horder2344

I have just purchased a Cannondale bad boy 3 with the sram i-motion 3 speed hub. The bike has developed what is best described as a ticking noise from the rear of the bike. It only happens when I put weight over the rear hub ( or sat in the seat) and is consistent if I am peddling as well as free wheeling in all gears. If I get off the bike and spin the rear wheel it doesnt happen so it must be weight related.

I know this particular hub isnt the quietest but it isn't the normal free-wheeling sound you get from a hub ratchet - it almost sounds like there is a stone in the tyre or a nail. I have checked the tyre and it seems clear plus it happens on grass as well. I have also noticed that it occurs once with each single revolution of the wheel.

Can anybody help or offer a suggestion please - I really dont want to have to go back to evans if I can solve this at home.

Thanks

Dave

Tinton

It could be the valvestem nut, if you have one. They can make irritating ticking noises if not removed or tightened against the rim...

Doohickie

...or a loose spoke.

horder2344

Thanks - I did hope but it hasnt made any difference

horder2344

I did wonder about that - I am not a great bike mechanic though so appologies for the lack of knowledge in this area- if a spoke is loose does it literally rattle about obviously? - Also I wonder why it doesnt happen when I spin the wheel when not on the bike

Al1943

Loose spokes ping.

hytam

Hi horder
I had a similar situation but from my front wheel. I found that when I had the tire inflated to the recommended pressure it would tick but on minimum pressure the sound would disappear. I later found a hair-line crack on the hub flange where the spokes were fitted and in good time too as I can't imagine what could happen if it broke on a downhill ride. Give your wheel a close inspection using a cotton bud to see if any cotton would catch on a break that could be too fine for you to see. Hope this helps.

cny-bikeman

Spokes don't have to be very loose to "tick. Try some dry lube on the spoke crosses. If the bike is used flex the crossing spokes toward each other, see if they catch. If the spokes were loose in the past they can rub a notch into each other that catches when flexing and unflexing. May not be the problem but thought I'd mention something I've seen for future reference.

horder2344

Many thanks for your responses - sounds like one of those problems that is going to be trial and error to get to the root cause - it doesnt help with the fact that I have to be on the bike to trigger it.

I did have a quick look earlier and I have a feeling it might be coming from the tiny join line in the rim. I cant be sure but I have marked it with chalk and will test it on the way onto work this morning.

bluenote157

sounds like my set of mavic wheelsets.. which are notorious for having this annoying clicking..

horder2344

Decided to put it back into Evans - the bike is only a week old after all. Narrowed it down to the area I described. Thankfully after a 10 mile ride into London and 'tick tick tick' all the way in it repeated it in front of a mechanic. He found if he applied pressure on the tyre in the area I described it made that popping tick sound

Basically they replaced the tube and re sat new rim tape plus pumped the wheel up to 110 psi. Which seems to have solved the problem - didnt hear a thing last night over 10 miles.

Sounds like the rim tape inconjuction with the tube only 75% inflated was not fitted properly in the factory and it was catching every time the wheel rotated and applied pressure in a certain spot.

Sounds feasible anyone?

Vidusa

What was the wheel catching on? Would be unusual for rim tape and a lack of pressure to cause a tick tick tick sound.

Couldn't have been the rear skewer could it? I had a similar ticking under pressure which was solved when i pulled the rear wheel out to inspect it, basically just put it back in again with a bit more tension on the quick release skewer and the problem was solved. Your mechanic wouldve done the same thing when he replaced the tube and tape.

cny-bikeman

That is the one of the most bizarre ones I have heard or seen, but reminds me of a humorous one I fixed. We had a customer who reported an annoying rattle when he went over bumps, but that it only happened in cooler weather. Well, we thought, maybe there's a very slight mis-adjustment that shows up only when metal contracts from the cold. So we did a full tune-up, which it needed anyway, with special attention to the headset, bars and front wheel, as he said the sound came from the front, just below him (downturn bars).

I test rode the bike over bumpy sections of road, sewer grates, etc. not a sound. The owner came in, tried the bike and said it seemed OK, but it was a warm day, so we said to come back if it reoccured. Sure enough one chilly morning he returned to report the problem was still there, even as he rode up to the shop. I hopped right on but the bike was still silent. At this point I was getting frustrated but I had an idea.

"Does it happen at slow speed?" The customer said it did. "And it occurred right here in the alley?" Yes again. I then asked him to get on the bike and slowly ride down the alley as I trotted alongside. Finally I too heard the sound, and fixed it as he rode, with no tools.
I just grabbed the zipper pull tab on his windbreaker and the noise stopped. That story was the source of many jokes around the shop for quite a while.

horder2344

Agree it does sound a bit strange - I did wonder if they just replaced the hub and wheel from another bad boy but it is unlikely a chain that large would just conjer up a random story!

The sound was more like that of a popping noise - a bit like when you squeeze a bubble wrap and pop the individual bubbles - every time the wheel rotated over that same spot it made the nosie and it might also explain why it only happened when full weight was on the tyre. The mechanic put all of his weight on saddle and rolled the tyre over the offending area and that was when the noise occured.

I will speak to the mechanic on Monday to ask him exactly what it was that caused it so that if I ever change a tyre again I know what to look out for.

horder2344

Got on the bike today and the ticking / popping noise returned! - 1st time I have ridden it in over a week and since the Evans rim tape / saga / repair - what anger I had on the ride into London today!. I took it straight back for 3rd time and they suggested it might be the valve cap. I showed them the rim joint and each time pressure was applied to that area (weight on the rear tyre) it clicked or made that sharp popping noise. I suspect it was as bluenote157 suggested and there might have been a fault on the joint line on the Mavic rim.

Evans put a brand new rear rim on today and so far it has been fine. Also the 3 speed Sram i-motion hub is a lot quieter too - so there is a little bit of justice at the end of the day.

Looking back as cny-bikeman said it seemed a bit far fetched with the rim tape story but what do I know.! The only thing I can think of is that I keep my bikes in a floor stand and the rear wheel was in the stand. Perhaps that damaged the wheel but I have kept numerouos bike in that with no problems. Thanks for everyones contributions in this thread

Doohickie

This is exactly why I ride old bikes. If it makes noise I tend not to obsess about it.

horder2344

Good call - although believe me this was a seriously irratating noise - with every rotation it made a popping noise. I didnt need a bell to let people know I was coming and after spending 800 quid thats hardly obsessive!

RaleighComp

Whoops. I thought this was a stoker thread.