Ambrosio P20 rims

[iandusud]

Thanks. They're a bit narrower than I am looking for though. Ryde Zac 2000s are the most likely choice, or Kinlins XR22/6RTS if I decide to splash out.

It's your call but I would have thought ideal for a 23mm tyre (not that I ride anything that narrow any more!

Me neither. I have confused things by hijacking Simon's thread about these rims.

It doesn't take much to confuse me these days

[SimonCelsa]

As a follow up to this recent-ish thread on subject;

Today I fitted a 23-622 Vittoria Rubino Pro Folding Clincher Tyre to the ambrosio P20 rim. Theoretically the tyre is too narrow for the rim, (or the rim is too wide for the tyre!).

However, when pumped up to 100 psi and with the beads fully seated I think it looks pretty good, if someone handed me this wheel to replace a buckled one for instance, then I would not give a second thought to just bunging it in and riding off.

A couple of images, which admittedly aren't brilliant, any comments?

Shortly after taking these photographs there was a very loud bang as the 'used but good' velox rim tape proved itself 'used but no good!'.

Additionally, the tyre went on the rim relatively easily (it needed kitchern cutlery to get the last bit on but no lubricant). I had heard that some tyres were extremely tight due to the fact the ambrosio p20's are tubeless ready.

Remains to purchase the spokes and some decent quality HP rim tape and job's a good 'un hopefully. Wish I'd bought a couple more of these rims now, looks like the SPA offerings are now almost all out of stock.

Cheers

[Mick F]

One, these rims are black, and two, these rims are wide.
Both these things put them out of my wants list.

Ambrosio Excellence in silver are great!

[SimonCelsa]

A further quick question; when sourcing rim tape for these rims, would it be better to go for a width just sufficient to cover the spoke holes in the concave rim bed, or go for a full width tape (20mm) to cover the entire width between the hooked sidewalls. I would guess it would be best to go for the former (narrower) option?

I'll have a quick gander at the Ambrosio Excellence rims Mick but if they're much more than £20........

Cheers

[Jamesh]

Hi that's interesting I hadn't thought of going down to 23mm as my pro 4 tyres were too large on the frame.

I used aci alpina spokes a good price.

https://www.cyclebasket.com/m9b0s454p97 ... r_Singles_

1.7 /2.0 Db.

I used bitex hubs for lightness.

For durability use Shimano or miche.

Cheers James

[Brucey]

A further quick question; when sourcing rim tape for these rims, would it be better to go for a width just sufficient to cover the spoke holes in the concave rim bed, or go for a full width tape (20mm) to cover the entire width between the hooked sidewalls. I would guess it would be best to go for the former (narrower) option?

these rims are designed to use a full-width (but thin eg DT) tubeless tape. Tapes that just cover the holes only tend to cause problems of one kind or another. Obviously anything on the rim will add to the diameter and will make a tyre a bit tighter.

The report in a post above of the 'fit being not too tight' sounds good until you get to the bit where tools were required to get the tyres on... . (Tools should only be required to get tyres off, not on). I would suggest it would be prudent to leave the tyres at full pressure for a few days and then see how easily they come off the rims; this is the acid test. if you can't get the tyres off the rims (by the roadside, when you need to) then they may not be as practical as one would hope for.

cheers

[Mick F]

I'll have a quick gander at the Ambrosio Excellence rims Mick but if they're much more than £20........

Yes, they are.
£50odd each, but I don't seem to find any online at the moment. Bought mine in March 2015 and they are hardly worn.

[Jamesh]

A further quick question; when sourcing rim tape for these rims, would it be better to go for a width just sufficient to cover the spoke holes in the concave rim bed, or go for a full width tape (20mm) to cover the entire width between the hooked sidewalls. I would guess it would be best to go for the former (narrower) option?

these rims are designed to use a full-width (but thin eg DT) tubeless tape. Tapes that just cover the holes only tend to cause problems of one kind or another. Obviously anything on the rim will add to the diameter and will make a tyre a bit tighter.

