What’s the lowest tyre pressure that’s sensable for a Tandem

[PeterCarole29]

We previously had a Tandem with front fork suspension and 26” wheels and never really noticed bad road vibration
Now I have 20” wheels no front suspension and fitted schwalbe marathon tyres and swytch electric kit over powered front wheel tyre pressure left high which I realise was too hard as test drive was awful terrible vibration
Being a novice thought I would ask what’s the lowest pressure I can sensibly go to and the I could work upwards from there
Cables not secure yet in photo but we’re on test drive

 

[mapman]

No experience of that set up but I have found that too low a pressure invites pinch punctures. Given the weight of bike, motor, plus two riders I would work the other way. Start at the recommended max pressure for the tyres and reduce by say 5 psi and see how they cope with sudden changes in surface like potholes and curbs. Even when running 27” wheels at 100 psi on regular bike I had pinch punctures a few times. I now run tubeless - you can run at lower pressure and no punctures to date.

 

[Lyrick]

We have the same bike and keep the tyre pressures at 55 psi, which is 10 psi below the maximum stated on the tyre walls. The tyres are the originals that came with the bike. Same set up with a front electric hub, not a Swytch though.

We've done a few hundred miles on it without any vibration . Could it be the motor causing the problem ?

 

[PeterCarole29]

No experience of that set up but I have found that too low a pressure invites pinch punctures. Given the weight of bike, motor, plus two riders I would work the other way. Start at the recommended max pressure for the tyres and reduce by say 5 psi and see how they cope with sudden changes in surface like potholes and curbs. Even when running 27” wheels at 100 psi on regular bike I had pinch punctures a few times. I now run tubeless - you can run at lower pressure and no punctures to date.

Thanks

 

[PeterCarole29]

We have the same bike and keep the tyre pressures at 55 psi, which is 10 psi below the maximum stated on the tyre walls. The tyres are the originals that came with the bike. Same set up with a front electric hub, not a Swytch though.

We've done a few hundred miles on it without any vibration . Could it be the motor causing the problem ?

Thanks the pressure I test road it at was 65psi and as said earlier will work down from that and see how it rides I have also altered the home made brackets the swytch kit is mounted to as it was flexing which also contributed to the vibration being extenuated

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[suavecarve]

I have a 20 inch wheeled electric tandem, make sure you have spare spokes !

 

[Guigsy]

I've got a Brompton that I run 100psi, and my mountain bike runs 17psi... It mainly depends on the tyre volume.

 

[Aireworth]

It depends on the width of the tyre, as well as the circumference - as Guigsy says the volume. What's sensible also depends on the weight of the bike + rider(s). What is the width - it'll say on the tyre wall 20 x something. There will also be an ETRTO number which give the same information but in a standardised metric form. There are sites which will give you ranges for the tyre size and the weight of the bike plus riders. Post the details here and I'll check, if you want.

 

[Guigsy]

It depends on the width of the tyre, as well as the circumference - as Guigsy says the volume. What's sensible also depends on the weight of the bike + rider(s). What is the width - it'll say on the tyre wall 20 x something. There will also be an ETRTO number which give the same information but in a standardised metric form. There are sites which will give you ranges for the tyre size and the weight of the bike plus riders. Post the details here and I'll check, if you want.

As with car tyres, the pressure stamped on the carcass is the maximum. You probably want to run quite a lot lower.

 

[PeterCarole29]

It depends on the width of the tyre, as well as the circumference - as Guigsy says the volume. What's sensible also depends on the weight of the bike + rider(s). What is the width - it'll say on the tyre wall 20 x something. There will also be an ETRTO number which give the same information but in a standardised metric form. There are sites which will give you ranges for the tyre size and the weight of the bike plus riders. Post the details here and I'll check, if you want.

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[PeterCarole29]

It depends on the width of the tyre, as well as the circumference - as Guigsy says the volume. What's sensible also depends on the weight of the bike + rider(s). What is the width - it'll say on the tyre wall 20 x something. There will also be an ETRTO number which give the same information but in a standardised metric form. There are sites which will give you ranges for the tyre size and the weight of the bike plus riders. Post the details here and I'll check, if you want.

