MTB Slicks...Disappointed

Bought some Specialized Nimbus 1.5 tyres to try out on my road trips this winter instead of the
Specialized Enduro 2.0 knobblies I've been happily using until now. (Yes my LBS is a Specialized
dealer). From listening to the perceived wisdom on this group and other places I was expecting a
marked upturn in speed but alas I can see sod all difference from first impressions. Still trundle
along at 14 -15mph for the same effort. Yes I do know how to set my bike computer up, it was
measured accurate for each tyre by where the mile markers for the local half marathon were. I'll see
if there's any significant decrease in time for my hour and a half weekend commute but I doubt it
somehow. Not impressed.

Were these vanilla Nimbus EX or the excrable armadillo variant?

I always got on ok with the Nimbus EX, & hated the armadillos.

Both, however, pale into insignificance in comparison to the mighty FatBoy.

Tim.

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AndyP wrote:
> Bought some Specialized Nimbus 1.5 tyres to try out on my road trips this winter instead of the
> Specialized Enduro 2.0 knobblies I've been happily using until now. (Yes my LBS is a Specialized
> dealer). From listening to the perceived wisdom on this group and other places I was expecting a
> marked upturn in speed but alas I can see sod all difference from first impressions. Still trundle
> along at 14 -15mph for the same effort. Yes I do know how to set my bike computer up, it was
> measured accurate for each tyre by where the mile markers for the local half marathon were.

Ok, but that's not as precise as doing a roll-out measurement.

> I'll see if there's any significant decrease in time for my hour and a half weekend commute but I
> doubt it somehow. Not impressed.

1. Are they pumped up enough?

2. How many rides on them so far? Takes a good few to get the difference as averages can vary so
much anyway because of other factors.

3. Nimbus ain't the best.

4. I'm not one of those people who promise a *huge* improvement with slicks so don't blame me! :-)
Even 0.5 to 1.5 mph faster is worth it, IMO - especially when it's combined with better grip on
road. The difference also depends on the particular knobblies of course - some aren't so
terribly slow on road anyway.

~PB

"Pete Biggs" <pbiggmellon{remove_fruit}s2000@onetel.net.uk> wrote

> Ok, but that's not as precise as doing a roll-out measurement.

Roll out measurement?

> 1. Are they pumped up enough?

Yes, deliberately pumped up harder than I usually would.

> 2. How many rides on them so far? Takes a good few to get the difference as averages can vary so
> much anyway because of other factors.

Only one but it was done one set of tyres straight after the others on the same road out and back in
the interests of scientific accuracy.

> 3. Nimbus ain't the best.

Apparently not.

> 4. I'm not one of those people who promise a *huge* improvement with slicks so don't blame me!
> :-) Even 0.5 to 1.5 mph faster is worth it, IMO - especially when it's combined with better
> grip on road.

But the ride quality is dreadful over the slightest bump. If I don't get 2mph difference I'll take
them back off. Might have looked for some of those Schwalbe Big Apples if I'd thought about it a bit
more but it was a bit of an impulse buy.

"AndyP" <AndyP@ajp100.freeserve.no-spam.co.uk> wrote
> "Pete Biggs" <pbiggmellon{remove_fruit}s2000@onetel.net.uk> wrote

> > 3. Nimbus ain't the best.
>
> Apparently not.
>
> > 4. I'm not one of those people who promise a *huge* improvement with slicks so don't blame me!
> > :-) Even 0.5 to 1.5 mph faster is worth it, IMO - especially when it's combined with better
> > grip on road.
>
> But the ride quality is dreadful over the slightest bump.

And they don't grip too well either. But they are like old boots. Would you go jogging in
Doc Martins?

> If I don't get 2mph difference

You might not get that by switching to a full blown road bike...

On Wed, 19 Nov 2003 23:07:34 -0000, "AndyP" <AndyP@ajp100.freeserve.no-spam.co.uk> wrote:

>Roll out measurement?

A method for getting an accurate measurement of your tyre circumference:

Find a suitable piece of flat, smooth ground. You could do this in your hall perhaps but I like to
do it outside for more room.

With a marker pen (or tippex or whatever) mark the ground and tyre at the point they contact. Or
just mark the ground and line up the valve... you get the picture I'm sure.

Get on the bike (to load the tyre to riding conditions) and roll forward in a straight line until
you have moved exactly one full revolution of the wheel. Mark that point on the ground and measure
the distance between this mark and the original. That gives you your roll out measurement for entry
into your cycle comp. You might want to roll out maybe three or four revolutions and average the
result for best accuracy.

>> 1. Are they pumped up enough?
>
>Yes, deliberately pumped up harder than I usually would.

That might not be sufficient, depending on what is normal for you and what pump you are using. Does
your pump have a pressure gauge so you can tell what you've pumped them to?

