This post compares the advantages and disadvantages of 32 and 34mm fork stanchions.
The Advantages of 32mm Stanchions
All things being equal (length, material, quality…etc.), stanchions with a 32mm diameter are lighter. Hence their presence on XC machines.
The table below contains the weight of popular forks with 32mm stanchions designed for XC riding:
|32mm Models||Weight||34mm Models||Weight|
|FOX Racing 32 FLOAT SC 29″ FIT4||1355g||Fox Racing Shox 34 Float Factory SC 29”||1496g|
|RockShox Recon Silver RL SOLO AIR 29″||2058g||Suntour AXON 34 BOOST SF18 RLRC PCS 29″||1900g|
|RockShox Reba RL SOLO AIR ONELOC 29″||1602g||ÖHLINS RXF34 M.2 AIR 29”||1.725g|
|RockShox SID SL Ultimate Race Day 2 3P Debonair BOOST 29″||1352g|
|DT Swiss F 232 ONE 29″ Fork||1510g|
On average, one can expect to save about 100-150 grams via 32mm stanchions when all other parameters are equal.
That said, some forks with 32mm stanchions will be heavier than others with 34mm stanchions.
- Cheaper & Widely Available
The lower price tag and the higher demand for 32mm forks result in a larger market share.
The Disadvantages of 32mm Stanchions
When all parameters such as material and wall thickness are equal, a pipe/cylinder with a larger diameter is stronger and stiffer than one with a smaller diameter.
This can be easily illustrated by comparing PVC pipes of different diameters and trying to bend them. As the diameter of the PVC pipe increases, the more difficult it becomes to bend it. At one point, it will be nearly impossible.
Having said that, forks of decent quality with 32mm stanchions are plenty strong for the vast majority of riders out there.
Even if you are on the heavier side (e.g., 220lbs/100kg), a good 32mm fork should be able to support you. It may flex more, but it’s unlikely to experience catastrophic failure.
In the past, fork stanchions were much thinner (e.g., 28mm) and yet they could still face a ton of challenges without disintegrating.
If a quality 32mm fork fails, it’s probably a situation when a thicker fork would have failed too.
The Advantages of 34mm Stanchions
- Strength & Stiffness
When all other parameters are equal, stanchions with a larger diameter are stiffer and stronger. Stiffer forks could make the ride harsher but give a feeling of stability and precision that a flexier fork cannot offer.
The additional strength of 34mm stanchions is why you see them on more extreme MTBs.
The Disadvantages of 34mm Stanchions
- Extra Weight
The larger diameter requires more material. Consequently, when all other characteristics are equal, forks with 34mm stanchions are slightly heavier.
That said, the extra weight (around 100-150 grams) is practically inconsequential in the world of MTBs.
- More Expensive
34mm forks are considered a higher-end product and thus they tend to cost more. If you are not doing extreme riding, the investment might not be justified.
- Fewer Options
At some locations, a 34mm fork may be harder to find, although most decent bike shops will have a good number of options.
The Fork Model Is Important Too
The qualities of a fork are not dependent solely on the stanchions’ diameter. Two forks can have the same size stanchions and yet feel different when it comes to stiffness.
It’s also important to note that people reviewing a fork can only do it from their own perspective.
For instance, if someone who weighs 200lbs/90kg reviews a 32mm fork on super harsh terrain and concludes that it’s too “flexy”, their assessment wouldn’t be all that useful to a 154lbs/70kg rider who does light XC.
FAQ: Is the upgrade from 32 to 34mm stanchions worth it?
An upgrade would make sense when:
- The 32mm fork is underperforming (e.g., it’s flexing too much and not tracking properly).
- The 32mm fork doesn’t offer a sufficient amount of travel for the terrain you want to cover.
- The 32mm fork is already too old and needs servicing which will cost a good chunk of money that can be invested into a better model.
If the fork is healthy and matches the discipline that you want to participate in, it makes little financial sense to upgrade it.
A switch from 32mm to 34mm is not necessarily an upgrade because a high-end 32mm unit will outperform a 34 model that isn’t of sufficiently high quality.
What to choose?
If you aren’t heavy (200lbs/90kg+) and don’t plan on doing extreme riding, a 32mm fork will be good enough.
If you’re heavier and plan on pushing your bike to the maximum, going for larger stanchions such as 34 or even 36mm is always a good option.
Ultimately, stanchion size is only one variable. Other factors should also be taken into consideration.
Those would be:
The class of the fork. (A high-end 32mm fork will outperform a poorly designed and made 34mm fork).
The travel of the fork. (If you want a fork for technical climbing, travel over 120mm creates issues. If you want a fork for descending, it will be beneficial to have more travel so that the fork can eat the irregularities.)
The condition of the fork (if buying second-hand)