Rolling resistance when cold?

[Dickster]

Hi

I have had this for time now but it occurred to me this morning that it may be the brakes dragging.

When I start out in the morning the bike does not freewheel very well and there seems to be lots of resistance - especially notice it when changing gear. After a couple of miles all is well.

Any ideas? Anyone else suffered? Is it likely to be dragging brakes? I guess I should try spinning the wheels... I'll give it a go at the weekend.

Cheers

Rich

[Wee Jack]

Try pulling in the clutch and pushing it around backwards and forwards.

If the brakes are binding you should be able to hear them.

Most bike brakes "bind" a bit if you put them away wet or even store them outside - its normal, as the disks get a thin layer of oxide on them over a very short period of time. Should go away after the first application of the brakes, one of the main reasons for doing a "rolling" brake test before you hit the main roads and a good habit to develop. Mandatory in advanced riding. I've got the end of my driveway and a couple of minor junctions that I perform a rolling brake test on before hitting the main roads.

[Dickster]

Wee Jack,

Mmmm, mine is left out in the elements but it does not disappear on first application of the brakes, it takes a good couple of miles!

Thanks, I'll try the clutch thing. You think the clutch is dragging? I never thought of that!

Rich

[sproggy]

If the gearbox is in neutral and the bike still feels as if it's pushing through treacle then it's not the clutch dragging since even if the clutch was fully engaged there'd be no resistance.

My 650VY doesn't suffer this - the front wheel spins quite freely when lifted off the ground, the rear slightly less so because of the chain, gearbox oil etc.

You're not using over-heavy oil in the engine/gearbox?

[Dickster]

I will try it in neutral as well. I am using a quality recommended oil so I don't think its that but I'll check. Its very pronounced so will probably be something obvious (to all but me!) .

[sproggy]

Just a thought - chain too tight? As the chain gets warm it'll stretch very slightly (not sure whether enough to make a difference to rolling resistance, though) but it's worth checking as an over-tight chain will resist rolling around the sprockets.

[Dickster]

Thanks for the thought but I don't think so. I generally run them the slack side of tight! Running a Scottie it rarely needs adjustment.

[Dickster]

My 650VY doesn't suffer this - the front wheel spins quite freely when lifted off the ground, the rear slightly less so because of the chain, gearbox oil etc.

Yep, I tried lifting and spinning the front wheel this morning and its as stiff as hell. Braking isn't effected but the problem only goes away after a mile or two. It doesn't therefore seem to be the oxide build up.

Time to strip and rebuild the calipers? Its due for pads shortly anyway.

Thanks

Rich

[sproggy]

You might not need to strip and rebuild them - it might be enough to clean them with an aerosol brake cleaner and a toothbrush. You might also find that the pads themselves are resisting movement in the caliper body (mine were) rather than it being the pistons sticking - when you replace the pads use copaslip where appropriate. If they're still tight, remove some paint with abrasive paper from the ends and then re-grease and re-fit. This shouldn't be necessary, but often is particularly with new pads where the backing plates have been painted rather enthusiastically.

[moon]

Yep, I tried lifting and spinning the front wheel this morning and its as stiff as hell. Braking isn't effected but the problem only goes away after a mile or two. It doesn't therefore seem to be the oxide build up.

Time to strip and rebuild the calipers? Its due for pads shortly anyway.

Thanks

Rich

this is what I've just done on mine, & for exactlt the same reason, front brakes binding meaning I sturggle like hell to back the beast out of the shed but problem dissappears after a couple of "rolling brake tests" as somebody called it earlier on.