Sun CR18 rims

[rualexander]

What is the general opinion on these rims? Just had a rear rim blow on Raven Tour while on holiday in Western Isles, bike shop in Stornoway unable to help so had to buy a cheap front wheel and dismantle the original front wheel (identical cr18 rim so knew it would fit with spokes) and transfer the rim to the rear using existing spokes, then try to rebuild wheel as best as i could in the frame. It worked ok and managed to finish our tour thankfully but the rim that blew only had about 5000 miles on it, if that.
 Also lost an eccentric BB shell bolt somewhere on the road, so worth carrying a spare I think. SJS sent one up to us c/o post office though.

[Fred A-M]

I've got CR18 rims on my RST and am also a little concerned about wear on them despite only having clocked up just short of 4,000 miles.  I bought a new set of Shimano brake pads prior to my just completed tour of Britanny and they seem to have inflicted some heavy wear, wearing grooves into the rims and making some pretty horrendous grating noises unless the rims were wiped immediately in the wake of frequent wet weather.  As SJS recommended CR18's as the best compromise ref wear/weight and judging from other comments ref Shimano pads, I'm inclined to conclude that its the pads which are at fault.  

This is a bit of a known problem and from vague memory, others on this forum have recommended Aztec and Salmon Koolstop(!?) pads as more rim-friendly alternatives to Shimanos. Confirmation of the names in addition to suggested outlets from anyone on the forum here would be appreciated as I want to replace the Shimanos at the earliest opportunity.  I'm also switching from Panracer tyres to the more reliable Schwalbes: my rear panracer tyre wall split in several places and had to swap it out: I could only get a 1.75 MTB tyre by way of replacement at the time in Britanny.  

Ref BB bolt, using loctite really does help the diminish the scope for these bolts coming loose: I had a similar problem which is now definitively solved.

[davefife]

I am at 4000miles on my CR18 rims on an RST and used kool stops from about 1000miles as the original shimano pads were eating the rims.  My wear indicators disappeared a long time ago and this thread has encouraged me to remove the front wheel(most used for braking), remove one tyre bead and get in there with a micrometer, i will post later with results.

[davefife]

the pads on my micrometer are too large, i just can't get them onto the rim to measure, anyone got a small enough micrometer?

[paulhipwood]

Can you put a ball bearing inside the rim and measure over the rim and the bearing?
All you need to do is subtract the diameter of the ball bearing from the reading.
regards
paul
ps my Sum rims have just worn down to the rim wear marks after 1500 miles. I think its the miles along the tow path in the wet weather.

[davefife]

Thanks for the ball bearing tip.
Measured:  Rim is ridged by brake pad wear on external surface so this is my best and most robust estimate 0.75 - 0.8mm. But it could be a deviation of 0.3mm either way; the chaos of accurate measurement. Its around 1mm!?!

My strategy is that this is too academic a pursuit, i really should be cycling! however, i plan to watch for cracks, splits, general deformation when giving the bike the once over as I do anyway.  If i get 8,000 miles out of these rims given the commuting and touring i do, in all weathers, that would be fair.
I also went to the sun ringle site and they have a dimensioned drawing of all their rims showing as a cut through.  I couldn't make out the dimensions as the text is too blurred, can anyone make them out?

[Fred A-M]

Dave

Looking at the CR18 diagram on the site I'd say that the two horizontal measurements are 22.5mm and 17.5mm and vertical ones 15.5mm and 11.5mm though it is difficult to read.  

I'm a bit shocked to learn that these rims will only last 8,000 miles or possibly less!  Is this normal!?

Have recently swapped Shimano blocks out for Aztecs and first impressions are that they are miles better as far as the rims are concerned, literally []

Have also replaced the tractor tyre I that I was forced to replace the split panracer with in France with a Schwalbe Marathon Racer: extremely fast and much thicker walls than the panracer so am expecting it to last much longer, especially in view of the considerable cost and my previous experience of the Marathon range!

[davefife]

No idea whats normal for wear on these rims, as i said i will look carefully for cracks etc and may get 10,000 or 20,000 miles; who knows, thats why we share info!  With the originator of this post having a rim blow at 5,000 miles, they do not inspire confidence in their longevity.
I was on an island hop at the weekend and came down the hill from North Glen Sannox to Lochranza on Arran a 200m descent in 2.5km in the torrential rain (i had a ferry to catch) and had to brake a fair bit as was loaded with rear panniers and tent, so thats more surface off my rims.
thanks and keep sharing the info on these rims - anyone another alternative thats a good compromise with weights vs longevity?

[freddered]

agree with comments about shimano brake blocks, they are like angle-grinders

[pdbike]

Hi, am going buy some strong touring wheels soon.
I gather that  sun rhinos are the strongest though heavy. How do the rhinolite, cr18s,and rigida sputniks rank in the tough/weight table. ie which are the next toughest.

advice please

[PH]

My Raven came with CR18s, the rear wore the indicators away around 6,000 miles and I did another 1,000ish before replacing.  The front is still on after around 14,000 miles, but the indicators have all but disapeared.  So an average of over 10,000 miles, nor exceptionally good, but OK.
I ride a mix of on and off road, have always used decent blocks (Kool Stop or BBB triple compound)and the rims and blocks are the one part of the bike I do keep clean.

[bukidnon]

My CR18 rims also failed to last long.  Thorn fitted new rims for me, but so far they have seen no use as I also bought some of those lighter wheels described in the new xTc brochure.  The difference is astonishing.  At least 20% more speed for the same effort.

[lewis noble]

Which rims do you mean, Bukidon?  the Carbide coated rims??

Lewis

[bukidnon]

quote:Originally posted by lewisjnoble

Which rims do you mean, Bukidon?  the Carbide coated rims??

Lewis

Sorry, but I'm not technical enough to know which rims have carbide coatings.  I had some rims with big CR18 stickers on.  They have worn out.  I bought them as part of an xTc in mid-2004 and do not consider myself a big mileage cyclist, lacking dedication for regular training, although I had some decent tours out of them.  Now I have some Mavic rims  (XC717 ?), with Revolution spokes and XTR hubs. The new tyres are Hi-Roads.  The performance difference is astonishing.  Dent to Lancaster with a stop for tea at the Crook of Lune in 2 hours 30 mins is something I could not have got close to with CR18 rims and Pasella Tour Guard tyres.

[jawj]

My experience with Sun CR18s is that they're an above-average rim: not too heavy, good braking, but not all that suited to full-on loaded ruff-stuff.

Mavic rims are the ones for me: XC717 for unloaded, 'road' bike lightweight speed (I can definitely see how you're amazed with them. Bukidnon) plus most mountain bike duties but it has to be the EX721 for general loaded use. Built tight, they rarely go out of true: my last ones lasted well over 6000 miles and (I kid you not) I never had to true them (a spoke broke at the same time that they finally wore out, but even then the wheel spun true). Sure they're a wee bit heavier but who notices a little more rotating mass when you've got three weeks' worth of pants and pasta in your panniers...?