Unblemished alloy rims...
30/04/23 17:24 Filed in: Gear
As a taller, heavier rider - one who doesn't take the smoothest line - I am well used to putting dings in my MTB rims. As a result, all my XC/trail bikes for the past while have had carbon rims. You can't ding it (though you can smash it/break it).
I've had two DH bikes. The V10 for several years and for the past 3 years, a Sender CFR from Canyon. The current bike has DT Swiss DH wheels on it consisting of 240 hubs, the wider of the two DH rim options and some DT spokes. (There is even a QR code on them for "more information" about the wheel, but it leads to an "unknown" type error. Leading me to suspect there are some special Canyon-only wheels that are somehow special.)
Normally, on the basis of both the experiences with the V10 and even the XC bikes, I would put at least one ding in a rim in a season of lift-serviced riding. To go three years without a mark is unprecedented for me. While the alloy used in rims has improved over the years, not so much that the rims by themselves get all the credit. The majority of the credit goes to the CushCore Pro foam inserts in the rims from day 1.
Yes I used proper (Maxxis in this case) DH tyres. But for the most part I did that on the V10 too. And given that the V10 had tubes inside for most of the seasons of action, I had to keep enough air pressure in them to prevent pinch flatting - something I did quite a lot when using tyres with too-soft a sidewall.
CushCore has allowed an amazing transformation of my expectations on the MTB. My hardtail and short-travel bikes have the smaller, lighter version of CushCore (an intermediate choice was just released this month so it doesn't come into play for me) while my Enduro and DH bikes have the Pro version. It means I can run as low as 16 psi in the front for excellent traction and low rolling resistance on irregular terrain while still getting adequate support in corners. I haven't been able to go quite so low in the rear without feeling a bit loose - I suspect I sit a lot of weight at the back of the bike much of the time. Still, I can routinely run 24 psi in the rear without feeling like the back end is moving too much.
The evidence that the foam is doing its job is the number of permanent marks in it where some edge has trapped the foam against the rim edge. Many of them on the Enduro bike (the first bike of mine to get CushCore and also the one that gets the most riding on rugged terrain) at the rear wheel - almost zero up front. I swapped them around when I replaced the tyres so the rear gets what is effectively a new insert and the front won't tax the insert the same way.
But the inserts are about more than protecting the rim and more than running low pressures safely. The inserts occupy roughly half the air volume of the tyres, causing them to ramp up in pressure more quickly than they would otherwise - much like a volume spacer in a fork or shock. The whole "insert" thing stems originally from attempts to more closely couple the movement of the tyre (soft, undamped, precedes any suspension movement) with movement of the suspension (well damped, trails the tyre compression - leading to an out-of-control phase at the edge of performance). Syntace and Schwalbe released ProCore (a road tyre inside your MTB tyre in essence) to force the suspension to activate earlier in the overall travel range with the unexpected benefit of tyre retention and rim protection.
Inserts like the Huck Norris occupy so little of the tyre volume that they are a good choice for those who do not want to alter the characteristics of their tyres.
I've written about CushCore before. I'm such a big fan. They've improved my tyre grip. Stopped the frequent burping of my tubeless setup. Prevented rim dings. Better coupled the tyre and the suspension (which I believe can be felt in certain situations). And I've even become quite good at changing tyres with a foam insert inside. The extra mass can be felt, but it's a small price to pay for the rest, and I think the mass can help with the grounded feeling of the bike too.
Inserts are the way to go.
I've had two DH bikes. The V10 for several years and for the past 3 years, a Sender CFR from Canyon. The current bike has DT Swiss DH wheels on it consisting of 240 hubs, the wider of the two DH rim options and some DT spokes. (There is even a QR code on them for "more information" about the wheel, but it leads to an "unknown" type error. Leading me to suspect there are some special Canyon-only wheels that are somehow special.)
Normally, on the basis of both the experiences with the V10 and even the XC bikes, I would put at least one ding in a rim in a season of lift-serviced riding. To go three years without a mark is unprecedented for me. While the alloy used in rims has improved over the years, not so much that the rims by themselves get all the credit. The majority of the credit goes to the CushCore Pro foam inserts in the rims from day 1.
Yes I used proper (Maxxis in this case) DH tyres. But for the most part I did that on the V10 too. And given that the V10 had tubes inside for most of the seasons of action, I had to keep enough air pressure in them to prevent pinch flatting - something I did quite a lot when using tyres with too-soft a sidewall.
CushCore has allowed an amazing transformation of my expectations on the MTB. My hardtail and short-travel bikes have the smaller, lighter version of CushCore (an intermediate choice was just released this month so it doesn't come into play for me) while my Enduro and DH bikes have the Pro version. It means I can run as low as 16 psi in the front for excellent traction and low rolling resistance on irregular terrain while still getting adequate support in corners. I haven't been able to go quite so low in the rear without feeling a bit loose - I suspect I sit a lot of weight at the back of the bike much of the time. Still, I can routinely run 24 psi in the rear without feeling like the back end is moving too much.
The evidence that the foam is doing its job is the number of permanent marks in it where some edge has trapped the foam against the rim edge. Many of them on the Enduro bike (the first bike of mine to get CushCore and also the one that gets the most riding on rugged terrain) at the rear wheel - almost zero up front. I swapped them around when I replaced the tyres so the rear gets what is effectively a new insert and the front won't tax the insert the same way.
But the inserts are about more than protecting the rim and more than running low pressures safely. The inserts occupy roughly half the air volume of the tyres, causing them to ramp up in pressure more quickly than they would otherwise - much like a volume spacer in a fork or shock. The whole "insert" thing stems originally from attempts to more closely couple the movement of the tyre (soft, undamped, precedes any suspension movement) with movement of the suspension (well damped, trails the tyre compression - leading to an out-of-control phase at the edge of performance). Syntace and Schwalbe released ProCore (a road tyre inside your MTB tyre in essence) to force the suspension to activate earlier in the overall travel range with the unexpected benefit of tyre retention and rim protection.
Inserts like the Huck Norris occupy so little of the tyre volume that they are a good choice for those who do not want to alter the characteristics of their tyres.
I've written about CushCore before. I'm such a big fan. They've improved my tyre grip. Stopped the frequent burping of my tubeless setup. Prevented rim dings. Better coupled the tyre and the suspension (which I believe can be felt in certain situations). And I've even become quite good at changing tyres with a foam insert inside. The extra mass can be felt, but it's a small price to pay for the rest, and I think the mass can help with the grounded feeling of the bike too.
Inserts are the way to go.