The optimal rim
for Schwalbe tubeless racing bike tires
For safety and performance, the tire and rim on a road bike must be perfectly matched. This applies all the more to tubeless racing cycle tires. In addition to the classic hooked rims (crotched type), so-called "hookless" rims (straight side) are becoming increasingly popular in the racing bike segment. For safe operation, "hookless" rims in particular place high demands on racing cycle tyres. The models Schwalbe One TLE and Schwalbe Pro One TLE (from model year 2020) are designed to meet these special requirements, especially in the bead core area, and are therefore basically compatible.
All values as per ETRTO standard 2019 (ETRTO: European Tyre and Rim Technical Organisation).
The wheel’s shoulder diameter is the diameter as measured from shoulder to shoulder. This corresponds with the ETRTO number after the hyphen. In the case of Schwalbe road racing tires, for example, it is 28-622.
The outer diameter of the rim is decisive for a safe fit. It is determined by the shoulder diameter and flank height, which are defined by the ETRTO standard.
|28''||622||621.95 +/- 0.5||5.5 +/- 0.5|
These values apply to all rims, whether they are tubeless, normal, crotched type or hookless rims. To guarantee a safe fit, it is generally important that the minimum flank height does not exceed 5.0mm. For tubeless tires, the shoulder diameter should be in the positive range of the authorized tolerance.
It is not absolutely essential that the rim is airtight. The rim base can be made airtight very easily using a corresponding tubeless rim tape. A welded rim with a smooth base is the ideal scenario. A double eyelet rim, on the other hand, cannot be made airtight with a rim tape. When using a pin joint rim, at least 30ml of Doc Blue sealant must also be used in addition to rim tape to ensure an adequate airtight seal.
EASY TO FIT
To ensure an easy tire fit, the drop-center of the rim should be 2.6 to 3.4mm deep, concave and at least 7mm wide. The rim width should be minimum 17mm; optimum dimensions are 19mm or 21mm.
Special notes on hookless rims and use with Schwalbe TLE racing cycle tires:
- Hookless rims, also called "Straight Side", are characterised by the fact that the small hook at the end of the rim flank is missing.
- The official designation for tubeless hookless rims according to ETRTO is "TSS".
- The rim used must comply with the ETRTO standard for hookless rims (straight side).
- The specified air pressure of tyre and rim must be observed. If the specified maximum pressure of the rim is lower than that of the tire, the maximum pressure of the rim must be observed. This is the rule with tubeless hookless rims (TSS).
- The compatible tire widths specified by the wheel/rim manufacturer must be taken into account. Especially the minimum tire widths.
- If hookless rims are only designated by the manufacturer for tubeless operation, they cannot be used with tube-type tires and therefore bicycle inner tubes.
Advantages of Hookless
- Less weight compared to conventional "hook" rims.
- Hookless rims produce a rounder tire contour, which has a positive effect on the riding characteristics.
- Due to the comparatively high volume of tires on hookless rims, the practical air pressures are significantly lower. This increases comfort and grip.