WELCOME! I've been cycling through the Southeast Valleys of Wales since 2010 and I can't say (or show) enough about the place. I just love it. So if you've got the interest and would like to spend some time... sit back and let me show you some of the fabulous places I've discovered.

February 28, 2016

Week Three; Getting Excited

It was a pretty relaxed week. The weather was mostly fine; a tad cold, but sunny and I had three respectable rides. I've had two days off the bike now and I'm feeling good.

Today was the first day since the "Wentwood Massacre" when my leg felt pretty good AND I was free to just ride. I set off in frosty but sunny weather with the plan to assess the time it should take me to complete the route in "ideal" conditions; to set the "Ride Standard".

Start Time; 9:00 am.
Section 01; Distance; 20 miles. Time to complete; 1 hour, 45 mins.

The first six miles are super easy, mostly downhill to Newbridge and then a straight shot over to Llanhilleth. This section is a great warm up because the next couple of miles are pretty tough. It's a 1.3 mile slog up to Swffryd (220 ft. +gain) with the last 100 yards at a brutal 16%.

A chilly morning along NCN Route 465 in Hafdrynys.

With that done, the next 12 miles are a breeze. It's an easy cruise into Pontypool, through town, a relaxed glide through the city parc, along the canal, then ripping it down the dual-carriageway to Little Mill, and zippity quick into Usk.

Break One; Time; 10:45 am - 11:00 am, Total Dist.; 20 mi., Travel Time; 1 hour, 45 mins.
Section 02; Distance; 14.5 mi. Time to complete; 1 hour, 30 mins.

Here, I usually pour a carafe of coffee in my system, stretch a bit, hit the can, and regroup. Heading out of Usk by 11:00 am and down to Caerleon is relaxed and fairly easy with some slight climbs over rolling hills. I take NCN Route 42 down to where it splits off to Wentwood and bear south toward Kemmy's Inferior along Bullmore Road. Once I reach the Celtic Manor golf course, the ride is halfway complete at 28 miles.

Ride Report
Ride Date: February 15, 2016
Distance: 55.8 miles
Elevation: + 2878 / - 2879 ft
Ride Time: 04:51:58
Weather: Cold & Sunny
Temperature: 3℃ / 37℉
The next 6 miles are a mixed bag of lovely traffic-free cycle paths (NCN Route 88), some annoying roads (Albany St. Lynn Road, and whatever you call the service roads along side the A4042, A4051 & B4591... ARRRRGGGHHH!), a bit of pedestrian dodging over and under catwalks and subways by the train & bus stations, followed by a glide along the lovely refurbished riverfront of Newport (NCN Route 47). Now at 34 miles; I generally stop for my second break down by the river bend and it's also where I plan to have lunch each day.

Break Two; Time; 12:30 pm - 12:45 pm, Total Dist.; 34.5 mi., Travel Time; 3 hours, 30 mins.
Section 03; Distance; 11 mi., Time to complete; 1 hour, 15 mins.

From here I then navigate alongside the busy A48 past the Transporter Bridge, down Docks Way, through scenic Duffryn, past Tredegar House, the monster A48 roundabout, and up Forge Road into Bassaleg (NCN Route 4). It's a crazy, busy, and hectic 5 miles... perhaps the hardest section of the entire route(?). It's definitely my least favourite.

Now at Bassaleg, the ride starts to wind down. I've got a couple of very slow, but mild climbs past the old aluminium works, a bit of busy traffic along the High Streets through Rogerstone, Pontymister, and Risca. But everything gets really quiet once I turn into the housing estates behind Crosskeys toward Waunfawr Parc. Now I can sit back and relax... the next 12 miles are easy-peasy.

I plan to glide into Sirhowy Parc for my third and last break by 2:00 pm. Again, this is a great place to stop, stretch my legs, hit the can, have a snack, and regroup for the last 10 miles home. The first 4 are through Sirhowy Parc itself and is wonderful. The ride is a quiet gentle climb and protected from wind and rain and perfect to prepare for the very last push.

Break Three; Time; 2:00 pm - 2:15, Total Dist.; 45.5 miles, Travel Time; 5 hours.
Section 04; Distance; 10.3 mi., Time to complete; 1 hour, 15 mins.

