approx 40w
new Aerostich electric jacket (I think 70w)
Lights approx 70w
BMW heated grips on full power ?w
iphone charging
ipod playing
Garmin 276c
engine (duh)

12.2v at idle
13.4 at 4500 rpm

normally runs about 14.1v with just the lights and engine

these are all measured using the built in volt meter on the Garmin.

Happy Campers!

With the stock alternator I could run the grips OR the Saingear electric vest, not both.

Mendo

How's 19V from the Enduralast system!!!
I have only had endless hassles with this system, over charging, no charging and only when it feels like it might produce the required 14V.
The problem with the Enduralast system is that if the battery is not good or the system under read the battery voltage it can over charge to as much as 19V.
The Bosch system in good condition will not produce the same output, but it will consistently produce a good current for the bikes electrical needs irrespective of battery condition.
Renew the rotor and diode board and alternator brushes and it will be reliable for many years. I believe it will cost less than a whole new charge system.

[Dustdevill]

Originally Posted by cenji

Have a 1981 G/S:

Like to add a wider rear-tire - 2mm to 4mm- BMW dealers only have four lugs and wrong diameters in stock. Does anybody know where to purchase spacer?

Did anybody add the oilpan extension and compared drop in temp before and after.Keep seeing the extensions popping up on ebay.de. Thinking about it, since I converted to 1000cc and don't run an oil cooler.

Your input is appreciated.

DO NOT USE SPACERS THEY ARE A BAD IDEA. Besides you will need more offset than 4mm.
If you want to fit 140 tires the safest way to do it is by offsetting the rim on the hub by 14mm.
This can be achieved by cutting 3.5mm of half the spokes(20). You might also need to extend the thread by an extra mil or two.
The shorter spoke must be fitted to the left side of the wheel and the offset can be measured between the rim and the hub using a straight edge leveled of on the hub.
The spokes on the right will eventually bend but this is normal.
If you are concerned about the strength I could also recommend using 4.5mm spokes and reaming out the holes in the hub.
Oil cooler is more effective than the sump spacer so I would rather fit this first.
The Sump with bash plate from HPN is the right choice as it does not influence the ground clearance and the sheet metal sump bottom / bash-plate will not crack or get a whole. All the BMW sumps are very brittle and will crack very easy leaving you stranded. Bolting the bash-plate to the sump with four 6mm screws is also flawed as a hard knock on the bash plate can do great damage to the sump.

[Dustdevill]

Originally Posted by zenben

The bike actually handles much better on original spec tires.
4.10 is as wide as I'd go. A 120/80 is usually too wide for the stock rim.
OTOH; You seem to realize that increasing rim size is required fror the wider tire.

What is the stock rim's width?
BMW fitted 2.15 inch rims to the first G/S's produced, but later models had a 2.50 inch rim. Change over seemed to be somewhere in 82 but I do not have exact info on when this occurred.
140 tires can very comfortably be fitted to a 2.50 inch rim. I would not recommend doing the offset and fitting wider tires if you have a 2.15 inch rim.

[davorallyfan]

Originally Posted by JRP

I agree with that, you should get it repaired though as the problem is certain to get worse and stop charging altogether.

You know what...















Sir, you are absolutely 100% correct in your diagnosis and prediction.


err.... thank you.

[cenji]

Originally Posted by Dustdevill

What is the stock rim's width?
BMW fitted 2.15 inch rims to the first G/S's produced, but later models had a 2.50 inch rim. Change over seemed to be somewhere in 82 but I do not have exact info on when this occurred.
140 tires can very comfortably be fitted to a 2.50 inch rim. I would not recommend doing the offset and fitting wider tires if you have a 2.15 inch rim.

Hi Zenben and Dustdevil,

thanks for the feedback. Reason for wanting to add the spacer is the opportunity to mount many more tires.I have run the Avon Gripster for road use and the Metzeler Enduro 3 Sahara for mixed use. Mixed use is 70 road and 30 for dirt , gravel, fire, logging roads. The dirt road to my pad is turning into mud in the winter months, the Sahara doesn't cut it. Can't mount TKC 80, Michelin Anakees, Pirelli/s(beside the MT 43 or MT 90), Dunlop to cut through the mud.

BMW (per manual for 81 G/S) specifies:
1.85 B-21 wheel design front
2.15 B-18 wheel design rear

to 1: 3.00-21 tire design
to 2: 4.00-18 tire design

Looking at the conversion chart:

3.00 is a 80
4.00 is a 110

ON the 3.00 you could also mount a 90
On the 4.00 you can also mount a 110

I know the 120/90 -18 , a Pirelli Rallyecross, is touching my fox shock (protected by thin neoprene sleeve to keep the dust out).

I have four rims:

front: 1.85 (BMW Original Akront)
rear : 2.15 Mann +2.50 Akront

If not adding the spacer (seems to be too much of a headache if done right) do you know of any other manufacturer that will offer more aggressive thread than Sahara, what are you using?

Any idea what the HPN addition is going to cost or the addition of oil cooler?
Thanks.

