Cycling UK Forum

I recently fitted a 700 Ambrosio rimmed rear wheel to my E-bike. The new rim is 7 mm narrower than the old and the Schwalbe Marathon 700x35C tyre that I swapped over is very tight to fit and so far will not go on parallel, however many attempts.
The rubbing strip is all over the place. Can anyone recommend a loose-fitting folding tyre C32, 35? maybe a folder as I don't fancy trying to swap a punctured tube on the road!
Are the Panaracer Gravel tyres worth a try?

Which Ambrosio rims?

Excursion, Evolution, Excellence?

The above are all narrow road rims, you can fit a 28 mm tyre typically, nothing bigger than that... ideally 23-25

I have p20 rims.

Tyres are a nightmare to fit.

I use wiggle kevlar which are tight but do go on. £10-15

I don't go far on these rims for that reason.

Cheers James

The P20 are wide rims for road standards, you can fit any tyre size you like, more or less... certainly 32-35.

They are tubeless ready rims, hence a bit tighter fit for tyres

Thanks all.
I have ordered a Panaracer Ribmo 32 wide folder.
Fingers (Cut and bruised) crossed!

https://www.ebay.co.uk/itm/Black-Bike-C ... 890.l49286

Bought one of these recently for fitting tight tubeless tyres, I haven't tried it yet though, so can't report anything useful other than it seems solid enough (think mine is BBB branded, either from Tredz or Tweaks iirc).

I'm a trendy consumer. Just look at my VOG-L09 using hovercraft full of eels.

I am not the least expert on tyre types and wondered what a "Crotched" rim is.
I noticed this evening a note on my Schwalbe Marathon front tyre to the effect that these tyres can only be fitted to Crotched type rims.
Anyone know the differences?

Have you tried knocking bead into centre and pedal strap or cable ties to hold it.
Last marathons I fitted were difficult

arnsider wrote: ↑16 May 2021, 9:26pm I am not the least expert on tyre types and wondered what a "Crotched" rim is.
I noticed this evening a note on my Schwalbe Marathon front tyre to the effect that these tyres can only be fitted to Crotched type rims.
Anyone know the differences?

They mean crotched rims ( from the French for hook ) -

viewtopic.php?t=97483

arnsider wrote: ↑16 May 2021, 9:26pm I am not the least expert on tyre types and wondered what a "Crotched" rim is.
I noticed this evening a note on my Schwalbe Marathon front tyre to the effect that these tyres can only be fitted to Crotched type rims.
Anyone know the differences?

Rim with a bead hook.

Many thanks.
I take it that a "Bead Hook" is a fold in the rim edge that traps the tyre bead.

arnsider wrote: ↑17 May 2021, 1:12pm Many thanks.
I take it that a "Bead Hook" is a fold in the rim edge that traps the tyre bead.

Yeah, a lip at the top of the rim sidewall.

The Ambrosio rim built into my replacement wheel is patently unsuitable and is just the another nail in the coffin of my E bike saga.
The rim is not crotched and it's obvious now why I cannot get my Schwalbes on correctly.
I just do not understand why the wheel builder didn't consider rim width and tyre compatibilty. After all, we rely on cycle shops to advise and supply accordingly, or are the usual cynics on here going to wag their fingers at my "ignorance"
I suffer badly with thumb arthritis so you can imagine how hard it is to fit tight tyres.
In retrospect, I might have taken the tyre and tube to the wheel builder before he commenced!
Such is hind sight.

arnsider wrote: ↑18 May 2021, 6:39am The Ambrosio rim built into my replacement wheel is patently unsuitable and is just the another nail in the coffin of my E bike saga.
The rim is not crotched and it's obvious now why I cannot get my Schwalbes on correctly.
I just do not understand why the wheel builder didn't consider rim width and tyre compatibilty. After all, we rely on cycle shops to advise and supply accordingly, or are the usual cynics on here going to wag their fingers at my "ignorance"
I suffer badly with thumb arthritis so you can imagine how hard it is to fit tight tyres.
In retrospect, I might have taken the tyre and tube to the wheel builder before he commenced!
Such is hind sight.

I recommended this approach in this thread viewtopic.php?f=5&t=145735

However, it seems to me that you know what you want from this wheel; you want a strong, wide rim which your tyres will mount on and off reasonably easily. If you made that clear to the wheelbuilder at the time then he hasn't followed your instructions.
The thread I linked talks about rims/wheels which are suitable for tubeless tyres. Now I don't know anything about tubeless tyres, and I'm not interested in learning a whole new load of stuff at my age; inner tubes have been OK for me all my life I know how they work and I can fix them when they fail. However, it seems to me (from my reading on here) that rims designed for tubeless are different to rims designed for tubes, and the tyres are very tight. Is it possible you have got a tubeless rim?

I took the faulty MT 500 wheel to the wheel builder to swap over the disc and block, so he must have known by looking what he was being asked to replace.
I scoured the Ambrosio web page to try to identify the wheel I had from the section... That was a waste of time!
What I did find were a number of far more suitable rims.
I take the point about tubeless rims not being crotched and the one I ended up with may well be such.
Eyeing down the rim top I could not see any fold or thickening in the rim edge so I am satisfied it was not crotched.