Silvio on 1200km ride across Tibet

[super slim]

How would my 15kg Silvio with the widest tyres possible (28? or 37?) go on 600km of bitumen and 600km gravel and rocky creek crossings on a supported ride across Tibet, from Lhasa to Kathmandu via Mt Everest base camp?

I hopefully will be going this September if the borders are open.
I currently run Continental GP4000 s 23, which a great on bitumen, but HOPELESS on gravel.

I bought a HP Velotechnik Scorpion Fx folding touring trike (25Kg with streamer bubble, racks, mudguards)to go last year , but riots in Lhasa stopped that!
I did an unsupported 1500km ride around Tasmania in Feb/March this year on the trike with 25 kg of camping gear and food, which went well, but SLOW, and Qantas baggage for 50Kg was only $0 to Tas and $22 from Tasmania!
That has all changed now to 23kg, then $35/kg each way!so every kg counts.

The Silvio has TWE 30mm deep Al wheels, and Ultegra SL running gear with a triple front 52/39/30 and 12/27 rear.
I bought a Schlumpf Mountain Drive (2.5 to 1 reduction) bottom bracket with 36/48 sprockets for the trike, as 8Km of 15% to 20% gradient with a 50kg trike killed me!
I have since fitted the mountain drive to the Silvio with 39/52 Ultegra sprockets , so I can climb 14% slopes in the Adelaide hills, where 8% was my limit before (Big engine (103Kg), but low power)


Regards

Super Slim

 

[JonB]

what do you do about cargo?

 

[Gromit]

JonB wrote: what do you do about cargo?

I've never been on a supported ride myself but as I understand it, the organisers carry your luggage for you and provide all of the meals et cetera on route. So I guess that Super Slim would just need to take hydration on the Silvio.

 

[super slim]

Yes, all cargo is carried in a 4WD and all I have to carry on the bike, is warm / water proof clothing and water for 2 to 3 hours riding.
Tents, sleeping bags, and mattresses are supplied, Tents put up?, but riders need to pack them up each morning.
Daily rides are 60 to 100 km and normally 800 m climb, but at 5500m(18,000 ft) breathing is going to be hard!
There will be 4 days of height acclimatisation in Lhasa at 3600m.
The main has be bitumenised for 50% of its length, 3600m to 4200m elevation, while the 5 passes that are 5000m high and above the snow line are still gravel

Most of the passes on the friendship highway are only 5 to 8% gradient, with short sections up to 12%.
I don't know the gradient of Pang La Pass as Google earth photos are not clear enough to see, but from the tourist photos its not too bad.

If things are too tough, especially the first couple of days riding, you can get a lift in the 4WD.

Has anyone riding the Silvio long distances on gravel roads

 

[John Tolhurst]

The key to riding on gravel roads is to forget about achieving low rolling resistance and let the pressure out of your tires. You will need about 40 psi. With this, the tires will deform over individual stones, rather than bounce you side to side. This is good because the bouncing will cause you to correct for balance constantly. Once the bounce is gone, you can settle back and enjoy the ride again.

For this ride, I would probably take a Sofrider. Its higher riding position and more forward seating position means that even if the bike gets seriously sideways on gravel you can still control. I've cruzed past some very experienced bent riders on my sofrider on gravel, it handles wonderfully. See my Keating Road post. http://www.cruzbike.com/forums/viewtopic.php?f=10&t=183&p=1373&hilit=Keating+Road#p1373

When other other riders are getting the yipes, the sofrider is just getting comfy. It handles extrodinarily well.

The specifications on the silvio show a max rear tire radius of 351 and on the front 352. Sheldon Brown quote the radius for a 700 x 38 as 347mm http://www.sheldonbrown.com/cyclecomputer-calibration.html Because this figure comes off a chart for calibrating your computer, it is not clear (to me) if it is the radius of the tire, or the distance from the axle to the ground under a particular tire pressure. Individual tire makes might have differences as well, so you will have to choose some 700 x 38s and fit them, adjust the pressure down and test over some gravel.

 

[super slim]

John,
I was hoping that a road bike would be OK on gravel!!!, but obviously not!

The video of the Softrider going off the road through soft sand, then back again is very impressive.

Is there an option for the Softrider V2 with cable Avid BB7 disc brakes, and how much would this bike weigh?

Is there an option for the Softrider V2 FRAME only + handle bars, like the Silvio, so I can use the disc wheels, Deore LX derailleurs, 11-32 9 speed cassette, 44 32 22 triple crank, quick shifters, Tektro Auriga Hydraulic Dics, from my GT Avalanche Disc 1 rigid tail mountain bike (15.0kg)

I looked at the 4.5Kg conversion kit on a dual suspension bike but most are 15.0 kg, so the total weight would be 19.5 -0.8kg (seat + post ) = 18.7Kg.

This seems to be the weight of a lot of the conversion bikes.

Is the low 14.5 kg weight of the Softrider due to its forks, compared to hydraulic forks?

What is the seat height of the Softrider?

For gravel riding what weight balance should I use?
Its good that the seat base can be moved!

Regards

Super Slim

 

[JonB]

Super Slim wrote: John,
I was hoping that a road bike would be OK on gravel!!!, but obviously not!

The video of the Softrider going off the road through soft sand, then back again is very impressive.

Where is that video?

Super Slim wrote: Is there an option for the Softrider V2 with cable Avid BB7 disc brakes, and how much would this bike weigh?

Is there an option for the Softrider V2 FRAME only + handle bars, like the Silvio, so I can use the disc wheels, Deore LX derailleurs, 11-32 9 speed cassette, 44 32 22 triple crank, quick shifters, Tektro Auriga Hydraulic Dics, from my GT Avalanche Disc 1 rigid tail mountain bike (15.0kg)

I use a 203 mm REAR disk on my front wheel with a rohloff. It works VERY well. Getting a diskbrake in back might not be that easy, but you cant brake hard anyway. What about a drumbrake?

As for dropping the weight. Consider getting the Carbon Trek Y-22? There was one for sale recently on the yahoo forum.

Or consider making carbon seat, and use carbon seat tubes or a aluminium tube, or titanium if thats possible. Use the same for handlebar and handlebar stemtube..

 

[Gromit]

Jon
I think that it is this You Tube video at about the one minute mark?
It is the "Cruzbike Features" video linked from the Cruzbike official site.

 

[JonB]

Gromit wrote: Jon
I think that it is this You Tube video at about the one minute mark?
It is the "Cruzbike Features" video linked from the Cruzbike official site.

i dont think i can see the loose sand in that video.

 

[JimParker]

Quote: i dont think i can see the loose sand in that video.

Actually, that is sand amidst the large gravel next to the railroad in that video (that's me having fun, and Maria doing the camera work). Lumberton is in the "Sandhills" of North Carolina. Geologically speaking, the ocean shore was here only a few blinks of an eye ago. We have sand everywhere. The Sofrider/Freerider do well on all but the deep, loose sand. I still end up riding my Silvio across some pretty rugged trails on the way out to the roads, but the Sofrider definitely is better for this application.

Jim