[StephenB]

Originally Posted by Dustdevill

The Bosch system in good condition will not produce the same output, but it will consistently produce a good current for the bikes electrical needs irrespective of battery condition.
Renew the rotor and diode board and alternator brushes and it will be reliable for many years. I believe it will cost less than a whole new charge system.

+1.

And then some ...

Stock everything here, Rick Jones refurbished rotor and stator, improved grounding of electrical system, especially the diodeboard, no bypass resistor but a digital LCD voltmeter (3 digits, 1% accuracy) instead, running HID headlights (half the amperage of H4, triple the light output), Panasonic 28Ah sealed lead acid battery, always 14.0 +/- 0.2V at over 3500rpm consistently.

[SOLO LOBO]

Originally Posted by cenji

. Can't mount TKC 80,

Why not a TKC? I've been running one on my G/S for a long time....

[StephenB]

Those 4mm spacer you're talking about, do nothing to your choice of tire! I have a 4-lug monolever conversion on a GS with a 2.50x18 X-laced tubeless rim , laced offcenter by about 1/4in = 6mm (this is the mac off center according to Woody's on X-lace designs).



The rear tire shown is a 50/50 knobby tire (Kenda 270) sized 4.50x18 (next up from 4.00x18). It rubs at the shock spring when the shock compresses.

You want wider tires: go paralever or oilhead swing arm modification.

By the way: I started off with a 250x17 (Excel rim) offcenter laced by 1/2in to allow 130 rear tires on the monolever GS. It was very tight and it would NOT work with any knobby tire. The rim cracked in the end because of the combination of x-lace hub with center lace hub which was needed to allow 130 tires.

I have tried both the obvious ways and it is a no go, definitely. Woody did all lacing work on the above trials and the offcenter lacing is very limited.

Now, if you take the 3-lug hub and and the stock 2.50x18 rim, I am sure you can get your 1/2in offset and run street 130s on the G?S. With a homemade 2-4mm 3-lug spacer you might be able to run knobbies as well.

Why didn't I do it? I wanted the advantage of 3 final drive ratios on my GS for both "extremes": 37:11 for off-roading and 33/11 for long distance street touring. Currently running the one in the middle: 32/10. TRire sizes on my bike: stock G/S.

Originally Posted by cenji

Hi Zenben and Dustdevil,

thanks for the feedback. Reason for wanting to add the spacer is the opportunity to mount many more tires.I have run the Avon Gripster for road use and the Metzeler Enduro 3 Sahara for mixed use. Mixed use is 70 road and 30 for dirt , gravel, fire, logging roads. The dirt road to my pad is turning into mud in the winter months, the Sahara doesn't cut it. Can't mount TKC 80, Michelin Anakees, Pirelli/s(beside the MT 43 or MT 90), Dunlop to cut through the mud.

BMW (per manual for 81 G/S) specifies:
1.85 B-21 wheel design front
2.15 B-18 wheel design rear

to 1: 3.00-21 tire design
to 2: 4.00-18 tire design

Looking at the conversion chart:

3.00 is a 80
4.00 is a 110

ON the 3.00 you could also mount a 90
On the 4.00 you can also mount a 110

I know the 120/90 -18 , a Pirelli Rallyecross, is touching my fox shock (protected by thin neoprene sleeve to keep the dust out).

I have four rims:

front: 1.85 (BMW Original Akront)
rear : 2.15 Mann +2.50 Akront

If not adding the spacer (seems to be too much of a headache if done right) do you know of any other manufacturer that will offer more aggressive thread than Sahara, what are you using?

Any idea what the HPN addition is going to cost or the addition of oil cooler?
Thanks.

[SOLO LOBO]

Originally Posted by Dustdevill

The Sump with bash plate from HPN is the right choice as it does not influence the ground clearance and the sheet metal sump bottom / bash-plate will not crack or get a whole. .

DD, HPN has the "rallye oil pan" picture on their site, but not listed in the price list... any idea what is costs? I also don't see how it can't decrease the ground clearance

[Dustdevill]

Originally Posted by SOLO LOBO

DD, HPN has the "rallye oil pan" picture on their site, but not listed in the price list... any idea what is costs? I also don't see how it can't decrease the ground clearance

It might be a small amount deeper than the stock sump and guard, but keep in mind that it does not have the cooling fins and then the corrugated bash plate at the bottom. The 5mm plate acts both as the bottom of the sump and the bash plate.
Part no.: 11.314 Mounting set conical rallye oil pan 340,00 €
Tried and tested. A hard knock on the front of the plate might deform it and cause a leak at the sump gasket but it will be slow enough to last till your next stop for a repair. Hard knock on stock setup can crack the brittle sump, loosing most oil in less than half an hour.
On very steep and rocky ascends I have on a number of times hit the sump so hard that I had to first stop and check to see if it was still OK.

[StephenB]

Originally Posted by SOLO LOBO

I am just doing the same thing my usual way - DIY. My machinist is fabrication the 1in extension, resulting in about 1qt more oil. I will be using the stock GS pan which is quite shallow and by that, arrive at the same oil amount that I am having now with my deep oilpan. I will also have a 3/16in aluminum bash plate done that looks a bit like the HPN one, slightly wider though. An oilcooler will be added too as my oiltemps with the deep oilpan were about 245F on average during my last trip.