Leaving the cover of the parc, I begin the last six miles through Blackwood on the High Street... which can be very busy. I then cross the Chartist Bridge and up around the back of Oakdale following Coal Yard Rise; which is a slow slog climbing 240 feet (over one mile) up to Cherry Tree roundabout. Then the last mile and a half I simply cruise into Croespenmaen, through the housing estates and back lanes to home.

Finish Time: 3:15 pm., Total Distance: 55.8 miles Total Time; 6 hours, 15 mins.

And that's how I did it Monday and how I'd like to do it most days... the "Ride Standard" so to speak. My main concern at this point is how long it will take me on rainy days... days when I'm not feeling great. A big question, eh? So... my next test ride will be in the rain!

It was another early start heading down to Rogerstone to meet John & Graham for a ride with the Kingfishers. It was also another sunny, but cold morning. I knew it would be a longer ride, but it was to be a slower ride with a nice lunch break in at Raglan Castle.

Looking out over Llandenny from "Lord Raglan's Bugatti".

We joined Eric at the common in Caerleon and headed out our usual route across the Celtic Manor Golf Course and Bullmore Road to Usk. It was a beautiful morning and we were all excited to be riding in the sunshine. It's a slower ride heading north along this route which gives us all ample opportunity to play whatever "jaw music" crosses our minds. It's an easy 10 miles to Usk where we stopped, had some coffee and snacks; bananas, and Twix candy bars.

Graham, John, and Eric... lookin' grand!

Warmed up and recharged, we headed out one of my favourite routes which runs past the former property of Fitzroy John Somerset, aka: Lord Raglan. Well known for his collection of antique cars - especially a 1933 Bugatti Type 51, I can easily imagine Lord Raglan speeding along these lanes in his little red car. I call this section; "Lord Raglan's Bugatti". Quite simply, everyone should cycle this short 3.5 route above Llandenny.

Ride Report
Ride Date: February 16, 2016
Distance: 76.4 miles
Elevation: + 3834 / - 3835 ft
Ride Time: 07:37:05
Weather: Cold & Sunny
Temperature: 5℃ / 41℉
Brian met us at Raglan castle for lunch, then we all sauntered off for a lazy ride back to Caerleon much the same way we had come. Of course, we again had a brief stop in the square at Usk, but then sorted our different ways and headed off to home.

It was a great day overall because it was sunny. Everyone enjoyed the relaxed feel and without much effort; the miles just rolled under us. This is precisely why I enjoy riding with these fellas so much... there's no concern with our speed, or heart rate, or cadences, or any of the nonsense so many "new" cyclists focus on. For us, it's just the joy of being out on the quiet lanes, enjoying the countryside, and simply riding our bikes.

I set out on Friday with my bike trailer to distribute promotional flyers and donation tins to various retailers along my 55 for 55 Event Route. I felt totally relaxed and kinda lazy with the knowledge that I'd be going slow and stopping often.

It's not much to read about, but here's a quick overview of the places that are posting a flyer and/or are hosting a donation tin.

In Oakdale:
  • The Oakdale Library
  • Oakdale Chinese Take Away
  • Pearn's Pharmacy
  • Oakdale Surgery
  • The Co-operative Food
  • Gulf Petrol Station
  • The New Forge

  • In Croespenmaen;
  • Nisa

  • In Pontypool;
  • Torfaen Leisure Center
  • Pontymoile Boat Basin

  •   In Usk:
  • Green Flute Cafe
  • Greyhound Inn

  • In Caerleon:
  • Celtic Manor Gold Club

  • In Newport:
  • Fanny's Rest Stop Cafe

  • In Pontymister:
  • Commercial Inn

  • In Risca:
  • Martyn Ashfields

  • Okay... that's if for now. One week to go. I'll keep you posted.

    Cheers! ~ cm

    February 14, 2016

    Week Two; Cherished Days

    What a week this has been. It turned out to be rather intense... still nursing the knee a bit, but overall getting into shape. At first, I felt bad for not riding on Monday, but I certainly mad up for it over Tuesday through Friday with a daily average of almost 60 miles. Today, I am relishing the time off the bike. The big issue still looming is non-stop cycling!

    MONDAY, FEBRUARY 08, 2016
    Amber storm warnings for gale force winds and heavy rain as Storm Imogen hits kept me safely inside, warm and dry today. However, all this lousy weather is supposed to pass tonight so the remainder of the week should be good for a few rides. This leisure time has provided the opportunity to install new brake blocks, tyres, tubes, and generally give the ole' girl a thorough tune-up. (and she looks smashing, if I do say myself!)

