zefal pump and tyre gap

[strictnaturist]

Dear team,
I am now running 2" supremes on the Sherpa, with plenty of space under the mud guards and around the forks and stays. However I have noticed that there is only about a max. 5mm gap from tyre rim to the Zefal pump handle, which I imagine could clog under wet mud tracks. Is the 2'' the widest tyre that the Sherpa can take? Do we just have to carry the pump in a pannier if we want the wider tyre?
Just curious 

[Danneaux]

Is the 2'' the widest tyre that the Sherpa can take?

Yes, effectively so if you are also running SKS P55 mudgurards (at least on the Mk2 Sherpas with pump peg on the seat stay).

I ran 2.0 Schwalbe Duremes and SKS P55 mudguards on Sherpa. Clearance with the Zefal HPX-series pumps is pretty tight where it passes the tire/mudguard is you use these tires, as you can see in my gallery photos of Sherpa here: http://www.thorncycles.co.uk/forums/index.php?topic=3896.0

There's a few alternative options...

• Rotate the handle at the peg end! They're often offset a bit, and you can typically gain 3-5mm extra clearance by this simple expedient. If clearance is an issue, try this first. It is free, quick, and easy and may solve the problem. Yes, the pump will stay put where you rotate it and doesn't seem to "unwind" with riding or vibration.

• Slightly emboss the mudguard at this point by heating it lightly with a heat gun or hair dryer till it is warm-through (but not "hot") and then pressing on it with a thumb wrapped in a towel. This will emboss the mudguard a bit to better clear the flare on the pump handle, but eats up clearance next to the tire.

• Slightly flatten the flare on the lower end of the pump handle. This is where the bulk of the interference occurs. It is easy to do against a piece of hardwood (hardwood other than your maple dining-room table, where it can be a bit of a shock the next time you change the tablecloth. Don't ask how I know this).

• Mount the pump to a Zefal nylon contracting-band pump peg and Doohicki so it rests behind the seat tube rather than alongside the seatstay. This may require the next size shorter Zefal HPX pump, as the Mk2 Sherpas use a fastback seatstay/seat lug connection that limits center clearance at the top (my Nomad has stay-ends set on either side of the seat tube so there's no blockage of an extra-long pump, which simply passes through between).

Most of these strategies would work if you just want to run a wider tire and forego the mudguard or need to better clear the rim with the pump, but be advised...there's not much more than 2"/50mm clearance in the fork at the widest part of the tire sidewalls, and the tire profile/width can change quite a bit with the amount of air it carries. Here's why there's space: Part of the reason to leave a bit of extra room is to allow for clearance against mud buildup or a broken spoke. Don't want the tire rubbing on the paint and such.

Hope this helps; I think you might well get away with running a little wider tire of you use a bit of care in the setup,maintain the bike, and stay out of deep muddy stuff.

All the best,

Dan.

[jags]

this is new to me i've never noticed it before,but to be honest my sherpa wont be doing any dirty cycling strictly tarmac.

[strictnaturist]

As ever, thank you very much for this info.
I am looking into a trip across Iceland this summer where wider than 2'' tyres might be required. But as you state, on the Sherpa, any wider might get jammed with mud etc on frame and definitely pump. If I make it there, and Easyjet are now flying from Edinburgh offering a return trip with bike for £250 in the summer, so very tempted. Got the all the gear, got the maps, got the legs. You know it makes sense! Wider tyres? who cares?
Thanks again for your comments. Better get the Sherpa out the dining room and that table out the shed incase Dan visits

Strict Naturist

[Andybg]

You know it makes sense.... Get it booked and there is no turning back

Andy

[Danneaux]

I stand corrected...by myself!  

A little question kept niggling at the back of my mind, so I unearthed my copy of the Summer 2011 Sherpa Mk2 brochure, and there on page 8, upper-right corner, are the following words by Andy Blance:

"The Sherpa frame can easily accommodate 2.1" tyres and mudguards, with enough clearance for them to be an asset, rather than a liability!"

