(warning: images may be slow to load, sorry) So you need some more range on your HP2 but don't want to drop $1,600 on an HPN big tank. Here's how you can do it for about $200 - $300. First of all, credit must go to GPSKevin ... http://gpskevin.googlepages.com/bmwhp2 Unfortunately, he didn't have any of his original drawings or dimensions so I had to start from scratch. First off make a few cardboard mock ups until you get it fitting right.. or you can just download the DXF CAD drawing I made from here then send it to your favorite plasma cutting or water jet cutting shop and you should get back some pieces like this. Tell them to cut it out of 18 gauge steel, although you might be able to get away with 20 gauge to save a bit of weight. Now either weld 'em up yourself or send out to your favorite welding shop and you should end up with something like this... Depending on how you want to mount it to the bike, you will need to weld on some mounting lugs. After a little clean up and some flat black (or color of your choice), you get this... Don't forget to clean and seal the inside with this stuff. This will avoid any future rust problems and seal any tiny pin holes left from welding I made a few mounting brackets out of aluminum. PM me if you want the CAD drawings for those, but you could probably get buy with something more basic. and End result is this... The tank holds 2.7 US gallons which on top of the 3.4 standard will give you 6.1 total or about 240-260 mile range. The tank fits very snugly under the seat so you will have to relocate the charcoal canister. There's just enough clearance for a 17" rear wheel, but an 18" will probably rub under full compression. You also won't be able to use the BMW pillion pegs. Next I'll cover the fuel plumbing and electrical.
If your looking for someone to do the cutting, contact Greg at... Greg Bledsoe Columbus Industries, Inc 17383 E IL Highway 116 Fairview, IL 61432 Ph: 309/245-1010 Fx: 309/245-4210 www.columbusindustries.com www.coot2.com He did a great job on the parts for a very reasonable price. He has my drawing and the machine is setup so can probably knock out the parts quite easily.
Excellent!! And it's very well integrated Maybe this thread should be moved to GSpot for its target audience.
Thanks for the move GB, I would have missed this. Excellent work. Thanks for provide the schematics as well. Have you tried it with the enduro rims? Does the rear clear it under full compression?
If this works with a off road setup, it may not be a bad idea to run a thicker gage steel where the tank faces the back wheel.
Gday, looks great but i cant download the Spec Sheet so I can have it cut out. Also what can be done as far as rocks go. Here in Australia that will have a hole in it in 10mins from the back tyre. Thanks Gum.
Saweet setup. Did you do any internal baffles to help reduce fuel sloshing? I would think that somewhere between full and empty that the sloshing around would make for some interesting handling, especially off road.
Right click on the link and then select "save target as". PM me with your email address if you're still having trouble. I can't comment on the rocks you have there in Oz, but I do know GPSkevin has done a few thousand miles on his offroad with no problems at all, and his steel is slightly thinner than mine 0.040" vs 0.049". It would certainly be possible to make the bottom panels out of thicker steel. Once you have the DXF file, it's easy enough to pull out those parts and put them on another sheet to be made out of thicker stuff. As far as clearance with the dirt tires on, it's pretty close but with the shock fully deflated it still clears (just). I'll post a pic when the dirt tires are back on it.
Actually, it's designed to be completely full or empty. When you fill up there's a pump to take fuel from the main tank and fill up the underseat tank. When you hit reserve on the main tank, you pump the underseat tank back into the main tank. That way you keep the reserve fuel warning system.
Gday, once again it looks very very well done. Are you interested in getting them cut and sending out, with the brackets of course. [ its just as easy to make 10 as to 1 ] Then we can weld them up and fit. Im sure you would have quite a few takers ????, including me. Im sure there is plenty of beer money it for you. One suggestion, im into old bikes and restoration, IMO the best product to seal the tank is POR15. With the product you have shown us, you will have issues down the track. Thanks Gum. PS I still cant download that file.
Here's a photo with the dirt tires on. It's pretty close. I don't know how much give there is in the shock bump stop, but it might hit on a heavy landing after a jump? I can modify the sheet metal CAD file to give more clearance if anyone wants. You will loose capacity though, I would guess about a 0.2 - 0.4 gallons depending on how much clearance you want.
