Side stand dangerous lean

Hi,, My 1970 750commando S has the orginal short side and centre stands on it and looks in constant danger of fallling over. I understand that later models rectified this issue. What year/model should i buy and will they bolt str8 on. I was hoping to buy a complete stand i.e springs/bolt , etc

Cheers

Rob

Do some reading here http://www.oldbritts.com/ob_start.html
look under restore your Commando scroll down to :
Upgrading the 1971 Side Stand Lug

Thanks for the prompt replies and info Norbsa

Norbsa sent you to the right link, but your stand is completely different from the 1971 style. The 1970 and earlier frame has the short leg with the half lug that bolts to the frame while the other half is welded (and maybe pinned?) to the frame. These are cast and are weak. In fact it is quite rare to find one of these frames with the original stand still intact. If you have one of these early frames, do not sit on the bike while it rests on the sidestand or leave the engine running while on the stand.

The 1971 mod will defiintely work on your frame. I just wanted to warn you that your frame will not look like the one in the Old Britts pictures. This also is not a bolt on modification, and the welding should be by a competent welder due to the light gauge of the frame tubing.

Since your bike is the relatively sought after 750S model I would recommend leaving the frame structurally the way it is for the sake of originality. You could probably purchase a 2nd-hand stand of the same type and lengthen it a bit (this would have been the same on all the earlier fastbacks, roadsters etc.). I would however echo Ron L's comments about being careful how you use these components.
I myself am building a 750S replica from an old fastback and have had to do a fair bit of work on both centre and side stands and their mountings to bring them back to standard spec. They are not as robust as the later types, but they do look right.

You could probably purchase a 2nd-hand stand of the same type and lengthen it a bit

Click to expand...

I would not recommend this. The stand mount is already weak and lengthening the arm increases the mechanical advantage operating on the mount and will lead to more stress on the mounting.

Commando frames go about 20 lbs and BSA and Triumph frames go about forty lbs. Kick starting or sitting or running the bike on the side stand are not good practice. The reading is for primer only, lots of ways to skin a cat. I was just teasing your brain on the magnitude of a fix you need to carry out.
Dave M brings up important info , it should influence the design of the fix. Keep in mind that furnace brazing a tight fitting tube over the frame can be very strong and do less damage to the frame tube. It's also a bit more reversible for a total just right restoration of the bike at some point.

Great info

Thanks for the info to date guys, its really been great to boune my questions off those in the know. This forum ppprovides a wealth of knowledge and info at your fingertips making things so much easier. I notice my stand has a welded tube (so it seems ) where the lug is and it has a bolt thru it not a pin or anything so it may have been stengethed already. Its off to the transport dept in the next day for registration i hope so then the real fun starts when i get it on the road and see what breaks

cheers

The old style stands don't stick out at such a severe angle as the later type. Thus if you lengthen the old style side-stand the bike will adopt a more upright position putting less weight on the stand and mount. Taking this to it's logical conclusion if you had a stand that kept the bike upright at it's balance point, there would be no weight on it whatsoever.

dangerous lean on my Mark III

I was just about to post a question on this topic this morning when I saw this discussion already in progress.

My Mark III leans over at a scary angle on the sidestand, and as a result I rarely use it. But since i have the bike up on a jackstand as of a couple of days ago (to pull of the wheel for respoking), this is a good time to deal with this inconvenience.

I didn't take the stand off yet, but on first glance, the stand itself looks straight. It appears that the stand just pivots around too far. Instead of stopping at, say 15 or 20 degrees past perpendicular to the bike, it's more like 30 or 40 degrees (I didn't measure any of this, just off the top of my head to describe the issue).

I suspect the surface of the lug or of the stand (or both) have worn. Looks like they are designed to hit against each other and thus stop further forward pivoting movement of the stand, but that hitting point seems to have rounded off its corners.

My thoughts:
1) get someone to braze some metal on one or both of the surfaces to square up the corners, back to original spec
2) maybe simple drill a small hole in the corner of the stand, and insert a small screw, the head of which would form a replacement for the squared off corner that's now worn round
3) try to accomplish the same as in # 2, but with JB Weld compound instead of a screw.

Anybody else dealt with this before?

pkeith...,

Indeed your sidestand is over rotating. This is because the stop-shoulder on the frame lug has worn down; this is a common problem. It's simpe to fix, however. Merely weld up the worn area and grind to suit.

pkeith,

If you weld the lug you may want to water quench it. Quenching will harden the steel. These lugs will bend sometimes. I believe I read somewhere the correct lug angle is 18°. Since you have to weld it would be easy to tweak the lug while its still hot.

trying JB Weld first, before welding

I agree that welding some mass back on to the sidestand lug to make up for the missing metal that has worn down is the best way to go.

But before letting someone under my bike on a critical spot with welding gear, since I had a bit of JB Weld compound lying around, i thought i would give that a try first.

Mixed some up last night and jury-rigged a small form out of popsicle sticks to hold the compound till it firmed up. By tonight it should be hard enough to grind off the rough edges and shape it properly.

Nothing to lose, right? If it doesn't work, i can grind it off (or maybe it wears/falls off by itself?) and do the welding then. I haven't used JB Weld for a long time, but have seen it do amazing things (cracked blocks, transmission housings, etc.) I'll find out how it holds up in this application, with metal-on-metal friction under stress.

Thanks for the suggestins,

Keith Kelly