    TUESDAY, FEBRUARY 09, 2016
    Out with the Kingfishers today. I don't know why exactly, but I've been saying to myself that I should try to keep these days down to about 50 miles. It never works out... I always end up riding over 70 miles. And today was long and wet and I am wiped out.

    Those crazy fellas... The Kingfishers - Caldicot, Oct. 2013

    Graham came out with us today and bless you fella!... If John starts going crazy fast, I can always sit back with him and regroup. It's mighty impressive that at 83 he can still go out and ride 50 - 60 miles and I hope I can when I'm his age... but he's the only person I've ever cycled with that can pedal at one (1) mph up a hill.

    We rode out to Blackrock; a place John has spoken of many times, but it was new to me. I failed miserably to take any photos (no excuses there...). The day started out lovely. It was chilly, but the sun was shining and looking out over the Severn Channel was beautiful. However, the skies darkened dramatically as we turned into Caldicot, so the decision was made to have lunch and head back early to avoid the oncoming storm.

    Ride Report
    Ride Date: February 09, 2016
    Distance: 72.8 miles
    Elevation: + 2740 / - 2763 ft
    Ride Time: 07:05:58
    Weather: Sun & Heavy Rain
    Temperature: 5℃ / 41℉
    We ate at a great little cafe in town packed with locals (insert name...) under threat of heavy black skies, but surprisingly enough when we left the skies opened, the sun came out and we had a wonderful little ride along the Gwent Levels back to Newport. But the rain was inevitable and it was at this point the weather decided to bite. It wasn't too bad coming around the sea front and up into Rogerstone, but just after we split up along the High Street heading toward Crosskeys, the rain came down in buckets.

    I finished up pedaling home slowly through Sirhowy Parc and the wet streets of Blackwood in the dark and pelting rain. I am tired. I am sore. I am going to bed.

    Riding yesterday in the cold and rain really zapped me of energy... always does. And today I had to ride down to the Newport Wetlands to meet with various folks on planning the "Newport Family Cycling Festival". Urgh.

    Newport Wetlands - Aug. 2015

    Up at 5:30 am, fumbling about the house, coffee, breakfast, check the bike, coffee, get dressed, check the weather, coffee, pack the bike... out the gate by 7:30, off to meet Mr. Dean Piper in Newbridge by 8. Urgh.

    Along the cycle path at Newport Wetlands - Aug. 2015

    It was overcast, but the sun seemed to be breaking through the clouds a bit. I met Dean and we set off on a relaxed ride down for our 10:30 meeting. After a few miles I began to get back into "the rhythm", but I was decidedly in the back for most of the ride... hollering ahead where to turn or stop or whatever. I'm still nursing the knee a bit... still feeling the day before as well. Urgh.

    We made it down through Newport without much hassle from traffic. The sun came out, we followed NCN 4 and 47 for most of the way and once we passed over the A48, the roads were quiet. We passed several other cyclists out for a morning ride too. Part one of the day was quite lovely. (He said yawning...) The only drawback was that my left pedal began creaking incredibly bad... clearly something wrong with the bearings? Urgh.

    Ride Report - Part 1
    Ride Date: February 10, 2016
    Distance: 21.7 miles
    Elevation: + 639 / - 1378 ft
    Ride Time: 01:52:47
    Weather: Overcast to Sun
    Temperature: 3℃ / 37℉
    Okay, we had a great meeting. The event is really starting to come together. We met with the the "Communities First" representative who will be handling a group of kids and most importantly... Dean scored a major win with successfully acquiring two buses to transport the little kiddies back and forth. Woohoo! Great job Deano! More on this event to come!

    So on a high note and with a lovely day ahead, we set off for home through Caerleon toward Cwmbran. Dean showed me a great new route and despite the very moderate climb, I was still nursing that infernal knee. After a week and a half, it's still bothering me some. It's not bad enough to prevent me from riding, but it's a nagging pain which I'm very concerned that I don't over-strain again. Right knee burns; left pedal pops and creaks... alternating annoyances.

