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I recently bought a second hand Giant Upland SE and to be frank, it is my first bike with multiple gears. The bike functioned normally for the first day or two. I could use all the gears. When the bike is stored indoors, the pedal and wheel work fine but once I take it out in the cold (anywhere from 0 to -30 degrees celsius), the pedals rotate freely and have no action on the wheel. Also I am not able use some gears on the rear wheel. Can anyone please help with an explanation and solution?

  • If you bought it new, and within the last few months, then take it back to the bike shop for its initial tuneup. All new bikes have cable stretch and settling in periods. Most bike shops do this first tune for free for bikes they sell. – Criggie Dec 8 '16 at 10:32
  • This is a good question, and you've asked it well. Have a browse through the Tour in the Help menu to learn how SE is different to most other web-based forums. – Criggie Dec 8 '16 at 10:35
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    Sorry for the not so specific details I provided initially. I bought it second hand. Also, It worked well and normal the first few days. Where I live, the temperatures right now are between -10 and -30 C. – Hari Dec 8 '16 at 16:04
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The pawls in your freehub are most likely getting stuck, causing them not to lock and transfer the force from the cassette to the wheel. In your case as the bike is new it is probably due to it being assembled with grease rather than a lighter oil, but the problem can also come with ageing. You will need to rebuild the freehub. This is not the easiest procedure and requires some specific tools (chain whip and freehub nut at least) so probably get your bike shop to do it.

The unusable gears on the back could be a number of things, rear derailleur limit screws, lack of cable tension, bent hanger/derailleur... If you are already taking it to a bike shop just ask them to fix it.

EDIT: Based on the additional information (-30 not 30 Celcius and secondhand), like others say the freehub is most likely frozen due to old grease and or water which has gotten inside the hub. Same advice still applies though, you will need to overhaul it and get new grease in there or just buy a new one.

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    Every freehub I've seen has been lubricated with grease – I thought this was standard? – Will Vousden Dec 8 '16 at 10:16
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    The bearings should have grease but the pawls will gum up with grease unless you use very little. If you have some sort of oil on hand it's much better to use that as it is so enclosed the oil will never run out. – Toby Dec 8 '16 at 10:27
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    Hope suggest grease for the pawls in their Pro <x> range of hubs, iirc it's mobil XHP222 (which is NLGI 2) they advocate. I've always used grease in mine and haven't had any issues. – Colin Dec 8 '16 at 13:01
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    Grease can work fine, and NLGI 2 is probably not enough to make it stick unless it is really pumped full. But if you take a higher viscosity grease you have to start being careful about where you apply it, where as an oil you can slap on relatively easy no worries. The problems start when you start getting a combination of grease, too much and age. – Toby Dec 8 '16 at 13:17
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    This answer is mostly there but not really correct. We don't know what freehub it's got or that it necessarily is a freehub as opposed to freewheel. If it is a freehub, different ones have different designs that will determine what lube is appropriate. Actually taking apart the freehub body is not possible in many cases, inadvisable in others, and many hubs (probably not this one) have a drivering and relatively exposed pawls. Of the hubs (Shimano and similar) where taking it apart is theoretically an option, it's rarely done because you can clean and lubricate the insides without doing so. – Nathan Knutson Dec 8 '16 at 21:12
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If it's "cold" - as in really cold - (and not 30 deg celcius which is actually very warm) - and given your bike is new - it sounds like your freehub froze. The pawls in the freehub are frozen in their un-engaged position. So there will be no drive to the rear wheel when pedalling.

Humorously, a few years ago - I was mountain biking in the snow. It froze. And the only option was to urinate on the freehub.

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    If that was on the return part of your trip, then it really was "wee wee wee all the way home" like the little pigs in the story! – Criggie Dec 8 '16 at 10:34
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    Highlights the importance of hydration in all climates :-) – OraNob Dec 8 '16 at 15:09
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    Sorry, I meant -30 C. Also, the bike is second hand. But what you have said seems to be the logical reason. Is there any other solution than marking our territory on it? :P – Hari Dec 8 '16 at 16:13
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  • I have heard this story repeated often. I've actually only seen it once. The time I witnessed it happen, it "patched" the problem for roughly 10 minutes until the freehub refroze. – Deleted User Dec 8 '16 at 23:39
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You say in comments that your bike was stored outside all summer.

I'd bet you have ended up with water inside the freehub, probably emulsified with the grease/oil that is supposed to be in there.

Since oil and water don't mix, you end up with a grey/brown mucky muddy mess that is either bubbles of liquid oil floating in water, or bubbles of water floating inside grease.

enter image description here Example of contaminated grease in a 4WD wheel bearing. It smells bad too.

Either way, when the water freezes your grease suddenly becomes more like putty and less like a lubricant.

So your answer is to clean and service the freehub and try to get all the water and contaminated grease out. If you can't get it out, then a new freehub body might be easier than disassembling.

Either way, stop storing your bike outside where it can get rained on, and where condensation might form. Even storing it under a carport or verandah is better than exposed to the raw weather.

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Your freehub is frozen. This is common in places with colder temperatures. Factories often assemble less expensive hubs with whatever grease is on hand and the temperature ratings of these can vary drastically. Your freehub needs to be overhauled and have the factory grease replaced with a winter weight grease. Many automotive style lithium complex greases are good to -48C (-55F).

You absolutely should not ride your bike in this condition. You have gotten lucky with no engagement. Often, people with frozen freehubs experience partial engagement, which leads to chipped teeth/pawls/mechanisms and ultimately a destroyed freehub.

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Fixed the issue with shifting and can use all gears now. Loose cable was the problem. Removed the whole rear wheel assembly including the hub and thoroughly degreased it before applying new appropriate lubrication (sram grease). The cycle works great now ! :) Thank you all for your help!

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