I'll just save the 22T and 44T for my bike.
Thought about cutting off the teeth, but only have an angle grinder.
Imagine that would be messy and ugly.

Ordered a 'luminum ring guard off Lazada, drop shipped from china for $4.
Should arrive the same time her frame arrives.


https://cimg7.ibsrv.net/gimg/bikefor...760839103.jpeg

https://cimg7.ibsrv.net/gimg/bikefor...858ee5175.jpeg

That's amazing, I thought it was only carbon that kersplodes.

Great price.

Yes, assuming it arrives. Many fake storefronts setup on these online sites, they add hundreds of items to inventory with no sales, in hopes (i guess) of selling the pre-packaged storrefront.

the ring guard is listed as packed, but that may be automatic, as once it's shown as packed it can't be cancelled. it times out after 5 days if not shipped. have had mostly good luck ordering from china, with only the occasional non-shipment. only loss is time, as these are all COD.

the frame is also coming from china, but at least that one has some reviews with satisfied customers.

Leonard Zinn used to have a column that I often read. He very strongly favored steel or titanium over aluminum due to characteristics of the metals and the potential for aluminum cracking. I have forgotten virtually all of the metallurgy that I learned in college, I can't explain his reasoning.

A google search helped me find one of them.
https://velo.outsideonline.com/road/...nkarm-fatigue/

Rodruiguez only builds in steel, and still manages very light bikes.
Here's an OLD article outlining the differences in materials.

https://www.rodbikes.com/articles/material-world.html

That's an amazing story. I've straightened aluminum masts that had a gentle bend with no kink. I've only worked with wet composites like fiberglass in resin, only if it was winter did I need heat to get the resin to cure, I usually filled a heavy ziplock bag with hot water and laid it across the patch. Was that why heat was needed for that broken mast? Or was the patch pre-impregnated ("prepreg") carbon fiber, where heat melts and cures the resin holding the layers together (in place of an autoclave)? I've never worked with prepreg, only know of it.

Even once fixed, re-erecting that mast with an improvised jib-crane(?) and side-stays, that alone would have been a great challenge. "That's tough, that's double-tough."

The wife's new frame is here. One week out of China. Came with derailler hanger, seatpost clamp, and some cable clips.
Frame was well packed in bubble wrap, and a custom carton, and shipping bag. No dings or scratches, headtube is round, BB threads are clean. The rock ring is in Thai customs now, should be here in a few days.

Frame cost the princely sum of $44.
I think they made their profit by overcharging on the shipping.....$4.50 !!!

I'm off to HomePro to pick up some threaded rod to DIY a headset press.


https://cimg0.ibsrv.net/gimg/bikefor...55e2002f7b.jpg
https://cimg1.ibsrv.net/gimg/bikefor...29970b0cbe.jpg

Hello there ! I put off seapost to clean it and i see this ! Carbon fiber there is loosen when i touch it with my finger . Is this ok? That area ----> seat tube connects with top tube .

https://cimg1.ibsrv.net/gimg/bikefor...6919af3a6b.jpg

I rode a 1983 trek for about 9 years all over, 63cm ive posted it on here. Trails, touring, whatever. I repaired it a couple times but when the head tube cracked I called it a day. I was not sad, because if it didn't eventually crack I would have been riding an overly heavy bike the whole time and having less fun. :)

The old woodworkers adage, "you can't have too many clamps". ;)

As for the pictured frame it would be junk to me. If its still under warranty see what you can get from the manufacturer. It might just be a frame and you have to swap over the components, or maybe they'll pay a bike shop to swap it for you.

That is correct; aluminum assplodes, especially if under the seat as shown.

I would send that photo to the manufacturer of the frame and ask them. Is it still under warranty? If so, I would also specify model, serial number, etc.

I have a very small frame defect on a bike I bought in 2018. A few months after I bought it, I took a photo of it, sent to the manufacturer with serial number, etc. They told me it was nothing to worry about. I sent a thank you to them, but let them know that I would keep records in case there was a failure later, that was my record that I had inquired about a frame defect while it was under warranty.

My bike is still fine, that defect has not been any problem, and I think it will stay that way. But if that defect gets worse, I have a record that they said it would not be a problem.

Yes MSN tourist thats fine move. I just receive this frame from warranty and its 3 months :D The thing is i remember the previus frame there looks like whole tube and not this thing with lossen carbon fiber and holes. I will contact the company for sure !

