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Replace 27.5 rims with 700

Posted: 14 Feb 2019, 10:24am
by Vetus Ossa
I have a lot of ideas, some better than others.
Could my learned fellow forum members comment on this one please.
First some info.
I ride a Cube ebike now because of health issues.
I love riding it but have never been happy with the wheels, I have commented here before about them.
They are 27.5 and the rims are tubeless ready.
Getting tyres on and off them is an absolute nightmare, even getting the bead free from the rim wall when removing is difficult, and I have watched and followed Colin’s excellent video.
Obviously a puncture miles away from home would be a problem so I have gone overboard with the tyres and inner tubes. I have a Marathon on the front and Marathon plus mountain bike tyre on the rear, and am using slime inner tubes which so far are okay. They are heavy.
Obviously sooner or later I will have the inevitable.
My thought is what if I fitted a pair of 700c rims to the current hubs and fit the largest Marathon tyres that will fit them.
The radius of my 700c rim on another road bike and that on my ebike are the same, 34cm.
Obviously I am not looking at new tubeless ready rims, but some that I can fairly easily change the tyres on when necessary away from home.
Daft idea or what?

Re: Replace 27.5 rims with 700

Posted: 14 Feb 2019, 11:03am
by Geoff.D
Not a daft idea, in my opinion.

Personally I like to be capable of keeping the bike running, whatever happens on a ride/day/tour. Obviously I can't cover every eventuality (crash/deep pothole/bearing collapse) but most things can be overcome.

P*******s are a real possibility, though Marathon+ tyres seem to have done the trick since I started using them 5 years ago. Like you I wouldn't want to be stuck for want of tyres that don't come off the rims easily, especially in the rain or cold. I'd swap to 700c rims in your position.

Re: Replace 27.5 rims with 700

Posted: 14 Feb 2019, 12:17pm
by Brucey
not a daft idea at all. In fact even if the overall wheel diameter is a bit different is this going to be a big problem? One of the objections to using 584 rims and tyres for touring is that they are not as widespread as 700C, so in the event of problems you are less likely to find bits that will keep you running. Most e-bikes are 'special' anyway, but being 27.5(584) just gives more ways to be tripped up.

cheers

Re: Replace 27.5 rims with 700

Posted: 14 Feb 2019, 7:37pm
by Vetus Ossa
Thanks chaps.
Can anyone recommend a suitable 700 rim that I can fit a 35-38 marathon plus tyre on please that doesn’t cost the earth.
Rims that are easy to get tyres on and off would be ideal.
Cheers.

Re: Replace 27.5 rims with 700

Posted: 14 Feb 2019, 8:50pm
by Brucey
drilling? Disc or rim brake?

cheers

Re: Replace 27.5 rims with 700

Posted: 14 Feb 2019, 8:52pm
by jerg
I've just bought some 700c/29er wheels from Spokesman Wheels to put on my longitude to replace the 27.5 ones.

I had the original problem as the first poster with 27.5+ tyres which were impossible to get off the rims, which wouldn't be much use on a bikepacking trip if I was stuck in the middle of nowhere.

Re: Replace 27.5 rims with 700

Posted: 14 Feb 2019, 9:20pm
by Vetus Ossa
Brucey wrote:drilling? Disc or rim brake?

cheers


Yes, good question...disc, and 32 spoke holes.

Re: Replace 27.5 rims with 700

Posted: 15 Feb 2019, 5:26pm
by 531colin
I'm using a pair of these....https://spacycles.co.uk/m2b0s116p3788/KINLIN-XD-230
They have a nice deep well, and I can get my 32mm Marathon Supremes (folding bead) both off and on without levers, even with arthritic thumbs.
They are a stiff rim and mine were true, so dead easy to build up into true wheels with even spoke tension.
I have also played with an H plus Son disc-specific rim (I forget the name, but the disc version of the Archetype). Pretty sure its more money, but again a nice deep well so the tyres go on and off easily, and again a good stiff rim.

Re: Replace 27.5 rims with 700

Posted: 15 Feb 2019, 7:08pm
by Vetus Ossa
531colin wrote:I'm using a pair of these....https://spacycles.co.uk/m2b0s116p3788/KINLIN-XD-230
They have a nice deep well, and I can get my 32mm Marathon Supremes (folding bead) both off and on without levers, even with arthritic thumbs.
They are a stiff rim and mine were true, so dead easy to build up into true wheels with even spoke tension.
I have also played with an H plus Son disc-specific rim (I forget the name, but the disc version of the Archetype). Pretty sure its more money, but again a nice deep well so the tyres go on and off easily, and again a good stiff rim.



Thanks Colin, they do look like nice rims.
I have problems with my thumbs also, they ache for a couple of day after every time I take tyres off and fit different ones on my rims, that’s part of the problem for me.
I have been looking at Sputnik rims, they seem very cheap, I guess that’s probably for a reason.
I know they are heavy but not too worried about weight.
I have been trying to calculate spoke length for the rebuild but I can’t find the hub measurements online for the dimensions I need. I have Shimano HB-M80000 front and FH-M80000 rear so still looking for that.

