another 29er / 700c disc wheel question

jomoj

I'm building up a CX bike with disc brakes on a budget and like many people it seems, given the lack of cheaper 700c disc wheel options, wondered if I could use a ready built 29er wheel and run narrower tyres in it.

Opinions seem varied although mostly negative but I'm confused: if a road rim like a velocity a23 has an internal width of 19mm and can fit a 25c tyre, is there a reason that a 29er rim with an internal width of 19mm couldn't at least fit a 28? Which is as small as I would want to run. Is the bead or profile different or is there some other reason.

Cheers in advance for any light you can shed on this.

ugo.santalucia

Seems to be trial and error, like most things in modern componentry

http://paolocoppo.drupalgardens.com/con ... ake-matter

How Far is too Far

The Canyon CX bikes come with Mavic and DT MTB wheels on them.

http://www.canyon.com/_en/roadbikes/bike.html?b=3200

So it they manage it can not see why not. I am in the market for some better wheels for my winter CX bike and was thinking of some Fulcrum MTB wheels, like these

http://www.chainreactioncycles.com/fulc ... -prod78576

jomoj

Thanks for the info, confirms that as expected, it's a bit of a minefield. A recent experience with some DT rims on my road bike showed that even in 700c there can be several mm difference in bead diameter. Might be worth taking a punt on some from a seller with a good return policy as I would like to be able to run 28c road tyres for commuting duties

How far - thanks for the tip on canyon but be warned, I think those fulcrum wheels have a different axle standard on the front and may not fit.

ugo.santalucia

look, velocity A 23 will take any tyre and so will H plus Son Archetype... they both look good enough in a disc fitted bike. Don't rule out Mavic Open PRO CD, it also looks ace and it's an awesome rim, which can take your 32-35 mm CX tyres no problem, as well as road tyres of course

jomoj

Yes, cost is the issue here unfortunately. A pair of wheels with those rims plus decent hubs is going to be 250+ so I was looking for a cheap option to get rolling with and then get some nice wheels later and relegate the others to utility work

jomoj

ugo - re: article on your blog, do you think the tubeless rim design is a bigger factor than the width in the ability to fit a narrower tyre?

ugo.santalucia

jomoj wrote:

ugo - re: article on your blog, do you think the tubeless rim design is a bigger factor than the width in the ability to fit a narrower tyre?

Yes, the older A 23 was super easy... the newer is a lot tighter, but the rim dimensions have not changed

maddog 2

I've tried Stans Crest 29er rims with 28mm road tyres and they were stupidly tight. Too tight.

Now I run Archetypes as my CX disc rims. Nice rim and much easier to fit tyres to, and tubeless too.

cycleclinic

Be ware that most MTB rims are limited to 4 bar or something like that, this is the biggest drawback.

How Far is too Far

thecycleclinic wrote:

Be ware that most MTB rims are limited to 4 bar or something like that, this is the biggest drawback.

surely a 25mm tyre with 100psi will have less effect on a rim than a 2.4" tyre with 50 Psi?

ugo.santalucia

How Far is too Far wrote:

thecycleclinic wrote:

Be ware that most MTB rims are limited to 4 bar or something like that, this is the biggest drawback.

surely a 25mm tyre with 100psi will have less effect on a rim than a 2.4" tyre with 50 Psi?

No... the size is irrelevant, the pressure is everything

How Far is too Far

I am after some disk wheels for my winter bike as well. Just found these which I can get for £270

http://www.kinesisbikes.co.uk/products/ ... ght-cxdisc

Not sure if they will be ok with 28mm tyres at 80psi? But the weight and price seem good.

Anyone know of any other wheels at this price?

Or am I better of going hand built? what will I get for £250 to £300?

Thanks

tincaman

How Far is too Far wrote:

I am after some disk wheels for my winter bike as well. Just found these which I can get for £270

http://www.kinesisbikes.co.uk/products/ ... ght-cxdisc

Not sure if they will be ok with 28mm tyres at 80psi? But the weight and price seem good.

Anyone know of any other wheels at this price?

Or am I better of going hand built? what will I get for £250 to £300?

Thanks

Bought those last week, slightly heavier at 1600g than on their website.
I am running Pro4 Endurance 25mm at 80psi with no problems, easy to get on, and measure up at 28mm when fitted

ugo.santalucia

If you go handbuilt you will spend the same for a very similar wheelset. The only difference is that Kinesis does not support you with spare rims, should you need one... as this rebuild clearly shows

http://paolocoppo.drupalgardens.com/med ... ail/16/561

How Far is too Far

Thanks Ugo.

What would you recommend for a hand built?

I am 80kg but not heavy on wheels.
The bike is a CX bike but is used on the road 90% as a winter/wet day bike
I would like to use 28mm to 32 mm tyres, but at the moment I have Duran Pluse 25mm on it
Prefer black hub/spoke/rims
Weigh around 1600grms

Budget around the £250ish

Thanks Richard...

majormantra

maddog 2 wrote:

I've tried Stans Crest 29er rims with 28mm road tyres and they were stupidly tight. Too tight.

Now I run Archetypes as my CX disc rims. Nice rim and much easier to fit tyres to, and tubeless too.

