Mountain Bike Reviews Forum banner

Another ironhorse mkiii frame cracks..

12K views 75 replies 13 participants last post by  KevinB 
#1 ·
08 comp here:

















Sure does suck. I have alot of miles on it, about 14 months of ownership is all though. I ride generally xc singletrack about 3 times a week. No jump/drops over 2-3ft, and even those are a rarity. I weigh between 190-195lbs and I'm 6 foot 1.

Sucks, I'm a college student and can't afford an ibis or a turner. I loved this damn bike, that's the crappy part. The ibis looks like it matches the geo pretty damn perfectly though and is slightly cheaper than the turner. I might buy a rear triangle since repairing this in so many different spots is just asking for trouble. But a rear triangle is (as we all know) just a band-aid and it WILL break again.

Funny thing was that I had read all these threads and never thought it would happen to me. Just plain sucks. :(
 
See less See more
8
#5 · (Edited)
redmr2_man said:
hope pro2 thru bolt conversion kit, stock mkiii comp 10mm qr "thru bolt".
So it's a quick release mechanism utilizing a cam?

I've never used a 10mm quick release. Something I've noticed with standard QR mechanisms is that the cam is designed to get incrementally tighter as you push the lever "closed". But, at the last moment, just before full closure, the cam usually loosens up a little bit. I think they're designed this way to help prevent the QR from accidentally opening.
 
#6 ·
yeah qr with cam, but instead of the standard 5?mm, its the solid 10mm bolt. Always super tight, like using tire levers and my pump to try and leverage it open when I would flat.

I honestly don't think a rws would have helped. We can all hope, but look at all those cracks. 5? 6? there are alot!
 
#7 ·
redmr2_man said:
yeah qr with cam, but instead of the standard 5?mm, its the solid 10mm bolt. Always super tight, like using tire levers and my pump to try and leverage it open when I would flat.

I honestly don't think a rws would have helped. We can all hope, but look at all those cracks. 5? 6? there are alot!
It sounds like you had it really tight. I think you're right; an RWS through bolt probably wouldn't have helped.

Thanks for posting the pictures. I appreciate seeing them as it gives me an idea of what to look for on my own bike.

I don't know what your budget is, but keep an eye out for used Mojos on ebay. I managed to snag a frame for my wife recently. I was worried that there might be something wrong with the frame, but I did a thorough inspection, and it all looked okay to me. Built it up last weekend; seems pretty solid so far.

I've been bidding on Mojo frames that'll fit me, but I don't want to go too high as I have a bunch of MkIII parts that I have to use up. My fear is that if I get a Mojo, I won't want to ride my MkIII any more. Still, if I can find a decent looking frame for a good price, I'll go for it anyway.

With regard to a replacement rear triangle, I agree that a replacement will most likely break in a similar manner. Even so, that may be more cost effective than buying a new frame. Figure that you'll get another 14 months of use for $200 + shipping.
 
#9 ·
I've been watching mojo's on ebay as well. I've seen shops go as low as 1700 for a frame only, and used on ebay a large just went for 1490 shipped last night.

That's really not that bad, considering almost everything except the bottom bracket can be swapped.. the problem is that I have a rs recon 327 (with pike internals/moco) and it's not a 20mm thru. I'd probably spring for that upgrade as well, but everything else could be swapped!

crappy truvativ firex crankset with new rings, hope pro2 / dt 5.1 wheelset and tires. sram 990 cassette and chain. Seatpost and seat. XT disc brakes. stem/bars/shifters!

It's the whole buying an ibis frame that puts me off man, lol I'm in college and although 1400ish is a DEAL on a barely used ibis mojo, it's still 1400 bux!

I think I'm gunna get a new triangle for sure, as it's the most cost effective, but damnit..
 
#10 ·
redmr2_man said:
I've been watching mojo's on ebay as well. I've seen shops go as low as 1700 for a frame only, and used on ebay a large just went for 1490 shipped last night.
Yeah, I was watching that one too.
That's really not that bad, considering almost everything except the bottom bracket can be swapped..
Well, the BB shell width is different: 68mm on the Mojo vs 73mm on the MkIII. The crankset will still work though provided you put spacers on each side. (I set my wife's Mojo up with the same type of crankset that I have on my MkIII.)
the problem is that I have a rs recon 327 (with pike internals/moco) and it's not a 20mm thru. I'd probably spring for that upgrade as well, but everything else could be swapped!
Actually, I think you might run into problems with the headset. The Mojo uses an internal headset in which the headset cups are part of the frame. On the MkIII, you have to press the headset cups into the frame. I'm not sure if the bearings from one will fit in the bearings of the other. They look to be of similar sizes, but I haven't measured to see if they're the same. The headset that I installed on my wife's Mojo had a couple of shims that went above the compression ring to hold it firmly in place. The price for a suitable headset isn't too bad though: $34.98 for a Cane Creek IS-3 at Price Point.

