rseeker

So I need to replace my frame. It's old, it's aluminum, I'm a big guy, I like to stand up on hills and work it, and I can see cracks forming.

I don't want to get a whole new bike because I like this one, I've nursed it back to health from being pretty far gone, and even though I will eventually have replaced everything, I still want to think of it as the same bike, the one I know every nut and bolt on.

I'll talk to the maker but I don't think they sell bare frames. If that's the case, who else sells frames? Is there the equivalent of bikesdirect.com for frames only? (I'll be looking at steel too, as well as aluminum.)

I'll be checking craigslist but ours isn't very good here, we don't have much of a bike culture (yet -- give it five years). Right now I'm stuck riding in my driveway and up and down my little street. If I run out of patience I'll just buy a new frame somewhere, and that's what I'm asking about.

I just saw the crack a couple days ago. The paint flaked off along the edge of it, which is why I noticed it. I went back and looked at old pictures and it definitely wasn't visible last year. I scraped some more paint off across that area and then buffed it with scotchbrite to get a clean surface. It's hard to see it even under magnification, but there is a thin line crossing the exposed area, it's a crack. Darn it. The bike has been creaking for a while, maybe this is why.

Slightspeed

My beloved old steel Bianchi road bike got killed by a car several years ago, though I survived. I bought an aluminum road frame from Nashbar on sale for $99, and transferred all but the fork and head set, which was different diameter from the old Bianchi. Later I updated the down tube shifters to STI also from Nashbar. Anyway, worth a try. They also have mtn frames, too. Also try craigslist, lots of frames there. Good luck.

HillRider

If you can truly see "cracks forming" in an aluminum frame, stop riding it NOW. Aluminum doesn't fail gently, and those cracks will fracture catastrophically sooner rather than later. You don't want to be on that bike when it happens.

rseeker

Yeah, thanks. I do know this, but it's worth pointing out.

rseeker

Thanks Slightspeed, I like the way that story ended up. Checking out Nashbar.

SkyDog75

Specifically what kind of bike do you have? Make/model/year? Framesets (frame and fork together) are available, but there are at least a few different standards for certain parts like bottom brackets and headsets and some frames will be more compatible with your current parts than others.

Another reason for asking what particular bike you have is that some companies offer lifetime warranties on their frames. Most require you to be the original purchaser to get full coverage, but a number of companies will offer 'crash replacement' discounts to replace damaged frames.

Since you mentioned BikesDirect... They do sell some bare framesets. HERE is a carbon frame and fork on their site, although they don't have any that'll fit a 6'3" rider. Bike Island, their scratch-n-dent site, sells 'em as well.

Nashbar is another source for bare frames and framesets. Their own aluminum road frame sells for $149. (I'm not 100% sure, but if I remember correctly, it's made by Kinesis, who also makes frames for BikesDirect.)

There are plenty more sources for frames and framesets, especially if you're looking for high-end bikes. But another possibility on the budget end of the spectrum is to find a used 'donor' bikes. Used bikes, even some pretty nice ones, can often be found for less than the price of a new frame.

HerrKaLeun

Unless you have really expensive and good components, you are financially better off buying a new bike and maybe sell the old components.
if you don't get the very same frame, your BB may not fit, and with that not the crank (at least possibly). Derailleur hanger may not fit as well. You may also want to upgrade the drivetrain depending on what you have.

And are your components really great if they came with a bike that frame breaks?

blakcloud

Buying a frame can be a worthwhile investment if you have the tools and knowledge to do this. You will want as many as the old parts to fit on the new frame as possible to keep the costs downs so be aware of seat post sizing, size of headset and bars, bottom bracket threading, OLD of rear wheel. If these components are not compatible, then as the poster says above, it might be more cost effective to just buy new an sell what you have.

I like the Nashbar idea if it fits. You could also post a photo and description of the frame you currently own and maybe someone in this community will have a donor frame or something inexpensive that might work and have it shipped to you. Good luck with your endeavor.

frankenmike 

OP, to answer the bolded question, bikeisland.com is bikesdirect for frames and componentry

fietsbob

Or, spring for Lynskey Titanium https://lynskeyperformance.com/ use the data off your existing frame for size.

cyccommute 

That has not been my experience with any aluminum frame or part failure. I've broken two aluminum frames and many aluminum wheels. None of them "fractured catastrophically". If you think about the material it's fairly easy to see that aluminum is unlikely to fail by "shattering" as well. Aluminum is soft and not brittle at all. It generally tears rather than experiences fracture. Aluminum also makes a lot of creaking noise after it cracks just like rseeker's bike did. I've often found that my bike "creaking" is due to some broken part that I just failed to understand was broken.