I've just built myself a set of Iron Crosses, which are similar to the Crests but a little narrower, and designed for CX tyres, so no problem fitting them. The rims are crazy light - mine were under their claimed weight, coming in at 370-something grammes each.

It will be interesting to see how the stand up. I'm light but they're 32/32h as I got a deal on the rims. With cheap DB spokes and heavy (but lovely) XT hubs the set comes in at under 1700g, and they're light where it matters (the rim). Especially as I've set them up tubeless, too.

ugo.santalucia

Out of budget though... and so are my Alpha...

majormantra

True, I was mainly looking to show off my bike.

I only spent about £160 on the wheels actually but I got the rims for £85 (unused) and built them myself, which helps!

ugo.santalucia

How's the PX riding? A friend of mine is considering it...

majormantra

I've ridden it only once so far, so I can't really review it, but first impressions are very positive - it feels nice and stiff under power and pleasingly 'poised'.

The frameset looks very nice in person although some of the minor details (e.g. the cable stops glued into the frame) are a little rough. The fork is not particularly light but the whole package is quite reasonable. Build as pictured is about 9kg or a little under.

Oh and the new XLS frames have BSA bottom brackets instead of PF30, which is a major plus in my book.

jomoj

nice couple of bikes there - I had both of those frames on my shortlist but in the end picked up a Kinesis pro6 for a good price.

re: the pressure issue - thanks for pointing that out. When I looked into it, most of the 29er wheels where rated to about 60psi so thats not a lot of good.

So I've pretty much realised that I'll need to spend a bit more to get something decent. Was thinking Archetype rim, XT hubs and DB spokes ought to come in about 270 ish? I did also look at the kinesis wheels but didn't fancy the alloy freehub or the potential spares issue as Ugo pointed out.

ugo.santalucia

jomoj wrote:

I did also look at the kinesis wheels but didn't fancy the alloy freehub or the potential spares issue as Ugo pointed out.

The good thing is that they are fully fixable, the bad one is that you have to make do with non original parts. The spokes are Pillar triple butted I seem to recall, which are not distributed in the UK, the rims are not available as spares... the freehub is a Novatec B1 type, so that can be had... bearings are bearings, so not an issue.
Considering it's all far eastern stuff, they could and should be cheaper

cycleclinic

Ryde Pulse comp disc is another rim to consider. I got the very first set of 32H rims that were available I think. They weigh 337g each. They are 24.8mm deep and 15mm internal width. They look good and they are stiff. So the archetype are good rim but the Ryde rim will do the job and weigh a lot less, not as wide though.

Alloy freehubs are not an issue. I have never failed to get a cassette of an alloy freehub even a deore cassette of the rather soft hope alloy freehubs. A screwdriver normally does the tick as do two chainwhips. Still I do like steel, or titanium for freehub bodies which is why I like Shimano CX-75, XT M785 or XTR hubs so much.

the reason why Kenesis wheels are not cheaper, Upgrade bikes buy then from somewhere and sells them to dealer for a profit and the dealer has to make a profit as well. It is not like an on line retailer going straight to whoever makes these wheels buying 50 pairs of each wheel type and spending £20k and then selling them with a 20% mark up (that's a guess) to shift them quickly.

ugo.santalucia

thecycleclinic wrote:

Ryde Pulse comp disc is another rim to consider. I got the very first set of 32H rims that were available I think. They weigh 337g each. They are 24.8mm deep and 15mm internal width. They look good and they are stiff. So the archetype are good rim but the Ryde rim will do the job and weigh a lot less, not as wide though.

How thick is the nipple bed? If you insert a nipple + spoke and mark the nipple at the entry point, you should have a good idea of the thickness of the rim

Moonbiker

Don't rule out Mavic Open PRO CD

Whats the CD coating for cosmetic?

ugo.santalucia

Moonbiker wrote:

Don't rule out Mavic Open PRO CD

Whats the CD coating for cosmetic?

Pretty much

maddog 2

which disc hubs are 11spd?

Can't imagine any of the mtb-derived ones are (XT, XTR, DT, Tune).

What does that leave... anyone know?

majormantra

Shimano CX-75, but 28h only. Novatec D712SB-11:

http://www.bdopcycling.com/Hubs-D712SB-11.asp

Also various posh ones like White Industries. DTs can be converted but I don't know if you can buy them with 11 speed freehubs fitted.

For my build I wanted 11 speed compatibility for future proofing but gave up on it when I realised how much more money it was going to cost me. XTs are only £55 a pair and work great.

jomoj

The cx75 look to all intents like the xt m785 with a shiny finish and 28 holes. Looking at the spec docs on the Shimano site they share lots of common parts so I wondered if it might be possible to fit the cx75 freehub onto the xt as well?

majormantra

I don't have the measurements of the CX75 to hand, but I suspect they will have moved the DS flange inwards to make room for the longer freehub. From a cursory glance at my XT hub it doesn't look like there would be clearance at the dropout for the longer freehub as is, but that's speculation.

Perhaps someone with a CX75 could confirm?

If you were starting from scratch I'd just choose CX75 hubs (or at least, the rear) and 28h rims. I went XTs because my choice of rims was already fixed.