Bicycle Mechanics - Isis Drive Problem

Hi There,

I bought a Cannondale R500 a few months back and it came with a sort of OEM FSA crankset with Isis Drive. Unfortunatly after about 1200 kms its started to creak under load and I can feel some play in the crank arms. Is there any adjustment I should be doing or have the bearings gone already? I know nothing about the Isis Drive system so Im reluctant to start attacking it with spanners because I know Ill make the situation much, much worse...

Hi There,

I bought a Cannondale R500 a few months back and it came with a sort of OEM FSA crankset with Isis Drive. Unfortunatly after about 1200 kms its started to creak under load and I can feel some play in the crank arms. Is there any adjustment I should be doing or have the bearings gone already? I know nothing about the Isis Drive system so Im reluctant to start attacking it with spanners because I know Ill make the situation much, much worse...

Anything is possible. However, you need to determine just where the play is coming from. The ISIS connection or is the bottom bracket loose in the hanger. There is, in design and function , other than spline attachment design, little difference between the ISIS and the other sealed/cartridge BB's. Check to see where the play is. If your crank to BB bolts are tight I'd bet the BB is loose in the hanger. If it is not then it tiz the BB. Replace it with a FSA Platinum or Platinum Pro. I venture to say that the BB they used is a OEM piece of crap by TH Industries. But it should be good for 5K kms at least.

Jude

It is very possible its the BB. But i agree with the poster above that your better off to replace with a higher quality unit. platinum prois very nice. Im personally using a Token model but those are not the easiest to come by.
http://www.hyperbolts.com/static/OnlineStore/BottomBrackets/index.htm
Theres a lot of negative hype about ISIS out there, this was discussed in the mountain bike forum not long ago you might want to check that out

Thanks for your reply.

Im pretty certain its not the cranks that are loose so it sounds like the bottom bracket has given up. This bike has been the worst bike Ive ever bought new, its total crap. The wheels are crap, the tyres were crap, the brakes are crap and now this trouble with the BB. Enough venting my spleen here, Im off to go off on one at Cannondale...

At the least there could be a loose bottom bracket cup/thread. They sometimes work loose or corrode. When there is corrosion on the threads it can make the threads creak/pop. To remedy this, remove it, clean it and grease the threads.
The other possibility is the arms/BB interface.

Even the cheapest OEM ISIS drive crank will last without creaking if it is maintained. I am willing to venture that you did not check your crankarm bolts before the creaking started. The arms will set in place normally, but some units will work themselves loose. This means the bolts should be loosened and retorqued at least monthly, if not more often. It is a risk otherwise, since when the creaking occurs it means there is a sizeable ammount of movement. That movement means wear on the interface is happening and can prevent the arm from bedding in the future.