Evening All

I am I'm the process of starting a rebuild and note the cross strap/brace between the left hand side frame tubes above the pegs has broken. Looking at other TYs this seems to be a common problem and as such there is clearly a load at that point. What is the best fix - weld up as is, replace with a stronger gusset, or remove?  If welded it may break again which would be annoying after powder coating so am tempted to replace with a stronger gusset. However this may send load elsewhere in the frame. Has anyone any thoughts or experience?

Interestingly the brace/stop light bracket on the other side doesn't seem to suffer the same problem.

Yes the one on the left seems to be the only one that cracks. One TY175 I bought has a triangular 6mm thick gusset there (goes right down to the junction of the frame tubes) and for what it is worth has no tube cracks at the upper ends of the gusset. The bike I'm referring to has cracks in the front uprights so it has probably been ridden very hard

Mine was cracked both sides (!) ... replaced with thick gussets while my mate was Majesty-fying the frame for me, should be fine now

(he also added slim gussets where the old shock mounts were, and a reinforcing strip above the new shock mounts)

Yes, drive side, in this case the L/H side of the frame will take more stress and strain than the non drive side, in this case the R/H side of the frame.

Thanks for your comments - have you any pics?

If the opportunity arises I'll take a photo for you this afternoon

That looks a bit too slim to be a load bearing web.  Could it just be a protection to stop you poking your fingers in the chain?   Manufacturers are required to put guards on the input side of chain-cogs, for safety reasons.

 

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That is a good point scifi. Considering that they all break would indicate it is under more load than it can handle. So either it is bracing the frame / stopping vibration and is under designed - and needs replacing or it is only stopping fingers and doesn't.

 

Just looked at three TYs....  One has a 1.6 x 20mm narrow web,  another has a 1mm x 45mm wide web, and the third bike has had it removed, along with some of the other frame add-ons ( for lightness.?).   So take your pick...

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Thanks all - I will replace with similar just need to find a good welder now.

Hi,

mine was cracked, same as yours ... I replaced it with a triangular brace with the top folded over and a lightening hole. No sign of any cracking in the couple of years since it was done. See pic below.

cheers

Richard