So I have just had my Singular Pegasus frame repaired by Enigma cycles, I caught the problem very early & the very small crack has now hopefully been sorted.
The crack was on the seat post top tube junction & I’m wondering how best to avoid the same problem happening again?

My thoughts & response thus far has been,

1, change to suspension forks from rigid to take some of the shock away.
2, change from a carbon layback post to a Thomson alloy in-line to give less leverage.
3, turn my Thomson seat clamp 180 degrees so the clamp is opposite the cut in the seat tube.
4, change to single speed so I go slower 😉

Apart from standing more can anyone think of something I have missed ?

Cheers guys.

Balls, I forgot the obvious, but no I’m not going to loose weight 🙄

stick with the carbon post, it will have a bit more give than Thomson,

Long seatpost into the frame?

Dropper post so your not tempted to sit on it over bumps?

Mainly I think try and ride as normal and hope frame is stronger post repair.

Speshpaul – Member
stick with the carbon post, it will have a bit more give than Thomson,

I thought that too, but then I thought a direct shock straight down would be better than a lesser shock with leverage???

Who knows, but that’s the question right?

Is the seat tube the same width all the way down or does it have a shim in it (some come like that)? If it’s at all wider at the junction of the tubes then a longer shim will provide some additional support.

You’re right that a layback/setback seatpost will create more leverage. If you can fit an inline one and still get the bike comfy then that would seem a smart move to.

Mine was shimmed I think. Bonded shim though. Is Sam on?

It has a shim which seems rather solid but not all that long, I don’t really want to try & get it out 🙁

Why a Thompson inline post? Surely a carbon one would be better if you’re going the inline route?

Did Enigma offer any advice on this?

I asked Enigma about a longer shim & they said they would have a look but nothing was done so I assume the original is well & truly stuck, I should of asked again after they had done the repair but I forgot.

It might not be relevant, but every frame will have a minimum insertion depth for a seatpost (the amount of post that needs to be in the frame to protect the frame itself); Sam should be able to tell you what it is for the Pegasus, but as a rule of thumb this point is usually just below the lowest point of the top tube/seat tube junction.

With a shimmed set up the depth of post in the frame is effectively just the depth of the shim (as any post below the shim won’t be in contact with the seat tube).

If your shim doesn’t meet the minimum insertion requirements of the frame I would guess that it might be worth replacing in with one that does (although getting a bonded shim out sounds a nightmare).