    Ride Report - Part 2
    Ride Date: February 10, 2016
    Distance: 33.2 miles
    Elevation: + 2088 / - 1353 ft
    Ride Time: 03:48:35
    Weather: Glorious Sun
    Temperature: 3℃ / 37℉
    I get red marks too for not taking any photos along the ride home. At one point we could see all the way down the valley to the Transporter Bridge. A surprising and stunning view that I will make a point of visiting again. (That's two days; two missed photo ops.)

    Once in Cwmbran we climbed onto NCN Route 492 to Pontypool. The day was getting late; we were both tired and it was close to rush hour as we started out Old Crumlin Road. Dean split off to climb his own personal monster while I suffered along toward Hafodyrynys, Crumlin, a few stiff climbs, a miserable attitude, a shower, and bed; creaking and popping up the stairs... feeling every inch old and worn out.

    Up early, drag out the trailer, jump on the bike and down to Blackwood by 8:30. Pick up the donation tins from the post office, load the trailer, ride back up Coal Yard Rise to home, quick breakfast, fast coffee, throw off the trailer, oil the bike chain... back in the saddle again by 10! Man it's cold out, but I'm already sweating.

    Looking down toward Gilwern from Clydach Gorge - Jan. 2013

    Sometime during all of that I had time to pull the pedals off the Trek and swap 'em out to the Dawes. Half way up the path toward Hollybush I look down at my feet and say out loud; "man... these pedals are great!". I guess I'm feeling pretty good? I've lowered my seat by 1/2" and feeling no pain whatsoever in my knee. The Upper Sirhowy Valley is my oyster and this little quiet ride along NCN Route 467; my pearl. I'm heading toward Tredegar, Brynmawr, and snow.

    Ride Report
    Ride Date: February 11, 2016
    Distance: 52.6 miles
    Elevation: + 3646 / - 3646 ft
    Ride Time: 05:40:40
    Weather: Overcast
    Temperature: 1℃ / 33℉
    Thursday was my first "free" day. No schedules, No one to meet. I could ride as fast or as slow as I wanted. I could go wherever I like. Along with the saddle height adjustment, different pedals, and a long hot shower followed with Deep Heat on the knee the night before... by Thursday morning I was feeling better than I had in well over a week. Good news indeed.

    So my thought was to have a big mileage day, but an easy day. Get myself up to Heads of the Valley, then drop down through Clydach Gorge to Llanfoist, hop on the canal path and slowly wander home. It proved to be a great decision. It was cold with some light wind, but what a good day. Just look at that big lazy loop on the map above! Big miles and big smiles.

    And that was just how the day turned out to be. I was relaxed. I took my time. I didn't work my knee too hard. Overall, it was the best day I've had since the "Wentwood Massacre". I made it home happy. I felt great.

    FRIDAY, FEBRUARY 12, 2016
    Day four on the bike this week. Gotta head down to Cardiff to join other Sustrans' Volunteers for the Annual Group Coordinators Meeting.

    I felt good. I'd come through three big days on a positive note... something important for my moral. This day was to be a fairly easy set of rides down to Cardiff, out to Penarth and Sully, an afternoon sitting around a conference table, followed by a quiet ride home.

    Sully Island - May, 2015

    This day too, should have been broken into two separate rides. The mileage in the Ride Report below is misleading because this was not one continuous ride; there was a significant (3 hours) break between arriving for the meeting and when we eventually left for home. As I roughly recall, the numbers were: 24 miles to Cardiff Central, 8 miles to Sully and back to Penarth, (break for meeting), 30 miles home. However, the Garmin Rules. You can trust my maps and reports are directly downloaded into Ride With GPS from that lovely little and essential unit. HA!

    Ride Report
    Ride Date: February 12, 2016
    Distance: 61.4 miles
    Elevation: + 3017 / - 3073 ft
    Ride Time: 06:28:05
    Weather: Sun, Clouds
    Temperature: 5℃ / 41℉
    The ride down was straight-forward. I've ridden it 100 times at least... it's lovely heading down Pandy Road, through Bedwas and Caerphilly, then onto the Taff Trail into Cardiff. Easy peasy.

    I then met up with the other fellas at the train station and we had a great ride out to Sully on NCN Route 88. The sun came out and it was quite scenic along the coast. AND guess what?!?!?! I missed yet another photo opportunity! AAAARRRGGGHHH!!!! I just cannot believe myself. Perfect time to get a shot of all the Group Coordinators together too. That's it. I have just given myself a red card for poor photography efforts for the week. Shameful behaviour.

