Replacing missing subframe bolt nightmare

[whizzit]

Has anyone else lost/stripped the lower bolt that attaches the sub-frame to the frame? I lost one at the race the other day, only to find its a nightmare to replace it.

No honda dealership in town to order from, all bolt supply stores in town do not carry this specific thread pitch, dealerships 4 hours away don't have it and will need to order it in. But then to courier it up to me is just a waste.

More or less venting here but I guess I do have one question, is Honda (I have a crf250r) the only company that uses this in between thread pitch for its bolts (1.25 I think) or do all the Jap bikes and KTM use it? The bolt in question is 10 mm by 26 mm long, I think it was a 1.25 thread pitch.

I'm not sure of the technical reason for choosing this thread pitch, but the practicality of using it is ridiculous :bang:

 

[IndyMX]

I'm betting that I could get a handful of bolts with that size and pitch at Home Depot or Lowes. It's really not that uncommon.

 

[Ol'89r]

That is a common pitch but a very special shouldered bolt. It would be best to wait for the correct one from Honda.

 

[IndyMX]

You could use a 10mm flange bolt in a pinch though.

 

[Steve St.Laurent]

It'll be far cheaper in the long run to buy a bolt kit for your bike. It's hideously expensive to buy a single bolt from the dealer. I bought one very reasonably on the auction site. Do a search there on "CRF250 bolt kit".

 

[whizzit]

Yea, that bolt kit is looking like a realy good idea. As far as the bolt being common, looks like it is common in the states but not in Canada. No Lowes or Home Depot up here, but I would seriously doubt Rona or Home Hardware would have the bolt over a dedicated bolt supply store, even Canadian Tire doesn't have it, looked like they only carried imperial sizes.

Maybe I could try sifting through the dirt at the track lol

 

[Chili]

I've yet to find a decent supplier of that kind of stuff in Canada, even local fastener shops like Adams supply and Fastenal had very little in the way of metric shouldered bolts.

I bought a bolt kit for a bike a few years ago, and suck it up and go to the dealer for anything that isn't inside the kit. I can tell you the drain bolt on a 2007 RM-Z 250 is the same pitch, learned that while looking for a helicoil for it last week :bang:

 

[FruDaddy]

In a pinch, I have used a non-shouldered bolt with a washer to hold a kick starter on.

 

[whenfoxforks-ruled]

That particular bolt is very special. Putting a "normal" bolt in will get you by. But the threads will dig into your subframe and elongate the holes, the more you use it.

 

[Ol'89r]

That particular bolt is very special. Putting a "normal" bolt in will get you by. But the threads will dig into your subframe and elongate the holes, the more you use it.

Foxforks is correct. It is a very special bolt. When properly torqued, it is designed to put just the right amount of pressure on the subframe mount without damaging the subframe. It is also a grade-8, hardened bolt. The bolts you can buy from Lowe's and Home Depot are not grade-8 unless you buy an allen bolt. The standard bolts are much too soft (weak) to be used for chassis bolts.

Another reason for using oem hardware is when you go to sell your bike. Any knowledgable person looking to buy a used bike will walk away from one that has a bunch of crap hardware on it instead of the proper oem hardware.

 

[whizzit]

Thanks guys for more technical info on that bolt, all this hassle is making a little more sense. I just thought it ridiculous how it can be so difficult to find a bolt, just one bolt. Anyways, I ended up ordering a new bolt from Honda. Although the bolt will be ordered in and in another city 3 hours away. Good thing a friend is making a trip down there anyways this weekend, so I should have the bolt it in a week.

Riding without the bolt however. Seeing how that bolt only supports the subframe (ie the seat); is riding without it that damaging? To me I would assume there isn't a terrible amount of stress put on that part, maximum stress would be in turns. Plus it fits into the groove of the frame anyways.

Only why I am asking this is because there is a race in 2 days, and I will have no bolt there. I could only find a course threaded bolt, and not a fine thread which the hole is tapped for

 

[whenfoxforks-ruled]

If you could get a sleeve/bushing to cover the threads, fine. As long as you do not ever sit on the seat, no stress.

 

[Ol'89r]

. is riding without it that damaging? To me I would assume there isn't a terrible amount of stress put on that part, maximum stress would be in turns. Plus it fits into the groove of the frame anyways.

The sub-frame supports the seat, silencer, rear fender and airbox. If it were me I would not ride without it. If you come down hard on the seat with your full weight it will bend the sub-frame and possibly break it.

If you can find a bolt with the right thread you could do as foxforks suggested and use a spacer of the right length around the bolt. If you jam in a bolt with the wrong thread you will damage the frame. Maybe you could borrow one from a riding buddy just for the race.