Stuck preload cap

savaphil

Evening all,

rode my "adventure cross" bike a month ago, it got VERY muddy. Neglected to clean it for a few weeks but gave it a wash, degrease and regrease and noticed the cranks were sluggish to turn (like a brake was being lightly held on - though sluggish in both directions). Dropped the chain off to see if I could narrow it down. Still sluggish with the chain off

Anyways, decided tonight that I should pull the cranks off and have nosey - maybe some sheeps wool has got clogged up in there or similar! (though I hadn't noticed anything untoward on the ride, I had been for a mid-ride swim, so was looking forward to a warming hot chocolate once back in Settle so threw the bike on the roof and jumped into the nearest cafe).

Loosen the 2 bolts on the left crank, go to remove the preload cap (with appropriate tool) and the thing seems jammed on tighter than a tight thing! I've never had the cranks off so don't know if this is a new thing or what...

Bunch of questions arise

1) Any ideas how to get a stuck pre-load cap off before I start stripping threads and causing havoc!?
2) Any ideas what could be causing the sticky/sluggish cranks?
3) Could a silly tight pre-load cap be the answer to number 2?? (I appreciate that it might not be silly tight and that simple physics of short lever (those removal tools are just small plastic discs afterall) may be the reason it is so difficult to remove)

TL;DR - possibly due to lazy cleaning regime, pre-load cap is stuck in cranks and cranks are being sluggish to turn.

All helpful points welcomed with a nod and a hello next time I see you on the trail/road/towpath/cafe...

Phil.

keef66

Well if the preload cap was over tightened it would make things drag a bit more than they should, and almost certainly accelerate the demise of the BB bearings, and once they are properly buggered you'll feel it.

Are the crank bolts completely removed? Do that, then try gently tapping a suitably sized screwdriver or similar into the split in the crank to open it up fractionally; might make the preload cap easier to free. Last resort you can destroy it in removing it; whack a chisel into it and use it like a big screwdriver. Pennies for a new one.

savaphil

Superb. Thank-you for your suggestions. I'll give those a go and see what happens

Matthewfalle

If you're going for the smash it to bits approach, may I suggest that you order a new cap before you start - that way you have one to hand to rebuild it all before you start and don't have to spend time off the road while you source a new one/get it sent down/miss the postman etc etc

thebadgerboy1982

i used a pair of mole grips to give the tool a bit of leverage. worked well and no issues with breaking anything.

jermas

Try spraying copious amounts of penetrating fluid (wd-40 or similar) around the cap and down the split in the crank arm. Leave it to soak in, it should help. If it's still stuck, try a gentle tap on the crank arm (with a soft faced hammer) inwards to release the tension on the cap.

crankycrank

Another method to spread the clamp opening is to thread the bolts from the outside of the crank and insert a thin piece of metal in the split of the crank clamp so the bolts can bottom out on the metal piece and spread the opening. Large steel washers will work well for the metal piece if you happen to have one around. Try the suggestions for penetrating oil, spreading and tapping the crank before using any destructive methods.

Rightarmbad

Walk into your local LBS, get them to use their U-beaut metal tool to remove the stuck cap, give beer and go away with a smile.
Maybe get them to look at the bearing while they are there.

savaphil

Thank you everybody for your advice and input.

I couldn't free it up in the end on my own so put all bolts back in place and rode it down to my LBS where they took the pre-load cap off without issue - d'oh! I spoke with the about it and they didn't think it was particularly sticky - so who knows what caused it in the end!?!

I did try the WD40 idea, I tried prising the crank apart slightly at the split, I tried a bit of a tap, I didn't try destroying the cap. All great ideas. Maybe it's like the jam jar lid issue - I loosened it ready for them to take it off ha ha ha!

The workshop guys had a good nosey and some impressive whistling at how worn out the BB bearings were. I didn't think that I'd had that much mileage from the bike (got it in June) but I guess it was a set of bearings from the lower end of Shimanos quality scale, it had done a summer, autumn and winter of commuting (only about 40 miles a week of that) and I had ridden it up hill and down dale both on and off road (it takes me back to when xc riding was a much simpler affair without suspension (other than your own legs)) so maybe it has just been worn out from grit/dirt/mud/water - unlike my pristine road bikes.

Wheels are out of true and the rear tyre has a wobble on (that's a new one on me, no blebs, just wont sit straight apparently! - I'll have a closer inspection once I get it back to understand). The good lads are putting some new Hope discs on for me to replace the stock ones that came with the bike (I upgraded to the Hope V-Twin brakes when I bought it but didn't upgrade the rotors - the braking is pretty shite IMO ATM so hopefully the Hope rotors will sort this out) so ready for some more adventures when I'm allowed back on my bike (dislocated shoulder 5 weeks ago - grrr).

TL;DR - thanks for the ideas, tried most of them out, didn't work, LBS came good as ever, upgrades on the way!