You'll need a different seatpost too. The Mojo uses 31.6mm seatposts; the MkIII uses 30.0mm seatposts. 31.6 is a more common size though. The seatpost clamp on the Mojo is kind of funky too. The seat tube on the Mojo is comprised of a tubular metal insert to which carbon fiber is bonded. For some reason, they've run the CF a bit higher on the sides than on the front and back. The Mojo's seatpost clamp is contoured to conform to this shape. A standard seatpost clamp really doesn't fit very well. The frame that I bought for my wife came with a suitable seatpost clamp. Ibis sells them at their online store too.
 
#16 ·
Just did a bunch of reading about the Jamis Parker frame, sounds like they have more issues breaking the rear dropouts than we have cracking the drive side of the rear triangle. Guess I will keep riding my 7 point and not worry about anything.

redmr2_man said:
lol...

jamis..

No thanks. Have you ever been on a jamis? I'd rather ride a frame that would crack than an fs jamis. They don't climb well at all and that's a 4inch bike. Thanks for the suggestion though! :)
 
#18 ·
I've seen enough cracked Jamis' (Jamii?).

Sorry to hear about your problems.

I'm actually happy to report that the RWS (10mm) through is treating me well. I'm about up to the same number of riding hours where the first rear triangle cracked. I think I'm riding a little harder than I used to as well. So far so good!

Maybe a new triangle and different axle is worth considering? I'm not convinced about the stock QR through axles personally.
 
#22 ·
jmontgomery said:
I'm 6'1 200 lbs. What are the odds of cracking a frame if I buy one of thes bikes? I've been thinking of getting one until I seen these threads.
I'm about the same weight as you - okay, slightly heavier, but not by much. I've already cracked one MkIII frame and am working on my second. I'm confident that, after a sufficient amount of use, it'll crack too. Even so, I like the bike, and have purchased some spare frame parts to keep me on the trail for a while, maybe even quite a while.

I would buy a Turner frame if they offered a longer warranty, but it's only two years. The Ibis warranty is somewhat better at three years. I'm thinking that the carbon fiber construction might be better at resisting the fatigue induced failures that my frames see. (As mentioned elsewhere, I've cracked six frames in seven years, none due to crashes.) So, after I use up my MkIII parts, my next frame will probably be an Ibis Mojo.
 
#23 ·
Really hard to say. Depends on riding style, abuse etc.

I'm 6'1 and was about 190 when I started with the MKIII and am around 180 now.

I cracked the first arm on a 2007 with a 5mm Salsa skewer and Hope hub. In hindsight I don't think this is the best setup. To last the back axle seems to need to be really really locked down. I now have a new arm and a 10mm RWS that I tighten as much as physically possible.

So far I have about the same hours on the new arm and no signs of cracking so far.

Naturally, your mileage may vary. Probably the bigger thing to consider is that if you do break one, getting parts is going to be random.

Other than that, they're a pretty damn sweet ride!
 
#24 ·
lol kevin and I are totally on the same page. IBIS>turner in warranty and weight and....they look cooler..annnnd with the lopes link they're supposed to be firmer in the rear than the turners. Can't say on that since I haven't personally tested the differences though..
 
#26 ·
redmr2_man said:
my friends want me to lower the rear shock to 50psi, huck a 5ft drop to flat, and videotape the whole thing.

lol i don't wanna die.
Plus, you don't want to bust the front triangle in the process. (Recall that I broke my front triangle not long ago.)
There may be some youtube awesomeness of me taking my anger out on this old swingarm though. I'll post up if I do it :)
It'd be interesting to see how much abuse a cracked rear triangle can take before it totally fails. Just make sure it's detached from the rest of the bike first. If the bearings are still good, you should probably press them out first too. (Who knows, if your replacement rear triangle lasts a long time, you might need those extra bearings.)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top