So, Strict Naturist, it looks like you can indeed fit a bit wider tire (tyre) for your proposed Icelandic trip -- yay! 0.1" is 2.54mm (1.27mm wider each side), so we're not talking much greater width and most of the caveats apply, but still...it is wider and it also means your Sherpa might well accommodate a knobbier tire, perhaps providing better traction at the sides in softer soils and alluvial gravel as you might expect in Iceland!

Do keep in mind, tire width and profile depend on pressure. My 26x2.0 Schwalbe Duremes caliper from 47mm to 50mm depending on inflation. A 2.1 tire calipers to a nominal 53.34mm, depending on pressure and whatever bits of tread protrude and where. If running mudguards in poor conditions, I go for a more generous mudguard line, setting them out a bit farther from the tire tread to avoid jamming by mud, sticks, leaves, dirt, and snow. If you need more clearance, it may be available by removing one or more of the spacers installed by Thorn at the fork crown and stay bridges. You'd likely need a bit longer stays as well.

I so hope the trip will work out for you; think of it this way: At such low fares, you'd have the chance for a trip with a lifetime of memories. Pass on this, and you might have a more conventional summer. I hear Opportunity knocking!

All the best,

Dan. (...who wishes he's remembered this brochure notation sooner)

[strictnaturist]

cheers Dan! you can't expect to keep us correct if you don't have a wee check on yourself now and again
True, I can imagine enough space for a knobbly tyre in there with room for mud ,lava, sand etc. Just might carry  a smaller pump for the trip, on the seat stay,as recommended,or in the bag.
Thank you very much for the update.

If anyone out there has been to Iceland recently and can let me know if I can buy meths for my Trangia, think thats all I would have to source speciality wise in Reykjavik. Ah! nothing better than a summer dream trip to see winter off the premises.

kind regards
SN

[Danneaux]

There is considerable information on international fuels availability here: http://fuel.papo-art.com/
...and here: http://www.mark-ju.net/juliette/meths.htm (though no word wrt Icelandic availability)

Methylated spirits (meths, or alcohol) are called "Raudspirit" in Iceland and is dyed red to distinguish it to prevent drinking. Possibly available here: http://www.tripadvisor.com/ShowTopic-g189952-i223-k1230501-Camping_stove_gas-Iceland.html

Some possibly useful links or contacts:
http://www.horizonsunlimited.com/hubb/iceland/availability-of-meths-stove-iceland-36398
http://www.masterlyinactivity.com/ivan/iceland.html <-- Extensive notes on bike touring there, says, "...Alcohol for Trangias can be obtained in a limited number of locations (usually garages), but is rather expensive. It is worthwhile checking out major campsites, especially Reykjavík, for fuel left behind by other campers".
http://userweb.eftel.com/~wheelbuddies/iceland/index.htm
http://bicycletouringpro.com/blog/planning-bicycle-touring-route-iceland/

Trangia have a list of meths suppliers geographically, but aren't much help in Iceland: http://trangiastove.co.uk/trangia-fuel-names.php

Hope something in the above proves helpful.

Best,

Dan.

[mickeg]

I do not use the pump peg on my Sherpa, thus pump clearance is not an issue.  I run 2.0 width Dureme on the front for off pavement trips and 2.0 Extreme on the rear.  I think the point with the tightest clearance on my front tire is the little bolt that holds the front fender where that bolt is threaded into the fork crown.  I have much more clearance for the rear tire than front.  Thus, I am a bit more concerned about my front fender bolt clearance than any other clearance issues.

I copied and pasted the text of an e-mail I received from Thorn on April 7, 2010 where I was asking tire size:

  Hi George,
  The Sherpa will accept tyres which measure 2" with guards. All tyres vary
  slightly from their stated size. I expect that 2.1" would be OK without
  'guards.
  Best regards,
  Andy B.

Hope this helps answer your question.  I attached a photo, you can see how close my front fender is to the tire.