Cycling in icy conditions, what PSI?

freehub
freehub Posts: 4,257
edited January 2010 in Workshop
Hi.

For my commute to college tomorrow, it's 3 miles in Manchester, gonna be some slipy areas, what PSI should I use in front and rear and how much extra grip does lowering the pressure give over standard 100-100psi?


Thanks
Will.
«1

Comments

  • whyamihere
    whyamihere Posts: 7,719
    It'll make no difference.
  • harkmeadow
    harkmeadow Posts: 193
    3miles.....walk?! After coming off last week, hihg or low pressure or no pressure aint going to help you when you hit black ice! Mind looks like skis may be your best bet tomorrow! :D
  • redddraggon
    redddraggon Posts: 10,862
    aigle-artemis-gtx-walking-boots.jpg
    I like bikes...

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  • sungod
    sungod Posts: 17,553
    like the others say, no diference to grip, but more likely to get pinch flats

    you could use knobbly mtb tyres (plus care!) if it is just snow and the odd slippery patch

    for grip on ice, fitting spiky/studded tyres is the way...

    http://www.icebike.org/Equipment/tires.htm

    ...but it's a lot of hassle/cost for just a few days a year
    my bike - faster than god's and twice as shiny
  • marin_maniac
    marin_maniac Posts: 513
    Don't even attempt it. Is it worth the risk of comming of and getting squashed?
  • iain_j
    iain_j Posts: 1,941
    Walk it. Only managed a couple of hundred yards of my ride to work this morning, it was lethal.
  • Bhima
    Bhima Posts: 2,145
    edited January 2010
    It DOES make a difference to grip, but you have to go REALLY low to the point where the tyres are bulging outwards a lot. I tried different pressures out on the ice/snow yesterday (26mm tyres). 90 was unridable. Too much slippage. 50 was fine if I took things slow. 40 psi was the difference between being able to ride or not!

    Best way to find out the ideal PSI is to just test out different pressures. Keep letting air out until it feels "better". If you have a pump you can always add more air if you overcook it. The sweet spot will feel "sluggish" though, and affect your average speed. :!: :roll:

    Anyway, if it's just 3 miles, walk it!
  • sturmey
    sturmey Posts: 964
    I rode Sale to Didsbury this morning and back at 6pm. It was a bit slow but definitely doable. I took an old rigid mtb with 40 psi knobbly tyres and lowered seat-just a few minor slides and had to get off and walk in a couple of places for a few yards. you would have been ok today but if it freezes up overnight some roads could be ice-rinks in Manchester . And if you've only got a De Rosa King with 23mm slicks , I'd leave it at home.
  • Monty Dog
    Monty Dog Posts: 20,614
    Wet rubber and snow has about zero co-efficient of friction - unless you're on an MTB / knobblies into fresh or partly-compacted snow, forget it - a broken collarbone or wrist isn't worth the hassle. I will be out on the MTB tomorrow - should be about 15-20cm of fresh snow by the morning!
    Make mine an Italian, with Campagnolo on the side..
  • iain_j
    iain_j Posts: 1,941
    Snow by itself is OK - I ride on 35C Marathon Plus so I suppose they grip more than narrow slicks. Have to ride carefully of course but perfectly doable. But when there's ice about, forget it.
  • amaferanga
    amaferanga Posts: 6,789
    I cycled to and home from work in Sheffield today and it wasn't too bad. The roads were completely deserted on the way back which actually made it quite enjoyable.

    But tomorrow I won't be cycling as the roads won't be cleared of snow and it'll likely freeze tonight and become very rutted. That means falls would be almost certain.

    Why not run instead? Makes a nice change from cycling.
    More problems but still living....
  • Bhima
    Bhima Posts: 2,145
    Yeah, i'll just add - I was on snow, not ice. Ice is a totally different beast. Pretty much nothing you can do against that.
  • Squillinossett
    Squillinossett Posts: 1,678
    Walk...
  • Anonymous
    Anonymous Posts: 79,665
    Walk.
  • Supergoose
    Supergoose Posts: 1,089
    Yep. Dont be a hero. Its really not worth it, what if you were to fall and break a bone? For the sake of a 3 mile ride? Walk.

    If you feel the need get on the turbo when you get home.
    Rock 'n' Roule
  • redddraggon
    redddraggon Posts: 10,862
    Don't bother going in.

    Manchester University is closed:
    http://www.manchester.ac.uk/aboutus/new ... y/?id=5342

    I reckon your college should be too.
    I like bikes...

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  • Smokin Joe
    Smokin Joe Posts: 2,706
    Don't ride, full stop.

    Remember Abergele? It won't be just you on the road, cars have been sliding all over the place the last week. It takes a hell of a time to stop a sliding car, even at 20mph.
  • Chip \'oyler
    Chip \'oyler Posts: 2,323
    freehub wrote:
    Hi.