I've also broken 2 steel frames...one several times... and several steel parts. Steel, on the other hand, has always fractured catastrophically like aluminum is supposed to do. The steel frames were just fine without any noises and then they went "ping!" and were broken. Same with steel spokes and pedal axles and hub axles. No warning, no bending, no creaking. They just broke.

cyccommute 

We don't know where "here" is but you can get a number of frames from just about any bike shop through QBP (Quality Bike Parts which is a major distributor of bike parts in the US). They might not be as cheap as Nashbar but they are still good bikes. They can get you All City and Surly as well as some others.

Another option is always Fleabay. You need to be discriminating but I've found some very good deals over the years...two titanium mountain bikes, a full suspension frame and a touring frame. One thing to look for now is titanium frames which are becoming dirt cheap as people dump their titanium for carbon...less so than about 5 years ago but you can still find some very nice Ti frames for a fraction of the original price.

On the other hand, it may just be cheaper to go with a new bike. Swapping parts from one frame to another is fraught with fit issues. Most of the time the parts fit but not always. Seatposts are the most common item I've found that doesn't make the transition but, if the new frame doesn't come with a fork, forks can end up too short and they are much more expensive to replace. There can also be issues with headsets. If the original bike has a classic headset and the new one has an integrated or zero stack, that's an added cost.

If you haven't swapped frame parts, the process can be daunting as well. You'll need tools you may not have...extra expense. You might need cable and housing...extra expense. If you don't have experience with doing the job, it's easy but not simple. I've done it many times and can generally build up the bike in an afternoon but for a newbie, you can make mistakes that can really screw up the bike. Crossthreading a bottom bracket can ruin your day and it is really easy to do.

I don't mean to put you off the idea of doing a bike frame swap...it's a lot of fun to do...but just realize that there are some pitfalls and try to avoid them.

cyccommute 

Good point. I think Bike Island is where Bike Direct's remainders go.

HillRider

The aluminum alloys used for bike frames and rims are by their composition and heat treatment chosen to be strong at the sacrifice of ductility. My experience is that aluminum does fail rather suddenly and, if the OP is already seeing crack, they will propagate rather quickly.

cyccommute 

While the alloys used are less ductile than pure aluminum, they still have similar properties and are more prone to tearing than shearing. Even the metal matrix (M2) alloy with boron fibers in it that Specialized used on mountain bikes in the late 90s didn't crack and fail suddenly. I know because I broke one. It creaked quite a bit before I noticed that it had cracked.

Even rims...of which I've broken many including one within the last month...don't fail suddenly. Cracks develop and propagate but the process has always been very slow and with lots of warnings...i.e. creaking. There is not "ping" involved as there is in steel failures.

I think a lot of the "sudden" failure of aluminum can be attributed to people not seeing the crack nor paying heed to the creaking and groaning of the frame. They ride for a long ways with a creaking bike and are suddenly surprised when the failure occurs but the damage has been there for a long time. That's been my experience even with my recent rim failure. The sidewall cracked and the wheel felt "weird" for a while and the tube blewout unexpectedly before I noticed the cracked sidewall. I probably would have noticed it sooner on a rim brake equipped bike because the brakes would have pulsed.

79pmooney

But - there have been bikes made where the very likely crack was in a place that was impossible to see without either destructive disassembly or X-rays. I rode one of those bikes and paid dearly. (Being an engineering student when I purchased the bike, I wondered how the fork crown/steerer was executed but because I had some engineering at that point, I knew that no one in their right mind would cast and machine a plug extending up from the crown that inserted into the steerer. So I kept riding in ignorance.) Yes, the crack that ultimately failed was well along for a while. But the crack was completely obscured by the steerer that covered it, then the headset over that, then the head tube over that. No easy way to check.

As for creaking and groaning: yes you are right, but a lot of stem/handlebar joints and crank/axle interfaces creak and groan, sometimes for years. It is good to know as best we can where they are coming from, but it often means either not riding a bike or riding in paranoia. I do make it a point to look for cracks when I clean an area up.

I did have a steel fork nearly break (after cracking a full circumference between the two blades from hydrogen embrittlement. My first warning was shudder braking. No sound ever. Yes, there probably had been a crack to be seen for a while but who looks regularly at the tops of their fork blades on traditional steel forks built by skilled framebuilders? (The embrittlement was caused by nickle plating and not heat treating after; something the plater knew but neither did nor alert the builder.)