>> 3. Nimbus ain't the best.

>Apparently not.

Hmm, sorry to poo poo your choice but I agree that Nimbus might not have been the best option if you
were specifically looking for fast tarmac tyres.

I'm not sure exactly which model or size you picked but having a look online the Nimbus I can see
seem pretty heavy and kinda clunky.

Fast tyres gain their advantage from a combination of size, light weight, high pressure and low
rolling resistance (which comes mainly from a supple construction and slick, no tread, surface).

You might want to consider something like the Specialized FatBoy. They're relatively light, will
take 100psi, and are full slicks. As a bonus they are only a tenner a tyre.

I have them on one of my bikes and am very impressed with them. I did originally have a bit of a
crises of confidence in them when they threatened a few times to spit me off, and eventually did in
fine style.

Over time I realised I was asking too much of them on nasty early morning winter roads and am now
completely comfortable with 'em. Just about to order another pair in fact.

I see pretty good things written about Vredestein S-Licks but they are more expensive and I don't
have any experience of them myself.

>But the ride quality is dreadful over the slightest bump.

This is the price you'll have to pay if you want a noticeably faster tyre. You need to run at much
higher pressures than is usual for mtb type knobblies, up towards 100psi or greater. This is going
to make the ride harsher, there's not much to be done about it unfortunately. I don't notice it
myself and I suspect you'd soon adjust.
--

"Bob"

Email address is spamtrapped. To reply directly remove the beverage.

"Call me Bob" <usenet@COFFEEtoomanypenguins.co.uk> wrote

> >Roll out measurement?

> A method for getting an accurate measurement of your tyre circumference:
>
> Find a suitable piece of flat, smooth ground. You could do this in your hall perhaps but I like to
> do it outside for more room.
>
> With a marker pen (or tippex or whatever) mark the ground and tyre at the point they contact. Or
> just mark the ground and line up the valve... you get the picture I'm sure.
>
> Get on the bike (to load the tyre to riding conditions) and roll forward in a straight line until
> you have moved exactly one full revolution of the wheel. Mark that point on the ground and measure
> the distance between this mark and the original. That gives you your roll out measurement for
> entry into your cycle comp. You might want to roll out maybe three or four revolutions and average
> the result for best accuracy.

Oh right. Well that's what I did before checking it against a measured
mile. Bang on to 100th of a mile the first time and 1/100th out the second...surprisingly accurate.

"AndyP" <AndyP@ajp100.freeserve.no-spam.co.uk> wrote in message
news:bpgt53$5ad$1@newsg2.svr.pol.co.uk...

> If I don't get 2mph difference I'll take them back off.

Better get your tyre levers out then. I achieved slightly less than that on my recumbent when I
moved to 120psi Schwalbe Stelvios, a tyre many HPV racers use on the track. The faster you go, the
less rolling resistance matters.

I have Specialized Crossroads tyres on my MTB and experience a huge difference between runnig at
45psi and running at 80+ psi, around 1mph faster. I think 1mph is a huge difference, anyway. And
going uphill is less like hard work.

--
Guy
===

WARNING: may contain traces of irony. Contents may settle after posting.
http://chapmancentral.demon.co.uk

On 20/11/03 1:43 am, in article bph69g$e0h$1@newsg1.svr.pol.co.uk, "AndyP"
<AndyP@ajp100.freeserve.no-spam.co.uk> wrote:

> "Call me Bob" <usenet@COFFEEtoomanypenguins.co.uk> wrote
>
>>> Roll out measurement?
>
>> A method for getting an accurate measurement of your tyre circumference:
>>
>> Find a suitable piece of flat, smooth ground. You could do this in your hall perhaps but I like
>> to do it outside for more room.
>>
>> With a marker pen (or tippex or whatever) mark the ground and tyre at the point they contact. Or
>> just mark the ground and line up the valve... you get the picture I'm sure.
>>
>> Get on the bike (to load the tyre to riding conditions) and roll forward in a straight line until
>> you have moved exactly one full revolution of the wheel. Mark that point on the ground and
>> measure the distance between this mark and the original. That gives you your roll out measurement
>> for entry into your cycle comp. You might want to roll out maybe three or four revolutions and
>> average the result for best accuracy.
>
> Oh right. Well that's what I did before checking it against a measured
> mile. Bang on to 100th of a mile the first time and 1/100th out the second...surprisingly
> accurate.
>
>
Having had a semi slick give up on me yesterday I bought some schwalbe city jet (only thing I could
find at 7.30 at night in Halfords.

They seem quite happy and are running at 90psi. My previous tyres were running at about 65 psi.

From previous experience:

studded knobblies in winter -> semi-slick (birkebeiner) +5kph semi-slick MTB -> road bike +5kph.

These values are valid for reasonably level road.

cheapo semi-slicks are nearly as slow as knobblies.