    Okay, great meeting. More to come on that. For the ride home I had the pleasure of Mr. Dean Piper joining me again. We left approximately at 3:30 from Penarth Pier (missed photo ops!) and cycled back across the Barrage to Cardiff Bay. Once into Cardiff proper, we scooted past the castle and joined the Taff Trail to Nantgarw, then the Celtic Trail (NCN Routes 8 & 4, respectively) up to Caerphilly.

    At this point, we joined the road for the remainder of the ride; passing through Llanbradach, Ystrad Mynach, and Hengoed. Then across the lovely at night viaduct and into Pontllanfraith where we went our separate ways. Dean heading down and up, and up again, then further up and up to his house on top of the world.

    I just toodled quietly through Blackwood and up the slow climb of Coal Yar Rise to Oakdale. It was a long day... and the end of a long week. I rode 249.5 miles, averaging just under 60 miles over four days. (You can see a monthly chart here: 2016 Monthly Details.)

    So I as sit here on this sleepy grey Sunday morning, reflecting back; I've not been in the saddle for two days and these are indeed "Cherished Days". Soon, I will not have these long periods, relaxing on the sofa, legs stretched out typing casually about my nonsense.

    In two weeks, I begin the crazy: 55 for 55, and I wonder if I'm ready for it?

    February 07, 2016

    Week One; Recovering Slowly

    On the previous Saturday (Jan.30th), I completely overworked myself on the "Wentwood Massacre" and I came home with a pretty sore knee. But I took the next two days off because of lousy weather and hoped the time away from the bike would be enough to heal. However, I rode pretty hard this past week, so here's a quick recap.

    TUESDAY, FEBRUARY 02, 2016

    (shhh... sneaking up on Raglan Caslte...)

    Ride Report
    Ride Date: February 02, 2016
    Distance: 74.4 miles
    Elevation: + 4254 / - 4314 ft
    Ride Time: 07:13:41
    Weather: Sun, Sun, Sun
    Temperature: 5℃ / 41℉
    I left home in the pouring rain at 8 am. By 10 the weather changed abruptly and became a fantastic sunny morning. Welcome to Wales! Protective of my sore knee, I joined Brian, Ivor, Eric, and John at the Boating Lake in Cwmbran and cautiously started our adventure on the new Community Links paths snaking along the banks of the River Avon Lwyd to Pontypool.

    We wandered from Pontypool through New Inn and Glascoed, passing along a ridge just north of Llandegfedd Reservoir for about 5 miles right until it joins with the A472 at Monkswood. The sun was shinning and day was looking to be perfect for a nice long day in the saddle.

    From Monkswood, we turned north and slowly wound our way through Goetre, Llanvair Kilgeddin, Clytha, Great Oak, ending in Raglan where we climbed up to the castle for lunch at the little cafe. It was a relaxing, easy morning, and a brilliant ride.

    After lunch, it was a slow and lazy ride back down to Usk. We said our goodbyes to Brian and Ivor (who went off toward Pontypool) while Eric, John, and I headed down Bullmore Road to Caerleon. From there Eric split off to Malpas while John and I continued into Newport on NCN 88. We went up along the canal on NCN 47 through 14 Locks where John split off and I continued on to Crosskeys. The last leg droped me down through sleepy little Waunfawr Parc and as the sun was setting I made my way slowly home alone under the heavy canopy of trees of Sirhowy Parc.


    A frozen lake at Parc Bryn Bach

    Ride Report
    Ride Date: February 03, 2016
    Distance: 58.1 miles
    Elevation: + 3515 / - 3631 ft
    Ride Time: 06:12:10
    Weather: Sun, Cold, Wind
    Temperature: 1℃ / 34℉
    My goal today was to find an alternative route for my "55 for 55" event. After speaking with Brian (of the Kingfishers...) he suggested that I should not only find an alternative route that is NOT prone to flooding, but one that offers a bit of shelter from the rain.

    Well, the first part of the ride on NCN 492 out of Pontypool was certainly sheltered, but once I came out of the trees at Blynavaon, I was completely exposed. It was very cold and very, very windy climbing up from Garn Lake along the path to Brynmawr. By the time I was up along NCN 46 on the Heads of the Valley, I decided that this route is entirely too strenuous.