Re: Replace 27.5 rims with 700

Posted: 15 Feb 2019, 7:40pm
by RickH
Vetus Ossa wrote:I have been looking at Sputnik rims, they seem very cheap, I guess that’s probably for a reason.
I know they are heavy but not too worried about weight.
I have been trying to calculate spoke length for the rebuild but I can’t find the hub measurements online for the dimensions I need. I have Shimano HB-M80000 front and FH-M80000 rear so still looking for that.

I found Sputniks very difficult to get tyres to seat properly without a low spot using the same tyres that fitted fine on other rims such as Mavic Open Pro. They were also much harder to get on & off. I wouldn't buy them again.

Re: Replace 27.5 rims with 700

Posted: 15 Feb 2019, 7:49pm
by Brucey
I've kept quiet about exactly what rims to buy because most of the ones that I know will be a loose fit are either too skinny for those tyres or are obsolete. I agree about sputniks BTW, except I would also add that they vary; some are worse than others.

FWIW any rim with a shallow, sloping rim well is liable to be awkward with M+ tyres; a good part of the problem is that the tyre is so springy that keeping the bead in the well is very difficult. Very old-fashioned rims (single wall with a deep and square rim well) are a lot easier with tyres, but don't build well into 32h wheels with lots of dish on them.

cheers

Re: Replace 27.5 rims with 700

Posted: 15 Feb 2019, 8:50pm
by Vetus Ossa
I think I may have to reconsider my tyre choice.
I don't mind mending punctures, it's getting them on and off the rim easily that does matter.
Like what I have read about supremes.

Re: Replace 27.5 rims with 700

Posted: 16 Feb 2019, 3:57pm
by 531colin
I suspect Sputniks are cheap because that's the sort of money they can get for them....its an old-fashioned extrusion and they are a workaday sort of rim, and people don't usually pay silly money for practical cycle stuff. Deep-section rims for spangly bikes with more gears than spokes are another matter altogether, it seems the more they cost the better they like it.

I'm running more than one bike with Rigida Grizzly rims just now, and the tyres fit OK. They are supposed to be a similar section to Sputniks.

I think theres a lot to be said for going into a bricks and mortar bike shop and trying the fit of the tyres on the rims before you buy anything. If you are going to use folding bead tyres, don't expect to fit a brand new one easily, they have been folded up in a box like Aladdin's genie, and they are any shape but round until they have been on a rim for a week.

There is variation in dimensions between batches of rims, and its possible that Sputniks suffer from being cheap rims. They may be made on the oldest machines, or the machines may be set up less carefully. (I imagine tyres vary too)
(My recollection is that the process is...extrusion...drilling and fitting eyelets....coiling...cropping to length....joining....machining sidewalls.)

Re: Replace 27.5 rims with 700

Posted: 16 Feb 2019, 5:17pm
by Brucey
531colin wrote:
There is variation in dimensions between batches of rims, and its possible that Sputniks suffer from being cheap rims.


that is my impression too but I have (less often perhaps) also seen variations in more expensive rims...

(My recollection is that the process is...extrusion...drilling and fitting eyelets....coiling...cropping to length....joining....machining sidewalls.)


I think

1) extrusion...…
2) coiling...
3) cropping to length...
4) joining..
5) drilling and fitting eyelets..
6) machining sidewalls

but 5 and 6 may be the other way round. If the extrusion were drilled before coiling and/or cutting to length you would see two things

a) uneven pitch drillings across the joint and

b) rims that are shaped like a thruppeny bit; they won't yield uniformly during coiling once they have holes in.

cheers

Re: Replace 27.5 rims with 700

Posted: 16 Feb 2019, 5:18pm
by Vetus Ossa
531colin wrote:I suspect Sputniks are cheap because that's the sort of money they can get for them....its an old-fashioned extrusion and they are a workaday sort of rim, and people don't usually pay silly money for practical cycle stuff. Deep-section rims for spangly bikes with more gears than spokes are another matter altogether, it seems the more they cost the better they like it.

I'm running more than one bike with Rigida Grizzly rims just now, and the tyres fit OK. They are supposed to be a similar section to Sputniks.

I think theres a lot to be said for going into a bricks and mortar bike shop and trying the fit of the tyres on the rims before you buy anything. If you are going to use folding bead tyres, don't expect to fit a brand new one easily, they have been folded up in a box like Aladdin's genie, and they are any shape but round until they have been on a rim for a week.

There is variation in dimensions between batches of rims, and its possible that Sputniks suffer from being cheap rims. They may be made on the oldest machines, or the machines may be set up less carefully. (I imagine tyres vary too)
(My recollection is that the process is...extrusion...drilling and fitting eyelets....coiling...cropping to length....joining....machining sidewalls.)


Thanks Colin, i'll think on it.
At the moment I am favouring the KINLIN XD-230 rims you mentioned earlier.
I sill have quite a few miles in the old tyre before I swap rims, fingers crossed I don't P******e before then.