OK, I have a weird question. Was it normal for early 80's Diamond Backs to have an OUTWARD ding on the right gusset? Kind of like this:



See the ding sticking out on the lower left corner of the gusset? Is this normal? Maybe the way the frame flexed after hard landings caused this? Anyone?

Here's the reason I'm asking: my old DB had the same ding on the same exact spot. I have no idea how it happened. I mean, it's easy to put put a normal inward ding on a gusset, but an outward one? Not with the other gusset in the way less than two inches away. And on the same spot?

Soooo... if this is NOT a normal thing because of frame flex or whatever, then is it possible that I have found my old bike??? That would be something else...

[ July 02, 2006, 09:40 AM: Message edited by: Squid ]

Matt has a weird looking ding like that on one of his DB frames in the same gusset area ,his DB frame is a small one (anything but a pro frame is a small DB frame to us) & he can no longer ride the bike due to its tiny wheelbase & weirdo frame geometry. I'll ask him to have a look or he might even see the post & answer your question , but the flaw does look somewhat familiar to me.

JB

Thanks Black. Dammit. And I just passed on that DB Senior Pro on eBay thinking this could be my frame. What's Matt's SN?

[ July 02, 2006, 12:31 PM: Message edited by: Squid ]

The gussets on a lot of Diamond Back frames would actually end up getting stress fractures if ridden very hard (thrasing/jumping) as far as that ding? Don't know but none of the DB's I have or have sold in the past couple of weeks have it.

Haven't got the number offhand , its from the good people @ Koizumi & the numbers say its an 1981 model medium pro.
One of the DB's with the built in in layback seatpost tube in the frame <heh>
Seems to be a common flaw other DB's for sale here have similar crinkles in that area

JB

What do you mean? Are you talking about the bike in the pic being a medium pro? By the way, here's tha auction: dinged DB auction

So you think most DB's are too small for a 5'-11" 185 lbs. rider? I should've got that Pro on ebay. $217 for a complete bike . Does anyone have a Senior Pro frame for sale? I really want to do a rideable DB build.

It really boils down to your personal prefereces & how you plan on riding it after you put it together.Looking at what you paid for the bike you bought , it shouldn't be too hard to slap some wheels , rubber & brakes onto the bike & see how it feels to _you_ when you take it out for a ride , there's no strict formula to building an old BMX bike that feels right to you to ride around on.

It's not as if your going to fit twin side draft twin webbers to that mini (in your avatar) & fit a crossflow cylinder head , do the some serious metal work to the bonnet in order to get clearance for the trumpets , incorporate a neat cold air intake & fabricate a new throttle linkage is it ?

BMX bikes are much easier to tweak , tune & modify to see if they suit your needs than cars will ever be

Here's Matt some time in 1982 age 11 , the bike was probably too big & heavy for him at the time.



Matt still jumps all our vintage 20 inch BMX bikes & races against the guys with the new school bikes for fun & still whoops it up during races , so we try & build our oldschool 20 inch bikes to suit those needs , a long wheelbase & good or workable frame/fork geometry is one of the traits we look for.

JB

Unless you get a real Senior Pro or Turbo, most Diamond Back frames are too small for larger riders, the Medium-Pro/Silver Streak is an awkward little bike to ride, even back in the 80's. The bottom bracket was high, the seat tube angle was way layed back...a lot of guys would put a lay back post on it which would put a lot of stress on the seat tube.

Personally, I always like the geometry of the Senior Pro and Turbo, longer, but not Cadillac long like today's frames, with steep seat and steerer tube angles, perfect for my 5' 6" height.

Yeah,
I'm with you Ramon. I'm 5' 11" and my 82' Senior Pro (19" front end) is still big enough. Hey thanks for that pad mate - turned up Monday - beautiful.

Couple of slight inward dings on my gussets too Squid.

So Ramon - what was the difference in the Pro and early Turbo geometry?

The other area to check in the front end is the welds around those gussets - a good mate cracked his '81 Pro in a couple of places right on the welds.