The report in a post above of the 'fit being not too tight' sounds good until you get to the bit where tools were required to get the tyres on... . (Tools should only be required to get tyres off, not on). I would suggest it would be prudent to leave the tyres at full pressure for a few days and then see how easily they come off the rims; this is the acid test. if you can't get the tyres off the rims (by the roadside, when you need to) then they may not be as practical as one would hope for.

cheers

Washing up liquid is your freind....

I wouldn't use them as a long distance wheel as they are thin on the braking surface and a pig to take tyres on and off.
For Sunday afternoon up the cow and calf fine...!

Cheers James

[SimonCelsa]

update for anyone interested:

After the initial blow out due to poorly fitting narrow (abt 10mm) cloth rim tape, I received and fitted some 20mm width schwalbe HP rim tape (normal not tubeless).

Subsequent attempts to fit the tubes and tyres were almost impossible due to the extremely tight fit. In my fits of pique I managed to pinch puncture 2 tubes, scratch the rims in half a dozen places and even offend myself with some of the choice cussing.

Just prior to admitting defeat I patched both tubes, liberally doused the tyre beads in neat washing up liquid and tried one more time. This time, after a battle, success! I pumped the tyre upto 100psi and left it in the shed for a couple of days.

Today, I removed both tyre and tube and attempted the refitting again, this time without lubrication. In less than 3 minutes the tyre was on, seated correctly and upto 100psi. I feel a little more confident about building up these rims now into a set of wheels for the daughters bike. Hopefully once the wheel is complete the spoke tension may help somewhat in reducing the overall diameter fractionally (??)

Findings; possibly the tyre has stretched a tad to facilitate fitment. Also better fitting technique this time - in addition to ensuring both beads were in the rim well I also focussed more on pulling and stretching the tyre towards the last part of the bead to snap over. Ho hum.

[Jupestar]

Very interesting, similar issue yesterday, same rim tape making it impossible to get tyres them on.

Now they are unwrapped anyway, I decided to put the tires on some spare wheels and put them in the cellar. Inflated to see if they would give a bit, just in case they get called into action (I.e. cannot get to a bike shop). I had no problem fitting them to my spares..

[SimonCelsa]

I think the 'squeezing & pushing' of the beads towards the area of most resistance is the trick. I have fitted many tyres without problem but am always on the lookout to improve technique. Perhaps I've been a bit of a 'butcher' in the past with my use of tools for getting the last bit of the bead on! This youtube video explains it fairly well (I think anyway!):

https://www.bing.com/videos/search?q=fi ... ORM=VDMCNR

[Eman Resu]

The P20 is a tubeless tyre compatible rim. Getting the tyre on may be an issue with some makes of tyre but the big problem I encountered was in seating the bead of a 700x28 Vittoria Rubino Pro III on a P20. A massive amount of tyre pressure (120+ psi) need to get the 'pop' which indicates successful bead seating ... similar to the 'pop, pop' in seating a tubeless tyre. I sold my P20 rear handbuilt wheel on with a stern caution on bead seating as I didn't like the idea of having to do a post puncture roadside inflation to seat the tyre with a hand pump!

A further quick question; when sourcing rim tape for these rims, would it be better to go for a width just sufficient to cover the spoke holes in the concave rim bed, or go for a full width tape (20mm) to cover the entire width between the hooked sidewalls. I would guess it would be best to go for the former (narrower) option?

these rims are designed to use a full-width (but thin eg DT) tubeless tape. Tapes that just cover the holes only tend to cause problems of one kind or another. Obviously anything on the rim will add to the diameter and will make a tyre a bit tighter.

The report in a post above of the 'fit being not too tight' sounds good until you get to the bit where tools were required to get the tyres on... . (Tools should only be required to get tyres off, not on). I would suggest it would be prudent to leave the tyres at full pressure for a few days and then see how easily they come off the rims; this is the acid test. if you can't get the tyres off the rims (by the roadside, when you need to) then they may not be as practical as one would hope for.

cheers

[Jamesh]

First ride on these rim / bitex hubs / 25mm wiggle kevlar Golding tyres.

They ride firm and stiff. On the flat speed was simalar to rs10/ aksium wheels up a hill they felt quicker even with my tired legs.

As others have said the tyres are hard to fit.

Maybe I should try them tubeless they take about 100psi to ping into place so them might work and they stay put when let down.

Cheers James