4-Bolt Mounts On Frames

[Sponge]

Hey,

So I've a friend who's custom making his own frames and forks over on the other end of Eurasia, and he's wondering what 'type' of 4 bolt mounts are 'best'?

By best, I'm guessing he's trying to find out which ones are theoretically least prone to cracking on the weld, hurting the tubes, etc.

Some pictures here should clarify what he's trying to get at:

All four have slightly different welding.

-Braced mounts with full welding all-round

-Braced mounts with welding just on the tabs

-Braced mounts with a strip of weld on one side

-Individual tabs welded on

Props to him for wanting to go into that kind of detail to make the best possible frames and forks for himself and local riders. Now I think about it, it is something that I've wondered at the back of my mind before. I seem to remember certain types cracking at the welds more frequently than others...

Any input or knowledge would be great!

Cheers

[i hope it's okay to use TartyBikes' images for clarity as they have the best shots by far, if not I'll take them down and replace them with others)

Edited November 11, 2010 by Ares

[Mark W]

These beauts are pretty win.

Smoothed welds = good times.

[eskimo]

Tis a good question. I'm only really posting so i'm reminded to come back.

But i do wish some companies would use a jig when welding their mounts, god that f**ks me off.

[AdamR28]

But i do wish some companies would use a jig when welding their mounts, god that f**ks me off.

For batch production, there's no way they wouldn't use a jig, it would be way too slow. The weld distorts in cooling and heat treating, which could throw mounts off a little theoretically.

[craigjames]

Tis a good question. I'm only really posting so i'm reminded to come back.

But i do wish some companies would use a jig when welding their mounts, god that f**ks me off.

Evidently some jigs are better than others, because some frames are so far off its nuts!

[eskimo]

Evidently some jigs are better than others, because some frames are so far off its nuts!

My point exactly. Making me think it's done with some sort of funny tool rather than a jig.

[SamKidney]

my old neon for instance, mounts angled in wards and high up the frame :/ had to file em flat and then run the wheel forward in the drop outs

[Mikee]

My mk1 inspired has the different 4-bolt mount welds to the blue one pictured. It has the same as the new inspired (with-out the weld up the middle). Did it change with different batches or something..?

[Rob Leech]

But i do wish some companies would use a jig when welding their mounts, god that f**ks me off.

Would of thought this would be human error, rather than the kit.

Quite easy to get a bit carried away on a friday afternoon .

Josh.

[Sponge]

My mk1 inspired has the different 4-bolt mount welds to the blue one pictured. It has the same as the new inspired (with-out the weld up the middle). Did it change with different batches or something..?

I noticed that too. I thought that maybe Inspired put the full-welded mounts on as an improvement against cracking? I may be wrong. Now that the Inspireds have end-welded mounts it's a little confusing, haha!

Pythons and Pitbulls of 05 and 06 especially suffered a lot from cracked mounts. They were all U6 tubing as well, so that's why I run the heaviest stiffest booster purely just to prevent that.

[super]

Whatever mounts you decide on going with make sureyou put them in the right place. Unlike echo who managed to put my control together so badly that at's impossible to get chain tension whilst having the pads line up with the rim! The more my chain stretches the more i hate what is otherwise a brilliant frame!

Allso built in boosters are def. the way to go.