Bike feels sluggish, rolls slow even on down slopes

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Bike feels sluggish, rolls slow even on down slopes
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flag Mexar
Posted: Jul 14, 2018 at 15:21 Quote
So I'm riding a Norco Forma 7.3... couple years old now.
Last year I started to notice that the bike felt sluggish at times, like I was having to pedal a lot harder than I thought I should. Had a friend that's an avid rider look it over, he proclaimed it fine!
This year, it got bad, really bad... so bad that even with a back wind, on a down slope, on pavement, 40+psi tires, the bike was slowing down unless I was on the pedals!!
I don't ride a lot in adverse conditions, I check / refill air pressure every 3-5 rides (Rides are 35-80 mins typically), I stay out of the water for the most part, little bit of mud but it's not caked all over the bike.
I use chain LUBE not GREASE, 2-3 times a season.
I DID have the rear tire hub redone, new bearings and grease, that definitely seemed to help, but still get that sluggish feeling every now and then.
Front hub maybe? Even though in the air the front rolls amazingly well it seems.
could it be the rear sprocket?
Any insight would be great!!
(No it's not me, or imagined, it happens mostly only after I've been riding for a time, so maybe heating up something?)
flag Steventux
Posted: Jul 16, 2018 at 8:40 Quote
@Mexar : There are a few things which can be slowing you down, all of which can be checked easily:

Brakes - Disc brakes binding is highly likely. With the bike upside down spin the wheels and listen to the calipers. It's not unusual to have a light scuffing on the pads/discs but if the wheels slow up or the noise is constant it sounds like the brakes either need repositioning, backing off or a decent service. Wheels should spin fairly freely after a hand-spin.

Hub bearings - Turn the bike upside down and spin the wheels - I'm sure you have tried this but listen to the hubs bearings. Do they sound like metal on metal? Is there a rumbling noise in there? Are the wheels loose at all?
Do they continue to spin freely or slow up quickly (you should get around 10 uninterrupted revolutions from a hand spin easily).
If you can't hear because of brake interference, remove the wheels and hold the axles and spin the wheels - see if you feel any interference.

Rear sprocket - take the rear wheel off and spin it while holding the sprocket/block, you should get a few revs out of it before it slows to a stop.

If something seems to slow you down after a period of time riding this could mean a part heating up and expanding.
Worth checking for build up of heat in the hubs or brakes when it actually occurs.
WARNING: Brake discs will burn your hands when hot!
flag slope
Posted: Jul 16, 2018 at 9:19 Quote
I think it is you.
flag Mexar
Posted: Jul 16, 2018 at 11:59 Quote
The front wheel spins VERY easily when I have the bike turned over... the back one not so much, but I did get the hub repacked and new bearings. It has gotten better since then, but there's still something going on.
I would think the brakes would get looser the longer it went lol... I'll check those.
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