[RadRat]

The Woman has a new Giant Rincon (3 months old) see here http://www.giant-bicycles.com/au/030.000.000/030.000.000.asp?year=2005&model=9851

It has TruVativ X-Flow cranks, they have a plastic or nylon? spacer behind the allen bolt to fasten them. The cranks keep coming loose and creaking, I tightened them before every ride thinking it was just settling in, but they would start creaking within five minutes of riding.

So I bought some Locktight (the locknut one) used that liberally, tightened them as much as I could, and went for a ride a few days later.

They stayed tight for about 15 mins, an improvement, but still very much ****ting me.

Is this a design fault in these cranks ? should I try for a warranty replacement ?

Any tips ?

 

[BikeGeek]

Sounds familiar. I have a pair of Truvativ cranks that do the same thing and I've heard the same from others. Unfortunately mine aren't covered by a warranty. Explain the problem and see if the shop where you bought the bike will swap out the crank for one of similar price. At the very least they should attempt to fix it or handle the warranty issue for you.

 

[RadRat]

Thanks for the reply Bikegeek, if others know of more cases of this happening could you also post here.

If you give your permission I will print this page out to take to the shop as testimony that the cranks have a design fault.

Cheers,
RadRat

 

[motomike]

Try a metal spacer behind the crank bolt. Try this first: i don't know exactly how you tighten your cranks, but I do know of the best way. Put your bike in a stand or stand over it next to the handlebars, facing toward the rear of the bike. To tighten the non driveside arm, insert the 8mm allen, and place the cranks in a horizontal position, with the driveside arm and the allen(in the non drive side) pointing to the front. Grab the drive side pedal with your left hand and the allen key with your right hand. Now, holding the allen still, push down on the pedal as firmly as needed. This gives you ginormous leverage and gets it very tight. Repeat for the driveside. Follow? You can print this if needed.

 

[RadRat]

Thanks for the tips Motomike, but after further investigation that isn't the answer. I took the allen bolt out again and looked at the nylon spacer and it isn't really a spacer at all, it's really just for show. I prized it off and it doesn't do anything but look good and sit flush with the crank arm.

So a metal washer won't help as it's already metal on metal. I have attached a picture of the offending bolt. (Both sides come loose)

I'm emailing SRAM who seem to be the distributor for TruVativ, to see if they have a solution. http://www.sram.com/en/sram/

 

[BikeGeek]

Another issue that I had with mine was that I was able to remove the crank from the ISIS spindle without using a crankpuller. All I had to do was remove the bolt and the crank was easily pulled free. I even tried a different BB.

 

[RideFour15]

I have Truvativ cranks that also came loose on me constantly, but after a shop's inspection and reassembly with Loc-Tite, they have been fine for two weeks now.

 

[krazykow]

try using red lock tite. Make shure that you let the bolt sit overnight for it to cure

 

[RadRat]

I first tried the blue loctite (lock nut) = useless

Then red 272 threadlocker = Better, but still came loose on first ride. (Yeah I left it overnight to cure, and cleaned all parts)

Now I have used GREEN loctite 680 retaining compound high strength = Much better, they didn't come loose on the first ride, fingers crossed they stay good.

I will post again when I have given them more use.

Thanks for your input everyone

 

[DROP]

ok im assuming that the bb is a square taper. so anyways next time the crank comes off look at the back where it goes on the spindle and check if its in perfect shape because if its deformed in anyway then it then the crank it ruined and that will cause it to keep sliding off. It happened to my crappy old iso flow cranks but it got deore cranks and haven't had anyproblems yet. :redX:

 

[mcA896]

yeah, drop is right. i went through 3 pairs of square tapers that way before i finally made the jump to cromo cranks, which have a splined spindle. even if you fix your cranks now, as your riding progresses they will break, so if i were you i would invest in a good set of cranks now. your riding styule and terrain will determine which style to get ( as in: if you jump or do dh get cromoly steel craks or something burly alu. like truvativ holzfellers or if you ride xc invest in something like shimano xt's).

 

[BikeGeek]

You guys are right. I did some surfing and it looks like the Rincon comes spec'd with a square-taper BB.

 

[DROP]

so whats up problem fixed??? personly i would buy a set of deore cranks there cheap square taper and there suprisigly strong and they would do u fine for cross riding

 

[RadRat]

The green loctite was not the final solution on it's own, they did start to creak again.

But I think the problem may now be fixed, I was going to go on a couple of more rides before posting here, just to make sure.

I took it back to the bike shop and they replaced the axle with a different one,(for free) then loctighted the crank arms to the axle and the allen bolts also, with the green loctite I supplied.

Been on two rides since with no creaking, will go again this afternoon, fingers crossed

I'm assuming the new axle has a wider taper that holds the crank arms more firmly.

If the woman's riding progresses to the point where she is doing jumps and breaking her cranks I will be amazed, and happy to buy her cromo cranks

She is still learning the basics, but having a good go and we both enjoy it

 

[RadRat]

Crapola, they are creaking again

I give up, will just put up with it, and look into getting different cranks if it gets too bad.

 

[DROP]

i don't know if its a problem with square cranks but mine creak all the time but there not loose i think its just my bb?