The key is getting the pressure up to the right level.

..d

My MTB has Nimbuses (Nimbi? Nimbu?) and they're not the best for speed. But they are just
about bullet-proof. If you want speed over p+nct+r+ resistance, try Continental Avenues or
Schwalbe Stelvios.

Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

In news:bpgq19$al3$1@newsg3.svr.pol.co.uk, AndyP <AndyP@ajp100.freeserve.no-spam.co.uk> typed:
> Bought some Specialized Nimbus 1.5 tyres to try out on my road trips this winter instead of the
> Specialized Enduro 2.0 knobblies I've been happily using until now. (Yes my LBS is a Specialized
> dealer). From listening to the perceived wisdom on this group and other places I was expecting a
> marked upturn in speed but alas I can see sod all difference from first impressions. Still trundle
> along at 14 -15mph for the same effort.

I think that the difference is more pronounced when cheap knobblies are replaced. My fairly posh
mountain bike has knobblies with a very flexible carcass, and it feels faster than my town bike with
cheapish slicks on, and I think also freewheels faster, but I've not tried an accurate test.

Still, it will probably corner and grip better with slicks, except on loose gravel.

>Yes I do know how to set my bike computer up, it was measured accurate for each tyre by where the
>mile markers for the local half marathon were. I'll see if there's any significant decrease in time
>for my hour and a half weekend commute but I doubt it somehow. Not impressed.

No, I think people often oversell it, too. But on the other hand cheap slicks tend to have huge
amounts of drag.

A

"AndyP" <AndyP@ajp100.freeserve.no-spam.co.uk> wrote in message
news:bpgq19$al3$1@newsg3.svr.pol.co.uk...
> Bought some Specialized Nimbus 1.5 tyres to try out on my road trips this winter instead of the
> Specialized Enduro 2.0 knobblies I've been happily using until now. (Yes my LBS is a Specialized
> dealer). From listening to the perceived wisdom on this group and other places I was expecting a
marked
> upturn in speed but alas I can see sod all difference from first impressions. Still trundle along
> at 14 -15mph for the same effort. Yes I do know how to set my bike computer up, it was measured
> accurate for each tyre by where the mile markers for the local half marathon were. I'll see if
> there's any significant decrease in time for my hour and a half weekend commute but I doubt it
> somehow. Not impressed.

I'm surprised at that -I got a good 2 mph extra after swapping knobblies for slicks, but these were
Nokian City Runners. Got loads of punctures though.

Simon

Conti Avenues work well for me - had them for 2 years now and subjectively they're max 5% quicker
than nobbies (Marin Ultimate MTB used as exclusively road bike down under now)

My proper road bike gains another few % points but NOT much over the Ave-equipped MTB - that has
older XTR pattern cranks (big 48 outer ring,
11/23 cassette) so you can hit 60/65 kph with the right conditions

Boz

"Dave Larrington" <legs_larry@yahoo.com> wrote in message
news:bpi5bq$1pf7cs$1@ID-120318.news.uni-berlin.de...
> My MTB has Nimbuses (Nimbi? Nimbu?) and they're not the best for speed. But they are just about
> bullet-proof. If you want speed over p+nct+r+ resistance, try Continental Avenues or Schwalbe
> Stelvios.
>
> Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
> ===========================================================
> Editor - British Human Power Club Newsletter
> http://www.bhpc.org.uk/
> ===========================================================

> Both, however, pale into insignificance in comparison to the mighty FatBoy.

Absolutely.

On my commute I average 15mph +-0.5 on 1.25" fatboys @ 100psi compared to 13.5 +- 0.5 on IRC Mythos
knobblies. (I'm geeky enough to keep records...would be nice to see the average speed actualling
increasing over time, but there you go)

Makes a large difference- slicks give a silky smooth ride compared to knobblies, and they feel more
responsive to acceleration because of their lower rotating mass.

z

the joy of slicks..mmmm, smooth black rubber ;+)

I have a pair of Nimbae sitting in my wardrobe waiting for the demise of my Continental Avenues
which are about half the weight, fabuloso on corners but try changing a tube in winter in the sleet
in a gale (yes, I was that man!).

Rear Conti lasted a couple of thousand miles before the sidewall gave up (usual Conti story?) but
what a hoot over the summer.

I'm gladly trading the speed for bullet proofing for commuting.

Try taking a roundabout at 25+ mph on knobblies...... most entertaining! My Contis regularly
embarrassed Jack-the-Nova-with-the-drainpipe-exhaust on local roundabouts hee hee.

> My MTB has Nimbuses (Nimbi? Nimbu?) and they're not the best for speed. But they are just about
> bullet-proof. If you want speed over p+nct+r+ resistance, try Continental Avenues or Schwalbe
> Stelvios.

Robert