Thankyou that would be good
Front rider me 11 stone wife is 8 stone bike with electric kit is 38kg
20” x 1.75 on a 406 rim

 

[PeterCarole29]

I have a 20 inch wheeled electric tandem, make sure you have spare spokes !

I had wondered about the strength of my spokes
On our last Tandem because we had to remove the front wheel to mount on the back of the camper i once forgot to put the front wheel in the van and drove off with out it,it was only a week old and lesson learnt. but the result was when i bought a new wheel the shop said i really ought to buy a wheel fit for a tandem with thicker spokes so i ended up buying front and back.
I,m hoping the front wheel supplied by swytch being electric will be fit for purpose just leaving the back end to consider at a later date

 

[PeterCarole29]

Its been a long time since i messed with push bikes 50yrs and had forgot everything
so far learnt to date . Also forgot how much you can spend on upgrades
Pedals are markes Left and Right got that wrong
one pedal got croosed threaded as the pedal had a dent on the thread posibly also as i started with the wrong pedal. So a thread tap ordered
New seat posts with suspension in them x 2
silocone seats x 2
Better tyres x 2

 

[Terry242]

A FRIGHTENING TANDEM TALE.

We were travelling in Germany when I got into conversation with a motorhomer pitched behind us. It turned out the motorhome had been loaned to him buy his insurance company after he and his wife had an accident on a tandem.

The couple were from New Zealand and were on a 3 month tour of Germany backpacking with there tandem. They had completed a previous tour on their old tandem but for this tour they had swapped their old heavy bike for the latest in lightweight kit.

On their 1st week touring they were going down a steep mountain decent. He was braking hard when they suffered a front wheel blowout which sent both of them into the scenery! He was quite badly injured whilst his wife was lucky and had just bumps and bruises. He explained the accident by saying that the lightweight wheels had been too lightweight and with a prolonged period of heavy braking, the lightweight wheel had transferred heat to the tube causing the blowout!

He spent 2weeks in a German hospital but was too injured to fly home so their insurance company provided a motorhome and they had been touring for about 6 weeks whilst he was recovering. He was due to return to hospital that week to be signed off so that they could fly home.

Terry

 

[PeterCarole29]

A FRIGHTENING TANDEM TALE.

We were travelling in Germany when I got into conversation with a motorhomer pitched behind us. It turned out the motorhome had been loaned to him buy his insurance company after he and his wife had an accident on a tandem.

The couple were from New Zealand and were on a 3 month tour of Germany backpacking with there tandem. They had completed a previous tour on their old tandem but for this tour they had swapped their old heavy bike for the latest in lightweight kit.

On their 1st week touring they were going down a steep mountain decent. He was braking hard when they suffered a front wheel blowout which sent both of them into the scenery! He was quite badly injured whilst his wife was lucky and had just bumps and bruises. He explained the accident by saying that the lightweight wheels had been too lightweight and with a prolonged period of heavy braking, the lightweight wheel had transferred heat to the tube causing the blowout!

He spent 2weeks in a German hospital but was too injured to fly home so their insurance company provided a motorhome and they had been touring for about 6 weeks whilst he was recovering. He was due to return to hospital that week to be signed off so that they could fly home.

Terry

An informative story to bear in mind
Although we are not enthusiastic bike riders that my wife is comfortable at 12mph poodlig along its worth being cautious down hills

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[Aireworth]

Thankyou that would be good
Front rider me 11 stone wife is 8 stone bike with electric kit is 38kg
20” x 1.75 on a 406 rim

I've been stymied, I'm afraid. The site I was using doesn't go lower than 26in. Sorry. I'll keep looking.

 

[Aireworth]

A FRIGHTENING TANDEM TALE.

We were travelling in Germany when I got into conversation with a motorhomer pitched behind us. It turned out the motorhome had been loaned to him buy his insurance company after he and his wife had an accident on a tandem.

The couple were from New Zealand and were on a 3 month tour of Germany backpacking with there tandem. They had completed a previous tour on their old tandem but for this tour they had swapped their old heavy bike for the latest in lightweight kit.

On their 1st week touring they were going down a steep mountain decent. He was braking hard when they suffered a front wheel blowout which sent both of them into the scenery! He was quite badly injured whilst his wife was lucky and had just bumps and bruises. He explained the accident by saying that the lightweight wheels had been too lightweight and with a prolonged period of heavy braking, the lightweight wheel had transferred heat to the tube causing the blowout!