    For my commute to college tomorrow, it's 3 miles in Manchester, gonna be some slipy areas, what PSI should I use in front and rear and how much extra grip does lowering the pressure give over standard 100-100psi?


    Thanks
    Will.

    Don't bother. Stay in and have a w**k
    Expertly coached by http://www.vitessecyclecoaching.co.uk/

    http://vineristi.wordpress.com - the blog for Viner owners and lovers!
  • skyd0g
    skyd0g Posts: 2,540
    Chip \'oyler wrote:
    freehub wrote:
    Hi.

    For my commute to college tomorrow, it's 3 miles in Manchester, gonna be some slipy areas, what PSI should I use in front and rear and how much extra grip does lowering the pressure give over standard 100-100psi?


    Thanks
    Will.

    Don't bother. Stay in and have a w**k

    Wouldn't Will be better off going outside if he wants to have a good walk?
    Cycling weakly
  • freehub
    freehub Posts: 4,257
    Maybe I'll walk, but 3 miles is a boring walk, can't run. It's annoying though if I walk there to find the lessons cancelled, communications between tutors is shite and I'll never hear from them. But at the same time I have an important lesson tomoz, if it's on.

    I do hope it gets better soon, gritter just went by again, It's getting hard to resist the urge to buy a turbo trainer too! I only have under 100 quid for one like.
  • Anonymous
    Anonymous Posts: 79,665
    freehub wrote:
    Maybe I'll walk, but 3 miles is a boring walk, can't run. It's annoying though if I walk there to find the lessons cancelled, communications between tutors is shite and I'll never hear from them. But at the same time I have an important lesson tomoz, if it's on.

    I do hope it gets better soon, gritter just went by again, It's getting hard to resist the urge to buy a turbo trainer too! I only have under 100 quid for one like.

    Jesus H Christ!

    In times past a 3 mile walk was a freaking luxury!!
  • Lagavulin
    Lagavulin Posts: 1,688
    edited January 2010
    freehub wrote:
    Maybe I'll walk, but 3 miles is a boring walk
    Would you rather spend your time being extricated from underneath a vehicles axle and your bike in pieces?
    2010 Cannondale CAAD 9
    2008 Wilier Izoard
  • skyd0g
    skyd0g Posts: 2,540
    A '3 mile boring walk' is better than trashing your bike / breaking an arm etc, which would stop you cycling for weeks.
    Cycling weakly
  • freehub
    freehub Posts: 4,257
    I never sugested I was going to ride the bike despite it being extreamly dangerous from what most people say. I just said, 3 miles is a boring walk, mainly because I hate walking!
  • softlad
    softlad Posts: 3,513
    freehub wrote:
    I never sugested I was going to ride the bike despite it being extreamly dangerous from what most people say. I just said, 3 miles is a boring walk, mainly because I hate walking!

    have you got a space hopper...??
  • Lagavulin
    Lagavulin Posts: 1,688
    freehub wrote:
    I never sugested I was going to ride the bike...
    I could tell that. As soon as I read the thread title Cycling in icy conditions, what PSI? I thought this lad is looking for alternate transport.
    2010 Cannondale CAAD 9
    2008 Wilier Izoard
  • Mike67
    Mike67 Posts: 585
    Saw two perfectly parallel, but very narrow, tracks in the (then) 4 inches of snow on the high peak trail at the weekend.
    I was slithering along on my totally unsuitable summer MTB tyres at 30 psi thinking ' Boy whoever is pulling that sled isn't struggling through the snow and must be walking in a dead straight line'
    After struggling for another mile a guy came speeding the other way on the narrowest skis I've ever seen following the same tracks back :)

    Short story is that skis are definitely the way to go in this weather.
    Mike B

    Cannondale CAAD9
    Kinesis Pro 5 cross bike
    Lots of bits
  • SBezza
    SBezza Posts: 2,173
    I wouldn't even dream of riding my road bike in the snow and ice, but my CX bike with knobblies on, now that is fun, and grip pretty well. Certainly didn't have any issues today in the fresh overnight snow.

    If you have knobblies on, then lower pressures do help, it is quite common in CX races to lower the pressure to get more grip in slippery conditions, but on a road tyre, forget it.
  • celbianchi
    celbianchi Posts: 854
    SBezza wrote:
    I wouldn't even dream of riding my road bike in the snow and ice, but my CX bike with knobblies on, now that is fun, and grip pretty well. Certainly didn't have any issues today in the fresh overnight snow.

    If you have knobblies on, then lower pressures do help, it is quite common in CX races to lower the pressure to get more grip in slippery conditions, but on a road tyre, forget it.

    Agree here - we have had stacks of snow in the north east. Riding mainly on the off road tracks into town on the cross bike with dugast rhinos on at 25-30 psi is no major problem.
    Hard workout mind you.
  • mmacavity
    mmacavity Posts: 781
    The hospitals are far too busy just now, choose a less busy time to break some bones.

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