Mountain Bike Reviews Forum banner

FYI Onza on Carbon

981 views 8 replies 4 participants last post by  derby 
#1 ·
I thought I would share something that I just discovered that could effect anyone with Onza lock on grips or perhaps all lock on grips.

I installed a pair of Onza grips on Easton DH carbon bars either last season or the season before (I can't remember but not many years ago) and have been riding with them. The rubber was not worn out yet so I normally wouldn't have any reason to take them off yet. Today I was going to a single front ring and so removed my derailleur and wanted to take off my front grip shift as well. First I couldn't get one of the bolts to come loose because of corrosion and had to drill it out then when I got the grips off there was a lot of *********** inside, between the aluminum grip sleeve and the carbon bar and the bars are pitted. They should be serviceable but if I had waited until the grips were worn out they might not have been. And even then I'm not sure I would have removed the whole grip assembly to replace the rubber.

There is likely a combination of sweat and galvanic corrosion going on between the 2 unlike materials which eats into the carbon. This is the only set of lock ons that I have used and I don't know if anything would have happened if I was running aluminum bars. I've never had anything like this happen before with carbon on aluminum parts but there is a lot of contact at the grip area obviously and sweat.

I don't know if all lock on grips are made this way or if dielectric grease would have prevented this without making them slip, or simply removing and cleaning every few months but personally I'm just going back to regular grips.

I don't know if anyone cares but I would have liked to have heard about it.

I'm posting this on the 29er forum too for those who don't look at both.
 
See less See more
#2 ·
Any way you can up some pics? I'm curious what the white powdery stuff and pitting looks like. Think the white powder is sodium bicarbonate via bar carbon and sodium chloride in the sweat? Test it w/ a bit of vinegar...it might just be salt crystals from your sweat. But if it is baking soda, I don't think that bar should be used anymore, but hey, that's just me.
 
#3 ·
Pau11y said:
Any way you can up some pics? I'm curious what the white powdery stuff and pitting looks like. Think the white powder is sodium bicarbonate via bar carbon and sodium chloride in the sweat? Test it w/ a bit of vinegar...it might just be salt crystals from your sweat. But if it is baking soda, I don't think that bar should be used anymore, but hey, that's just me.
I am very interested too...please let us know
 
#4 ·
With an aluminum bar the same thing happened to my Odi lock-ons after a couple years. The little bolt at one end of both grips corroded and wouldn't turn. Had to cut them off with a dremel tool. And there was lots of aluminum corrosion white dust underneath. Probably from salty sweat and rainy rides. Maybe blue lock tight might have prevented the bolt corrosion. Probably a good idea to remove and clean up the clamps every year or more often.

Been using Ergons for the last 4 years and had no issues removing after 2.5 years to replace with a wider bar.
 
#5 ·
derby said:
With an aluminum bar the same thing happened to my Odi lock-ons after a couple years. The little bolt at one end of both grips corroded and wouldn't turn. Had to cut them off with a dremel tool. And there was lots of aluminum corrosion white dust underneath. Probably from salty sweat and rainy rides. Maybe blue lock tight might have prevented the bolt corrosion. Probably a good idea to remove and clean up the clamps every year or more often.

Been using Ergons for the last 4 years and had no issues removing after 2.5 years to replace with a wider bar.
I'm just going to stick with rubber grips from here on out.

Not surprised that someone else had a similar experience. 3 of 4 bolts came loose but the last one was stuck and the allen head striped out.

I cleaned off most of the white powder but there is still some in the pits and after my camera charges I'll see if I can get a pic that shows something.

Since the pitting is only under the grip area I don't think this is a high load location so I'm fairly confident they will be ok. Plus carbon is built up in layers and there are other unaffected layers below. I think they will be ok.

Btw...nice avatar Derby ;)
 
#7 ·
modifier said:
Ok this is all I could get. The other side was not as bad. It is rough to the touch and you can feel the pits but I think it is fine to ride.
Run some vinegar across the white stuff and see if it bubbles up. Rinse throughly after. You can also thin the two part epoxy glue w/ rubbing alcohol...make it runny so you can brush it on. Then wrap pkg tape around the wet until it cures. This will reseal the pits.

If the white stuff bubbles, the carbon might be compromised in the chem reaction to produce the powder.
 
#8 ·
The bar had already been cleaned off 2 times with brake cleaner when this shot was taken so there wasn't much white stuff left. I tried the vinegar on the bar and nothing happened. I hadn't cleaned out the grips yet so I was able to tap them on the bench and get a good little pile of the stuff and put vinegar on that and also no results. When I first discovered the stuff I did taste a bit of it to see if it was salty since that was my first thought and it was a little but. Didn't want to put much on my tongue so I didn't get much of a taste but yes a little salty but not like pure salt.

The pits aren't very deep and after a little light sanding with fine paper it's not too bad. Basically cosmetic so I don't think I'll try and fill anything since you can't see it. Might make the grip grip better.

So I guess for those who want to run lock on grips take them off and clean them every few months or put some grease on the bar before you install the grips or both.

I wonder if that Ritchey Liquid Torque gritty grease would help any? That stuff is great for seat posts btw.

I still think it was galvanic corrosion stimulated by the sweat. Maybe...

A metallic connector between the anode and cathode. ... plastics reinforced with carbon fibers can induce galvanic corrosion in attached aluminum structure. ...
www.boeing.com/commercial/aeromagazine/.../corrosn
 
#9 ·
modifier said:
Btw...nice avatar Derby ;)
I was going to mention the same! Looks like the same bike by different artists. I like your avartar's artwork better.

I was doing a google search on "derby" to update my avatar a while back and found that the velocipede (pedal bike) was invented by a French immigrant living in Derby, Connecticut, in about 1863 if I remember correctly. My avatar is a picture taken from the patent. The original single speed trail bike (no pavement back then).

BTW, the pitting in the carbon fiber you have found is disturbing. It's probably just into the finish coat and not structural, but none the less a bit scary. In the Ibis forum, aluminum seat posts are reported to get stuck in carbon seat posts, probably due to accelerated corrosion between the chemistry as you suspect. Carbon prep is recommended by Ibis to prevent that.
 
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