Horizons Unlimited - The HUBB

Horizons Unlimited - The HUBB (http://www.horizonsunlimited.com/hubb/)
-   BMW Tech (http://www.horizonsunlimited.com/hubb/bmw-tech/)
-   -   Frame mods, ala HPN (http://www.horizonsunlimited.com/hubb/bmw-tech/frame-mods-ala-hpn-7759)

Mombassa 14 May 2002 23:26

Frame mods, ala HPN
Hi all, I have a 1986 G/S and am going to have the frame reinforced by a local welder. I was thinking of having him copy some of the frame reinforcements HPN makes, without going to the extent of creating a center shock conversion. Does anyone have some good pics of the HPN reinforcements? Any other ideas? They guy I found welds just about everything, he’s done work for NASA and Ballard, I saw his stuff and had him do a small repair on my RT. I was even thinking of having him build a titanium rear sub frame, but I have no clue what the cost and other potential downsides would be. Any ideas welcome.




Timo 15 May 2002 00:41


If you haven't already looked at it, is the photo of off HPN's site. There are a few people on the web (mostly through Mica peak's web loop) that have old HPN race bikes or have paid for the modifications; you could likely find some better photos there. I braced my frame myself, and found it easy and effective. The main areas of weakness are in the rear subframe, extra struts from the rear footpeg mounts to the rear of the frame help the most. I also welded gussets into the front frame, tying in the frame tubes around the steering head more tightly.

I think you really need to answer the question of: Do you want an off-road racing machine, or a travel bike? The HPN modifications are nice, but have you looked at the seat hight? One of the modifications that they do that makes lots of sense to me is the lengthened rear swingarm, which gives more suspension travel.

I think Grant's advise on using mild steel for frame and rack material is wise - easy to work with, ductial, and easy to repair. You gain a few pounds over more exotic material, but for a heavily loaded overland bike, this is not the best place to save weight.

All times are GMT +1. The time now is 21:09.