You might not have a problem there. IF that area is all within the area where the top tube is hollow, so all inboard of the joining fillets between the two tubes, that area may be unstressed. It still would be weird having a thin spot like that be coincidentally lined up with the top tube, so my guess is it might be a part of the building process, don't know. It would be good to know if that is present on other frames by the same maker.

EDIT! That might also be wear from the bottom of the seatpost rubbing there. One of my previous bikes had a bushing between the seatpost and seat tube, and early version was plastic (later was aluminum), which allowed enough flex that the bottom of the seatpost rubbed on the inside of the frame. Fortunately a steel frame. But the frame cracked at the top of the seat tube for other reasons.

Does your frame use a bushing between the seatpost and seat tube?

Hunny-bunny's bike is about done. Picked up a bag o'bolts at home pro yesterday, installed the headset and bottom bracket last night. Most everything bolted on easily. Had to cut down the kickstand, and will need to find some stainless mending plates and a disc brake spacer to get the rack to fit. Either that or buy a cheap disc-ready rack.


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Duragrouch sorry to hear that the frame cracked ! Hope you didnt fall. So why it cracked there? What is bushing ? I had a photo from my previus frame and the "connection hole" there was filled. Here is it..
https://cimg1.ibsrv.net/gimg/bikefor...7526f840d0.jpg

The bushing, what Dahon calls a shim, is a thin-wall cylinder between the seatpost and the seat tube at the clamp. Early versions were plastic bushing, later were aluminum. I think these bushings are unique to folding bikes, to reduce the seatpost contact length, for easy raising and lowering, as the super long seatpost would require the seat tube to be perfectly straight to go fully down, and with all the welds to it, I think without a bushing and seat tube at seatpost size, seatpost would jam.

My first Dahon Speed frame (4130 steel) cracked due to a combination of design flaws:
- The seatpost clamping slot was on the front of the seat tube, not the back as on most bikes. When under bending load from rider, front means loaded in tension, rear is loaded in compression. Fatigue stress happens in tension. Bottom of slot (inverted T) acted as stress riser for crack to initiate there.
- Seatpost bushing was plastic, so for sufficient clamp force for seatpost to not slip, this overcompresses the clamping slot and increases stress at the bottom of the slot.
- Seatpost is long so exerts a lot of moment, no way around that. Dahon said I had it too far extended up and I was over bike weight rating. At the time I was 50 lbs under their weight limit and 7" below their height limit.

Solutions on frame I bought to replace that:
- Later versions use a bushing material of aluminum, far less compression, and reinforces the seat tube. (I would prefer a bushing from high strength stainless steel, even better than aluminum). Plus, I also fabricated a soda can shim added there, so seatpost has almost no slot compression when clamped. This makes the seatpost a tight fit, but I fold my bike seldom.
- Much later versions move the clamping slot to the back, just like Dahon's aluminum frames.
- Had I caught the crack early, I could have filed out the crack, burnished the surface to introduce residual compressive stress (works like shot-peening) as others on here have done, and upgrade bushing to aluminum, and saved the frame. But I didn't see it until too late. After these pics were taken, crack eventually worked around all the way to the back on both sides, and started down the seat tube. End of story.

https://cimg5.ibsrv.net/gimg/bikefor...b136c20811.jpg

That bike looks nice enough you might have to pay more for the lock than you paid for the frame.

When I bought my Lynskey frame (disc only), instead of buying the $300 fork that was available for it, I used an old rim brake fork that I had in storage, the headset race crown to axle and fork rake specifications for the frame were correct for my old fork. Thus, I have disc rear, rim brake front.

Your build is only the other time I have seen someone build up a bike with brakes that way. I assume for the same reason.

I can easily imagine that they saw no reason at the factory to clean off a few excess strands of fiber in that hole before attaching the top tube, as it would be well hidden. I assume it is nothing to worry about, but like I said, it is good to have documentation if there is a problem later.

Built up several while in China, as I had a box of leftover Deore v-brakes. The BMC started off with a non-disc front fork that migrated from another broken frame. Add to that I need a larger frame, and the available forks (even in china) with a super-long steerer tube (even with extender added) were limited. Wife's bike has a little more than an inch of steerer tube above the stem. I really don't want to cut it down.....just in case.........