Ben

nfmisso

My observation is that most people (more than 50% = most) are not aware of things around them.......

rseeker

Guys, wow, thanks for all the great ideas. I'm still here, just keeping the rest of my life in motion too. I'll be back with measurements.

rseeker

The thing to know about this bike is I got it to be a beater that could get me to hiking trails, where I could lock it up and leave it for a few hours. It couldn't be an expensive bike because I'd worry about it the whole time which wouldn't be any fun at all. It had to be a cheapie, so I got a used bike off Craigslist for $50 and then did the work to fix it up.

I also decided it was time to learn about maintenance, another reason to start with an old bike. I had a good bike shop bike in the past, but it never needed work and I didn't learn much. I took on this bike as a learning opportunity.

So far:
- cleaned and lubed both hubs, the headset, and the bottom bracket
- replaced one pitted cone in the rear hub
- cleaned and lubed the inside of the freewheel
- cleaned the drivetrain and added a SRAM missing link so it opens up
- made custom padded grips out of a puffy doormat and some zip ties
- replaced the rear brake at the wheel and cable
- trued and dished the front wheel, replacing some spokes and spoke-prepping all the nipples to get them to thread freely
- trued (but not dishing yet) the rear wheel
- with a metal engraver, added ridges to the seatpost so it stays up (separate problem, it's bending under my weight, not good)
- added pedal extenders to fit my big feet
- added a little "fender" under the seat to keep rocks from bouncing into the seat post and going down into the bottom bracket (for real! it was like a little terrarium in there)
- and some other stuff, but basically a complete overhaul

What's funny is that even though I got this to not care about, at this point I'm attached to the thing. It's been an odyssey, lots of challenges met and overcome. Got all the tools (made some tools), watched a hundred hours of YouTube tutorials, learned more than I even knew there was to learn. Now I know the bike inside and out, and it feels like an extension of me.

I don't think there's any way after all this I can just say "chuck it all" and buy a new bike. This story can't end that way. That's not how the Hero's Journey* ends. I have to get to my hike (I haven't yet, only about halfway there) and it has to be on this bike. And if I have to do mental gymnastics to call it the same bike with a new frame, well, I can flex that much.

* Joseph Campbell reference

rseeker

SkyDog75, definitely not a high-end bike, I have a department store bike. It's a Genesis GS29, hardtail 29er. I couldn't tell ya when it was made, but I'm the second owner (bought it used off Craigslist). I'm watching CL for a donor bike, that's a good idea.

rseeker

Totally agree with everything you said, except this is a passion project. Normally you'd try to get the most bike for your money, but if the bike gets too good I can't leave it alone in the woods. The components are definitely not good, but that's a virtue here.

rseeker

I think I'm ready to take on a whole-frame transplant. I've got most of the tools (still need a cable cutter) and I've had most everything off at one time or another. I agree about being cost-effective, but, passion project ...

If someone has a compatible frame they want to sell down I'd be happy to hear about it. I'll post the spec and measurements. Thanks for the heads up and your ideas.

rseeker

Bike Spec:

Genesis GS29
Model #GS32936
Hardtail 29er "mountain bike" with suspension fork

aluminum/not steel/not magnetic: frame, rims, pedal exterior cage, crank chain guard
steel/magnetic: seat post, spokes, nipples, fork, stem, handlebars, crank arms, front chain rings, pedal spindle
unsure: head tube (magnet attracted but only weakly, probably steel stem/fork inside aluminum head tube)

top pull FD
no RD hanger; just sits on the axle, alongside the frame, clamped by the axle nut, with a fixing screw into the frame to keep it from twisting

brake mounts: for V-brakes

BB/crank spindle = traditional square taper, cup and cone with caged bearings

headset type = traditional threadless with press-in external cups (not zero stack, not integrated)
headset bearings 22 balls, 3.93mm = 5/32 inch, caged
head tube diam = 42.164mm = 1 21/32 in = 1.66 in
steerer tube = 1 1/8 inch

seat tube diam = 32.1mm
handle bar diam = 22.05mm (apparently 25.4mm is some kind of standard?)
top tube diam = 38.3mm
seat post diam = 27.1mm

