Cracked seat back on early Quest

bret

Well-Known Member
The seat back has a horizontal flange at the bottom, with the holes through which bolts attach it to the seat pan.

The bottom of the seat back is cracked on both sides, just at the bend for the flange, or a bit above.

Suggestion on what I can do?

Thanks,
Bret
 

DavidJL

Well-Known Member
If cracks aren't too long, could try locating the tip of each crack and drilling a stress relief hole to keep crack from spreading. Due to my extensive modding, I had this issue. I also took two strips of aluminum and joined the two halves of the seat together, using the water bottle holes and drilling new holes to attach the strips. Guess I need to take a pic of this.
 

Dudley

Member
I have the same problem on my Q3. The cracks showed some time ago but I didn't do anything. I just checked and it has got a lot worse. I'm going to have to fix it asap. I was thinking of drilling holes closer to the centre of the seat but I'll check with my local bike shop.
I just checked my partner's Q2 and it has the start of the cracks - about 1 cm long but still just hairline.
 

Attachments

  • Cracked Seat.JPG
    Cracked Seat.JPG
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trapdoor2

Zen MBB Master
Wow. I would figure out some way to get rid of those elastic stop nuts on the 'sitting' side of the seat. A pan-head bolt (similar to the ones already in use) is going to be much better on your back!
 

trapdoor2

Zen MBB Master
I probably wouldn't feel them in normal ops. either. I would be worried about hitting a pothole or something.
 

MrSteve

Zen MBB Master
This reminds me:

When I assembled my bike, I added a strip of innertube to the seat assembly.
It was sandwiched between the two halves of the seat, where they are bolted together.
Also, the assembled seat sat on rubber strips which insulated it from the steel.

Why?
One of my old jobs was motorcycle test rider and I learned that both aluminum and plastic
accessories almost always crack around their mounting holes.
Mounting the accessories on rubber or urethane really really really helped.

(I ride on my own homebuilt composite seats for both custom comfort and practicality:
The stock aluminum seats look pretty mounted on the garage wall.)

You guys now owe me money.
 

DavidJL

Well-Known Member
I guess those two little rubber washers weren't quite enough to do the trick. I was considering making the seat hinged.
 

Patineto

New Member
A pic of the repair I did.View attachment 4898
next time try chainring bolts, super slim heads (in fact you can even counter sink them) and really wide diameter so they spread the stress very well too..
really%20big%20boxes%20024.jpg
 
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Patineto

New Member
I'm digging the safety wire sutures.... :D
Thanks Eric sadly I don't think they will do much for the carbon..

This is another of my ''best proud of you F £cku&s'' that may work better on the carbon..

Umm for some reason I can not upload the picture, I made this about 12 years ago and still holding, after at least 130.000 since the bubu

Sorry, no picture, no links, I guess I'm to new, I show you later but I think it will work very well, silly strong..
 

bret

Well-Known Member
"Reduce, Re-use, Re-cycle"

Given your skills, I'm surprised you even bought a bike. You should just grow one...
 
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