lostcarpark: (Lego Jordan F1 Car)
lostcarpark ([personal profile] lostcarpark) wrote2004-06-30 05:47 pm

Tyres

My mountain bike needs a new tyre, so I popped into the bike shop and asked for one.
"Slick or bumpy?" asked the man in the shop.
A rather odd question, I thought.

Apparently, the "bumpy" are the traditional mountain bike tyre, with big groves to give lots of grip off-road. However, "slick" tyres have more modest groves, causing less drag when riding on roads.

As the only time my bike goes "off road" is when I ride it across the lawn to put it in the shed, I decided to try the slicks.

If it works out well, I might go back for another one for the front.

[identity profile] 66steve.livejournal.com 2004-06-30 04:25 pm (UTC)(link)
James, you muppet!
NEVER ride on city streets with bumpy tyres, (otherwise known as off-roads) unless it's dryer than a bone and you're planning on escaping cops or robbers or somesuch.
slicks, the narrower the better, ie skinny-as-yer-rim-can-take tyres, provide as little rubber as possible to the road.
By the fundamental laws of phys this means that they can exert the highest pressure over the least possible area and hence hold the stronest torque (armada).
As i'll be home in the 1st two weeks in august we realy should hook up for a half-hour-techie sesh for your bike.
man must know his tools

[identity profile] hawkida.livejournal.com 2004-07-01 02:23 am (UTC)(link)
Or unless your bike comes fitted with them and you can't be bothered to shell out the dosh to upgrade them until they wear out. That's why I've got bumpy tyres.

[identity profile] 66steve.livejournal.com 2004-07-01 03:26 am (UTC)(link)
problem with that approach is you could well be under a car long before they wear out. At 30 quid a pair it's not *that* much of an investment is it?

[identity profile] hawkida.livejournal.com 2004-07-01 03:45 am (UTC)(link)
Well I barely ride the roads and the roads I do are quiet. I'm mostly on a cycle/pedestrian path so I'd only be going under another cyclist or someone walking their dog. I might consider it more if I were on the roads a lot.

[identity profile] lostcarpark.livejournal.com 2004-07-01 05:41 am (UTC)(link)
I've been riding mountain bikes for years with chunky tyres in all weather and never had any problems (yet). I have occasionally done a little off-roading, but that was quite some time ago.

Hope you don't cream someone's dog!

[identity profile] hawkida.livejournal.com 2004-07-02 04:01 am (UTC)(link)
Funny you should say that yesterday, given [livejournal.com profile] lproven's post later that evening!

[identity profile] lostcarpark.livejournal.com 2004-07-06 01:32 am (UTC)(link)
Saw this message days ago, but the email notification only arrived now. Very odd.

[identity profile] hawkida.livejournal.com 2004-07-06 01:54 am (UTC)(link)
I got one of those this morning - it seems LJ is catching up with all the notifications it forgot to send out. It's like Jack Dee's video recorder with an attitude: "Oh yeah, programme you wanted to see was on. I forgot to record it. It was rubbish anyway."

[identity profile] lostcarpark.livejournal.com 2004-07-01 05:37 am (UTC)(link)
Steve, who let you on LiveJournal. I knew getting rid of invite codes would lower the tone of the place. :-)

I understand the physics, and I'm well aware that skinny racing tyres make less contact with the road, so they go faster (although they do have a tendancy to be too fragile for Irish roads). It's just I'd never given the specific tyres on my bike a lot of thought, or considered whether I could get more suitable ones for road use. I imagine that most people buy a bike to ride and don't about these things. Manufacturers really ought to make the road tyre the default, since I expect the vast majority of "mountain bikes" don't go off-road apart from the odd short-cut across the football field.

I changed the inner tube recently (after nine patches, I think it was time for a new one), and noticed the tyre was rather worn. I probably ought to change the front tyre too, especially since it too is bumpy.

I do have a suspicion that it ought to be possible to design a tyre which minimises surface contact on a straight road, but with chunky bits on the side that bite in on softer ground. Hmmm must give that further thought.

What tyre pressure would you recommend?

[identity profile] lproven.livejournal.com 2004-07-01 10:39 am (UTC)(link)
Oh, balls. Unless you're a really seriously extreme rider who always nails it along flat out and gets his knee down on corners, it'll make next to no difference whatsoever. I always used to ride my MTB everywhere on knobblies and I never came off due to poor traction - and I *do* ride fast and hard.

[identity profile] lostcarpark.livejournal.com 2004-07-02 06:05 am (UTC)(link)
With no mercy for dogs that get in your way, apparently!

It's early days yet, and while I agree that the bumpy tyres are perfectly safe for road use, there's no doubt that the smother back trye makes a difference. I reckon it shaved about a minute the trip to the train station, which has already saved me from missing a train.

[identity profile] lproven.livejournal.com 2004-07-02 07:54 am (UTC)(link)
/Ouch!/

The tyres wouldn't have mattered in that case, I'd still have hit the poor stupid little thing.

This wasn't on an MTB, incidentally, but one of these:

http://www.r-m.de/english/1_katalog/birdy/model/blue.html

[identity profile] lostcarpark.livejournal.com 2004-07-05 03:50 am (UTC)(link)
Tell that to the jury! Admit it, you've been living with cats too long. The creep into your room at night and whisper, "you will flatten the dogs!"

The front forks look wrong. Our new tram system opened at the weekend, and people are already complaining that they can't take their bikes on it. I wonder would your's be allowed?

[identity profile] lproven.livejournal.com 2004-07-05 12:28 pm (UTC)(link)
The cats are locked downstairs and there they stay. Otherwise, I'd kill the dogs by drowning them in nasally-administered mucus. (There's a pleasant image for you.)

No bikes on Croydon trams, /except/ folders, which of course mine is, so I'm OK. I've been nagged about it if unfolded, tho'. They won't let you on. Same on the Tube.

The forks are a but like primitive motorcycle "girder" or "springer" ones. Look weird, but work, and fold well.

[identity profile] jamesb.livejournal.com 2004-06-30 05:16 pm (UTC)(link)
are you mixing cross-ply with radials?

James

[identity profile] lostcarpark.livejournal.com 2004-07-01 05:21 am (UTC)(link)
If I'd thought of it at the time, I'd have asked the guy, "have you got intermediates?"

[identity profile] reverendjim.livejournal.com 2004-07-01 08:45 am (UTC)(link)
Is that freeride or freestyle?