Thorn Cycles Forum

Community => Thorn General => Topic started by: BobScarle on September 30, 2019, 10:10:13 pm

Title: Tyres on my Club Tour
Post by: BobScarle on September 30, 2019, 10:10:13 pm
Bought a Club Tour at the end of last year with some very specific goals in mind. For various reasons these had to be abandoned and I have ended up doing less than 500 miles on it. I have to say that I am very pleased. It is a lovely bike to ride.

But I do have a problem, whilst not directly Thorn related it is affecting it. I have never used tubeless tyres before but I thought that it would be a good idea when spec'ing the new bike, after all who wants to be fixing a puncture in the middle of a tour?. So I went for Schwalbe G-ONE speed 30c tubeless tyres. They are fitted on DT Swiss rims on handbuilt wheels from SJS. The problem, they go down. They lose pressure. Both tyres about the same amount. No obvious punctures. Never had a problem with tubes. Is this normal?
Title: Re: Tyres on my Club Tour
Post by: Mike Ayling on October 01, 2019, 12:08:32 am
Bought a Club Tour at the end of last year with some very specific goals in mind. For various reasons these had to be abandoned and I have ended up doing less than 500 miles on it. I have to say that I am very pleased. It is a lovely bike to ride.

But I do have a problem, whilst not directly Thorn related it is affecting it. I have never used tubeless tyres before but I thought that it would be a good idea when spec'ing the new bike, after all who wants to be fixing a puncture in the middle of a tour?. So I went for Schwalbe G-ONE speed 30c tubeless tyres. They are fitted on DT Swiss rims on handbuilt wheels from SJS. The problem, they go down. They lose pressure. Both tyres about the same amount. No obvious punctures. Never had a problem with tubes. Is this normal?

Tubes lose pressure too.

How long do your tyres take to lose pressure?

Mike
Title: Re: Tyres on my Club Tour
Post by: BobScarle on October 01, 2019, 12:31:40 am
I've never really noticed a problem with tubes. Yes, I know they will lose pressure but not as much.

It has been nearly two months since I last rode the bike and the tyres now are pretty flat, certainly too flat for me to be confident enough to go out for a ride. They just feel as if they go down more than the tubes on other bikes.
Title: Re: Tyres on my Club Tour
Post by: BobScarle on October 01, 2019, 12:41:20 am
Just been looking through the Mega Brochure again and saw this

"PLEASE NOTE - Fiona and I have these tyres on our lightweight Mercuries - we don’t often use these bikes on consecutive days, consequently I pump the tyres up to pressure whenever we ride them. When we use these bikes on longer tours, I use slightly higher pressures (56 and 61psi) I pump them up weekly and I expect them to have lost around 7psi."

Looks like it was in the brochure all the time. And they do lose pressure.
Title: Re: Tyres on my Club Tour
Post by: JimK on October 01, 2019, 04:12:55 am
back in the 1970s I had a beautiful Legnano bike, with lightweight rims and sew-up tires. For sure I had to pump up those tires before every ride. They didn't hold pressure well at all! And I had to true the rims like every week or so. But that bike could fly!
Title: Re: Tyres on my Club Tour
Post by: geocycle on October 01, 2019, 09:06:57 am
Yes all tyres lose some pressure but it is more obvious and important the lower the volume and higher the pressure.  My Thorn with 26 x 1.6 tyres gets pumped up to 60 psi once every few weeks and is around 50 psi after that period which is acceptable.  In contrast my audax bike has 25mm tyres inflated to 100 psi and is down to 80 psi in a week which would be barely minimum for the Durano tyres and therefore I have to inflate each ride. 
Title: Re: Tyres on my Club Tour
Post by: Swislon on October 02, 2019, 06:06:03 pm
I use the Schwalbe G-one all round 35mm tubeless on DT Swiss rims on my Mercury in the winter.
Yes they lose pressure over time. More so than tubes. However it isn’t a great deal and in winter particularly when they have been trimming (ripping to shreds) the roadside hedges tubeless are a godsend.
I check them once a week but also check my tubed tyres about the same.
Title: Re: Tyres on my Club Tour
Post by: martinf on October 06, 2019, 07:12:06 pm
Tubeless looks to be the same trade-off as with latex tubes, which I have on 3 of my bikes.

Slightly better performance, better puncture resistance, but more regular pumping up necessary.
Title: Re: Tyres on my Club Tour
Post by: mickeg on October 06, 2019, 09:07:15 pm
I have never used tubeless tires.

I expect to pump up my tires after about a week to a week and a half, some bikes seem to hold air longer than others.  I do not keep a record of which bikes have which brands of tubes.

I usually run the front at about 75 to 80 percent of the pressure that I have in the rear.  But on one trip I ran my front tire as low as half as much pressure as I have in the rear when I was on really rough pavement (tarmac) to reduce vibration on my hands, that was on some really rough chip seal in West Texas. 

I think the rear that I pump up to greater pressure loses air a bit faster.  Thus the pressure in the rear is the one I use to decide if I need more air or not.
Title: Re: Tyres on my Club Tour
Post by: Andre Jute on October 06, 2019, 10:46:29 pm
I use 60mm Big Apples inflated once a month to something over 2 bar. The tyres actually feel hard to the hand but are very comfortable. I use a gauge to determine whether they've lost air. In my experience the amount or harshness of riding has little to do with how much air is lost. I suspect the change over a month has more to do with barometric pressure and temperature changes. As far as I can tell, the normal Schwalbe tube and the thinner, lighter Ultralite, which I use interchangeably, lose air at the same rate. So I have data points going back ten years (when I switched over to the Big Apples) but no really helpful conclusions. Perhaps that's how it's supposed to be on an almost Zero-Service Bike.