bottom bracket lock ring (NDS, "adjustable cup" side) outer diam = 45mm
bottom bracket adjustable cup (NDS) at threads = 34.6mm (measured)
bottom bracket fixed cup (DS) wrench flat span = 1-13/32in = 35.81mm
bottom bracket shell width bike-left-to-bike-right = 68mm (bare frame only; 74mm if including the cups)
bottom bracket shell outer diameter = 43mm (measured)
bottom bracket shell inner diameter at threads = 33.7mm (measured)
- so presumed BB standardized size spec is 68 x 34
bottom bracket bearings, each side = 9 balls, 1/4in, caged

bb height (from bb center to ground) = 13 1/4 in
bb drop, vertically down from line connecting front and reat axles = 1 1/4 in
chain stay length, bb center to rear axle = 18 1/2 in
seat stay length, seat tube center to rear axle = 19 1/2 in
wheelbase, front axle to rear axle = 44 1/2 in
axle height above ground = 14 1/2 in

frame reach = 40 5/8 in - 24 9/16 in = 40 10/16 - 24 9/16 = 16 1/16 in
frame stack = 36 3/4 in - 13 1/4 in = 23 1/2 in
standover height above the crank = 31 in
top tube length, along angle of tube, seat tube center to head tube center = 23 in
top tube length, along flat top only = 21 1/4 in
down tube length, bb center to head tube center = 27 5/8 in
down tube length, along flat side only = 26 1/4 in
seat tube length, BB center to seat tube top edge = 19in
seat tube length, BB center to seat tube-top tube intersection center = 17in
seat tube angle = 75 degrees (74.74 degrees)
head tube length = 4 3/4 in (between cups, not including cups)
head tube angle = 71 degrees (70.79 degrees)
head tube height above ground, from below top cup to ground = 36 1/2 in
steerer height above ground, from top of top CAP to ground = 39 in
stem length, top cap center to handlebar center = 3 13/16 in
stem length, overall end to end = 5 9/16 in

fork length, from bottom of lower stem cup to end of fork arm = 19 5/8 in
front axle offset/rake = 2 1/4 in (rough estimate)
front wheel trail = 3 1/2 in (rough estimate)

rear v-brake arm length: 122mm end to end, 102mm axis to axis
axle nuts (front and rear): 15mm
rear brake cable length: 51in = 1,295mm
tires = 29 x 2.10 (marked ISO 622-54) Kylin brand
rim diam with tire off (front) = 25 inches (need to recheck this since different from rear)
tire diam (front) = approx 29 inches (or maybe 28 7/8 with wear)
rim diam with tire off (rear) = 24 13/16 inches
tire pressure = 40lb
all the way around chain = 4 turns of the crank on small chainring
chain = KMC Z-series (probably z51, maybe z7, z72 or z8) 116 links, non-bushing
chain master link = KMC Missing Link II Reusable
front chainrings: 3, 48T/38T/28T
freewheel: MF-TZ21
rear cogs: 7, 28T/24T/22T/20T/18T/16T/14T
crank arm length, crank length = 6 11/16 inches BB spindle center to pedal spindle center = 170mm
pedal = maybe sunlite?
pedal threads = 9/16" outer thread diameter
rear axle slightly bent or hub axis drilled off-center- slight waggle of rear gear stack as wheel rotates
rear axle diam = varies, but 8.85mm in center, 9.4mm at threads
rear axle length = 7.25 inches
total wt approx 32lb

rseeker

Here is a southern U.S. city in the process of getting big and techy after being mostly agricultural. There's just no pool of good used bikes to buy, it's really paltry, but with the boom we'll have plenty of bikes in a few years. I watch Craigslist every day, and what I see is 70% BSO/department store bike, 10% antique/classic/vintage, 10% kids bikes, 5% high quality road/full suspension MTB, and the rest is farm equipment (in the bikes category). Nobody sells used bike tools or gear on our CL. The bike parts category is mostly trailer hitch bike racks and kid-hauling trailers.

Thanks for the advice, especially about being careful around the BB, and for sharing your experience.

ptempel

OP, that bike from wallmart new was around $150. You might spend that or more just trying to replace the frame and fork. If I were you, I would look for another good used 29er complete bike deal on CL or Ebay locally. I know that you are attached to your current ride. However, you need to consider how much your time is worth. Its good that you learned more about bike mechanics and became more self-sufficient. But I think you could exceed the price for a new one with famset cost and time to build it up. Also, if you are willing to broaden your search for 26-inch MTBs, then there should be a veritable plethora of old school hardtails around in that form factor as well. Many folks take them and convert to touring/commuting bikes as well. There are many threads here on it.