KH 29 inch Rim 38mm vs 47mm Comparison
The new KH 47mm Freeride rim seems to have opened up a new world of off road riding on the KH 29′er. But can 9mm really make that much difference?
I’ve been riding the 38mm and 47mm fitted with the Schwalbe Racing Ralph 2.4 and WTB Stout 2.3 on separate rides, but I thought a back to back test where the trail would be broken into sections and each section ridden with both the 38mm and 47mm rims during a ride would be fun and hopefully making any difference obvious.
KH 29" Rim 38mm vs 47 mm Comparison
(So you’re thinking… this clown has two 29′ers? In my defense I never intended to. I ended up with a spare 29″ frame due to a Schlumpf compatibility problem with my original 29″ last December, and have since gathered enough spare bits and pieces since to build up a second 29′er to sell/loan)
After a week or so of cold drizzly rain, the rain clouds finally parted and I headed out with the two 29′ers to one of my favorite parts of the forest which includes dirt road, bush track and single track set in hilly terrain. The slippery tracks would just add to the fun!
Final Showdown, 38mm vs 47mm
I warmed up soon enough, riding sections of trail, running back and forth swapping uni’s, and stopping now and then for photos.
Move to the side, the Freeride is coming through!
The Bottom Line?
The short version is there wasn’t one situation where I preferred the feel of the 38mm rim over the 47mm. Climb or descent, single track or fire trail, smooth or rough. The 47mm comes with a dumb grin that gets plastered over your face as you roll along.
The 47mm feels much more stable than the 38mm. The 47mm seems able to eat rough terrain, or ‘run over children’ as Eric the Red described it. It encourages you to ride the 29′er harder and attempt more difficult terrain.
Swapping back to the 38mm rim it always felt ‘tall and narrow’ in comparison, a hybrid uni feel, not as stable even with 2.3-2.4 tires fitted — leading to an approach of weaving your way through terrain versus ploughing on through with the wider rim.
If there is a downside to the 47mm rim it’s the reduced brake clearance. With the Magura’s set right back there isn’t a lot of room to spare.
Reduced Brake Clearance with 47mm Rim, KH 29" Rim Showdown
However… the slippery conditions magnified the differences between the two rims — the 47mm gives the 29′er tractor properties through mud and slush… FUN.
Freeride rim + Stout 2.3 = 1x1 Wheel Drive Tractor
Eric the Red and I comparing 29′er notes at ‘the office’ during an earlier ride.
The Office, KH 29" Rim Showdown
The new 47mmFreeride rim makes the KH 29″ a better off road machine (It also gives the 29′er a much clear identity in the KH line up IMO). That doesn’t mean however that in technical/extreme terrain the Freeride 29′er magically replaces smaller MUni’s like the 24″ – it’s still a 29″ wheel.
Freeride Clarity
If you’re building up a new 29′er for off road use get the 47mm rim. 9mm does make a significant difference. It’s as clear as mud, IMO anyway! 
ps. Second 29′er now sold
Related posts:
- Stout 2.3 + Freeride Rim = Mud Machine The rain clouds cleared briefly and I headed out with the Freeride 29′er. The combination of the 47mm rim and Stout 2.3 was great fun on the wet muddy tracks, like a 4×4 wheel drive… a 1×1? Stay tuned for the upcoming 29 inch Rim 38mm vs 47mm Comparison story…...
- Kris Holm Freeride 29 Project My KH Freeride 29″ Project kicked off last week with the arrival of the 2009 Freeride rim and 2009 Moment Hub. The KH 29″ is my second most ridden unicycle off road – first is the 36″. The 29′er is such a crazy light unicycle, so nimble and zippy. The...
- Dog·gone Crank Lengths The KH Freeride 29er has already got me riding familiar trails harder and faster. I’m also trying out stuff on the 29er I wouldn’t have before, I guess due to the steamroller go anywhere feel the 29er has with the wider rim. Is it all in the mind? Who knows!...
- Goodies for Sale Time to part with a few goodies, parts of projects that didn’t work out for various reasons. For Sale: Garmin GSC 10 Speed and Cadence Sensor, New KH ISIS Moment Hub 07/08 and KH 29″ 38mm Rim. Garmin GSC 10 Speed and Cadence Sensor Excellent condition, limited use. Works with...
8 Responses to “KH 29 inch Rim 38mm vs 47mm Comparison”
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I’m curious how much dirt & debris collects in the rim’s holes? Is it difficult to clean them out?
Tom P.
Hi Tom, to date stuff collecting in the holes hasn’t been a significant problem – my 20, 24 and 29 have the drilled rims – but keeping the holes in mind I tend to avoid running through deep mud as it would be a hassle to clean out.
Have you gotten a chance to try the 47mm rim on the road with a tire like the Schwalbe Big Apple?
heya Scott, I haven’t had a chance to try out the 47mm rim with the Big Apple (have both the 2.1 and 2.3 here). It probably won’t be until after our winter, as ATM the forest trails are great fun with the WTB Stout.
Hi Pete,
Thanks for putting so much effort in your site – lots of interesting stuff…
I just bought the 47mm rim to replace my 38mm. I hope I will experience the benefits you mentioned!
I was wondering for the spokes: were you able to re-use the same spokes? if not, which would you recommend? (my current uni is stock KH29 2007)
Thanks,
Teddy
Best bet is to not re-use spokes IMO. Also in this case keep in mind the different hole pattern of the 47mm rim.
Re spoke recommendation, with 29′er MTB’s being popular there are a few options so worth talking to a good wheel builder. Generally I go for a lighter gauge spoke and good quality nipples.
Hey there, just wondering how wide the Racing Ralph is when mounted on the 47mm rim. Might pick one up for my bike
Kerosian unfortunately ATM I can’t tell you exactly how wide the Racing Ralph is on the 47mm rim as I’m running the Stout 2.3 on the rim over the winter. The Racing Ralph is hanging from ceiling, waiting for next Summer — I really like it as a fast, light hard pack / dry weather off road tire.
I have posted some pics of the Ralph on the 47mm rim before Winter though:
http://unplannedismounts.com/2009/05/02/kris-holm-freeride-29-road-test/
and:
http://unplannedismounts.com/2009/04/30/kris-holm-freeride-29-project/
FWIW the width of the casing on the Stout is very similar to the Ralph and that is around 62mm, and unlike the Stout the knobbies don’t protrude beyond the casing, so you could work with that as the width.
Hope that helps!