Subframe

[jocce]

Does anyone know what is the difference between SWB and LWB subframe?
I have -72 SWB frame and want a little shorter subframe to make a cafe´style seat
but keep the opportunity to give the blonds a ride

[bmweuro]

You have the short one. The LWB is about 2" longer. Cut it if you need it to be shorter.

[jocce]

Originally Posted by bmweuro

You have the short one. The LWB is about 2" longer. Cut it if you need it to be shorter.

Ok they seem hard to find used, do you know any firm making shorter subframes, so i don't have to cut the oem one ?

[disston]

Never heard of anybody who makes what you want. You will have to make it yourself. If you make the sub frame shorter you will also possibly move the upper shock mount which could have undesirable effects. The rear fender will have to be mounted somehow, or maybe you just plan the throw it away?

Look at some other custom made bikes here on Adventure Rider. There are tons of these things with smaller single seats. I think you might get an idea of what is possible from what has been done by others.

[Big Bamboo]

The LWB subframe is longer behind the cross member(s) and the shock mounts are further back too. The tabs for the /5 chrome battery covers are smaller and different location than for the later fiberglass ones. '73 LWB subframes are unique in that they have two parallel crossover tubes and take the shorter toolbox. '74 on LWB have a stamped steel plate for the crossover and take the longer toolbox.

[bmweuro]

Originally Posted by jocce

Ok they seem hard to find used, do you know any firm making shorter subframes, so i don't have to cut the oem one ?

I modify them here in the USA, but you are far away.

[jocce]

Thanks all, i guess i just chop the one i got
Ore do you think this is an option ?

http://www.ebay.co.uk/itm/VONZETI-BM...-/251102831160

and then maybe this seat

http://www.oldbikebarn.com/Flatty-Ca...tegory=1440699

[cycleman2]

That sub frame looks pretty good and would address your issue. As for the seat you might want to look at the seat that is meant to go on that style of sub frame. You should be able to find some combo pictures.

Me I'm a little cheaper, and like to mess around so this is what I'm doing.

I'm currently putting together a 1971 R50 SWB with the complete drive train from an R75/6. I've kept the stock SWB sub frame and the first generation SWB seat. The early SWB seats where smaller and a different shape than the later slash 5 seats. The early seat had 2 grab rails on the sides, instead of the big wrap around bar on the later models, and the seat itself is smaller with a more rounded shape.

On mine I just wanted to clean up the front end a bit and get rid of the rear portion of the stock fender that goes down below the tail light. The rest I'll keep fairly stock. I'm using a R90 front fender, and I picked up an extra rear fender that I cut down at the rear and then have built a plate that goes up under the rear portion to help support the stock taillight ( using it so far, unless I find something better looking ) and the license plate holder. I'll also incorporate the signal lights into this mount set up as well.

[jocce]

Originally Posted by cycleman2

That sub frame looks pretty good and would address your issue. As for the seat you might want to look at the seat that is meant to go on that style of sub frame. You should be able to find some combo pictures.

Me I'm a little cheaper, and like to mess around so this is what I'm doing.

I'm currently putting together a 1971 R50 SWB with the complete drive train from an R75/6. I've kept the stock SWB sub frame and the first generation SWB seat. The early SWB seats where smaller and a different shape than the later slash 5 seats. The early seat had 2 grab rails on the sides, instead of the big wrap around bar on the later models, and the seat itself is smaller with a more rounded shape.

On mine I just wanted to clean up the front end a bit and get rid of the rear portion of the stock fender that goes down below the tail light. The rest I'll keep fairly stock. I'm using a R90 front fender, and I picked up an extra rear fender that I cut down at the rear and then have built a plate that goes up under the rear portion to help support the stock taillight ( using it so far, unless I find something better looking ) and the license plate holder. I'll also incorporate the signal lights into this mount set up as well.

Cycleman i might go your route, i got rid of the rear fender today and moved the light assembly up
on the subframe, and made a fast photoshop test of how a seat could look.

looks like this


Also thinking of a very short rear fender to put the license plate on, and a ultra short front fender