He spent 2weeks in a German hospital but was too injured to fly home so their insurance company provided a motorhome and they had been touring for about 6 weeks whilst he was recovering. He was due to return to hospital that week to be signed off so that they could fly home.

Terry

Another reason for disc brakes, and tubeless tyres.

 

[clanjones]

So we use 700 x 28 mm hand built tandem wheels (40 double butted spokes) on continental Gator skin tyres and generally run them at 100psi. We do have carbon front forks ( hence the reason for from v brakes) and handle bars, which does dampen the vibration.

We have a 203mm rear disc and front v brakes. Yep we have had front blow outs on descents and they have been generally due to rim tape issues which with the heat causes the end of the spokes to puncture the inner tube. We now double the rim tape and don't have that issue.

Always managed to stop safely - long may it continue!

 

[Aireworth]

So we use 700 x 28 mm hand built tandem wheels (40 double butted spokes) on continental Gator skin tyres and generally run them at 100psi. We do have carbon front forks ( hence the reason for from v brakes) and handle bars, which does dampen the vibration.

We have a 203mm rear disc and front v brakes. Yep we have had front blow outs on descents and they have been generally due to rim tape issues which with the heat causes the end of the spokes to puncture the inner tube. We now double the rim tape and don't have that issue.

Always managed to stop safely - long may it continue!

Deleted - I was wrong!

 

[Lyrick]

Its been a long time since i messed with push bikes 50yrs and had forgot everything
so far learnt to date . Also forgot how much you can spend on upgrades
Pedals are markes Left and Right got that wrong
one pedal got croosed threaded as the pedal had a dent on the thread posibly also as i started with the wrong pedal. So a thread tap ordered
New seat posts with suspension in them x 2
silocone seats x 2
Better tyres x 2

In the process of building another one with a rear hub motor. On this bike I've found quite a few bolts/nuts not fully tightened/loose. Might be worth checking yours.

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[clanjones]

Just some experience of tubeless. On a long trip we did last year (1750 Miles) one of the guys on a solo used tubeless tires and in his words, fine for day trips, but for extended touring never again. He had no end of issues and ended up with a tube inside! I am not trying to start a debate on tubeless versus tubed - it is horse for courses. If you are happy with your set up stick with it!

We have ridden thousands of miles on the tandem with very few issues in some quite remote areas and my main concern is that I can always repair a puncture on a tubed tire.

We do get punctures but not that many but when a Gator skin costs £40.00 (I can hear the "How Much chorus"!) then hopefully we shouldn't get many! As an side we also carry CO2 cartridges to inflate the tyres and these are a godsend when trying to get to 100 psi! In my view they are essential. They are also sooo much quicker.

Right that’s me off to finish repairing the bike box that Easyjet so kindly damaged!

 

[PeterCarole29]

Just some experience of tubeless. On a long trip we did last year (1750 Miles) one of the guys on a solo used tubeless tires and in his words, fine for day trips, but for extended touring never again. He had no end of issues and ended up with a tube inside! I am not trying to start a debate on tubeless versus tubed - it is horse for courses. If you are happy with your set up stick with it!

We have ridden thousands of miles on the tandem with very few issues in some quite remote areas and my main concern is that I can always repair a puncture on a tubed tire.

We do get punctures but not that many but when a Gator skin costs £40.00 (I can hear the "How Much chorus"!) then hopefully we shouldn't get many! As an side we also carry CO2 cartridges to inflate the tyres and these are a godsend when trying to get to 100 psi! In my view they are essential. They are also sooo much quicker.

Right that’s me off to finish repairing the bike box that Easyjet so kindly damaged!

Thanks everyones experience is helpful. Although we are day trippers so to speak i do like to limit any mishaps or breakdowns which is why i have gone for the marathon tyres but £29 each they aparently have some punture protection i also was sold an inner tube with goo in whick i have put on the front electric wheel. ( This may or may not have been a mistake) I will however when we go for a bike ride take a punture kit, spare inner tube, and pump so we can at least get back to the camp site

 

[clanjones]

Marathon tyres are a good quality robust tyre and will cope with more trail type riding than the gators!

We always take 2 inner tubes with us, for the weight difference it gives us peace of mind and we have had to use both with in the space of 30 minutes!