    So... it was a good day for training. I had a good workout, but I was still nursing a sore knee. Once I got to Merthyr, I turned onto the Taff Trail. It was a lovely late afternoon. The temperature warmed a bit, the sun started setting, I turned on my dynamo light, and I had a relaxing ride down the valley. However, despite being mostly downhill, I was exhausted by the time I made it home.

    Just look at that elevation profile! It seemed like a good idea... but having made the ride now, I think I'll keep looking for an alternative route for my big event.


    Along the river-front in Newport

    Ride Report
    Ride Date: February 04, 2016
    Distance: 72.4 miles
    Elevation: + 3070 / - 3112 ft
    Ride Time: 07:03:28
    Weather: Sun, Mild
    Temperature: 9℃ / 43℉
    I set off on a fairly easy ride to Cardiff. Still nursing this infernal knee, I rode down through Sirhowy Parc to Bassaleg where I joined NCN Route 4 across to Draethen. From there up through the crazy "Alice in Wonderland" tunnels at Lower Machen and into Caerphilly via the old railway line and Riverside Parc.

    From Caerphilly it's an easy-peasy coast into to Cardiff along the Taff Trail through Taff's Well and Tongwynlais. By the time I arrived it was nearing noon, the sun was out, and it was warming up nicely. Most folks were in work, so the the mid-town streets were fairly quiet.

    However, heading toward the docks along Newport Road, it's always congested and busy. Turning right onto Rover Way I fought my way through the multiple roundabouts to where it finally quietens at "Gypsey Squats". (I cannot wait for Sustrans to develop an alternative route!)

    Once past all of that nonsense, the road is absolutely lovely with very little traffic as it winds along through the tall sea-grasses of the Gwent Levels. Passing through Peterstone and St. Brides should have been easy going with the wind at my back. The road is absolutely flat.

    It should have been, but at this point my knee started acting up. So I took my time through Newport and up to 14 Locks. I must say at this point I was worried. I actually wondered if I could ride my bike home. I got off and walked along the canal path toward Risca. And fortunately enough, walking felt fine. Good news.

    Frustrated about whatever could be the cause of my knee pain, on a whim; I lowered my bicycle seat. I hopped on and voila! After about ten minutes not only did my knee stop hurting, it actually felt good... really good! What a great surprise.

    I pedaled home through Sirhowy Parc and up the back road to Oakdale without a thought. This simple 1/2" adjustment to my saddle height seemed to have solved the problem. Brilliant.

    FRIDAY, FEBRUARY 05, 2016

    On Manmoel... The road is out there somewhere?

    Ride Report
    Ride Date: February 05, 2016
    Distance: 24.9 miles
    Elevation: + 1668 / - 1599 ft
    Ride Time: 02:30:25
    Weather: Heavy Rain
    Temperature: 7℃ / 44℉
    Okay... day four; a short ride to check my knee. I've a wonderful little route up to Manmoel and back, then a short hop up to Hollybush and back. The combined routes total about 25 miles and I really enjoy it. I get a good climb along with a fair amount of steady pedaling on a mostly traffic-free ride.

    And the real test for Friday was my saddle adjustment; could that simple issue be the cause of my knee pain? Of course too, I had to deal with rain. And not just a sprinkle or moderate rain... but heavy, hard rain with strong gusty winds. Lovely.

    The ride up to Manmoel went really well despite the rain. I felt at first as if I was riding a kids bike with the saddle set so low, but not having any knee pain was wonderful, so I gladly accepted the adjustment.

    The ride down and over to Hollybush was good too. However, riding in the rain always adds a bit of strain to my efforts and by the time I started up Coal Yard Rise heading back home to Oakdale, I began to feel a bit of pain in my knee.

    Of course, tyre issues can also add to one's concern. Thankfully, I made it home without a puncture and oddly enough, the worry of my tyre distracted me from focusing on my leg.

    Well worn after 3k miles... good job Conti!

    And today it's Sunday... I've had another couple of days off my bike. The leg feels good. I need to change those tyres, replace the brake blocks, and give the ole' girl a good tune-up. This will be just in time for storm Imogen tomorrow and a trail event ride! Woohoo... check back and see if I'm cheering this time next week. cheers ~ cm