Road bike fixing?

VaSteve · 08-11-2013, 04:50 AM

I know there are some riders here and people that can fix bikes. I'm sure I can fix mine as well, but I don't know where to start.

I have an 8 year old Cannondale road bike. When I was riding yesterday, I could feel a click in the right pedal. When I got home, I looked at it and it seems there is a little play where the crank is. Meaning if I grab the pedal and rock it side to side, I can see the big cog move side to side.

Nothing *looks* loose, but I don't know exactly where to look. The left side seems to have no play.

Thoughts? Thanks.

flatbutt · 08-11-2013, 04:59 AM

Crank bearing?

greglepore · 08-11-2013, 04:59 AM

the crank is loose on the bottom bracket spindle., or the bearing gave up. What brand/model crank is it? They tighten differently-most likely there is a 15mm bolt or an alln bolt (usually takes a 10mm) to tighten, that would be my first guess.

Mrmerlin · 08-11-2013, 05:17 AM

post a few pictures of the crank assembly,

from your info it sounds like the crank arm bolt has come loose,
and the crank is rocking back and forth on the crank spindle.
Tighten the crank arm bolt,
if the spindle is loose then you will have to readjust the crank spindle

jyl · jyl's Garage

If only the drive side crank has play, I'll guess it is the crank bolt that is loose.

cruisin · 08-11-2013, 07:19 AM

I probably can't add anything more than has already been said but if you need to dig deeper, go to Bike Forums; Bicycle Mechanics section. There is a huge membership there with hundreds of experts on fixing & building bikes.

VaSteve · 08-11-2013, 07:25 AM

Quote:

Originally Posted by cruisin

I probably can't add anything more than has already been said but if you need to dig deeper, go to Bike Forums; Bicycle Mechanics section. There is a huge membership there with hundreds of experts on fixing & building bikes.

Thanks. I'm sure it's very basic, I don't want to wade into a new forum ( do a SEARCH n00b!!!!) unless I have to. Pelicans usually have the answers!

I will get a photo up al little later.

vash · vash's Garage

Quote:

Originally Posted by jyl

If only the drive side crank has play, I'll guess it is the crank bolt that is loose.

Even if the bolt is loose the crank should stay tight no?

Bad bearing in that pedal. Called it

cruisin · 08-11-2013, 08:36 AM

Quote:

Originally Posted by VaSteve

Thanks. I'm sure it's very basic, I don't want to wade into a new forum ( do a SEARCH n00b!!!!) unless I have to. Pelicans usually have the answers!

I will get a photo up al little later.

yeah, you hit the nail on the head there; a lot of those guys can get pretty tacky with new members.

look 171 · 08-11-2013, 09:00 AM

Quote:

Originally Posted by greglepore

the crank is loose on the bottom bracket spindle., or the bearing gave up. What brand/model crank is it? They tighten differently-most likely there is a 15mm bolt or an alln bolt (usually takes a 10mm) to tighten, that would be my first guess.

without looking, this should be it.

nostatic · nostatic's Garage

If the crank bolt needs tightening it might be 15mm bolt and most standard sockets are too thick to fit inside the hole. There is a bike-specific wrench (of course - there is a freakin' bike-specific everything) but some regular ones can work. If it is a newer bottom bracket it could be allen or other new fangled setups. I frankly don't understand some of the new builds - I need to investigate as I have them on my new bike

VaSteve · 08-11-2013, 01:25 PM

Ok here's a little video

YouTube

It's kinda hard to see, but if you look at the reflections you can see the movement. On the right side is a deep cylinder with nothing to tighten in there. The other side has an Allen bolt. But the other side is not loose at all.

Scott Douglas · Scott Douglas's Garage

Vid is marked private. Can't view it via link.

VaSteve · 08-11-2013, 01:59 PM

Quote:

Originally Posted by Scott Douglas

Vid is marked private. Can't view it via link.

OK, I fixed it, try it now.

jyl · jyl's Garage

Ugh, that is one of them there new fangled crank/bottom bracket. I think the drive side (right) crank arm is one piece with the hollow shaft that goes through the bearing cups that are screwed into each side of the bottom bracket shell. The non-drive side (left) end of the shaft has splines at the last inch and a threaded hole on the end. The non-drive side crank arm fits on to the splines and an Allen bolt tightens into the hole. So there is only one bolt holding the crank together and to the bottom bracket.

I'd check if the Allen nut is tight. Otherwise, it is possible one or both cups are loose, but they require a special tool to tighten/loosen, or the bearings could be worn out.

jyl · jyl's Garage

Ugh, that is one of them there new fangled crank/bottom bracket. I think the drive side (right) crank arm is one piece with the hollow shaft that goes through the bearing cups that are screwed into each side of the bottom bracket shell. The non-drive side (left) end of the shaft has splines at the last inch and a threaded hole on the end. The non-drive side crank arm fits on to the splines and an Allen bolt tightens into the hole. So there is only one bolt holding the crank together and to the bottom bracket.

I'd check if the Allen nut is tight. Otherwise, it is possible one or both cups are loose, but they require a special tool to tighten/loosen, or the bearings could be worn out.

See Park Tool Co. » ParkTool Blog » External Bearing Crank Systems (Hollowtech II, MegaeXo, Giga X Pipe, X-type, Campagnolo Ultra Torque)

herr_oberst · 08-11-2013, 03:45 PM

You'll need a special tool for this job. A Friendly Local Bicycle Shop is going to be your best bet, unless you want to start doing research and buying tools - a slippery slope, because it can be a lot of fun!

jyl · jyl's Garage

I've seen where the bolt gets loose then after awhile the crank gets loose on the spindle, often damages the crank and it can't be effectively tightened again. But OP's situation is, it turns out, different. He doesn't have the standard square taper spindle.

Quote:

Quote de jyl

If only the drive side crank has play, I'll guess it is the crank bolt that is loose.

Even if the bolt is loose the crank should stay tight no?

Bad bearing in that pedal. Called it

VaSteve · 08-11-2013, 05:22 PM

Quote:

Originally Posted by herr_oberst

You'll need a special tool for this job. A Friendly Local Bicycle Shop is going to be your best bet, unless you want to start doing research and buying tools - a slippery slope, because it can be a lot of fun!

I love buying tools, but am not a fan of research. I might just swing by a shop and have them assess it. Thanks guys.

greglepore · 08-12-2013, 08:42 AM

Actually, just for reference (Steve apparently has it under control) there are two small allen bolts that clamp the non drive arm on the the shaft after you tighten the preload bolt in the center. The preload bolt is very lightly tightened (mine are just had snug-Shimano even uses a plastic bolt at that spot)and it does indeed call for a special tool, although I've always been able to fake it with a large allen key (12 or 13mm I dunno). After this is snug you torque the nds crankarm on, 10 nm or so if you care.