Why am I knackered?

[Gearoidmuar]

I recently rode my fourth CTC Lejog with the incomparable Chris Ellison and following that went for three and a half weeks to our apartment in Andalucia where I did a load of cycling with my Spanish cycling friends. Lejog I did on my Thorn Raven Tour and in Spain was on a really light 29er, Carbon. We do a lot of tracks, farm roads and some genuine off-road there.
Understandably I was really tired initially but refrained from doing much pushing and felt ok when I returned to Cork. Did nothing for 5 days.
Out I went yesterday on one of my winter bikes, a cheap 29er shod with Schwalbe Green Apple Liteskins. Felt the tyres, good and hard. Fine. Met my cycling friend Mick off we went on a shortish 35m jaunt I'm well used to. Was going well initially but as the ride wore on I began to get more and more tired. Had to drop off from him and he waited for me at the end.
"What's wrong with you?", he asked. "I'm knackered," said I. "I think my fitness has collapsed. Maybe it's the tyres or something."

Got home. Measured tyre pressure. 20 psi in both.

Don't trust your thumbs!

Big Apple are close to slick, but they're punctured protected stiff tyres and not as fast as thin-walled flexible light knobblies. I have 2.2in Maxxis Ikon knobblies on my bike in Spain and they fly.
There are two reasons to use Big Apples. No punctures (I've one pair with 9500 miles and no puncture) and durability. Speed is NOT one of their features.

[NATURAL ANKLING]

Hi,
Never bought a PP tyre but used several, a bit like chain maintenance science.
Thorns that go through motorcycle tyres make light work of any bicycle tyre.
You need to get out more , had no less than three the other day, that's thorns, one tyre same time.
Where and when you ride, not science.

[Gearoidmuar]

I got one puncture on Lejog this time. Schwalbe Kojak. It was a big thorn that was hard to dig out.

Pumped tyres to 60psi, went out yesterday and I was flying.

[Annoying Twit]

I'm a bit confused by this post. Surely 20psi would be so little air that it would feel like riding on flats. No?

[mjr]

I'm a bit confused by this post. Surely 20psi would be so little air that it would feel like riding on flats. No?

Depends on the tyre and width. I think some advertise as run-flat - they get much draggier and I can still feel that there's a problem, but they don't bottom out like you might be thinking of.

[reohn2]

I'm a bit confused by this post. Surely 20psi would be so little air that it would feel like riding on flats. No?

Depends on the tyre and width. I think some advertise as run-flat - they get much draggier and I can still feel that there's a problem, but they don't bottom out like you might be thinking of.

Agreed,after some experimenting with TP's,I run very supple Conti X King 29er(700c)x2.4in (actual width 65mm)at 15 front and 25psi rear for offroad MTBing.
On tarmac road sections they don't feel very draggy but do sound it,the tyre drop isn't a lot either,if I put 10psi more in them I'm riding on just the knobs which makes them feel very insecure on tarmac and they bounce around too much off road.
Tyre pressures are crucial for two wheelers IME,especially on bad roads especially chip n seal and in the wet.
20psi in a 2inch tyre will drag but will still ride OK unless the rider is going fast,say down hill,then cornering will become an issue,that said Id never ride a 2inch BA @ 60psi,way too much air probably 35f/50r(we only run 65psi on the Circe tandem with 2in BA's) theyre not a very supple tyre on the tread though have supple sidewalls and the TPI count is low,though they do roll well.
My 2d's worth.

[Annoying Twit]

I'm a bit confused by this post. Surely 20psi would be so little air that it would feel like riding on flats. No?

Depends on the tyre and width. I think some advertise as run-flat - they get much draggier and I can still feel that there's a problem, but they don't bottom out like you might be thinking of.

This may say something about the range of tyres I've had experience of. I've never had something that you could ride on while they were flat. Or even 20psi.

I can imagine such would be knackering.

[Gearoidmuar]

I've found it depends on the tyre. These tyres are stiff when deflated. They behave differently to very flexible sidewalled tyres in that respect. As an example, I rode a tour in Germany with the front tyre on a 26" Schwalbe Big Apple at 25 psi. Felt perfectly normal. Wouldn't on a thin-walled tyre.
When I did get on the 29er first when it was at 20psi, I thought my balance was adjusting to the change of bike. That will make you dismiss such considerations of low inflation.
The one thing about the 20psi, or 25, is that it's decidedly comfortable on a lousy surface!

[Flinders]

My road tyres -ribmos- only have to be a little or so under their ideal pressure (110-120) and it's noticeable that it's harder work/I go slower, much lower and they feel unpleasantly 'squidgy' to ride. And I'm under 10 stone, surely it must be worse if you're heavier. (Given my light weight, I asked the LBS if I should use lower than recommended pressures, they said, really, no, and I find that's right.)

By and large, if I can get any movement at all in the tyre by pushing on the tread with my thumb, or more than a tiny bit by squeezing the tyre laterally between my fingers, they're to all intents and purposes, too low.

[RickH]

OTOH I'm now riding a bike fitted with 40mm Vittoria Voayager Hypers running at 30psi front/35psi rear (unless I have a significant extra load aboard in which case I may up the pressure by around 5psi in one or both tyres). My previous bike was running 28mm Conti GP 4 Seasons at around 75F/85R (& is also a couple of kg lighter). For reference, my weight is about 12.5 stone/79kg.

Whilst I don't "do" segments on Strava, I upload all my riding to keep a log of where I've been & totals of how far (backdated to mid 2014 so far). I've noted that Strava still keeps telling me (after the ride is over) that I've achieved personal bests on segments regularly even with the heavier bike & squiggier tyres (& almost certainly reduced fitness compared to a couple of years ago).

It takes a little while to get used the lack of road buzz not equating to lack of speed. The lack of pounding to the body on a long ride with poor road surfaces is something I do appreciate. I did try running the tyres a bit harder for a while but it made no difference to my average speed but I did have a noticeably bumpier ride.

I may have mentioned this before but, there's interesting discussion (for me at least) in this podcast between Jan Heine (of Compass Tires fame) & Josh Poertner (former technical director at Zipp Wheels).

[reohn2]

RickH
Some people have found the holy grail,others are still seraching

PS,stock up on the Hypers whilst they're still going cheap:- https://www.on-one.co.uk/i/q/TYVIVOHY/v ... lding-tyre